(PDF) Different generation of controlled moraines in the glacier foreland of Midtdalsbreen, Norway

Master’s thesis

Physical Geography and Quaternary Geology, 45 Credits

Department of Physical Geography

Different generation of

controlled moraines in

the glacier foreland of

Midtalsbreen, Norway

Xavier Allègre

NKA 223

2018

Updated version, september 2019

Preface

This Master’s thesis is Xavier Allègre’s degree project in Physical Geography and Quaternary

Geology at the Department of Physical Geography, Stockholm University. The Master’s

thesis comprises 45 credits (one and a half term of full-time studies).

Supervisor has been Benedict Reinardy at the Department of Physical Geography, Stockholm

University. Examiner has been Arjen Stroeven at the Department of Physical Geography,

Stockholm University.

The author is responsible for the contents of this thesis.

Stockholm, 14 June 2018

Lars-Ove Westerberg

Vice Director of studies

Comment: This thesis version was updated September 2019, no changes have been made to

course grade or original archive version.

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Abstract

A series of small mounds (< 3m) were sampled in the foreland of Midtdalsbreen outlet glacier, southern

Norway. These landforms were interesting, especially at site number 1 because they were located very

close to a higher Little Ice Age (LIA) moraine (> 5 m), thereby informing the dynamic of the glacier after

the LIA at this location. It was yet to determine if these specific mounds are controlled moraines. If they

are controlled moraines, then this would have implication for the glacier dynamics and the geometry of

the snout after the LIA. It could be determined, based on the landform record evidence, whether the ice at

the snout of Midtdalsbreen was thin and cold shortly after the LIA. Furthermore, whether the landscape

was deglaciated by downwasting and then by backwasting was the main question addressed in relation to

the nature of the mound and the thickness of ice at the snout during and after the LIA. In order to better

understand the nature of the landform record and the mounds near the LIA moraine, satellite imagery

coupled with careful field investigations were used in the foreland of the Midtdalsbreen outlet glacier. A

geomorphological map was produced, and it was useful to thereby put the mounds in a geographical

context. Further sedimentological investigation; including clast-shape analyze, produced more evidence

about the inner nature of these landforms. Both few controlled moraines and other landforms throughout

the glacier foreland indicate that the ice geometry for Midtdalsbreen, shortly after the LIA was such that

the snout of the glacier was a thin sheet of ice flowing against the previously deposited LIA moraine. The

sedimentology of the controlled moraine is such that the sediments are deposited in steeply dipping

layers, and they could even be misinterpreted as permafrost terrains at first glimpse. However, other

sedimentological evidences such as the presence of sorted sand and sometimes dipping beds of gravels in

addition to the geomorphological mapping make it meaningful to interpret few of the mounds as

controlled moraines. A modern analogue to these controlled moraines is dirt cones present on top of the

glacier snout as well as controlled moraines a few hundred of meter from the snout. Observations both on

the glacier snout and on the foreland involve that dirt-cones later evolve into these sedimentological

hummocky units with steeply dipping layers within the paleo-landscape. These observations constrain the

thickness of ice at the snout of Midtdalsbreen after the LIA as well as the glacier dynamic during its melt:

for controlled moraines to be generated by glaciers, these accumulations of sediments would have had to

thaw by downwasting and then by backwasting, directly at the glacier snout. This process -comprising of

different stages- allows enough time to deposit controlled moraine. It is then a thin, cold-based sheet of

ice which is by the end responsible for the deposition of such a landform record. There was even dead-ice

present on the landscape at that point. After deposition of dirt cones on top of the ice, important meltwater

action is contributing to the glacifluvial origin of these hummocks which evolve from dirt-cones onto the

glacier, to ice-cored moraines, and then to controlled moraines onto the foreland. Details about the multi-

stage processes leading to the formation of controlled moraines is also at the center of the investigations.

 

  
  
Contents  
Introduction ......................................................................................................................................................7 
1. Reminders about the thermal regime of glaciers ..........................................................................................7 
2. Climate change: how does it affects glaciers worldwide? ............................................................................8 
3. Background information on moraines and controlled moraines ..................................................................9 
4. Aims and objectives .................................................................................................................................... 13 
5. Study area ................................................................................................................................................... 15 
6. Geology around the study area .................................................................................................................. 18 
7. Sites of interest ........................................................................................................................................... 19 
8. On the creation of polygenetic landforms in the ablation area of a cold-based glacier ............................ 20 
Methods ........................................................................................................................................................ 20 
Results ........................................................................................................................................................... 22 
1. Geomorphologic map ................................................................................................................................. 22 
2. Sedimentological results ............................................................................................................................ 26 
2.1. Flute at the snout of Midtdalsbreen: additional site .......................................................................... 27 
2.2. Sections – site 1, near the LIA moraine ............................................................................................... 30 
2.2.1. Site 1A: Composite section through a mound .............................................................................. 33 
2.2.2. Site 1B: Section through a flat-topped mound ............................................................................. 38 
2.2.3. Site 1C: Section through a high (>2m) flat topped mound cross-cut by a small meltwater 
channel ...................................................................................................................................................... 41 
2.2.4. Site 1D: Two sections through the same mound .......................................................................... 44 
2.3. Site 2 in the vicinity East of the glacier snout ...................................................................................... 50 
2.4. Site number 3 and unique section F through the flat-topped landform at this site ........................... 57 
2.5. Site number 4 (G) to the south East of the glacier foreland ............................................................... 61 
3. Moraine morphology and sedimentology: co-variance analyses .............................................................. 65 
  Interpretations .......................................................................................................................................... 66 
1. Interpretation of the sedimentology .......................................................................................................... 66 
1.1. The fluted landscape: additional site ................................................................................................... 67 
1.2. Site n°1 ................................................................................................................................................. 67 
1.3. Site n°2 – recent controlled moraines ................................................................................................. 69 
1.4. Site n°3 ................................................................................................................................................. 70 

 

  
1.5. Site n°4 ................................................................................................................................................. 71 
2. Interpretation of the clast co-variance analyses ........................................................................................ 73 
Discussions ..................................................................................................................................................... 76 
1. Review of the processes leading to the creation of controlled moraines .................................................. 76 
2. Nature of the warm-ice cold-ice interface (WI-CI) ..................................................................................... 78 
3. Controlled moraines are found on the foreland of Midtdalsbreen, at the WI-CI type of interface ........... 81 
4. Paleogeographic implications of this controlled moraine land-record ...................................................... 83 
5. Unidentified landforms and possible interpretation .................................................................................. 87 
6. Factors of uncertainty for the identification of the landform record ........................................................ 89 
Conclusion ...................................................................................................................................................... 90 
1. Main findings .............................................................................................................................................. 94 
Acknowledgment ............................................................................................................................................... 95 
Appendix ............................................................................................................................................................ 97 
References ....................................................................................................................................................... 111

 
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Table of figures (and tables), excluding appendix 
Tables: 
 
Table 1: Distinctive signs for controlled moraine identification, after Evans (2009), Goldthwait 
(1951) and own observations during a field campaign at the end of the summer 2017. ........... 11 
Table 2: Criteria for the identifications of the landform record .......................................................... 22 
Table 3: Lithological facies code and description ................................................................................ 26 
 
Figures: 
Figure 1: Norwegian current against the coasts of Norway. ............................................................... 16 
Figure 2: Close-up view of Hardangerjøkulen ice cap.. ....................................................................... 17 
Figure 3: Geology around Hardangerjøkul .......................................................................................... 18 
Figure 4: Close-up view of the study area (Norge i bilder, screenshot: http://norgeibilder.no/) ....... 19 
Figure 5: Geomorphologic map of the latero-frontal western part of the glacier foreland ............... 24 
Figure 6: Cross-section in a flute in the glacier foreland of Midtdalsbreen. ....................................... 29 
Figure 7: Study area on Norge-i-bilder (https://www.norgeibilder.no/) ............................................ 29 
Figure 8: Paleo-controlled ‘LIA moraines’ at site n°1, see fig. 7. ......................................................... 31 
Figure 9: Section A is the top section dug inside the hummock, site 1 ............................................... 32 
Figure 10: site 1 - sub-section A through an unidentified rounded hummock (top of fig. 9) ............. 33 
Figure 11: Bottom of the section A’ at site 1 (bottom of fig. 9) .......................................................... 34 
Figure 12: Section A and A’ composite section, fig. 10 and 11 ............................................................ 35 
Figure 13: Site 1 – sub section A: close-up view of the section…………………………………………………36 
Figure 14: Landform B (fig. 8) - section through a flat-topped mound, see fig. 8 for location ........... 38 
Figure 15: B – Section B at site 1 (1B), see fig. 8 for location .............................................................. 39 
Figure 16: site 1 section B: zoom in at the ‘twisted-V-shape’ on fig. 14.. ........................................... 39 
Figure 17: site 1 section C, see fig. 8 for location ................................................................................ 41 
Figure 18: Section through C, see fig. 17. ............................................................................................ 42 
Figure 19: site 1 cross-section D, see fig. 8 for location. ..................................................................... 44 
Figure 20: Cross-section D at site number 1, fig. 19 ............................................................................ 45 
Figure 21: Cross-section D’ facing West, see fig. 8 for location .......................................................... 47 
Figure 22: Site 2 near by the very snout of the glacier, proximity South-East of the snout ............... 49 
Figure 23: Section E through a recent mound at site 2 ....................................................................... 51 
Figure 24: Section through mound E at site 2, fig. 23 ......................................................................... 52 
Figure 25: Cross-section E’ through a mound at site 2, see fig. 4 for location .................................... 54 
Figure 26: Cross-section E’ through a recent controlled moraine at site 2 ......................................... 55 
Figure 27: Logging of cross-section F at site 3 to the Southeast of the glacier foreland .................... 57 
Figure 28: Cross section F across a mound at site 3, see fig. 4 for location ........................................ 58 
Figure 29: Cross section F at site 3 through a flat-topped mound, figure 27 ...................................... 59 
Figure 30: Cross-section G facing ESE at site number 4, see fig. 4 for location .................................. 61 
Figure 31: Cross-section G’ through a ridge at site number 4, facing WNW, see fig. 4 for location ... 63 

 
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Figure 32: Co-variance analyses for 5 landforms throughout the foreland ........................................ 65 
Figure 33: Glacitectonites identified to the right-hand side of the section of fig. 31 ......................... 72 
Figure 34: Taken from Reinardy et al., (2013). .................................................................................... 73 
Figure 35: Comparison of the samples from Reinardy et al. (2013) with the co-variance (fig. 32) .... 75 
Figure 36: Debate on the presence of thrust planes/shearing transporting debris ............................ 77 
Figure 37: De-icing progression of ice-cored terrrain, from Krüger & Kjær (2000) ............................. 79 
Figure 38: Widening of crevasse .......................................................................................................... 80 
Figure 38 a.: Model for the deglaciation above Midtdalsbreen area, and site 1. ............................... 84 
Figure 39: A picture of a large cavity ................................................................................................... 86 
Figure 40: Previous meltwater channel (fig. 39) viewed from above – fig 4………………………………86 
Figure 41: Dirt-cone located on the western side of Midtdalsbreen – fig. 4 ...................................... 92

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1. Introduction

1.1. Reminders about the thermal regime of glaciers

A small reminder about the thermal regime of glaciers is necessary. Controlled moraines may be

landforms that are found in the glacier foreland of Midtdalsbreen and these are supposedly found near by

a thermal boundary. The snout of Midtdalsbreen is indeed polythermal. The literature uses an abundance

of different terminologies. Thus, there is a need to describe a little bit more this terminology, before it is

possible to start any more complex analyses.

This section is a glossary for words further used in the text:

Cold-based ice: It is dry-based ice, and it refers essentially to ice without presence of water at the base of

the glacier. This is because the pressure melting-point is not reached at the base.

Temperate glaciers: Temperate glaciers are one of a kind included in a geophysical (Ahlmann, 1948)

classification of the glaciers worldwide. Other glaciers are by opposition continental in that they are

located further away from the coast, and in that they are dominated by more extreme climate settings and

defined tipping points when it has to do with alternance seasons in-between. They are, specifically,

glaciers with a sliding sole and a higher occurrence of water at their base because the pressure melting-

point is often reached there, due to either the thickness or the surrounding climate or the nature of

substratum. Most often it is however a conjunction of parameters which create basal melting. Thus,

temperate glaciers primarily designate glaciers in a climatic context and a glacier in a temperate climate

does not necessarily always mean that the glacier is always going to reach the pressure melting point at

the base, although it is most often the case.

Wet-based glaciers: They are essentially the same as temperate glaciers and warm-based glaciers, but

this classification is more precise than the former. Temperate glaciers primarily designate glaciers in a

climatic context and this does not necessarily mean that the pressure melting point is always reached at

the base of the glacier. The pressure melting-point is reached throughout at the base of any wet-based

glacier. It is the glacier which is important here.

Cold-based glacier: This refers to a glacier with cold-based ice. These glaciers are usually slow-flowing,

and this can often be correlated with the nature of the bedrock or sediments or even the climate. Water is

nearly absent at the base of this kind of glacier. They are thus even described as dry based.

Polythermal glaciers: They are glaciers comprising of both cold-ice and warm-ice patches.

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Warm ice-cold ice interface: This kind of boundary is of interest, and it is situated at the snout of

Midtdalsbreen where controlled moraines are produced. Although, this kind of boundary does not exist

only at the snout of glaciers. This interface can be located everywhere throughout the glacier and it is

even a moving boundary throughout the years/seasons. Fracturing takes place in an area where debris can

sometimes accumulate. In the case of a warm ice-cold ice interface, the pressure melting point is thus not

reached anymore at the glacier snout. Thinning of the snout can then even occur simultaneously.

Therefore, the interface sometimes can be materialized by a large arcuate fracture or a net of fractures,

and even cracks near by the debris-filled fractures in the ablation area of a glacier. Water must evacuate

through this fracturing, thus facilitating the accumulation of debris that can take place following a

fracture plane. In the case study of circular moraines feature deposited below an ice cap the authors Ebert

& Kleman (2004) write about the moraines deposited there and describe the difference in thermal regime

of the glacier from warm-ice up-glacier to cold-ice down glacier. This boundary is thought to appear there

in reason of a change in topography below an ice cap which was thin enough to produce cold-based ice,

where it was flowing above a slightly more elevated area than the surroundings. This is also called

gradient and is going to be indirectly or directly, at the center of the investigation throughout the

following report - as well as the processes involved behind the formation of mounds in the foreland of

Midtdalsbreen.

The warm-ice cold-ice interface is in that way a descriptive boundary which, much like the temperate

glacier typology (or the continental glacier typology), for that matter allow us to understand more fully

the slightly unorganized drainage at the snout of Midtdalsbreen. It is also a geographic boundary. The

drainage at the snout of Midtdalsbreen is directly related to the nature of some of the landform in the

glacier foreland as the mounds we are trying to characterize in the further report are directly affected by

meltwater action in a stepwise fashion.

1.2. Climate change: how does it affects glaciers worldwide?

Climate warming is one of the major issue society is facing during the 21st century. Indeed, many

glaciers are melting on the planet and this is happening at an increasingly alarming rate. Although,

climate warming does not have the same impact everywhere. Thus, the rate at which glaciers are melting

can be different depending on their geographic position; near the sea, or far away from it, for example.

Melting mountain glaciers contribute to a rise in sea level and thereby could trigger flooding of some area

lying near by the sea level. However, it is not yet the case in Scandinavia. Climatic refugees are still one

of the principal new kind of refugees during this century, and this kind of refugee is related to climate

warming and the melt of mountain glaciers has a global effect. Therefore, it seems to be relevant to study

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how glaciers are melting since the Little Ice Age, which was the last cold period during the Neoglacial.

Moraines are ridges mostly made from till and typically deposited at the extremity of a glacier. They are a

kind of landform giving evidence about the past dynamic of glaciers and they also give information about

the climate. Any glacial landform is nowadays today more and more exhumed. Different types of glaciers

are going to deposit different kinds of moraines and it is thus important to inform which glacier seems to

be associated together with which moraine in order to better be able to document the melt of the mountain

glaciers worldwide (Benn & Evans 2014). Identification criteria are given by a wide variety of

textbooks/handbooks and the one in brackets is very useful, especially on the field, since it regroups

relevant identification criteria for a wide variety of glaciers. This is based on the relevant literature,

mostly inside the Anglo-Saxon world but also sometimes inside the Nordics.

In Norway, the glaciers are mostly in deficit regarding their mass balance and in overall retreat.

However, in maritime Norway, the winter precipitations sometimes can contribute to minor winter

readvances of some glaciers, triggering the creation of push moraines annually. Continental glaciers are

very different from maritime glaciers. These former already receive very few snow precipitations during

the winter due to a cold and dry climate. The controlling factor for their mass balance is the amount of

precipitation during the winter, if one should compare them to more maritime glaciers. Maritime glaciers

always receive a high amount of snowy precipitations, but a small increase in temperature can drastically

shorten the accumulation season. Nevertheless, some particularly snowy winter can trigger advances of

the more maritime Norwegian glaciers, and melt can even occur during extended summer. However, it is

when summer are getting cooler and longer that the higher degree of glacial advance is likely.

1.3. Background information on moraines and controlled moraines

A set of “recent” mounds is present at the immediate vicinity southeast of Midtdalsbreen by its

snout (site 2 on figure 4). Their genesis is not obvious. After having a direct look at the snout of

Midtdalsbreen, it might be possible to guess about the nature of these mounds. A careful sedimentological

investigation of glacial landforms throughout the foreland is then necessary. Indeed, these hummocky

mounds as we can see them at site 2 can sometimes be of different nature. They could be controlled

moraine, but they can also be fluvial deposit modified by meltwater action directly in front of the glacier

(cartographic work by Sollid and Bjørkenes, 1978). The foreland of a glacier is often dynamic, and it is

then more difficult to give interpretations about the nature of younger and smaller landforms. It is

however easier to interpret the nature of these hummocks if we can compare their sedimentology to other

kind of landforms on the same foreland. Sollid and Bjørkenes (1978) wrote about the older landforms in

the foreland (at site 1, 3 and 4 as well as site ?: represented on figure 4) and described them as a set of

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stratified fluvial moraines, as an example, but the interpretation of these authors is not supported by any

convincing sedimentological evidence that we know of. The recent set of mounds (site 2) is thought of as

an analogue for the older mounds present on the landscape (site 1, 3 and 4). No stratified fluvial moraines

could be found at site ? in accordance with the map by Sollid and Bjørkenes. They were probably eroded

away before we could dig through them.

Salient uncertainties exist regarding these stratified mounds, even in more recent studies, e.g. the

study by Reinardy et al. (2013). They were, even back then not characterized, and this motivates indeed a

new study. Piles of debris or even dirt cones are sometimes sitting on top of the glacier snout as for the

modern set of evidence. These are likely to evolve into a hummocky moraine set after total deglaciation

of the landscape. This is supported by several references from the literature (Benn and Evans 2004,

Evans, 2009, Lukas et al., 2005, Goldthwait, 1951 concerning the list of direct sedimentological evidence;

and Schomacker 2008 as well as several studies by Krüger and Kjær were used, and those are all

mentioned in the reference list at the end of this report). As mentioned above, controlled moraines

initially form at a cold ice-warm ice interface, inside the glacier snout. The debris forming them are found

englacially and then on a superglacial position (Evans, 2009) in relation to the glacier’s dynamics and

general flow towards downvalley. Sub-glacial sediments are lifted-up inside the ice of the ablation area of

the glacier, along fracture planes, and then deposited up on the surface of the glacier, thereby insulating it.

The glacier is fractured there because it is slowing down towards the snout - the difference in velocity

between different blocks of ice may occasionate this fracturing present at the very snout together with the

warm ice-cold ice boundary downstream.

For the sake of conciseness and simplicity, the cold-ice warm-ice interface always designates a

geographical boundary located at the glacier snout in this report. This does not preclude that these

moraines can build up at the glacier sides otherwise. Although, it is good to mention the moraine creation

process always primarily depends on the availability of debris at any given snout/glacier. The controlled

moraines have been defined by Evans (2009) as moraines and these are created at a boundary between

cold ice and warm ice in theory. Much like moraines, they are depositional kind of landforms created at

the extremity of a glacier with the difference of having more of a superglacial and englacial origin.

Controlled moraines are thus created when a conjunction of a high availability of debris and a fracturing

can take place within a polythermal glacier. It seems, that one most often encounters these moraines

owing to the higher density of fractures and cracks in the snout of any given glaciers at their snout – i.e.

Storglaciären, nearby Kebnekaise, in Northern Sweden, seemed to display a similar kind of protuberances

above the fractures of its snout. This has been observed during a field trip to Kebnekaise in 2016. Any

glacier would slow-down at their very snout, due to the difference in balance velocity. This facilitates the

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formation of fractures there. Simultaneously, cold-ice is present due to the ice peripheral thin-out and

lower overriding pressure. In the ablation area the velocity decreases on land towards the margin, since a

lesser amount of ice is present at the very snout. The pressure-melting-point is not reached there. The ice

has been thinning enough, and a warm-ice cold-ice interface appears at the glacier snout. It might then

make it easier for the meltwater combined with some subglacial debris to evacuate englacially and freeze

on towards the glacier surface.

Based on the literature it was possible to produce a table which sums up the characteristics used to

identify controlled moraines (table 1).

Table 1: Distinctive signs for controlled moraine identification, after Evans (2009), Goldthwait (1951)

and own observations during a field campaign at the end of the summer 2017.

Type of glaciers Description and characteristics

Temperate to polythermal glaciers Sedimentology

The characteristic sedimentology is material which becomes

supraglacial, but it has not a superglacial origin,

which is to say from the cliffs surrounding the glaciers.

The till constituting this kind of ablation moraine must be more

sandy and stony due to the abundance of meltwater that might

wash-away the finer sediments. It is not impossible to have

some silts on the proximal side of a moraine because some

small lakes can be impounded there. Also the over saturation of

some layers might allow to observe the silt that is penetrating

in some other layers located above it. Surficial boulder rich

areas were also observed.

Lenses of sorted sands and gravels may be present, most likely

on the proximal side.

Fans of dipping gravels are banked up on the distal side of the

moraine.

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Structures

Vertical to steeply dipping layers.

Structures that can indicate the melt of an ice-core have a ‘V-

shape’ or other paleo-channel (e.g., site 3 in the thesis) and this

could indicate the melt of an inner ice-core

Morphology

Hummocky shape, with non-linear crest once the ice-core

melted-away

Cold-based to polythermal glaciers Sedimentology

The characteristic sedimentology is englacial and supraglacial

materials. More important supraglacial signal. Cold-based

glaciers erode less their beds and no subglacial/

englacial material, or few materials (from warm-based patches)

are deposited at the surface of the cold-based glaciers.

Meltwater channels on the side of the cold based patches might

make it easier to transport supraglacial debris.

The till constituting this kind of ablation moraine must be

sandier and stonier due to the abundance of meltwater washing

away the finer sediments during different stages. It is not

impossible to have some silts on the proximal side of a moraine

because some small lakes can be impounded there. Also, the

over saturation of some layers might allow to observe the silt

that is penetrating in some other layers located above it. Surficial

boulder rich zones were also observed.

Lenses of sorted sands and gravels may be present, most likely

on the proximal side.

Fans of dipping gravels are banked up on the distal side of the

moraine.

13

Structures

Vertical to steeply dipping layers.

Structures that can indicate the melt of an ice-core have a ‘V-

shape’ or other paleo-channel (e.g., site 3 in the thesis) and this

could indicate the melt of an inner ice-core. The dipping layers

only occur if the glacier is very fractured.

Morphology

Hummocky shape is one characteristic once the ice-core totally

melted-away. Non-linear appearance of the crest after the melt.

Although, a crest can sometimes be observed before the ice core

has melted away.

1.4. Aims and objectives

A ‘LIA dated moraine’ is sheltering a set of mounds on its stoss side at site 1 (fig. 4). The

mounds are in a latero-frontal position, much like the mounds present at site 2. Sollid and Bjørkenes

(1978) produced a geomorphological map of our study area, the foreland of Midtdalsbreen. Observations

by recent satellite imagery confirm the results of their mapping. These authors identified these moraines

as being constituted of both fluvial material and as being stratified moraine. They differ enough in

appearance from the surrounding landscape for them to be identified as moraines. The aim of this thesis is

thus to determine if the mounds in the glacier foreland are controlled moraines. If the mounds are indeed

controlled moraines, then this would have implication for glacier dynamics and the geometry of the

glacier snout soon after the Little Ice Age. Whether or not the ice was thin after the LIA can be

determined by understanding the nature of the mounds at the sites of investigation throughout the glacial

foreland, and this can give data about the retreat of Midtdalsbreen since the LIA. Both downwasting and

backwasting are possibly processes leading to the melt of Midtdalsbreen during the LIA. Identifying the

nature of the mounds may reveal which processes were predominant during the melt, and even if both

occurred at the same time or separately. This is also relevant for the dynamic of the glaciers, if not

14

worldwide, at least in southern Norway during the LIA. Glaciers presenting similar settings to

Midtdalsbreen may have shown a similar dynamic and pattern during deglaciation. However, it is difficult

to compare different glaciers, although they may be located close to each other. The local settings are

responsible for the creation of controlled moraines and the glacial dynamics is also very relevant. For

example, Midtdalsbreen is located to the North-East of the Hardangerjøkul ice cap and is part of the

drainage area of the ice cap. Additionally, the condition at the bed and on the side of Midtdalsbreen might

also make it a very different glacier from the surrounding ones. Midtdalsbreen is nonetheless relevant and

is a good example for what could have been the impact of the climate at the end of the LIA over this part

of Norway.

In order to assess the nature of the mounds in the foreland of Midtdalsbreen, sedimentological

investigations as well as geomorphic mapping were undertaken. The sedimentology of different

landforms throughout the foreland may lead to a better understanding about the nature of the mounds at

site 1, and the geomorphological mapping at site 1 is also relevant to put the landform record in context

regarding how the landscape was deglaciated. It is important to compare landforms of different type in

term of sedimentology in order that no misinterpretation regarding the nature of the mounds can be made.

Geomorphological mapping was already undertaken by Reinardy et al. (2013), but a more

detailed, larger scale map can give information about the conservation of the landform record as well as

new evidence for interpreting the mounds in relation to other landforms in the glacier foreland. Both

maps are based on field observations and were realized after the map by Sollid and Bjørkenes (1978).

Some of the landforms were perhaps previously overlooked in reason of the small-scale mapping and the

very ambitious (although, very useful) character of the study. The investigations will lead to consider the

processes involved in the formations of controlled moraines, and these processes will finally be discussed

together with the results of the sedimentological interpretations and the clast co-variance analysis in

section 5 and the following conclusion. A second geomorphological drawing/model might even give

information about the deglaciation pattern over the study area - if the hypotheses are verified. The main

findings in term of paleogeography are also presented at the very end of this report immediately after the

section conclusion, which also encompasses a section in hope that it describes the step-process complex

way leading to the creation of controlled moraines mounds in a more precise fashion than the so far

available literature.

15

1.5. Study area

Midtdalsbreen (60° 34´ N, 7° 28´ E) is an outlet glacier of a relatively small ice cap,

Hardangerjøkulen (figs. 1-3). His accumulation area is situated in southwestern Norway (figs. 1, 2) as

well as maritime Norway broadly speaking. Yet, in 1978 it was known as being partly cold-based at its

snout (Etzelmüller & Hagen, 2005) which is overlooking towards North-East. The present-day ice body

can be subdivided into smaller sheets of ice that plunges from 1865 to 1020 meters a.s.l. over the southern

Norwegian mountains: the so-called “kaledonske fjellkjede” (Giesen and Oerlemans, 2010).

These mountains are part of the mountain chain which creation is triggered by the opening of the

Atlantic Ocean. It was occurring about 425 to 400 million years ago, during the Acadian orogeny

(Seppälä, 2005). After this geological period, it is subsequent stadials and interstadials - considering a

smaller glacial time-frame- that are going to shape the southern Scandes as we can look at them nowadays

(fig. 1). Hardangerjøkulen is sometimes thought to be a remnant of the last Pleistocene ice-sheet and its

recent history starts during the mid-Holocene (Åkesson at al., 2017).

Vorren, T. O. (1977) described the geology of the study area nearby Midtdalsbreen and he also

studied the old ice movements above the study area during a period extending from the Weischelian until

the Preboreal age. Based on the ice maps of his report, the ice divide shifts were reconstituted at that time.

It was located not so far away from the contemporaneous Hardangerjøkul ice-cap. However, there is still

uncertainties about the presence of ice during the time span of the MIS 5 (Helmens, 2014). Nesje et al.

(2008) as an example, inform that most Norwegian glaciers were probably gone from 8.000 cal. yr BP to

4.000 cal. yr BP. This owe to the extended summer and/or reduced winter season. The seasonality is very

important when one deals with a maritime ice-cap because the glaciers there are in close relation to the

nearby ocean which brings heat and snowy precipitation. The ocean-pump over this part of Norway is

characterized by both the Norwegian current and the gulf stream. It is important to note that this ocean

overturning is probably less efficient during cooler period thereby explaining that glaciers might have a

slightly less dynamic action on its bedrock (Briner, J. P. et al. 2014, Bromley, G. R. et al., 2014)

16

Figure 1: Norwegian current against the coasts of Norway. The blue square indicates the location

of the Hardangerjøkul ice cap (the figure is taken and modified from Jansen, et al. 2016). The map to the

right is an overview map of the south-western Scandes: the Hardangerjøkul ice cap is located about 115

km away from the city of Bergen and the nearby coastline – Google Earth.

Only 73 km2 of ice is today located inland, at the head of Hardangerfjord. The fjord is extending

inland 115 km East from the city of Bergen (fig. 1) and the nearby coast (Giesen and Oerlemans, 2010).

Jøkul, from the Old Norse jǫkull designs in Norwegian the “maritime ice-cap”, Hardangerjøkul is locally

maritime when one has a look at the branches of ice on its western half. It means its mass balance is

mostly constrained by the variation in temperatures during the winter time – i.e. it constrains the

extension of melt season. Midtdalsbreen is however an outlet glacier that has a direction facing towards

Northeast and it is located on the Eastern part of an ice cap (fig. 2), which is an area that is susceptible to

be affected by a slightly more continental kind of climate, or at least a weaker maritime climate.

Midtdalsbreen translates to ‘mittdalsglaciären’ in Swedish language or the ‘middle-valley glacier’

in English language (i.e. central relative to the northeastern part of the ice cap) and this glacier is part of a

more extensive group of outlet glaciers draining the whole circumference of the Hardangerjøkul ice cap.

Midtdalsbreen is the fourth largest outlet glacier in term of drainage area around Hardangerjøkulen after

Rembesdalskåka, Vestra Leirebottsskåka and another non-identified large drainage area (fig. 2).

Midtdalsbreen has an area of about 6.8 square kilometer (Andreassen et al., 2012). It flows

towards a larger valley than the valley in which it sits, for about 477 m. This relatively large valley is

termed Finsedalen (a ‘dal’ is a valley, in Norwegian). Midtdalsbreen flows from an elevation of 1861 m.

above sea level (a.s.l.) until an elevation of 1384 m. a.s.l., downglacier, with an average slope of 8 along a

representative transect (Andreassen et al., 2012). This is useful information if one were to retrieve the

Hardangerjøkul

17

stress and strain and then calculate Glen’s flow law in 2D along this transect – see discussion of this

thesis (page 72). The following section about the Geology of the study area will also be of interest in

relation to the method section of this report. Indeed, clast shape analyses will allow us to extrapolate and

presume we know more about the physics at the center for the creation of controlled moraines.

Figure 2: Close-up view of Hardangerjøkulen ice cap. Midtdalsbreen outlet glacier (60° 34´ N, 7° 28´ E)

is located at the North-East of this ice body. The figure is taken from Andreassen et al. (2012). The black

square indicates the position of the foreland near Finsevatnet. The numbers correspond to different

drainage area of the ice-cap in the original paper but are not important here.

Finsevatnet

18

1.6. Geology around the study area

Figure 3: Geology around Hardangerjøkul: 135: Porphyritic granite, coarse grained with phenocrysts of

orthoclase feldspar, 138: Fine to medium grained granite, 14: Charnockite to anorthosite rocks and

granitic to monzonitic gneiss, not divided, 78: Phyllite, mica schists. Geological Survey of Norway,

Bedrock geology map. 1:1.250.000

A wide amount of different geologies is present near the study area (fig. 3).

A lot of charnockite to anorthosite rocks and granitic to monzonitic gneiss, are not divided

(14), and few not identified lithologies, as well as few patches of green labelled 78 are representing a mix

of phyllite and mica schists. These rocks are presents at the immediate vicinity of the Midtdalsbreen’s

snout. A little further away, downvalley from Midtdalsbreen; there is a boundary between two geological

units: fine to medium grained granite (138) and porphyritic granite, coarse grained with phenocrysts of

orthoclase feldspar (135). Gneiss and anorthosites as well as granites and few phyllites are most likely to

be found in the study area.

19

1.7. Sites of interest

It is interesting to compare the mounds at study site number 1 to other mounds throughout the

landscape. Thus, other sites were selected throughout the landscape (fig. 4). The reason why these

specific sites were selected is specified in the section result about the sedimentology.

Figure 4: Close-up view of the study area (Norge i bilder, screenshot: http://norgeibilder.no/),

“Midtdalsbreen glacier foreland” in this report designates the area immediately down-glacier up until the

second structural cliff parallel to the glacier margin. This area was recently modified by the ice

movements after the LIA until today. The red dashed-lines are structural cliffs.

The approximate LIA limit is given by the LIA moraine, represented by black lines – Sollid and

Bjørkenes (1978) and this limit appears to somehow coincide with the second lowermost structural cliff

(uppermost red line on the figure).

The landscape itself is constituted of two pseudo stairs, with a wide range of recent landforms that

are present up above the uppermost cliff towards glacier (red dashed-line) and a less important variety of

older landforms found up above the lowermost buttress/cliff (second red dashed line coinciding with the

LIA-limit, at least punctually).

Site 2 is situated within the part of the foreland constituted of recent landforms and site 1, site ?,

site 3 and site 4 are located within the part of the foreland constituted of older landforms. The question

mark stands for a potential site that I visited based on the map by Sollid and Bjørkenes (1978): no

significant hummocks were found there, and a lake although present there in the past, had practically

disappeared (fig. 5: semi perennial lake). The location of figs. 39, 40 and 41 (photos) is also indicated.

20

1.8. On the creation of polygenetic landforms in the ablation area of a

cold-based glacier

Waller et al. (2013) wrote a review about the interactions between glacier and permafrost. Cold

based ice can still create landforms because of the presence of pre-melted water at its base. This may

happen inside soft sediments that are affected by permafrost. It is not essential to look for an area of cold-

based ice as well as an area of warm based ice at the glacier snout. The glacier is slowing down in the

ablation area and landform are thus created. This process is time-transgressive in the sense that it is

operating continually throughout the year. Landform may develop in a different way. Erosional landforms

are rarely created because of the ice flowing in the upglacier direction thereby facilitating the

accumulation of different kinds of sediments. The sediments can even be lifted along fracture planes of

the glaciers up to an englacial position which has for effect the stiffening the ice. This ice must be flowing

above a soft bed with pre-melted water inside it in order to continue fracturing according to Waller et al.

2013. The strain increases down-glacier with the decreasing average velocity of the glacier. Mostly, one

could picture this as varying conditions, and concentration of pre-melted water, at the base of the glacier

throughout the year. Sometimes frozen water is present inside the soft-bed, and this water is going to

reach the pressure melting point. This contributes to an increased sliding of the glacier in that specific

zone of the glacier snout. As previously mentioned, pre-melted water can be present inside these soft

sediments.

2. Methods

The methods Lukas (2007) used in his paper when he produced data about the paleoglacier dynamic

at Krundalen were also used here, except for the RA index. The description of our methods is thus

inspired by this paper and follows the same logical order. Geomorphological mapping was carried out at a

scale of 1:90 enlarged from the geomorphological map by Reinardy et al. (2013) and aided by both aerial

photographs on ‘Norge I Bilder’ (http://norgeibilder.no/) and the map of the glacial geology by Sollid and

Bjørkenes (1978). Measurement of the landforms in which were dug into was also undertaken. The

location of the additional study sites to the East of study site number 1 are presented in fig. 4, and they

were obtained from the glacial geology map of the area (Sollid and Bjørkenes, 1978). Some of the

mounds which were dug into were described like stratified fluvial moraines by Sollid and Bjørkenes

(1978) on their glacial geologic map. Sedimentological logging was carried out on a waterproof field

notebook ‘Rite in the rain’, and square millimeter paper was used to redraw the larger sections that could

21

not be drawn directly in Adobe Illustrator unless digitizing their scale drawing first. Photography was also

used to ensure planimetric accuracy. When the cross-sections were too high and narrow to permit good

photography, then square millimeter paper had to be used to redraw the sections in addition to the pictures

and the field notebook. The sedimentary units were identified based on visual properties such as grain

size, compaction, sedimentary structures and clast shape measurement were also undertaken following the

guidelines given by Evans and Benn (2004). The dip angle of sedimentary units and structures was also

measured. The logging was made using a version of the lithofacies code introduced by Eyles et al. (1983)

and further slightly modified by Evans and Benn (2004). The clast shape measurement was introduced by

Benn and Ballantyne (1993, 1994) and their method was used as for the clast shape analysis. An amount

of 50 clasts were selected for measurements of their three orthogonal axes for each landform that

contained enough clast, or a unit of gravel, and later compared with control samples of known origin

sampled by Reinardy et al. (2013) during a previous field season (supraglacial control, englacial control,

fluvial control, subglacial control). Benn and Ballantyne (1993, 1994) wrote about two variables that

allow to discriminate the transported clasts. The RA index which allow to understand the edge rounding

of the debris was not used in our case study because a sufficiently high population of Angular and Very

Angular clasts was not obtained in order to apply this method. However, it was possible to use the RWR.

It allows to discriminate between the transported clasts, and this method is believed to be sometimes more

efficient than the RA index (Lukas et al., 2013). The RWR index accounts for the population of rounded

to well-rounded clast, which plotted against the C40 index allow us to tell the difference between clast

transported by different processes in a given glacier foreland. The C40-index is defined as the percentage

of clasts with a c/a ratio (shortest to longest axis) of 0.4 and this index allows to discriminate blocky clast

from the other type of clasts (platy and elongated). A low C40 means a high blockiness, and vice and

versa. Typically, the subglacial transport tends to produce blockier clasts.

22

3. Results

3.1. Geomorphologic map

Based on the material available (Sollid and Bjørkenes, 1978, Reinardy et al., 2013) and the

field investigations I could produce a geomorphological map of the study area at site 1, the most

important location over our 4 sites, in reason of its proximity with the LIA moraine. This

geomorphological mapping was drawn using field-based evidences and significant differences with the

map by Sollid & Bjørkenes (1978) were observed. This is due to the time-transgressive character of the

landform record.

One of the most prominent landforms is probably a small, minor moraine sitting on bedrock. It is a small-

scale landform compared to the LIA moraine and the set of either paleo-controlled moraines or terraces,

but it is a relevant landform since it indicates the past glacier flow direction. It is therefore possible to

obtain information about the deglaciation after the LIA moraine was deposited and, because of that a

modification of the mapping undertaken by Sollid and Bjørkenes (1978) and Reinardy et al. (2013) was

undertaken. In reason of the smaller cartographic scale of their map Reinardy et al. (2013) missed some

details, and more flutes are present on the latter map (fig. 5). Table 2 informs the reader about criteria

used to identify the landform record, and the associated uncertainties.

Table 2: Criteria for the identifications of the landform record.

Geomorphology Uncertainty

_____________________________________________________________________________________

LIA Moraine Ridge-shaped type of deposit The ridge shape is common for other type of glacial

Perpendicular to flow landform such as eskers, but eskers are parallel to the

Large dimensions (> 5m) flow direction.

Essentially a voluminous end moraine

Minor Moraine Ridge-shaped type of deposit The small size of the ridge (about 1 m) could raise

Perpendicular to ice-flow misinterpretation and its position relative to the

Small dimensions (< 3m) previous flow direction could make it a till

accumulation in a moulin for example, although it

is not as likely.

23

End Moraine Ridge-shaped type of deposit Few uncertainties associated to the identification of

Perpendicular to flow this landform.These are relatively small because they

Shows the retreat pattern were created during winter re-advance as a push-

Small dimensions (< 3 m) moraine or they could indicate a break during retreat.

Today small push-moraine are created at the front.

Glaci-fluvial Hummocky mounds The deposits could also be more traditional till but

hummocky shape indicated some degree of

modification by meltwater

Meltwater channel Channel where meltwater

drains

Semi-perennial lake Lake whose level is changing

throughout time

Flutes Elongated features Few uncertainties. These landforms often appear in

Small size (< 1m high) swarm which makes their interpretation easier

Cliff Structural cliff in the landscape

24

Figure 5: Geomorphologic map of the latero-frontal western part of the glacier foreland, based on Sollid

and Bjørkenes (1978) and Reinardy et al. (2013) as well as field investigations (2017). Zoom-in of fig.4,

scale is 1:90. The minor moraine (medium-light gray), medium-sized line is at the center of our

investigation and may allow to later on discriminate the nature of the mounds at site 1.

25

On the map above (fig. 5), the past flow direction is indicated by the flutes. The maps by Sollid &

Bjørkenes (1978) and Reinardy et al. (2013) were modified after field investigations in order to produce

the geomorphological map above. A lesser number of flutes are present on the landscape nowadays. Site

1 is the westernmost glaci-fluvial mounds deposits on the map. The LIA moraine is present in different

locations, and it is larger in the West than in the East over the study area. The latero-frontal LIA moraine

was most likely fed by supraglacial debris coming off from the cliffs in the vicinity of the glacier, in the

West, compare to its frontal part most likely fed predominantly subglacially, in the East. The

differentiation between stratified glacio-fluvial moraine (westernmost fluvio-glacial deposits on the map

above) and terraces of Sollid and Andersen (1978) was abandoned. It was indeed impossible to

distinguish between these two types of landform, while missing the identification criteria. The following

sedimentological investigation is allowing to tell more about the westernmost fluvioglacial deposits at the

westernmost part of the map, as well as about other deposits, and this without any preconceived view.

This area was selected for further investigation in reason of the flat topography, precluding any

significant fluvial modification of the landscape by meltwater channel. This involves that the steeper

areas of a foreland are likely to erode, or undercut, in an easier fashion because of meltwater action. It is

even possible that incised terraces as well as “fluvial” hummocks are found more easily in the landscape

if there is a knickpoint or at least enough gradient in elevation. In addition, as for the latero-frontal

position there it excludes that the fluvio-glacial mounds west of the mounds at site 1 could have been

created by a sandur since a sandur is usually only found in frontal position.

Based on the map it is possible to visualize two areas:

- A Pre-LIA scouring area

- A Post-LIA landscape

The former has an aerial scoured appearance because of an abundance of smooth bedrock, and an

absence or scarce abundance of glacial till.

The post-LIA landscape contains the fluvio-glacial deposit close by a LIA moraine in latero-

frontal position – West on the map –, and this area has lot of tills and glaci-fluvial deposits on it. The

post-LIA (recent) landscape hasn’t been eroded as much since it is of younger age.

26

3.2. Sedimentological results

The geomorphological map alone (fig. 5) does not allow to identify the nature of the mounds at

site number 1. Much like Sollid & Bjørkenes (1978) and Reinardy et al. (2013) solid sedimentological

evidences are still missing in order that it is possible to interpret the mounds at site 1. The map of the

previous section is not enough (fig. 5). However, an improvement was made in term of scale in

comparison to the maps by Sollid & Bjørkenes (1978) and Reinardy et al. (2013) and this altogether with

the higher level of accuracy of the map that was produced (fig. 5) is a first step towards the identification

of these mounds. Currently, the geomorphological map on its own does not allow the reader to answer the

question about the nature of the mounds at site 1, nor does it allow to answer the two questions about the

thickness of the snout and the thermal regime since the LIA as well as the mode of deglaciation following

the LIA. The sedimentology should give additional evidence and thus, complete the detailed mapping in

order that an interpretation regarding the nature of the mounds at site 1 will be possible. Table 3 is the

lithological facies code which was used for the description of the sections and cross-sections at every site.

Table 3: Lithological facies code and description: the facies code is based on Evans and Benn (2004) and

Eyles et al. (1983). Granules are particles from 2 to 8 mm according to Evans (2014) whereas sands are

particles from 0,063 to 2 mm. Granules and sands are therefore in a continuum in term of particle size.

More details are given on the Evans (2014) regarding the size of the particles.

Facies Description

Fl Silt often with minor fine sand

Fp Intraclast or lens of silts

Fm Massive silts

Sm Massive unit of sands, medium to coarse sands with some occasional gravels,

sometimes faded stratification

Sh Very fine to very coarse sands and sometimes horizontally/plane bedded or

low angle cross lamination

Sp Medium to very coarse sands

Sps Sheared medium to very coarse sands

Suf Upward fining sands

Gm Clast supported massive gravels

27

Gms Matrix-supported massive gravels

GRm Granules, massive and homogeneous

GRmc Granules massive with isolated outsize clasts

Gcu Upward coarsening gravels

BL Boulder lag or pavement

The labelling of the landforms was thought of such as there is only one landform A throughout

the glacier foreland. The sections that are dug through landform A will be called A and A’. If there would

be three sections through landform A, they then would be called A, A’ and A’’ for example, but the

maximum which was excavated through one single landform is 2 sections. Cross-sections A, A’, B, C and

D (D’ facing D) are present at site number 1; sections E and E’ are present at site number 2; cross-section

F is present at site number 3 and; finally, cross-sections G and G’ are dug into a mound at site 4.

3.2.1. Flute at the snout of Midtdalsbreen: additional site

In order to be able to identify the mounds at site 1, it was interesting to dig into a flute at the

immediate vicinity of the glacier snout. The flute is likely to be representative for other flutes present in

the foreland. It is important to dig into different kind of landforms throughout the foreland because it can

be used to interpret of the nature of the material at a given foreland. Some flutes might get sandier in a

given part of a foreland or in a given foreland, for example, although they are most often constituted of

silt and clay, and the till throughout a foreland can vary in clast size regarding its matrix. If the material

constituting the mounds at site 1 is the same material that is found in the flute near the glacier snout then

maybe the mounds are reworked flutes and not controlled moraine, or the mounds are controlled moraines

overprinting flutes. It could also be that the mounds at site 1 have nothing to do with the flutes.

As described in table 1 and 2, the identification criteria for the sedimentology in this foreland is

mainly based on a variety of scientific articles and a handbook for the field, and of course the

identification of a flute as being a flute and of till as being a till serves us in this specific foreland together

with the handbook/identification criteria presented inn table 1 and 2.

The glacier foreland of Midtdalsbreen is a typical “fluted morainal”-landscape of different

generation, following the two steps/structural buttresses of the foreland (fig. 4) and similar forelands with

similar landforms can be observed to develop in a similar fashion in other locations such as in Kebnekaise

28

(Baranowski, 1970). They are landforms indicating the past glacier flow direction. Flutes are today

emerging directly from the cold-based snout of Midtdalsbreen. Caution should be used when looking at a

fluted landscape for us to interpret the thermal regime. Based on Baranowski (1970) research, silty areas

as well as small blocks are determinant for the creation of flutes, as well as the availability of meltwater.

Small blocks likely act as an obstacle for the glacier flow at the base of the ice and sediments are going to

accumulate following a line behind these small blocks in the direction of the ice flow. Gordon (1992)

agrees with Baranowski (1970) and specifies that flutes are primary features formed by deformation of

the basal ice layer around subglacial boulders or other obstacles. Birnie (1977) seems to see some sort of

correlation in the deposition of squeezed snow bank pushed ridges with the squeezing that would also be

responsible for the creation of secondary flutes created during the advance of an ice margin and forming

perpendicularly to the ice-edge. One flute was observed in the foreland of Midtdalsbreen (fig. 6). Flutes

were not identified very near site 1, but the older map by Sollid and Bjørkenes (1978) displays more

flutes than the map of the previous section (fig. 5). Probably, flutes were even degraded due to the amount

of time they were exposed and their likely small dimensions.

29

Figure 6: Cross-section in a flute in the glacier foreland of Midtdalsbreen: immediate vicinity of

the snout. A. Facies codes. B. Unit numbers. Two units were identified here: unit 1 is a unit consisting of

massive silts and constitutes most of the section while unit 2 is a small unit of clast supported gravels

within unit 1. The cross-section is facing North-East-North. Table 3 explains the facies code.

The section is dug acrossa flute 33 meters away from the glacier (fig. 6) because the same flute at

the immediate glacier snout was too saturated and it was therefore quite difficult to dig into it. The section

is facing NEN, on the distal side of the flute. The section is 35 cm high and 60 cm across, which makes it

as tall as the flute itself. In-between two flutes there is flat areas of sand and silt which is laying at 0 cm in

height. The section has only two units. Unit 1 extends across the section and is as high as the cross section

(35 cm) itself. It consists of silt often with minor fine sand (Fl). The unit is matrix supported and some

occasional gravel that are more important in size (> 7cm) are found inside it. Unit 1 surrounds unit 2

30

which is located inside unit 1. Unit 2 has a sharp contact with unit 1 and is located within the latter unit.

Unit 2 consist of a line of clast supported massive gravels (Gm).

3.2.2. Sections – site 1, near the LIA moraine

The landforms there can be described as mounds with a hummocky shape. There were

either flat-topped mounds or more traditional rounded mounds (fig. 8). Site 1 is the site near the LIA

moraine included in the detailed geomorphic map (fig. 5). The mounds there are of interest to determine

the nature of the thermal regime of the glacier since the LIA, and the geometry of the snout as well as the

mode of deglaciation. It is suspected they may be controlled moraines, and this assumption is based upon

the previous study in the study area as well as on the new detailed geomorphic map (fig. 5). Although,

accurate sedimentological investigation is still needed, and it might give more solid evidence regarding

the nature of the mounds at site 1 (figs. 8, 12).

Figure 7: Study area on Norge-i-bilder (https://www.norgeibilder.no/), zoom-in of fig. 4, site 1,

and same scale as fig. 5. The black lines are classic end moraines; the thicker the line, the higher the

moraine. The red dashed-lines are cliffed structural edges present on the landscape and displayed here

owing to a shading, approximately from SW – matching the glacier flow direction, parallel, of the

present-day glacier. The glacial geologic map by Sollid and Bjørkenes (1978) was used to locate the

moraines and potential sites.

1

?

31

Figure 8: Paleo-controlled ‘LIA moraines’ at site n°1, see fig. 7, A: section of a supposed

controlled moraine, A’: section at the bottom of this supposed controlled moraine, B: section on top of a

supposed cut-through fluvial terrace, C: section on top of another cut-through presumably fluvial terrace,

D: cross-section across an assumed controlled-moraine sitting on top of the terrace (B). The dashed black

lines tell the reader about the position of the ice at different point in time. Those are moraines, and they

are constituted for the most of diamict material, except for the dashed line seen just on the right-hand side

of the C square. This could just be a till deposit within glacier in reason of the absence of ridge shape

regarding the morphology of the terrain form there. The dashed red lines are structural cliff. Fig. 9

displays a close-up view of the cliff on the right of the picture.

Sections A and A’ in landform A were chosen because landform A was considered a typical

mound for this mound landscape at site 1, and then it would allow to eventually extrapolate the nature of

mound A to the similar looking mounds at immediate proximity. Landform B and C were selected in

reason of their different morphological aspect of flat-topped mounds and they seemed to constitute the

32

boundaries of this mound landscape on its both sides. They looked slightly different morphologically

compare to landforms A and D. Landform D was chosen because it would be possible to observe two

typical sedimentology for the rounded mounds. It is likely some natural variability is involved during the

creation of these rounded mounds, thus the necessity of digging into at least two of them in order to

interpret about their characteristic formation pattern/nature on this foreland.

Figure 9: Section A is the top section dug inside the hummock, within the hummocky plain

observed in fig. 8. Spade for scale down the bottom section A’. One can see the cliff on the background

(which corresponds to the upper red dashed line in fig. 8) as well as a glacial erratic sitting on top of the

cliff. The erratic (red arrow) is either made of phyllite or granite. Fig 10 and 11: close-up views of

sections A and A’.

33

3.2.2.1. Site 1A: Composite section through a mound

Two sections (A and A’) are constituting a composite section in landform A at site 1. They

were the first dug into during field investigations, and it were interesting to dig into this mound, since

these sections are spanning the whole landform regarding its height on one side of it. It is indeed a

composite section of landform A.

Figure 10: site 1 - sub-section A through an unidentified rounded hummock (top of fig. 9), on the

stoss side of the LIA moraine. At the bottom one finds massive compacted sands with stratification of

granules and a lens of silts to the right-hand side of it. A pocket of gravel is massive and matrix-supported

above it, and a unit of granules with stratification is found within it. Just above it is present a unit made of

silt often with minor fine sand. On the top of the unit is another unit consisting of massive matrix-

supported sands, a bit less compacted than at the bottom. Table 3 describes the facies code.

34

Figure 11: Bottom of the section A’ at site 1 (bottom of fig. 9). Massive matrix-supported sand to

the bottom right-hand side, massive matrix-supported granules with occasional outsized clasts to the top

left-hand side. Pocket of clast-supported massive gravels in the middle of the section. Few stratifications

of granules throughout the section are present. Table 3 explains the facies code.

35

Figure 12: Section A and A’, fig. 10 and 11 (dip-angles, and granulometry; interpretation is based

on the Evans textbook, Evans (2014) according to the method section, as well as a photography dataset

from the field). A. Facies code for section A’, bottom section with legend based on Evans (2014). B. Unit

numbers for section A’. C. Facies codes for section A, top of the mound; based on Evans (2014). D. Unit

numbers for section A. The yellow color stands for sands and/or granules. The grey color stands for silts

and/or clays. The white color stands for gravels. The composite section is facing NWN. Table 3 explains

the facies code used.

Section A and A’ consist of one composite section dug into a ~3 m high mound at site 1 (figs. 9-

12). The dip of the overall mound into which the section was dug is 20 °, which is the dip taken on the

left-hand side of the section, towards the reader (fig. 12), and in a direction almost perpendicular to the

previous glacier flow direction over this area. The crest of the moraine itself is dipping at 5 ° towards

ENE, which is equivalent to the left-hand side in fig. 12. The bottom section is 110 cm high and 120 cm

36

across. The top section is 150 cm high and 70 cm across. Both section A and A’ make together a 260 cm,

which is almost as high as the whole section dug through landform A. This composite section A has been

subdivided onto 27 units. Unit 1 is 80 cm wide at the bottom, although less wide towards the top, with a

highly variable thickness, also, from almost 0 to 100 cm and it consists of massive matrix-supported

sands. Unit 1 has a sharp contact with unit 2 that is dipping at 60°. Unit 2 is located within unit 1 and is a

unit of massive matrix-supported granules 5 cm wide and 20 cm thick. Unit 1 has a sharp contact dipping

at around 60° with unit 3. Unit 3 is 40 cm at the bottom of the section and larger towards the top,

following the contact with unit 1. The thickness of unit 3 goes from 10 cm to 110 cm towards the lefthand

side. Unit 3 consists of massive matrix-supported granules with occasional outsized clasts. There is a

sharp contact between unit 3 and unit 4. Unit 4 consists of massive silts and appears to the very lefthand

bottom of the section. Unit 3 has a sharp 20° contact with unit 5. Unit 5 is 30 cm wide and 10 cm thick

and is made of massive matrix-supported granules. Unit 3 has a sharp contact with unit 6. Unit 6 is 30

cm2 pocket of clast-supported massive gravels. The granules of unit 3 (fig. 12: B) probably have a contact

with the sands of unit 7 above (fig. 12: D), but it is not known for sure since the two section A and

A’ don’t reach each other. Unit 7 extends across the top-most section and is 40-50 cm thick. It consists of

sands that are massive and matrix-supported. Units 8-12 are made of slightly coarser sediments than

sands (massive matric-supported granules) and are found throughout unit 7 and all present sharp contacts

with the rest of the unit. Those former units have also similar dimensions, which is to say around 20 cm

wide and >5 cm thick and are dipping from 12-13° for units 9, 10 and 12 to 30° for units 8 and 11. Unit

13 has a sharp contact with unit 7. Unit 13 is a lens of silts of 15 cm wide and 10 cm thick present within

unit 7 to the right-hand side. Unit 14 has a sharp contact with unit 7. Unit 14 is a 30 cm wide and 10 cm

thick pocket of gravels that are massive and matrix-supported. Units 7 and 14 have a sharp contact with

unit 15. Unit 7 has a sharp contact dipping at 5° with unit 15 to the right-hand side of the section. Unit 15

extends across the section and is >10 cm thick and is made of granules with occasionally outsized clasts.

On the right-hand side of this unit, within it, are present units 16-19. They have a sharp contact with unit

15 and are constituted of granules that are massive and clast-supported, without outsized clasts. They are

all dipping at around 20° and are not very thick (>5 cm) and are less than 15 cm wide. Unit 15 has a sharp

contact on top with unit 20. This is a contact of undulating nature. Unit 20 extends across the section and

is > 20 cm thick and consists of massive matrix supported silts often with minor fine sands. Unit 20 has a

sharp contact with unit 21 dipping at 5° on the right-hand side of the section. This is also an undulating

contact. Unit 21 extends across the section and is 80 cm thick. It is made of sands that are massive and

matrix-supported but not so compacted as unit 7. It has some units (22-27) present within unit, but they

do not have sharp contact maybe because of the low level of compaction for the top-most part of the

section. Units 22-27 are dipping in different directions and at different angles. Unit 22 is made of massive

matrix-supported granules and is dipping at 15° in a different direction compare than the units 23- 27.

37

These remaining units are all dipping in the same direction at an angle of 10°. They are made of the same

sediments as unit 22 was made of.

Figure 13: site 1 – sub section A: close-up view of the section where gravels are present inside the

relatively sharp contact between units 20 and 21 (fig. 12: D). The gravels are of different sizes

(from 1 cm to around 3 cm)

The fig. 13 displays a sharp contact with gravels between unit 20 and unit 21 and is an

evidence for the compaction of the section at the top of the landform that is slightly less important than at

the bottom of the landform. Landform A here is probably older and has had more time to compact itself

more relative to other potential sections located directly at the very front of the glacier snout (the other

site, number 2, is a location for recent mounds).

38

3.2.2.2. Site 1B: Section through a flat-topped mound

Landform B was selected in reason of its different morphological aspect of flat-topped mounds

and it seemed to constitute the boundary where the mound landscape finishes towards the LIA moraine

side (fig. 8). The morphology and the sedimentology in that case are interesting to interpret in order to

contrast them to that of the rounded mounds.

Figure 14: Landform B (fig. 8) - section through a flat-topped mound, see fig. 8 for location, unit

1 at the bottom consists of massive silts (Fl); just above it, unit 2 consists of massive matrix-supported

sands (Sm), see below, fig. 16, for the zoom-in of unit 3 that is made of very fine to very coarse sands

(Sh), unit 4 consists of gravels that are massive and matrix-supported (Gms). Table 3 gives the facies

code description.

39

Figure 15: B – Section B at site 1 (1B), see fig. 8 for location; A. Facies codes, with legend based

on Evans (2014). B. Unit numbers. The yellow color stands for sands and/or granules. The grey color

stands for silts and/or clays. The white color stands for gravels. The section is facing the north on the ice

distal side of the mound. Table 3 explains the facies code used.

Section 1B is dug through the side of a flat-topped mound approximately 2 m in height (fig. 14

and 15). The section is 120 cm high and 40 cm across. The section has four units. Unit 1 extends across

40

the section and is 20-25 cm thick and consists of silt. The unit is massive except for a lens of less compact

material. There is a sharp contact between unit 1 and 2 dipping at 10 degrees to the right of the section

and >10 degrees to the left of the section. Unit 2 extends across the section and is 60 cm thick. Unit 2

consists of massive to poorly stratified sand with rare larger (>5 cm) clasts. Unit 2 has a gradual contact

with Unit 3 which consists of a 20 cm thick lens of fine to coarse sand with occasional gravel. The upper

contact between unit 2 and 4 is sharp and “wavy”. Unit 4 extends across the section, is 40-45 cm thick

and consist of massive matrix-supported gravel.

Unit 3 has the shape of a ‘twisted-V-shape’ (fig. 16).

Figure 16: site 1 section B: zoom in at the ‘twisted-V-shape’ on fig. 14. The depth is wrong on

that figure, but the scale is indicated on the left-hand side to give an idea about the dimension of the V-

shape.

41

3.2.2.3. Site 1C: Section through a high (>2m) flat topped mound cross-cut by a

small meltwater channel

Like landform B, this landform C was chosen because of the morphology of flat-topped

mound and because it was situated on the side of the swarm of mound landforms. It was then expected a

different sedimentology inside that mound, compared to the more central rounded mound in the swarm.

Figure 17: site 1 section C, see fig. 8 for location. Unit 1 is made of massive silt (Fm). Unit 2 is a

boulder lag (BL). Unit 3-6 are made of sands (Sp, Sm). Unit 7 and 8 are made of gravel (Gcu and Gms).

The yellow stands for sands and the black for rocks, but the drawing was not complete at this stage. The

methodology used can there be understood. Table 3 explains the facies code.

42

Figure 18: Section through C, see fig. 17. A. Facies code. 8 units, from bottom to top massive

silts, boulder lag, medium to very coarse sands, massive matrix-supported sands, medium to very coarse

sands, upward coarsening gravels, massive matrix-supported gravels. B. Facies associations. The yellow

color stands for sands and/or granules. The grey color stands for silts and/or clays. The white color stands

for gravels. The black color stands for the boulders. The section is facing SE on what is likely to be the

proximal side of the mound. Table 3 explains the facies code.

43

Section 1C is dug through the middle of a flat-topped mound of important dimensions (> 3m), and

the side of it is eroded by a meltwater stream (figs. 17 and 18). The section is 110 cm high and 60 cm across.

The top of the mound is dipping at 10° towards NE. The section has 8 units (fig. 18: A) and one relevant

facies association (fig. 18: B). Unit 1 extends across the section and is 20 cm thick and consist of massive

silts. There is a sharp contact between unit 1 and unit 2 and it is of undulating character. Unit 2 extends

across the section and is 25 cm thick and consists of a boulder lag. There is a sharp contact between unit 2

and 3 and 4 and a boulder as well. Unit 4 extends across the section and is 20 to 5 cm thick, where the

boulder is present. It consists of massive sands. To the right-hand side of the large boulder is present unit 3.

Unit 3 is present within unit 4 and just above unit 2. It does not extend across the section and it is 10 cm

thick and consists of medium to very coarse sands. There is a sharp boundary between unit 4 and unit 5. It

is slightly disturbed on the left-hand side. Unit 5 consist of the same material as unit 3, which is medium to

coarse sands with occasional gravels, and it extends across the section and is 15-10 cm thick. There is a

sharp contact between unit 5 and 6 that is dipping at 10° on the very right of the section. Unit 6 extends

across the section and is 5-10 cm thick. It contains medium to coarse sands and very few occasional gravels.

There is a sharp contact between unit 6 and unit 7. It is also dipping at 10°. Unit 7 extends across the section

and is 10-5 cm thick. It consists of upward coarsening gravels. There is sharp contact between unit 7 and

unit 8 that is dipping at 10° on the right-hand side. Unit 8 extends across the section, is 10-20 cm thick, and

consist of massive gravels, matrix supported. Facies association C consists of unit 3, 5 and 6 and consists

essentially of medium to very coarse sands.

44

3.2.2.4. Site 1D: Two sections through the same mound

From the morphological point of view, mound D has a crest like the crest forming in some

present dirt cones that one can observe standing on top of the actual glacier snout. I chose to dig twos

cross-sections across this mound because it would give a second sedimentological example of the

sedimentology of the rounded mounds in this part of the landscape, after digging in landform A.

Figure 19: site 1 cross-section D, see fig. 8 for location. Fig. 20: C cover approximately the same

area of the cross section: Horizontal structures within a mound. The picture shows the section right after

digging, with the spade for scale. Table 3 explains the facies code.

45

Figure 20: Cross-section D at site number 1, fig. 19. A. Cross section with dip angles, facies code

and unit numbers. B. Cross-section with facies association, the relevant ones are A to E. C. zoom in:

rectangle of A. The surface is looking slightly different compare to A. and B. because the zoom allows a

higher level of details. The yellow color stands for sands and/or granules. The white color stands for

gravels. The cross-section is facing East. Table 3 explains the facies code.

Section D is exposed across a mound approximately 1 m high (figs. 19 and 20). The section is

100 cm high and 500 cm across. The section has twenty-one individual units all orientated vertically thus

unit 1 is on the far left of the section while unit 21 is on the far right. Unit 1 is 20-25 cm wide and 30 cm

46

high and consists of granules. Unit 1 has a sharp boundary with Unit 2 that is oriented vertically. Unit 2 is

75 cm wide and 30 cm high and consists of massive sand that are matrix supported. Unit 2 has a sharp

boundary with unit 3. Unit 3 consists of fine to coarse sand. The boundary between unit 2 and unit 4 is

sharp. Unit 4 consists of the same type of sediments that constitute unit 3. Unit 2 has a sharp vertical

boundary with unit 5 that is dipping at 57°. Unit 5 is constituted of the same type of sediments than unit 1

with the difference that there is less outsized clast in unit 5. This unit has a sharp boundary with unit 6

and 7 that are located within the overall unit. Unit 6 and 7 consist of gravel that are clast supported. The

boundary between unit 5 and 8 is sharp, is dipping at 37° towards the top. Unit 8 is constituted of the

same type of sediment than unit 2. There is a sharp boundary between unit 8 and unit 9 almost at 17° in

the middle of the section and more vertical for the rest of the contact. Unit 9 consists of the same type of

sediments than unit 1. The boundary between unit 9 and unit 10 is sharp and unit 10 is located inside unit

9. Unit 10 consists of massive sands. The boundary between 9 and 11 is sharp. Unit 11 is constituted of

the same kind of sediments than unit 5. The boundaries between unit 9 and unit 12 and between unit 11

and unit 12 are two sharp boundaries. Unit 12 consists of granules, which is the same sediments of unit 2.

The boundaries between unit 11 and unit 13 and between 12 and 13 are two sharp boundaries. Unit 13 has

the same nature of unit 12. Unit 13 has a sharp boundary with unit 14. Unit 14 has the same sediments of

unit 11. There are two sharp boundaries between unit 14 and unit 15 and unit 14 and unit 16. Unit 15 and

unit 16 are of the same nature of unit 1. Unit 14 has a sharp boundary with unit 17. Unit 17 has the same

nature of unit 2. Unit 14 and unit 17 have a sharp boundary with unit 18. Unit 18 consists of gravels that

are massive, and matrix supported. Unit 18 has a sharp boundary with unit 19 and unit 20. Unit 19

consists of medium to very coarse sands. Unit 19 and unit 20 do not have a sharp boundary. Unit 20 has

the same sediments of 9 and 1. Unit 19 and 20 have a sharp boundary with unit 21 to the very right-hand

side of the section. Unit 21 has the same sediments of unit 18.

Section D has been divided into 5 relevant facies associations (fig. 20: B). Facies association A

consists of units 1,9, 15, 20. Those units reunited were probably deposited at the same time and they are

constituted of granules with outsized clasts. Facies association B consists of unit 5 and 11. These units are

granules. Facies association C consists of unit 2, 8, 12 and 13. These units are made of sands. Facies

association D consists of unit 3 and 4. They are fine to coarse sands. Facies association E consists of unit

6 and 7. They are clast-supported gravels. Facies association A to C look similar since they all appear like

vertical layers to the left of the cross section in different location and they are present and slightly thicker

and more vertical towards the middle of the cross-section whereas they are bending a bit more and are a

bit less vertical towards the outer end of the cross section. They are also intercalated with each other.

47

Figure 21: Cross-section D’ facing West, see fig. 8 for location, A. Facies codes B. Facies

associations. The yellow color stands for sands and/or granules. The grey color stands for silts and/or

clays. The white color stands for gravels. The section is facing West. Table 3 explains the facies code.

Section D’ is exposed through a mound of approximately 1 m high facing section D (fig. 21). The mound

here is dipping at 15° towards N on the distal side and 10° towards S on the proximal side. The section is

100 cm high and 500 cm across. The section has thirty individual units all orientated vertically thus unit 1

is on the far left of the section while unit 30 is on the far right. Unit 1 is 50-100 cm wide at the top and

100 cm thick. It consists of gravels that are massive and matrix-supported. Unit 1 has a sharp contact with

48

units 2-7, 12-14 and 19. The contact is dipping at 34° towards the base and becomes horizontal with a

changing dipping direction towards the top of the mound. Unit 2 is 40 cm wide and 20 cm thick and

consists of medium to very coarse sands that are massive and matrix supported. Unit 2 has a sharp contact

at 62° with unit 3. Unit 3 is 10 cm wide and 15 cm thick and consists of very fine to very coarse matrix-

supported massive sands. Unit 3 has a sharp contact with unit 6. Unit 6 is a very thin (>5 cm) unit of

massive matrix supported sands extending throughout unit 4, 5 and 7 and it has a sharp contact with these

three units as well. Unit 4 is 10 cm wide and 15 cm thick and consists of the same material of unit 3. Unit

5 has a sharp vertical contact with unit 10 on the right-hand side of it and a sharp contact at 66° with unit

6. Unit 5 is 20 cm wide and 40 cm thick and consists of the same material of units 3 and 4. Unit 7 has a

sharp contact at 66° with unit 6. Unit 7 is 25 cm wide and 60 cm thick and consists of the same material

of units 3, 4 and 5. Unit 10 has a sharp contact with units 7 and 8. Unit 10 is of the same nature and

thickness of unit 6 and extends throughout the section a little bit less distance. Unit 8 is 5 cm wide and 15

cm thick and is almost like unit 3. Unit 9 has a sharp contact with unit 11. Unit 11 is similar to units 6 and

10. Unit 9 is 5 cm wide and 10 cm thick and resembles unit 8, although slightly smaller. Unit 12 has a

sharp contact with unit 7 and 13 and is almost vertical. Unit 12 is 5 cm wide and 50 cm thick and consists

of massive matrix-supported sands. Unit 13 has a sharp, almost vertical contact with unit 14 to the right-

hand side of it. Unit 13 is 20 to 60 cm wide and 80 cm thick and consists of the same material of units 3-

5, 7-9. Unit 14 has a sharp contact with units 15-19. Unit 14 is ~65 cm wide and 80 cm thick and consists

of massive matrix-supported sands. Unit 15-18 are made of the same material which is medium to very

coarse matrix-supported massive sands and they are all present unit 14. These former units are of different

dimensions. The more voluminous unit is unit 18 that also displays a sharp contact with unit 24 on its

right-hand side. On its left-hand side, unit 18 has a sharp contact with unit 14 that is dipping at 55°. Unit

18 is 40 cm wide and 45 cm thick. Unit 19 has a sharp contact with unit 14 on its left-hand side and

another sharp contact with unit 24 on its right-hand side. Unit 19 has a very variable width from almost 0

to 60 cm and is 50 cm thick. It consists of very fine to very coarse massive matrixsupported sands. This

unit contain more very fine sands to the left of the unit and more very coarse sands to the right of the unit.

It is thus displaying a coarsening trend towards the proximal side of the landform. Within unit 19 are

present the small (smaller than unit 10 and 11) units 20-23. They are all made of medium to very coarse

massive matrix-supported sands. Unit 24 has a sharp contact with unit 18 and 19 on its left-hand side and

another sharp contact with unit 25 on its right-hand side. Unit 24 is 30 cm wide and 70 cm thick and

consists of medium to very coarse massive matrix supported sands that are sheared. Unit 25 has a sharp

contact with unit 26 on its right-hand side. This contact is slightly deformed in one part only. Unit 25 is

~30 cm wide and 60 cm thick and consists of massive matrix-supported sands. Unit 26 has a sharp contact

with units 27 and 28 on its right-hand side. Unit 26 is 80 cm wide and ~45 cm thick and consists of

medium to very coarse massive matrix-supported sands. Unit 27 has a sharp vertical contact with unit 28

49

on its left-hand side. Unit 27 is 50 cm wide and 30 cm thick and consists of massive matrix-supported

sands. Unit 28 has a sharp contact with unit 29 on its right-hand side. Unit 28 is 10 cm wide and 35 cm

thick and consists of massive silts. Unit 29 has a sharp contact with unit 30 which is located within unit

29. Unit 29 is 50 cm wide and 35 cm thick and consists of the same material of unit

27. Unit 30 is a small lens (5 cm2) of massive silts.

Cross-section D’ consists of 4 relevant facies associations (fig. 21: B). Facies association B

consists of units 3, 15-18, 20-23 and 26. All of these units are medium to very coarse massive matrix-

supported sands and units 26 and 18 are the more voluminous units. Facies association C consists of units

3-5, 7-9, 13 and 19. These units consists of very fine to very coarse massive matrix-supported sands.

Facies association D consists of units 6, 10-12, 14, 25, 27 and 29. Unit 14, 25, 27 and 29 are vertical

layers progressively becoming less vertical and reducing in size towards the right-hand side of the cross-

section. Facies association F consists of unit 28 and unit 30. These units are massive silts present to the

right-hand side of the section.

50

3.2.3. Site 2 in the vicinity East of the glacier snout

At site number 2, near by the glacier snout –South-East of it– 1 sections and cross sections

through landform E were observed. It was of interest to dig there (fig. 22) because the morphology of the

mounds there could lead to assume that these mounds are modern analogue to controlled moraines. The

aim was thus to double-check if the mounds there are indeed controlled moraine, and if they are then

these could be modern analogue to eventual controlled moraines at site 1.

Figure 22: Site 2 near by the very snout of the glacier, proximity South-East of the snout, fig. 4

for location. The red arrow indicates the location of the mound for the following sections.

51

This first section (fig. 23) is either on the proximal side of the mound or on the side with the

proximal side to the Northeast and the distal side to the Southwest. This is so because this site is south of

the present-day snout. However, despite the proximity with the glacier snout it was here more difficult to

determine the proximal and distal sides and there is some degree of uncertainty regarding the

measurement of the direction with the compass given the poor quality of the instrument. Another

compass was used for the other sites.

The second section is probably dig on the distal side of the mound, E.

Figure 23: Section E through a recent mound at site 2, see fig. 4 for location and table 3 for the

facies code.

52

Figure 24: Section through mound E at site 2, fig. 23, A. Facies codes and dip angles. B. Unit

numbers. Unit 1 consists of granules with outsized clasts. Unit 2 consists of sands that are fining upward.

Unit 3 consists of gravels that are massive and matrix-supported. Unit 4 consists of granules dipping at

50° The yellow color stands for sands and/or granules. The white color stands for gravels. The section is

facing Southeast. Table 3 explains the facies code.

53

Section E is exposed through the bottom of a mound approximately 2 m high (figs. 23 and 24).

The section is slightly larger than 100 cm wide and around 100 cm high. Unit 1 extends across the section

and is almost as thick as the section taken as a whole, with other units within it. It consists of granules that

are massive and matrix-supported with occasional outsized clasts. Unit 1 has a gradual contact with unit 2

at the bottom of it, and the contact is quite wavy as well. Unit 2 is 70 cm wide and 5 cm to 20 cm thick

and consists of upward fining sands that are massive and matrix-supported. Unit 2 has a sharp deformed

contact with unit 1 on top of it. Unit 2 also has a sharp contact with unit 3, at the left-hand side of unit 2.

This contact is dipping at 19°. Unit 3 is 20 cm2 and consists of a pocket of gravels that are massive, and

matrix supported. Unit 4 are four units with the exact same dipping angle. They are having a sharp

contact with unit 1 and they are all located within the latter with the same dipping angle at 50°. They are 5

cm wide and around 25 cm thick and consists of granules that are massive and matrix-supported.

54

Figure 25: Cross-section E’ through a mound at site 2, see fig. 4 for location, unit 1 consists of

granules, unit 2 of massive matrix-supported sands, at the bottom left-hand, unit 3 consists of the same

kind of sands, in a lens, unit 4 consists of very fine to very coarse sands, and unit 5 and 6 are of the same

nature of unit 1. Table 3 explains the facies code.

55

Figure 26: Cross-section E’ through a recent controlled moraine at site 2, fig. 25. A. 6 units and B.

1 relevant facies association: A. The yellow color stands for sands and/or granules. The section is facing

Northeast. Table 3 explains the facies code.

56

Cross-section E’ is exposed across a mound approximately 2 m high. The section is 120 cm high

and 90 cm across (figs. 25 and 26). The section has six individual units and 4 facies associations. Unit 1

extends across the section and is 50-55 cm thick and consists of massive matrix supported granules. There

is a sharp contact between unit 1 and 2. Unit 2 is located within unit 1 to the left-hand side and is slightly

bending following an undetermined changing dip-angle. Unit 2 is 50 cm wide and 25 cm thick and

consists of massive matrix-supported sands. Unit 1 has a sharp contact with unit 3. Unit 3 consists of a

lens of massive sand of small dimensions (~ 20 square cm). There is another sharp contact between unit 1

and unit 4. This contact is dipping at a bit less than 15°. Unit 4 consists of very fine to very coarse sand

and extends almost across the section and is widely variable (5-20 cm) regarding its sickness since it

extends onto two branches to the left of the cross-section. Unit 5 has a sharp contact within unit 4 that is

subdividing itself onto two branches. Unit 5 has a twisted V-shape and is dipping at 15° towards its upper

and downmost contact. Unit 6 has also a sharp contact with unit 4, with this contact dipping at 15° to the

left-hand side of the cross-section. It is as well consisting of granules that are massive and matrix-

supported.

Cross-section E’ consists of one relevant facies association (fig. 26: B). Facies association A

consists of unit 1, 5 and 6. They are matrix-supported massive granules.

57

3.2.4. Site number 3 and unique section F through the flat-topped

landform at this site

Site 3, like site 4, was part of the sites selection because this site was part of the mapping of

Sollid and Andersen and they identified the mounds there as stratified moraines, like for site 1. One of the

aims of this thesis is to get more information about the nature of the mounds at site 1 and if similar kind

of mounds are then found in the foreland it is useful to have information about them as well in order to

compare the mounds at site 1 with the mounds at other sites.

Figure 27: Logging of cross-section F at site 3 to the Southeast of the glacier foreland/previous

glaciers snout, see fig. 4 for location.

58

Figure 28: Cross section F across a mound at site 3, see fig. 4 for location. From left to right one

finds here 6 facies association. The most noticeable here is the three lenses of very fine to very coarse

massive matrix-supported sands, units 7, 8 and 9 towards the middle of the cross-section (Sh) – fig. 29: A.

They are part of the facies association A with units 1 and 11 to the very left and the very right of the

cross-section, respectively. Table 3 explains the facies code.

59

Figure 29: Cross section F at site 3 through a flat-topped mound, figure 27. A. Facies code: 13

individual units. From left to right, very fine to very coarse sands, medium to very coarse sands, lens of

silts, medium to very coarse sands, massive silts, medium to very coarse sands, very fine to very coarse

sands, massive matrix-supported sands, very fine to very coarse sands, gravels that are massive and

matrix-supported B. Facies associations. 4 relevant facies associations: facies association A consists of

units 1, 7-9 and 11, facies association B consists of units 2 and 4, facies association C consists of units 3

and 5, facies association F consists of units 12 and 13. The yellow color stands for sands and/or granules.

The grey color stands for silts and/or clays. The white color stands for gravels. The section is facing SE.

Table 3 explains the facies code.

60

Cross-section F is exposed through an asymmetrical flat-topped mound slightly higher than

100 cm dipping at 7° towards SW and at 22° towards NE (figs. 28 and 29). The proximal and distal sides

are not indicated but probably the section is facing the past direction of glacier flow. The section is ~60

cm high and 190 cm wide. The section has 13 individual units and 4 relevant facies associations for most

of them orientated vertically thus unit 1 is on the far left of the section while unit 13 is on the far right.

Unit 1 is > 50 cm wide and 20 to 40 cm thick and is made of very fine to very coarse matrix-supported

sands. Unit 2 is located within unit 1 at the top right-hand side of unit 1 and has no real contact with unit

1. Unit 2 has thus undefined dimensions and consists of medium to very coarse matrix-supported sands.

Unit 3 has a sharp contact with unit 1. Unit 3 is a small (~5 cm2) lens of massive silts. Unit 4 has a sharp

54° contact with unit 1. Unit 4 to the right-hand side of unit 1 is 125 cm wide and very variable in

thickness from around 5 cm to 50 cm with a less important thickness towards the right-hand side of the

unit. It consists of medium to very coarse matrix-supported sands. Unit 5 has a sharp undulating contact

with unit 4 above it and a sharp vertical contact with unit 1 on the left-hand side of it. Unit 5 consists of

massive silts that are 25 cm wide and 20 cm thick. On the right-hand side of it unit 5 has also a sharp

vertical contact with unit 6. Unit 6 is 1 m wide and 30 cm thick and consists of medium to very coarse

matrix-supported sands. Unit 6 has a sharp contact with unit 7,8 and 9 that are sitting just above it. They

are three 10 cm2 lenses of very fine to very coarse matrix-supported sands. Unit 10 has a sharp contact

with unit 4 below it. This contact is of undulating character and its dipping angle changes from 37° to 31°

towards the right-hand side. Unit 10 is made of massive matrix-supported sands and has a very variable

width as well as thickness. Its width extends from almost nothing to 125 cm and its thickness is from 5 to

45 cm. Unit 11 has a sharp contact dipping at 18° with unit 6. Unit 11 is 40 cm wide and 35 cm thick and

consists of very fine to very coarse matrix-supported sands. Unit 12 has a sharp contact with unit 10. Unit

12 is less than 5 cm2 and consists of gravels that are massive and matrix-supported. Unit 13 has a sharp

contact with unit 10. Unit 13 is of the same nature of unit 12 but is of much larger dimensions. It is

around 45 cm wide and 40 cm thick.

Cross-section F consists of 4 relevant facies associations (fig. 29: B). Facies association A consists of

units 1, 7, 8, 9 and 11 that are very fine to very coarse matrix-supported sands. Facies association B

consists of units 2 and 4 that are medium to very coarse matrix-supported sands. Facies association C

consists of units 3 and 5 that are massive silts. Facies association F consists of units 12 and 13 that are

massive matrix-supported gravels.

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3.2.5. Site number 4 (G) to the south East of the glacier foreland

As discussed above, this site was chosen for the same reasons site 3 was chosen. Site 4 was

identified on the map by Sollid and Bjørkenes (1978) as a site with stratified moraine. Since one of the

aim of this thesis is to better characterize the mounds at site 1 that are also identified as stratified moraine

by Sollid and Bjørkenes (1978) then it is important to look at the sedimentology of the mounds at site 4.

Figure 30: Cross-section G facing ESE at site number 4, see fig. 4 for location. A. Unit numbers

and facies codes as well as dip angles. B. Facies associations. The yellow color stands for sands and/or

granules. The grey color stands for silts and/or clays. The white color stands for gravels. A rock is drawn

using black color. The section is facing East-South-East. Table 3 explains the facies code.

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Cross-section G is exposed across a ridge approximately 3,60 m high and 20 m long (fig. 30).

The section is 100 cm high and 570 cm across. The section has fourteen individual units and seven facies

associations all orientated vertically thus unit 1 is on the far left of the section while unit 14 is on the far

right. Unit 1 is 1-2 m wide and 50-60 cm thick and it consists of gravels that are massive, and matrix

supported. Unit 1 has a sharp boundary with unit 2 that is dipping at 7° on the top of it. Unit 2 is a pocket

of gravels that are massive, and clast-supported. Unit 3 has a sharp boundary with unit 1, almost vertical.

Unit 3 is 20 cm wide and 30 cm thick and consists of massive silts. Unit 1 has a sharp vertical contact

with unit 4. Unit 4 is 20 cm wide and 40 cm thick and consists of massive sands that are matrix supported.

There is a sharp contact between unit 4 and unit 5 that is almost vertical and parallel to the contact

between unit 1 and unit 4. Unit 5 consists of gravels that are massive and matrix-supported. This unit is

50 cm wide and 5-30 cm thick. There is a sharp contact between units 1, 4 and 5 and unit 6. The dip of it

is around > 7°. Unit 6 is around 100 cm wide and 50 cm thick and consists of matrix supported massive

sands. A boulder is present at the bottom left of this unit. Unit 6 has a sharp dipping contact (>7°) with

unit 7. This contact is almost parallel to the one contact previously described, although dipping a bit

more. Unit 7 is less than 100 cm wide and approximately 40 cm thick and consists of sands that are

matrix supported and medium to very coarse in term of grain size. There is a sharp contact between unit 7

and unit 8 that is almost parallel to the contact between units 1, 4 and 5 and unit 6 and the contact

between unit 6 and unit 7. Unit 8 is approximately 100 cm wide and 35 cm high and consists of massive

matrix supported sands. Unit 8 has a sharp contact with unit 9 and this contact is almost parallel to the

contact between unit 6 and unit 7. Unit 9 consists of clast supported massive gravels that extend for more

than 100 cm wide and ~ 25 cm thick. There is a sharp contact between the units 1,4-9 and unit 10 that is

dipping from 16° upward to 24° downward. Unit 10 is made of massive matrix-supported sands that are

70 cm wide and 80 cm thick. There is a sharp contact dipping at 36° between unit 10 and units 11 and 14.

Unit 11 consists of granules that are matrix supported and massive, with outsized clasts occasionally

present. This unit extends for 100 cm wide and 100 cm thick. Unit 14 is made of the same kind of

sediments without the outsized clasts. It extends for 100 cm wide and 20 cm thick. There is a sharp

contact between unit 14 and unit 11. Unit 11 has also a sharp contact with unit 12. Unit 12 consists of

massive matrix supported sands that are 80 cm wide and 20 cm thick. Unit 13 has a sharp contact with

unit 11. This contact is dipping at 12°. Unit 13 is 90 cm wide and ~ 20 cm thick and consists of massive

matrix supported granules.

Cross-section G has been subdivided into 4 relevant facies associations (fig. 30: B). Facies

association A consists of unit 1 and 5. They are gravels that are matrix supported and massive to the left

of the section. Facies association B consists of unit 2 and unit 9 that are clast supported massive granules.

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Facies association D is made of unit 4, 6 and 8 that are massive matrix-supported sands. Facies

association F consists of unit 10 and 12 that are massive matrix supported sands.

Figure 31: Cross-section G’ through a ridge at site number 4, facing WNW, see fig. 4 for location.

A. Unit numbers, facies codes and dip angles. B. Facies associations. The yellow color stands for sands

and/or granules. The grey color stands for silts and/or clays. The white color stands for gravels. The

section is facing West-North-West. Table 3 explains the facies code.

Cross-section G’ is exposed across a ridge approximately 3,60 m high and 20 m long (fig. 31).

The section is 100 cm high 570 cm across. The section has twenty-one individual units and nine facies

associations for some of them orientated vertically thus unit 1 is on the far left of the section while unit 21

is on the far right. Unit 1 is made of very fine to very coarse matrix-supported sands that is 100 cm wide

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and 70 cm thick. Unit 1 has a sharp boundary with unit 2 that is dipping at 23°. Unit 2 consists of massive

matrix supported sands that are 90 cm wide and 80 cm thick. Unit 1 has a sharp boundary with unit 3

dipping at around 30°. Unit 3 is 45 cm wide and 40 cm thick and consists of medium to very coarse

massive matrix-supported sands. Unit 2 has a sharp boundary with unit 4 dipping at 20°. Unit 4 is 90 cm

wide and 30 cm thick and consists of very fine to very coarse massive matrix supported sands. Unit 3 has

a sharp boundary with unit 5, with a dip-angle of 22° to 30°. Unit 5 is 90 cm wide and 90 cm thick and

consists of very fine to very coarse massive matrix-supported sands. There is a sharp contact between

units 2 and 4 and unit 6. Unit 6 is 90 cm wide and 20 cm thick and consists of very fine to very coarse

massive matrix-supported sands. Unit 6 has a sharp vertical contact with unit 7. Unit 7 is 90 cm wide and

25 cm thick and consists of massive matrix-supported sands. Units 5 and 7 contacts with unit 8. Unit 8 is

100 cm wide and 20 cm thick and consists of massive matrix-supported sands. Unit 5 has a sharp contact

with units 9-14. Unit 9 is 180 cm wide and 10 cm thick and consists of massive matrix-supported sands.

Unit 9 has a sharp horizontal contact with unit 10. Unit 10 is 200 cm wide and 20 cm thick and consists of

massive matrix-supported sands. Unit 10 has a sharp horizontal contact with unit 14 that is dipping at

overall 17°. Unit 14 is 270 cm wide and 30-50 cm thick and consists of massive matrix supported sands.

Unit 14 has a sharp contact with units 11, 12 and 15 that is dipping at 18°. Units 11, 12 and 15 are small

units (30-70 cm wide and 5-10 cm thick) made of very fine to very coarse massive matrix-supported

sands. Unit 14 also has a sharp contact with unit 13. The dip of this contact is going from 28° on the

lefthand side to 8° in the middle to vertical on the right-hand side. Unit 13 is 120 cm wide and 40 cm

thick and consists of very fine to very coarse massive matrix-supported sands. Unit 14 has a sharp vertical

contact with unit 17. Unit 17 is a pocket of gravels of 45 cm wide and 25 cm thick that are massive and

clast-supported. Unit 16 has a sharp contact with units 10, 14, 15 and 17. Unit 16 is extending around a

boulder (the same as the one of cross-section H) and is 180 cm wide and 30 cm thick while consisting of

medium to very coarse massive matrix-supported sands. Units 13, 14, 16 and 17 have a sharp contact with

unit 18. Unit 18 is 100-180 cm wide and 50 cm thick and is made of massive matrix-supported gravels.

Unit 18 has a sharp contact with unit 19. Unit 19 is 90 cm wide and 5-10 cm thick and consists of massive

matrux-supported silts. Unit 18 has a sharp contact with unit 20. Unit 20 is a lens of very fine to very

coarse massive matrix-supported sands surrounded by unit 18. There is also a sharp contact at 66°

between unit 19 and unit 21. Unit 21 is not so wide (~ 5 cm) and 40 cm thick and consists of gravels that

are massive and clast-supported.

Cross-section G’ consists of 5 relevant facies associations (fig. 31: B). Facies association A

consists of units 2, 7 and 8 that are massive matrix-supported sands. Facies association B consists of units

1, 4-6 that are very fine to very coarse massive matrix-supported sands. Facies association D consists of

units 9, 10 and 14 that are massive matrix supported sands. Facies association E consists of units 11-13,

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15 and 20 that are very fine to very coarse massive matrix-supported sands. Facies association G consists

of unit 17 and 21 that are clast-supported massive gravels.

3.3. Moraine morphology and sedimentology: co-variance analyses

Clast co-variance analysis are commonly used in glaciated landscape to determine whether the

origin of a material constituting a landform is subglacial or fluvial or supraglacial. C40 on the x-axis

versus RWR on the y-axis means that the quantity of platy-elongated-blocky clasts are plotted against

an index of roundness. A low C40 represents a high blockiness, and vice and versa. The RWR index

considers the well-rounded and rounded clasts in a population of 50 clasts.

Figure 32: Co-variance analyses for 5 landforms throughout the foreland; A: Landform A, unit 4

at site 1. D: Landform D at site 1. E_1: Landform E, unit 1 of granules with occasional outsized clasts

(GRmc) at site 2. E_3: Landform E, unit 3 of massive matrix-supported gravels (Gms) at site 2. G:

Landform G, at site 4.

It is important to understand if the results of the clast co-variance analysis (fig. 32) cluster

or not. In a paper by Lukas et al. (2013) the limits and strength of the clast shape co-variance analyses

were examined. These authors tell us that the analyses by the means of a co-variance in-between the

RWR index versus the C40 index is in average more efficient than the analyses by the means of the use of

D

A

E_1

E_3

G

0

4

8

12

16

20

24

28

32

0

2

4

6

8

10

12

14

16

18

20

C40

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the co-variance of the RA versus the C40. The full definitions for RA, RWR and C40 are given in the

methodology section. Figure 32 displays the RWR versus the C40. The very angular and angular clasts

were too few throughout the foreland, thus too few samples were retrieved in order to undertake a RA

versus C40 analysis (see appendix). On the Y-axis, the RWR are the results I have gotten for different

landforms possessing large clasts (above 5 cm) varying between 4 and 18 approximately, which equals to

a variation of 14. There is a picture of some clasts used in the appendix (fig. 52). On the X-axis the results

are constrained in-between 8 and 20 approximately, which is a less important variation of 12 for the C40

index. A low C40 means an important blockiness whereas a high C40 means the opposite, which is to say

a high platiness. The samples are overall a population of quite blocky clasts. The clasts cluster on the X-

axis at least; the one with less variability, and they show a population of not very platy clasts. On the Y-

axis the variability is only slightly more important and concerns another parameter: the roundness. The

scale of the figure could eventually be misleading. Indeed, the Y-axis displays clasts based on a measure

of platiness and this varies between 4 and 20 while the C40 on the X-axis varies between 8 and 20. Let us

remember that the RWR index essentially has to do with the ‘outliers’ inside the population of gravels,

which is to say the very rounded and rounded gravels summed up together.

Based on these results, further interpretations are going to be given in the following section when

interpreting these results alone and then while trying to compare these populations of gravel with other

population of gravels obtained by Reinardy et al. (2013).

4. Interpretations

This section presents the interpretations of the sedimentology and the clast co-variance analysis

results. Both will give evidence for identifying the mounds at site 1.

4.1. Interpretation of the sedimentology

A total of 12 sections were dug into the proglacial landscape of Midtdalsbreen. The first section

(fig. 6) is a cross section across a flute in the glacier foreland and it is of use for showing what is

happening at the glacier snout in terms of thermal regime. Also, this is the only cross-section throughout

the glacier foreland of Midtdalsbreen for which we are already certain about the nature of the landform

before digging through it. Further, 11 sections and cross sections through mounds at 4 different specific

sites will be presented. These section and cross-section are labelled A, A’, B, C, D, D’, E, E’, F, G, G’.

Section A and A’ are excavated through landform A, section B through landform B, section C through

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landform C and cross-sections D and D’ are excavated through landform D, and so on. It is based on the

figures of the previous section result (3) that interpretations about the nature of unidentified mounds are

being made, as well as links with the available literature.

4.1.1. The fluted landscape: additional site

This additional section is located nearby site 2, northeast of it, towards the eastern half of the

glacier snout. The section dug through the flute contains massive silts (unit 1) with a unit of clast-

supported gravels within it (unit 2). Baranowski (1970) observed the same characteristics for flutes in

another foreland and the sedimentology observed in the flute at Midtdalsbreen corresponds to the typical

composition of flutes. Based on these sedimentological characteristics and on the shape of low-ridge of

the landform the interpretation of this landform being a flute is confirmed. It has some implications for

the proglacial foreland that will be further described in the discussion.

4.1.2. Site n°1

At site number 1, 6 sections/cross-sections were dug through 4 landforms (A, B, C and D).

Sections A and A’ will form composite section A and together with sections B and C and cross-sections

D and D’ their location is displayed on fig. 8. For the composite section A one section was dug at the top

of the landform (A) and the other one at the bottom of the same landform (A’). The nature of these

landforms was uncertain when only morphology was considered. They were interpreted as glaci-fluvial,

but the interpretation given was lacking details. Facing section C, a test pit was also dug-through there.

The composite section A located at site 1 contains silts (units 4, 13, 20), sands (units 1, 7 and 21),

granules (units 2, 5, 8-12, 16-19, 22-27) granules with outsized clasts (units 3 and 15) and two pockets of

gravels (units 6 and 14). Unit 3 is dipping at 60° above unit 1, and towards the top is many small units of

granules, that resemble stratification. Based on the lithology as well as the lenses of gravels and the

dipping bed the section is interpreted as a controlled moraine. Section A is similar to section E and E’

which also has a controlled moraine interpretation (see below). Goldthwait (1951) found out about some

characteristics for the controlled moraines. He described them as having a more stony and sandy character

and lenses of sorted sands and gravels as well as fans of dipping gravels on the outer side of the moraine.

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Section B located at site 1 contains silts (unit 1) overlain by poorly stratified sand and wavy

bedding (unit 2). There is also a disturbed boundary between units 2 and 4. Based on these

sedimentological characteristics and the morphology of the flat-topped mound, landform/section B is

interpreted as a glacifluvial deposit affected by permafrost. Section B is similar to section C which also

has a glacifluvial interpretation (see below) and the ‘V-shape’ within section B is also similar to section

E’, although the two landforms are of different nature (see below). Flint observed a similar disturbed

contact in a deposit within a permafrost area, referred to as frost-stirred ground (Foster Flint 1971, fig.

108, page 284).

Section C located at site 1 contains massive silts (unit 1), a boulder lag (unit 2), medium to very

coarse sands (unit 3), massive matrix-supported sands (unit 4), medium to very coarse sands (units 5 and

6), upward coarsening gravels (unit 7), massive matrix-supported gravels (unit 8). Unit 7 is characteristic

in that the gravels coarsening upward is an evidence for a glacial advance. In reason of its position

throughout the glacier foreland it was cross-cut importantly by a meltwater channel thus maybe

explaining the larger exposure here. I did not excavate just at the bottom of this landform nor at the top

but in the middle instead. It is important to notice that the terrace in which the section was dug through is

dipping at 10° towards NE, and so are the top-most layers of this landform. This is the direction of

today’s glacier flow. This 1.40 m section was dug approximately in the middle of the flat-topped mound

which was considered a relevant position because it could give an evidence for past meltwater activity

before today’s drainage. The landscape is nowadays dominated by snowmelt and frost action and this

may have installed a new geomorphological dynamic within the landscape at the very location of site 1.

As mentioned above, section C has similar sedimentological characteristics to section B, and both are

interpreted as glacifluvial deposits. However, section C was dug through a higher landform in elevation

compare to section B, and section C displays a boulder lag (unit 2). The boulder lag is an evidence for

important meltwater activity during deposition. The finer sediments could be washed out by the current.

Facing section C on the other side of the meltwater stream another test-pit was dug through a

landform which first appeared to us like a cross-cut terrace, but this was instead some kind of massive till.

This section has no name since no pictures nor drawing are available from it. The harsh meteorological

conditions did not allow to log this section; however, it was possible to be certain of the nature of the

section before logging it. It is certainly some kind of plucked till, since it was very hard to dig through it

in reason of the density of large rocks through the section and because very fine sediments were also

found in-between the rocks. It was different from every other landform into which digging was

undertaken during our field campaign at Midtdalsbreen.

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Cross-section D located at site 1 has a facies association of granules with outsized clasts (A), one

simply of granules (B), one of massive matrix-supported sands (C), one of very fine to very coarse sands

(D), one of gravels (E), and so on. All these facies association are dipping vertically or very steeply.

Cross-section D’ across the same landform tends to show an evidence for the same nature of sediments and

similar very steeply dipping layer. Additionally, both cross-section D and D’ display gravel which is dipping

at an important angle on the distal side: facies association J for cross-section D and facies association A for

cross-section D’. Based on these sedimentological characteristics and on the morphology of the landform,

landform D is thus found to be a controlled moraine. Landform D is similar to landform G which also has

a controlled moraine interpretation on the same basis (see below). Landform D was clearly affected by

either permafrost or slumping, and this structure of almost vertical layers is the result of fractures in the ice

core which was sheltered by a thin layer of debris progressively filling cracks in the ice-core. The three

processes may account for the nature of the sedimentology. Although, the almost vertical stratification of

layers of sand of different clast sizes interbedded with some vertical layer of granules (fig. 20: C) allow to

interpret this moraine D as being a controlled moraine deposited at the time of the LIA. These layers are

likely to form at an interface within the snout of the glacier between warm-ice and cold-ice.

Landforms A and D are different than till and regular glaciofluvial deposits. They are interpreted

as controlled moraines. Landform B and C were interpreted as terrace deposit and the test-pit facing

section C was interpreted as massive till that is plucked.

4.1.3. Site n°2 – recent controlled moraines

Here, one single moraine E was investigated: - a section and a cross section. The section is

labelled E and the cross section is E’.

Section E located at site 2 contains granules with occasional outsized clasts (unit 1), few units of

granules without outsized clasts (unit 4) dipping at 50°, some upward fining sands (unit 2) and a pocket of

gravels (unit 3). As mentioned above, section E has similar sedimentological characteristics to composite

section A and both are interpreted as controlled moraines. However, section E have more steeply dipping

layers of granules than in section A and the sands present in section E do not display a sharp contact with

the unit of granules with outsized clast while at the same time being fining upward sands.

Cross-section E’ at site 2 consists of granules (facies association A) and different clast size of

sands (units 2-4). Unit 4 has a sharp contact with unit 5 that has a twisted ‘V-shape’. Unit 4 consists of

very fine to very coarse sands while unit 5 pertains to the facies association A and is thus granules. As

70

mentioned above cross-section E’ is similar to section B concerning the V-shape, although the same

interpretation is not chosen regarding the origin of the ‘V-shape’. Here the difference with the ‘V-shape’

of the section B at site 1 is that here two lithologies are in presence and therefore one can get more the

idea of an ice-core melting away below a layer of debris and thereby creating this ‘V-shape’. No previous

evidence for this ‘V-shape’ associated with an ice-core melting away were found in the literature, but

observation of the sedimentology of controlled moraines is scarce (Evans 2009). Based on these

sedimentological characteristics and on section E as well as the morphology of the landform I interpret

landform E as being a controlled moraine.

The presence of landforms such as controlled moraines not only indicate something about the

past glacial regime of the glacier but also something about the availability of debris at this precise

location of the snout. One can imagine the availability of debris was more important here since the study

area is located near by a cliff thereby increasing the presence of superglacial debris, although further

analyses of clast shape covariance doesn’t confirm that. Probably, the debris present in this ridge were

modified by water at some point – see following section of the results. Shakesby (1989) also analyzes a

neo-glacial moraine morphology in a glacier foreland at Storbreen in southern Norway and interprets the

difference in size of this moraine like a difference in the availability of debris and not in erosion. The

same interpretation is valid here. Controlled moraines are easily eroded in reason of their small

dimensions; thus, the erosion rate might not have been very important here. The important size of the LIA

moraine at the latero-frontal western position is an evidence for low erosion rates as well as a high

availability of debris, which allows the controlled moraines to be created here and to be in a relatively

good state of conservation.

4.1.4. Site n°3

At site 3 only one side of the cross-section which was dug was photographed. Therefore,

one only obtains one digitized cross-section on Illustrator for the analysis. As previously mentioned, the

mapping campaign that was undertaken by Sollid and Bjørkenes (1978) determined the study sites. Here,

these authors found one more stratified moraine near terraces. It was interesting, and even though the

morphology of this landform which was investigated appeared like a fluvial terrace, it was still interesting

to confirm or deny the assumption of Sollid and Bjørkenes (1978) that this landform is of the same nature

as the rounded mounds at site 1. This was also a convenient study site given the proximity to the locality

of Finse and the uncertainties regarding the weather forecast at that time.

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Cross-section F at site 3 consists of, from left to right, very fine to very coarse sands (unit 1),

medium to very coarse sands (unit 2), lens of silts (unit 3), medium to very coarse sands (unit 4), massive

silts (unit 5), medium to very coarse sands (unit 6), very fine to very coarse sands (units 7-9), massive

matrix-supported sands (unit 10), very fine to very coarse sands (unit 11), gravels that are massive and

matrix-supported (units 12 and 13). The sedimentology inside this landform was unexpected and lead to

reconsider the first interpretations that were solely based on the morphology. Even though this landform

initially appeared like a fluvial terrace - based on the morphology – it finally appeared that this

interpretation was wrong. Through considering carefully the sedimentology here, one can have a look at

three layers of fine to coarse sands (units 7-9) that seem to be related to an old meltwater channel that was

present over a melting ice core. This is the main evidence that could lead to reconsider the interpretation

previously made while based only on the morphology. Other layers are sometimes dipping quite

importantly without necessarily matching the surface slope and this is another evidence for a melting ice-

core. A layer is dipping at 54° within the landform versus 7° and 22° for the two surface slopes of the

landform is an important difference and the slope within the landform had therefore to be created

otherwise than by simple adjustment to the surface slope during deposition of the sediments. Based on the

sedimentological characteristics of this landform, as well as the dipping layers this landform is thus

interpreted as a controlled moraine.

4.1.5. Site n°4

The fourth site was chosen on the same basis than site 3. Sollid and Bjørkenes (1978)

identified this site as well like a site with stratified moraine. Here the ridge is of large dimension: 20

meters long, with a side on SWS side measuring 3,60 m long and a side towards NEN measuring 4,80 m

long. This ridge is symmetrical regarding the slope and measures 20° on both sides. Cross -section G at

site 4 contains gravels that are massive, and matrix supported (facies association A), gravels that are

clast-supported (facies association B), silts that are massive (facies association C), massive matrix-

supported sands (facies association D), medium to very coarse sands (facies association E), and so on. As

mentioned above, sections G and G’ have similar sedimentological characteristics to sections D and D’

and both landforms are interpreted as glacifluvial deposits. Both landforms G and D present ultra-

saturated silty sediments that are displaying vertical layering inside another unit. Unit 28 for cross-section

D’ and unit 3 for cross-section G. A controlled moraine is essentially a glaciofluvial deposit but here

some major differences between landforms D and G allow to differentiate these two landforms. Despite

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the similarity in sediments and vertical layer structures, landform G is much larger (dimensions above),

and its morphology is such of a ridge compare to a small mound for landform D. Something interesting

about the landform G is the apparent slumping with two groups of units with layers dipping following

different directions: e.g., facies association A, B and C versus the other facies association for cross-

section G’.

Glacitectonites were also identified within one side of the cross-section G’, which is the section facing

towards WNW (fig. 33).

Figure 33: Glacitectonites identified to the right-hand side of the section of fig. 31, above the

boulder.

Dredge & Grant (1987) identified similar glacitectonites to those (fig. 33) in their study from

Canada (Fig 9, page 188 and figure 14 and 18, pages 189 and 191 in the same book). In their article,

Dredge & Grant (1987) further describe the paleogeographic significance of glaciotectonites. They

propose 6 scenarios of ice-sheet that could lead to the same kind of deposit. They sum up their study

mentioning that ‘any of these hypotheses could explain the close association of till, as produced by warm-

based ice, with widespread deformation indicative of bonded (cold-based) ice’ (page 194-195). Pagé

(1999) defined the glacitectonism as every mechanism of structural deformation triggered by ice and

affecting glacial sediments or bedrock directly by the action of its movement or its mass and this is the

definition used for the glacitectonites identified in fig. 33.

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An overriding of the previously deposited moraine might have occurred, and that could also have

triggered a new layer to slump over what was previously deposited. However, it is possible that the

landform at site 4 could be the result of snow bank push mechanism as described by Birnie (1977) with

resulting slumping. Although, this author mentions that these kind of ridges as observed in South-Georgia

were often low till ridges and it seems here that the ridge in which I dug through is of larger dimensions

than the ridge which Birnie (1977) analyzed in South-Georgia.

4.2. Interpretation of the clast co-variance analyses

It is important to obtain controlled samples in order to be able to compare the results of a

co-variance analysis to clasts of known origin. A study by Reinardy et. al. (2013) already sampled

controlled samples that could be used to interpret the clasts co-variance in the foreland of Midtdalsbreen.

Figure 34: Taken from Reinardy et al., (2013): (x): Englacial control sample; The cluster at the

bottom right is constituted mostly of fluvial control samples as well as one moraine –i.e. the horizontally

shaded square to the half. The cluster at the uppermost corner (+) represent subglacial control samples,

whereas the squares located outside of any so-called clusters, and displaying a different shading every

time, are all results for co-variance analysis of clast “blockiness” -relative dimensions- (C40) versus

roundness (R + WR = RWR) taken on moraines. Granites, at the top-left of the figure indicates the

lithology used for the study.

The axis limits for fig. 32 were chosen to be able to further compare our results to those of the

previous related study in the study area (fig. 34). It might be possible to make cluster the results in fig. 32

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regarding their roundness even though the roundness varies more than their C40 index. The paper of

Lukas et al. (2013) gives more information about clustering of results. These authors, in addition to

assessing the role of the lithology when performing a clast shape co-variance analyze and the variability

between different catchment were also interested in the variability of result which could be obtained

within a catchment for one method. They found there could be a different spread of values obtained for

different environments for a given lithology. Proximal fluvial samples seem to vary by 10 % for the

lithology sandstone, and by 30 % in the supraglacial environment. A different result is obtained for

different environment and for the C40 – for example, gneisses. A range of variation of 20 % is obtained

for the subglacial environment to 45 % for the fluvial and supraglacial environment. The variations of the

results in fig. 32 seem to match the accepted range of variation mentioned; therefore, my results cluster

together into one group.

The nature of the debris covers of controlled moraines ‘reflects both the initial sediment source

and any subsequent modification by re-sedimentation in the dead-ice environment’ (Schomacker 2008).

As one can today observe at the recent glacier margin there can be spatial proximity between controlled

moraines and glaciofluvial deposits. Probably, a sandur plain (and above it some supraglacial deposits),

so-called controlled moraines, survived within the sandur plain in a very localized area during their

deposition. Today, there is a large amount of sand and gravel which is deposited at the exit of a very large

dimension ice-cave and on top of it one can even find “controlled-mounds” sitting on top of arcuate

fractures – see pictures in the discussion and conclusion. If standing above water exiting glacier, then the

ice-cored controlled moraines are not washed-away by meltwater activity and then they can eventually be

found today on the paleo-landscape. If meltwater action is affecting the base of the ice-cored moraines, by

undercutting for example, as well as the rest of the ice-cored moraine standing above water, then they

would obviously be destroyed.

It seems the samples of the most recent field season (fig. 32) display a slightly wider variability

on the Y-axis, which is the axis corresponding to the index of R + WR clasts. Conversely, the clast family

of the most recent field season seems to match the cluster of fluvial control samples from the field-study

by Reinardy et al. (2013) - fig. 34. The meltwater action has an inherent role in the development of these

dirt-cones throughout the recent pro-glacial landscape. A post-glacial sorting operates within the landform

during the melt of their ice core, and even subsequent slumping of rounded material in the case of the

foreland, here at Midtdalsbreen. The fluvial clustering is different amongst study sites, but this does not

necessarily indicate a difference in the nature of the hummock. Instead, it is possible to interpret it as the

natural variability. The position of controlled moraines and hummocky mounds throughout the foreland is

prominent when it has to do with natural variability in landform formation. The fracturing of the glacier is

indeed slightly different in different zones of the glacier, and eventual enlargement of fractures into

75

cracks initially depends on the actual subglacial topography and substrate initially – Glenn’s flow law is

based on empirical parameters. Slightly different fracturing takes place depending on where we are

located on glacier, and the related subglacial mode of drainage sometimes also differs.

Figure 35: Comparison of the samples from Reinardy et al. (2013) with the co-variance (fig. 32).

The labels displayed on the figure are corresponding to the mounds sampled for this report, and the labels

below are from the study of Reinardy et al. (2013)

D

A

E_1

E_3

G

0

4

8

12

16

20

24

28

32

0

2

4

6

8

10

12

14

16

18

20

C40

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The population of moraines seems to be close to the cluster of the fluvial controlled from

Reinardy et al. (2013) in the same glacier foreland, except for one moraine represented by the letter G

(fig. 35). The controlled moraine compared to annual moraine would thereby be moraine constituted more

of fluvial material. This is understandable since the creation of this moraines involves water in arcuate

fracture planes at the warm ice-cold ice interface. These controlled moraines contain melt-out material.

The silt that is mentioned above is also an evidence for that and for small lakes impounded towards the

proximal side of the ice-cored moraine, long before the ice-cored moraine became a controlled moraine.

They are well sorted and modified by meltwater as the ice-core melts out, and possibly further modified

by meltwater in the foreland. That is the reason why a fluvial signal is obtained.

The following interpretations can also be made, at greater level of details:

The unit of granules at site 2 gets a very slightly higher blockiness. Although the units of granules

(E_1) and gravels (E_2) mainly differ on the y-axis regarding the RWR. Granules appear to be both more

rounded, and slightly blockier bigger-sized rocks (< 5cm) are found inside unit E_1. Landform G at site 4

obtains a similar RWR value, although clasts there are even more well-rounded, and this one dot would

seem like an outlier if it wasn’t so far right on the x-axis for blockiness (C40). It has indeed an RWR as

high as the RWR for the controlled sample taken at a subglacial position, and its C40 is very high as well.

However, it wasn’t true for the controlled sample.

5.Discussions

Both the formation of controlled moraines and the nature of the mounds at site 1 is essential to

answer the question relative to the thickness of ice, and the question about the geometry of the snout

during deglaciation after the LIA. The formation of controlled moraines will further be discussed based

on the available literature as well as in which way this literature links to the landforms in the foreland of

Midtdalsbreen. By these means, the validity of the initial hypothesis can be examined.

5.1. Review of the processes leading to the creation of controlled moraines

Following the result section and building on the previous two-folded interpretation section, a model

for the formation of controlled moraine will then be proposed:

- Controlled moraines are most often located at the snout of glaciers. A thinning snout is

present, thereby allowing the water to drain upward and freeze (fig. 36) and thus, even

depositing debris that will not be removed, directly on top of the glacier snout (fig. 41).

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Figure 36: Debate on the presence of thrust planes/shearing transporting debris. Sketch by

Röthlisberger, taken from Hallet (1981 a.). Hallet (1981 b.) suspects that there might exist a boundary

within glacier that is in relation with the concentration of debris, since a high concentration of debris

tends to slow down the velocity of ice-sliding. It is likely that this effect of debris is superimposed to the

slip/no slip boundary that is itself resulting from the warm ice-cold ice interface. The dirt-cone on the

surface of the glacier at the warm-ice cold-ice interface can be seen on fig. 41.

The presence of thrust planes transporting debris contributes to take debris from a subglacial

position to an englacial position and then to a supraglacial position. If too many debris are present inside

the ice, then the ice may stiffen, and fracturing might occur less easily. Besides, ice is not a material in

which thrusting typically occurs. However, fractures still occur inside the glacier, especially at the snout,

and this is due to a difference in velocity at the terminal. Debris having an englacial source contribute to

feeding the dirt-cones on the surface of the glacier. They can initially be of subglacial origin or

supraglacial origin. If the glacier is frozen at its very bed throughout, then more debris from a direct

supraglacial provenance are expected (table 1), and this happens directly on top of the glacier.

Conversely, a warm ice, cold-ice type of interface makes it easier for the debris to be transported from a

subglacial to a supraglacial position. Indeed, Glen’s flow law (1955) in 2D confirms this:

𝜀̇ = 𝐴 𝜎𝑛

where A = 1/Bn is the fluidity; the larger B, the smaller A, the less fluidity, and B is the viscosity; the

larger B, the stiffer the ice; 𝜀̇ and σ are effective strain and effective stress; and n is “Glen’s exponent”. A

is function of the temperature of the ice and the anisotropy of the ice crystals. Warm ice is much softer

than cold ice. The interface between warm-ice and cold-ice is found in englacial position and the

difference in slip between two blocks of ice might transport debris upward to the glacier surface, where

the debris will further be insulating the glacier surface. If the presence of a warm-ice cold-ice interface

initially helps to transport debris, then the ice might slow down after some time due to the too high

amount of debris, and the interface might move towards up-glacier.

Warm ice

Cold ice

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5.2. Nature of the warm-ice cold-ice interface (WI-CI)

Moore and al. (2010) write that evacuation of water is happening in conjunction with this

slip/no slip boundary at the warm ice- cold ice boundary or BTT (basal thermal transition), further

facilitating the transfer of sediments towards the surface of the snout of the glacier. Hooke (1989) writes

that this might happen through an arborescent net of small cavities. Before that, the water might have

been circulating subglacially through a net of broad and low cavities (Hooke, 1990). However, the nature

of the fractures through which this transfer of sediments happens and the how the water can drain in

polythermal glacier, at the BTT, is subject to debate. Even though he does not fully agree with Moore

(2010), Hambrey et al. (1999) explains that there is a transfer of sediment which exists inside the glacier,

from a subglacial position to an englacial one and then finally eventually to superglacial position at a

boundary between slip and no-slip at the glacier snout. Both authors agree on the existence of a boundary

and the fact that this boundary is exploited for evacuation of water, and further freezing with transfer of

sediments to the glacier surface, but they do not agree about whether thrusting occurs or not, at this

boundary. Moore (2010) rationale makes more sense to date but that does not avoid the transfer of debris

through fractures that are not necessarily associated with thrusting.

Pohjola and Hooke (1990) describe a mechanism happening in the overdeepening of the polythermal

glacier Storglaciären, in Northern Sweden. This happen at a boundary termed the basal thermal transition

(BTT) and this is even allowed to happen without thrusting due to an upward ice flow that is

accommodated by a vertical extension of the BTT up-glacier (Moore, 2009). This zone of transition is an

area of transition between slip and no slip, thereby between active ice and dead ice.

This explains the presence of stripes of debris which are present directly inside glaciers snouts (Evans,

2009). Fig. 39 is an example on that:

- After deposition on the glacier foreland, these controlled moraines have an ice core inside them

which melts away, and this is happening in a relatively slow fashion since the more the ice-core

melts, the thicker the layer of debris above the ice-core becomes (fig. 37).

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Figure 37: De-icing progression of ice-cored terrain in a humid sub-polar climate, the figure is

taken from Krüger & Kjær (2000). It takes approximately 50 years for these given climate conditions to

obtain controlled moraine, which is to say ice-cored moraines in which the ice-cored would have totally

disappeared. Everest & Bradwell (2003) tell us that the melting of the ice-core can sometimes even take

centuries, depending on the climate. For the melting of ice cores previously sheltered by cover of debris at

Midtdalsbreen it is most likely that the melting took decades than centuries because I did not find any ice-

core in the controlled moraine that I investigated at site 2 and at the other sites.

The steps described in fig. 37 contribute to the degradation of the dirt-cone/ice-cored-moraine

continuum. The melt, occurring in chain reaction can already start after the initial deposition of a thin

layer of debris on top of the glacier snout. These moraines are not easily well-conserved throughout the

foreland in reason of their fragile nature. Before their actual transfiguration in controlled moraine, the

dirt-cones or ice-cored moraines can often be totally eroded-away:

- They can be destroyed so easily due to their inner nature: sand and/or gravel piles are not

very compacted owing to the slumping processes involved during their deposition, especially if melt

occurs during summer.

- These controlled moraines can even be fully destroyed before their deposition while they

are located on top of the glacier snout (fig. 38).

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Figure 38: Widening of crevasse. A potential future ice-cored moraine or controlled moraine is

destroyed while present on glacier. These debris sitting on top of the glacier snout are instead going to

slump in the crack that is progressively enlarging itself as a major fracture on the glacier.

Before deposition on a foreland, a controlled moraine is primarily a dirt-cone present on the

surface of the glacier, and then it becomes an ice-cored moraine present on the same foreland. It is

through de-icing that an ice-cored moraine is starting to become a controlled moraine. When the debris

cover tends to be thick enough above the glacier snout, (Östrem, 1959 and Lukas et al., 2005), then

insulation occurs. Although, the relation between debris cover and insulation is not linear. If a thin cover

of debris occurs, then the melt is enhanced, while with a thicker cover of debris the melt is decreased –

this occurs in an almost exponential fashion. This may happen at the snout of the glacier for instance, up

above the fractures of the ablation area of Midtdalsbreen and it is then possible to come across developing

dirt cones there. This insulating effect seems to be more efficient towards the lateral parts of the glacier

snout regarding the quantity of debris which can be found there. This large amount of debris could either

be due to the high availability of debris, more important around cliffed-edges of the glacier or to the

supraglacial drainage which could be less efficient on the glacier’s sides, thereby potentially washing-

away less the lateral supraglacial and thus dynamically evolving dirt-cones. Since some edges of the

glacier are cliffed then the shadow developing over the glacier during one part of the day might make it

easier for the glacier to be less sensitive to direct exposure of the sun, thereby reinforcing the insulating

81

effect there. During the erosion of ice-cored moraine one finds the processes of backwasting and

downwasting to be predominant, as described by Krüger & Kjær (2000). Backwasting is “defined as the

lateral retreat of near-vertical walls of ice, or steep, ice-cored slopes” and downwasting is “defined as the

thinning of the ice core by melting along the top and bottom surfaces”. Throughout the history of ablation

of the ice core constituting the ice-cored moraine, backwasting and downwasting are thought to dominate

at different moment, and this could possibly influence the sedimentology of a given controlled moraine.

When the environment is fully ice-cored and thereby in contact with the glacier, the processes of

backwasting and downwasting by bottom melt dominate (Krüger & Kjær, 2000).

When dead ice blocks are present on the landscape Kjær & Krüger (2001) wrote that it is through

retrogressive rotational sliding or backslumping of the ice-cored slopes that the degradation of ice-cored

moraines takes place. This is of greater relevance for this report, since it will further allow to determine

the nature of the mounds at site 1 (see table number 1 for the identification criteria used for the controlled

moraines land-record). In the ice-free landscape, controlled moraines are thought of as being structures

that are mainly related to the formation of sinkholes and fractures are mainly remaining imprinted on the

sediment succession so generally, no inversion of the topography occurs during the final phase of de-icing

(Kjær & Krüger, 2001). Although, in the final stages of melt, the “soon-to be” controlled moraine has

already started to be almost stable due to a thicker sediment cover, and the insulation eventually increases

due to increased amount of vegetation and a decreased through-flow of water (Krüger & Kjær, 2000).

Kjær & Krüger (2001) after their study in 2000 identify three stages for the melt of ice-cored moraines,

which approximately correspond to the fig. 37 above. The first stage which they identify for the creation

of dirt cones as ‘overthrusting’ gives the idea of a block of ice sliding over another block of ice thereby

transporting debris to the glacier surface. Water might circulate in englacial conduits of the glacier,

thereby bringing up sediments and freeze-on might also occur in order to stop these sediments from being

evacuated at the top of the glacier (Waller, 2012).

5.3. Controlled moraines are found on the foreland of Midtdalsbreen, at

the WI-CI type of interface

‘

Based on the previous interpretation at each study site, 4 controlled moraines could be identified:

at site 1, controlled moraine A and D, at site 2, controlled moraine E, and at site 3 controlled moraine F.

Both are similar since they also are highly glacitectonised. At site 1 a set of controlled moraines were

identified at the immediate proximity of a LIA moraine. Their position by itself – i.e. almost flat

topography there, somewhat prevents them from being cut-through terraces created subsequently to the

melt of the glacier after the LIA. The glacier, when it melted-away, might have eroded the landscape in

this area but this might have been likely to happen in the immediate lateral proximity of those landforms

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where one can observe what seems to be a genuine cut-through glaciofluvial deposit. A small minor

moraine was observed on the field, and this allows us to build on Sollid & Bjørkenes (1978) map and

further modify their geomorphological map (fig. 5). This small minor moraine is perpendicular to the LIA

moraine and the slope which water drainage uses nowadays. Just below this small perpendicular moraine,

one finds this set of supposed stratified fluvial moraines sitting on a yet relatively flat area of the

topography. Two of these moraines could be identified as controlled moraine (moraines A and D).

Steeply dipping layers and sorted sands and gravels are an evidence for the controlled moraine

interpretation. An uncertain deposit was identified at site 4, and it may be a controlled moraine, but it

could be some other kind of other deposit as well. The clast co-variance analyzes gave evidence for the

nature of the controlled moraines being glaci-fluvial.

The warm-ice cold-ice interface might not always match the boundary between wet-base and dry-

base at the glacier snout, but both boundaries are time-transgressive and are changing in position

throughout the year in a similar fashion. During both season (melt-season and accumulation season) the

water that is available at the glacier sole is going to help greatly for the creation of fluted ridges and the

presence of water depends on both whether or not the pressure melting point is reached at the glacier sole

and the supercooling mechanism. In the same fashion the presence of water is also going to explain the

creation of the large-dimensions LIA moraine which is located near one side of the valley - where it is

found of larger dimensions (West). Such a high moraine (approximately 8 meters high) is deposited under

cold climatic settings during the LIA, and this is occurring by the means of a thick, warm-based ice-sheet.

Although, controlled moraines were interpreted as such down on the stoss side of the LIA moraine. This

is even an evidence for thin ice. If the sediments constituting the dirt-cones at the snout of the glacier

today and the sediment near the LIA moraine (site 1) can be associated to the same mechanisms, then the

snout of Midtdalsbreen was as thin as it is today, and this is true already a short time after the LIA.

Controlled moraines with a signal such as that obtained in the clast shape analysis (fig. 35) are

often created in an area of the glacier with an interface between warm-ice and cold-ice (table 1 and

interpretation section). These glaciers are often warm-based throughout with a cold-based snout. They are

warm-based throughout because of the climate, but it is possible that they have a cold-based terminal if

the pressure melting point is not reached at the base of a thin sheet of ice. Midtdalsbreen glacier had to be

cold-based after the LIA at its snout, and for that condition to be fulfilled the ice had to be thin. The

interface between warm-ice and cold-ice existed well back in time after the LIA, under cooler climatic

conditions. The glacier had to be thicker in order to reach the pressure melting point at its base and for the

warm ice-cold ice interface to occur under colder climate settings. The glaciers during the LIA extended

further downvalley, and they were therefore impacted by warmer climatic conditions for their lower parts.

This effect might however be negligible.

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5.4. Paleogeographic implications of this controlled moraine land-record

Erratics over cliffs (fig. 9) indicate that the glaciers were much thicker at one point in time, but it

could have been during the Younger Dryas and not during the LIA. The LIA maximum for Midtdalsbreen

is dated to AD1750 with lichenometry (Andersen and Sollid, 1971, Åkesson et al., 2017). “The

importance of bedrock troughs and overdeepenings is illustrated by Hardangerjøkul’s nonlinear volume

increase ca. 2300–1300 BP, a period when volume increases faster than area” (Åkesson et al., 2017).

There is an evidence that bedrock throughs contribute to an increase in ice volume happening quicker

than the increase in area, and even though Midtdalsbreen at its LIA position is not characterized by an

overdeepening it is possible to imagine that the cliffs in the landscape (fig. 4) could have contributed to a

convergence of the ice-flow at site 1 – this is true at least during the YD.

Besides, a retreat minor moraine of much younger age (it is labelled as a minor moraine on the

geomorphological map: figure 5) is sitting on bedrock, and as just mentioned this is shown on the

geomorphological map of section 3.1 dealing with the most recent period of deglaciation – this minor

retreat moraine is located to the west of the study area, slightly above the paleo-mounds at site 1. This

moraine is nearly perpendicular to the LIA moraine. One of the major implications of the

sedimentological analyses is the following sketch/paleo geographical model (figure 38 a.):

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Figure 38 a: Model/sketch for the deglaciation above Midtdalsbreen area, and site 1.

85

The model above is based on the previous discussion and interpretation section. The

maritime glaciers of Norway are directly affected by climate after the LIA and the sequence of events

might have occurred as pictured above (fig. 38 a). Several lines of evidence point to such a sequence of

event: - first, the geomorphology, then the interpretation of the landforms as controlled moraines, and

finally the fact that this landform record is typical for this clockwise retreat of the ice present on a type of

plateau, as observed above. The minor moraine, in addition to the very fact that controlled moraines are

present at site 1 is very important for us to determine the phases of the ice retreat after the LIA. They

might even have been dead-ice present on the landscape at some point after the deposition of this

landform record, if the ice was disconnected from the main glacier.

Based on this, it is then possible to find more about the ice flow direction after the

deposition of the LIA moraine and the subsequent retreat of the ice by downwasting and then by

backwasting. The ice had to retreat in a clockwise fashion following the main slope of the valley in-

between the two structural steps in the landscape or so-called buttresses (figure 38 a.). For this to occur,

the thickness of ice would have had to be sufficiently low in order that the ice-flow could be constrained

by this "secondary valley". This secondary valley is almost perpendicular to the main valley in which

Mitdalsbreen is sitting – see even the area on figure 4 with a realistic scale factor; it is the area in-between

the two red-colored dashed-lines/buttresses which constitutes this so-called "secondary valley". The ice

was likely forming an elbow at this position during the retreat after the LIA, and the passage between the

two pseudo steps of the landscape. In addition to being reworked one time after the total deglaciation of

the study area, the paleo-mounds- now interpreted as controlled moraines- at study site 1 might have been

re-worked twice during the ice retreat above the study area itself. This would strengthen the hypothesis

that paleo mounds at site 1 are controlled moraines, as well as it explains their multi-directional character,

which is to say the internal variability of the landform record at site 1 as well as the relatively strong

meltwater signal obtained from the clast-shape analyzes.

Topography is an evidence for a thicker Midtdalsbreen at its snout during the LIA,

compared to today. The volume increased faster than the area. For the pressure-melting point not to be

reached at the base, Midtdalsbreen had then to first loose volume by downwasting and then by

backwasting. If the glacier would have first retreated by backwasting it would have been difficult to

deposit controlled moraines A and D at site 1 near the LIA moraine. It is also understandable that the

glacier first melted vertically and then retreated horizontally, because its dynamic is controlled by the ice-

cap which has a highly non-linear dynamic regarding the area and volume that evolve differently

(Åkesson et al., 2017). Midtdalsbreen lost first volume after the LIA and stagnated enough time at site 1

in order to deposit moraine A and D and then to operate a retreat in area later on. Since a part of the

glacier was warm-based near the cold-based ice at the very snout then the ice flow velocity was increased,

86

and this may explain the melting of the ice first by downwasting and then by backwasting. Both the

convergence of ice flows and the presence of a warm-based ice patch are necessary for the creation of

controlled moraine together with the cold-based very snout or frozen toe:

- downwasting occurred first and lead to the appearance of a cold-based frozen toe without

any change in area regarding the glacier snout

- then backwasting could occur when the controlled moraines A and D were deposited at site

1. The temperate character of the upglacier part of Midtdalsbreen could be due to both the present climate

warming trend as well as to past higher thickness of ice during a past climate period that was more

favorable to glacier’s growth than today.

Figure 39: A picture of a large cavity that allows higher fluxes of water to evacuate at the Eastern

half of the glacier at the end of the melt-season – fig. 4 for location. Many stripes with debris present in

the glacier snout. This image is essentially a very zoomed-in view of fig. 22.

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Figure 40: Previous meltwater channel (fig. 39) viewed from above – fig 4.

5.5. Unidentified landforms and possible interpretation

The landforms in the glacier foreland for which the interpretation was uncertain are unidentified

hummocks or ridges (e.g., site 4, fig. 4). Hummock is a quite general term and it designates a landform

having the shape of a hummock, but many different genetic processes could be involved in its creation

(Benn 1992), thus the need to specify what other kind of hummocky moraines were observed in the

foreland. Benn (1992) in fact came across recessional moraines, drumlins, and genuinely chaotic

assemblages while investigating hummocky moraines on the island of Skye and thus question the

usefulness of the such terminology. Could a hummocky moraine be both depositional and erosional?

Munro & Shaw (1997), tend to think that these kinds of hummocks found in central Canada could also

constitute erosional landform but based on the study by St-Onge & McMartin (1999) it will be further

demonstrated why they are wrong and why hummocky landforms are most often associated with

depositional landform. Although most authors (St Onge & McMartin, 1999, Lukas, 2005) will agree for

88

hummocks being depositional landforms, an uncertainty remains about the deposition of this hummocks

at a temperate or polythermal margins. Lukas (2005) proves to be wrong that englacial thrusting occurs

for the creation of such hummocks and he discovers more terrestrial ice-contact fan in his study area in

Scotland. However, it is important to remember that not all hummocky moraines constitute a terrestrial

ice-contact fan. It is the case for Lukas (2005) for his study area in Scotland, but polythermal snout can

deposit landform that look sedimentological similar, if a dirt-cone thaw away after deposition on top of a

glacier snout (Weertman, 1961, Evans, 2009). Erosional kind of hummocks were mentioned in some

studies (Munro & Shaw, 1997) but the seriousness of these study could be questioned. In fact, in their

paper St-Onge & McMartin (1999) believe that the landscapes of hummocks are essentially the result of

the melt of buried glacier ice. They don’t agree with the catastrophic subglacial drainage hypothesis by

Munro & Shaw (1997), and it would make sense that hummocky terrains most often constitute

depositional landform and not erosional landform, especially where one can find them i.e. at the snout, in

the case of the case study at the glacier foreland of Midtdalsbreen. Besides, in the case of the study by

Munro & Shaw (1997) it is also unlikely that any catastrophic subglacial drainage happened in Canada. It

is difficult to determine the water source as well as where the material transported during the flood event

can be found today - and what are the corresponding δ18O values in the Ocean? No evidence was given

by Munro & Shaw (1997) therefore they are probably wrong and St-Onge & McMartin (1999)

interpretation is considered as valid.

For the depositional kind of hummock, it is sometimes possible to distinguish between

segregation ice and glacier ice (St-Onge & McMartin, 1999), but Dyke & Evans (2003) note that it can be

complicated to differentiate between segregation ice and glacier ice, especially when one is dealing with

pseudo-moraines whose ice-core already melted-away. Although, it is often likely to obtain freezing of

water and sediment at a glacier toe, as notes Alley et al. (1997), therefore increasing the chances for

obtaining moraines with an ice core then. Such a basal freezing, like described first by Weertman (1961)

was further described by Harris & Bothamley (1984) with englacial deltaic sediments that could

sometimes be an evidence for basal freezing as well as marginal shearing.

Other landforms that were associated with past ice-sheet and that are thus of larger dimensions and

occurrence compared to controlled moraines are the so-called circular moraine features and they were

described by Ebert & Kleman (2004) on the Varanger Peninsula, in northern Norway. They seem to be

associated with polythermal ice and one difference is that the material constituting them derivates from

englacial fracturing only.

The snow-bank pushed ridge described by Birnie (1977) is a landform that is affected by the

fundamental variability in snow-depth, the ice edge thickness, the till character and the local topography

thereby resulting in a whole range of interactions and resultant forms. Maybe the variability of the

89

controlled moraines is constrained differently but it is not rare to have a landform pertaining to one class

of landform created by one general mechanism that expresses itself on different way in the natural world.

This natural variability is partly explained by the fact that the snout of the glacier is not as fractured in

every location and the subglacial drainage is not the same to the East and to Center and West of the

glacier (Willis et al. 1990 and 2012) thereby contributing to spatially different expression of the same

kind of landform in different locations. Andersen & Sollid (1971) described the difference in landform to

the West and Center compare to the Eastern part of Midtdalsbreen and tell us about the “meltwater

channels of varying size and fan-like deposits” to the East of the glacier foreland, “while the ground in the

western and central areas is uneven, with morainic ridges, hummocks and glacio-fluvial terraces”.

Regarding the flutes found in the landscape one can imagine that if the glacier has a sole frozen to

its bed, then maybe the water evacuates in some cases through the sediments at the base of the glacier; if

the sediments are permeable enough, thereby helping for the creation of flutes.

5.6. Factors of uncertainty for the identification of the landform record

During the melt process, the structure of this landform is owing to the slumping processes taking

place in the glacier foreland and inside the fractures. It is the main uncertainty in this report. A wide

diversity of fractures and cracks are present inside the snout of Midtdalsbreen. A dirt cone which sits on

an ice-core displays more cracks into it, and it might then display a greater variety of steeply dipping beds

compare to a dirt-cone developing above an almost fractureless glacier/ice-core. As well as a change in

sedimentology during the melt of their ice-cores, these controlled moraines also undergo a change in their

morphology. They get to be hummockier in appearance, e. g., viewed from satellite imagery, after their

ice core melted-away. Dyke & Savelle (2000) write about the evolution of ice-cored moraine into

hummocky moraine, and they would not tend to associate these hummocky moraines with period of

stagnation of the ice but with an active retreat of the ice instead. The process of slumping is also supposed

to stop for a long time, unless these landforms would be disturbed again or even destroyed by the

meandering of the proglacial drainage pattern or the melt of the perennial snow-patches and even

subglacial flooding. The morphological appearance of these hummocks has been observed in other area

than just near by the glacier snout. Despite their dynamic evolution both on glacier and on the foreland,

the characteristic of controlled moraines was given in the previous sections and based on those, it was

then possible to be almost certain about the landforms that were interpreted as being controlled moraine

(table 1 and interpretation).

90

6. Conclusion

The paleo-controlled moraines which were sampled down in the glacier foreland are displaying a

crest which is less fresh, morphologically speaking and some moss and lichens on top of them. In other

words, they look hummockier. It is possible to observe a variety of dirt-cones of different shapes and

sizes present on Midtdalsbreen. They seem to be a very fragile landform. Indeed, some of them already

de-integrate while present on the glaciers surface, by enlargement of some fractures or changes in the

glacier’s drainage pattern. The melt of their inner ice core probably starts already when these dirt

accumulations are present above glacier and so when they are still in connection with the glacier

movement. This probably happens during summertime although these glacial debris have an insulating

effect on the glacier snout. These proglacial mounds possess an ice core on their inside.

By walking a few hundreds of meters from the glacier snout it is possible to see a change in their

morphology. When these hummocky mounds are present above glacier snout, these dirt cones display

steeper sides and sharper crest, whereas, when the same mounds are present above the proglacial till,

these landforms start to progressively ‘melt-away’ from the inside, and this is giving them their

appearance of pro-glacial hummocks. The ice core inside them melts away completely when they are

present above the proglacial landscape. Sedimentological evidence of the thaw process versus melt-

process might nonetheless be hard to find on the landscape.

A 'controlled moraine' is a bump on top the glacier. It is owing to some, potentially

multidirectional, debris-filled fractures reaching a glacier surface. These cracks, present in the ice of the

ablation area, are full of debris and one can observe the accumulation of these dirt cones sheltering an ice

core in many ablation areas of different glaciers around the world (e.g.; Storglaciären and neighboring

paleo-evidence at Isfallsglaciären). The settings are similar. The controlled-moraines found in today's

paleo-landscapes are glacifluvial landforms in origin, and they resemble a sort of mound presenting a

hummocky shape. They could be included in the broad spectrum of the ‘hummocky moraines’ because of

their morphological appearance after one analyzes them in the paleo-landscape. The real nature of these

hummocks could even be characterized after careful sedimentological investigations.

Controlled-moraines reveal the existence of slowly melting-away cores of ice inside them during

their sedimentological as well as morphological dynamic evolution on the glacier surface as a dirt-cone.

The resulting morphology for an ice-cored moraine is a sharp linear crest and the sedimentology is that of

a controlled moraine after melting of the ice core. When the ice-cored moraine becomes ice-free, then it

can be described as a controlled moraine. Its morphology is such that the crest is not linear anymore and

91

its sedimentology is such as the one observed in controlled moraines A and D at site 1 or controlled

moraine E, at site 2, for the most recent ice-free example:

- steeply dipping layer are present, sorted sand and granules material, occasional lenses of

silty material and dipping gravels on the distal side of the moraine.

After apparition of an insulating layer of debris over glacier during the melt-season, these ice-cored

topographical inversions are going to be developing. The dynamic evolution of these ice-cored mounds

present on the glacier surface contributes to sorting of the debris constituting them during their melt

throughout the year. Meltwater action is prominent during this stage. This is already happening before

their eventual deposition on the glacier foreland and continues when their ice cores are still melting once

they are laying on the foreland. They go from sharp linear accumulation as seen from satellite imagery to

more hummocky terrains. Their evolution directly on the foreland can even lead to topographical

inversion depending on the initial size of the landform (fig. 37 describes the time-scale involved).

Dirt-cones on the glacier surface are fed by debris whose origin is immediately englacial, or

subglacial, at the same time as they are ‘over-feeding’ themselves by successive slumping due to the

fracture -evolving into cracks- present within them and in glacier. Meltwater action might impact the

glacier foreland, during the deposition of controlled moraines, and by the means of a covariance analysis

between the roundness -i.e. RWR index- plotted against the shape or blockiness of the clasts -i.e. C40

index- one can then try to decipher whether the landforms were formed predominantly by meltwater

action or, in a more direct fashion, by subglacial processes. Although subglacial processes might exist

here, a strong meltwater signal was extracted from the clast co-variance analyze, which indicates the low

degree of supraglacial and proglacial reworking of the debris that constitute the landforms that were

interpreted as controlled moraines.

Midtdalsbreen is a temperate glacier which is polythermal at its frozen toe. Temperate glacier is a

geographical as well as geophysical type of classification. Ahlmann (1948) describes temperate glacier as

consisting of “crystalline ice formed by fairly rapid recrystallization of the annual surplus of solid

precipitations due to great quantity of fluid water. Throughout these glaciers the temperatures correspond

to the melting-point of the ice, except in winter time, when the top layer is frozen to depth of not more

than a couple of meters. The glaciers of Scandinavia and the Alps are included in this group.” However,

this kind of classification could be considered as a little outdated. Today, Midtdalsbreen is more thought

of as being a temperate glacier with a polythermal snout (Reinardy et al., 2013). Field observations of

both a water-saturated flute directly at its terminal and an ice-cored till deposit in spatial proximity,

regarding the glacier geometry, is an evidence for that. Controlled moraines there are created in relation

92

with a boundary located immediately upglacier from the glacier frozen-toe. This so-called boundary

would be a boundary between warm 'wet' ice upglacier and cold ice (the frozen toe of the glacier) at the

very down-glacier, where initially subglacially transported debris are brought up along fracture planes by

meltwater action, first onto an englacial position, and then deposited on the surface of the ablation area of

the glacier. A preferential concentration of debris seems to occur at this kind of interface, where

supercooling also occurs (Lawson et al., 1998). Although, in the complexity of the real world it appears

that one single boundary in term of debris does not exist. Instead, one can observe many cracks filled with

sediment towards Midtdalsbreen snout (figs. 39 and 41), and this kind of pattern in the ice is described as

an arborescent structure by Hooke (1989).

Figure 41: Dirt-cone located on the western side of Midtdalsbreen – fig. 4. This dirt-cone shelters

an ice-core; and here is the result of an ongoing so-called ‘developing topographical inversion’. As well

as giving an idea of how dynamic an ice-core covered by debris up above glacier might be, this illustrates

the fracturing (background) that contributes to the vertical dipping units that one might expect on such a

landform after deposition on the glacier foreland. Then, further slumping occurs due to the melt of the

previously sheltered ice core, and the structure resulting from this kind of slumping might be different

than the slumping over glacier – I assume this latter to be more vertical if occurring onto ice cracks.

Arcuate fractures are common inside glaciers. They develop low down in the area of ablation of a

glacier. Sediments (glacial or not) are laying on top of the glaciers. Midtdalsbreen shows these arcuate

fractures in the fronto-lateral position close by the cliffs furnishing debris to the glacier. It is indeed

93

common to find more debris on the glaciers side due to the cycle of freeze and thaw, and sometimes even

permafrost is present in the cliffs overlooking in direction of glacier. Debris are falling directly from the

cliffs surrounding the glacier, sometimes even directly on top of these arcuate fractures. Fractures and

cracks are therefore an evidence for the ‘controlled’ nature of the moraine. The ice flow direction as well

as by the ‘warm base-cold base’ snout boundary are parameters in general responsible for the

development of dirt cones.

These analyses of the landform record at the glacier foreland of Midtdalsbreen in south-western

Norway was initially guided by the foundations laid by Andersen & Sollid (1971), Sollid & Bjørkenes

(1978) and the more recent study of annual moraines in this glacier foreland by Reinardy et al. (2013).

One of the main finding is that hummocky landforms located close by the stoss side of a LIA moraine

(site 1) resemble the actual controlled moraines which are deposited nowadays in a fronto-lateral position

at the East of the glacier snout (site 2). Both landform present similar sediment composition and the

vertical structures found inside some of them are best explained by the direct observation of dirt-cones

above the glacier snout (on fig. 41). Other potential processes leading to the formation of the landform

record were discussed, but it was found that the landforms at site 1 (A and D) are most likely paleo-

controlled moraines deposited short after the LIA. This indicates that the Hardangerjøkul ice cap

terminated in a thin frozen toe, at the location of its outlet glacier Midtdalsbreen overlooking towards

East after the LIA. A thin snout is necessary to deposit debris on a supraglacial position at an interface

between warm-ice and cold ice. If the snout reaches a too thick and steep profile, then the pressure

melting point is likely reached at the base throughout, and as a result no warm-ice cold-ice interface is

present at the glacier snout. This overall decreases the number of dirt-cones on glacier and controlled

moraines are not seasonal landform because of their size at the study area number 1.

Site 1 is in a position where ice-flow converged and the present thermal regime of

Midtdalsbreen, i.e. temperate throughout with a cold based frozen toe, is an evidence that the thickness of

the glacier after the LIA was such that the glacier went from temperate to polythermal – at the snout –

which is the same as the conditions today. In addition, a warm-based glacier flows faster than a cold-

based glacier and this is one additional evidence for the glacier stagnating at the LIA margin; first

downwasting, and then operating by backwasting (e.g. Glenn’s flow law let us assume the flow direction)

over study site 1. Midtdalsbreen glacier was first melting by downwasting and then by backwasting, but

this also depends on local conditions such as the topography. The glacier might have been stagnating at

the LIA limit enough time before retreat. The thermal transition from warm-based snout to cold frozen

toe, the sufficient availability of debris and the time-scale parameter are three parameters that are

determining for controlled moraines creation at site 1.

94

6.1. Main findings

The main finding is the following:

The traditional reworking of controlled moraines (which is to say the evolution from dirt-

cone to ice-free controlled moraine and then the subsequent reworking by meltwater) is taking place

throughout the glacier foreland of Midtdalsbreen,

Controlled moraines at site 1 might have been deposited during two phases of ice retreat;

Dead ice was even present on the landscape at this location since one can observe an elbow on the

landscape at this location – topography is even flat there. The 3 steps re-working (clockwise fashion)

would explain the multi-directional character as well as the pretty strong meltwater signal obtained from

the clast shapes for the controlled moraines at the time. Backwasting consisted of two sequences of events

with two different ice-flow directions associated, over the study area at site 1, after the LIA:

- a first one when the ice was still active and thick and depositing the LIA moraine,

- a second one when the ice-flow direction had changed, and a block of dead ice was left

alone at this elbow's/tipping point's position (site 1 would then have to be ice-free).

The presence of controlled moraines gives information about the thermal regime of

Midtdalsbreen during the LIA. ‘The response of a glacier to climate change depends on its geometry and

on the climatic settings’ (Oerlemans, 2005). The climatic settings during the LIA in southern Norway are

mostly known as well as the overall response of the glaciers following the LIA (i.e. melting glaciers) thus,

based on the controlled moraines landform record it was then possible to tell more about the past glacier

geometry at the LIA limit. The glaciers were thin with a cold-based snout. They could then deposit a set

of glacitectonised controlled moraines - at least the slightly more continental glaciers on the Eastern part

of the Hardangerjøkul ice-cap could. Further research could be undertaken at site 1 – personal

communication from Reinardy suggests the presence of glacitectonites. This would even strengthen the

hypothesis for the formation of controlled moraine over this part of the foreland. Although, it would be

good to dig into one additional landform – a landform looking towards downstream, so the whole scale of

this landform complex could be further determined. The model by Benediktsson, Í. Ó. (2009) in

accordance with the Croot’s model could then be further examined. This would increase the accuracy of

the investigations, especially regarding the natural variability of the mounds/controlled moraines which

may or may not be explained by slumping and the mode of drainage in the foreland. The natural

variability could even be further described and in this way, it would then be possible to get more accurate

regarding the processes leading to the creation of controlled moraines.

95

Altogether, satisfying accuracy was reached with the landform record investigated here,

and the conclusions presented above are coherent as for the several step-process responsible for the

creation of these landforms as well as for the meaning these controlled moraines have for the post-LIA

deglaciation in this area of Norway.

Acknowledgment

Many thanks to Benedict Reinardy! Thank you for your Scottish energy /spontaneity and

the supervision of my master thesis. I want to say a special thank you to Stefan Wastegård, since he let me

borrow from him different master thesis from the glaciology students who were interested about similar

topics before me - at Stockholms Universitet during the previous years. Writing this report full time, even

though it was a 45 credits master and working part-time as a GIS-assistant for the department of human

geography, at the same time, was no doubt a challenge. I could thereby get well acquainted with

sedimentology in mountainous terrains, and the fast changing, dynamic, character of it. It was very

rewarding to finally apply a lot of theories I had only heard about. The foreland of Midtdalsbreen surely

made these theories more real as well as glacitectonised!

I am very grateful for the fieldtrip to Finse and Midtdalsbreen in southern Norway. It was

an amazing long week characterized by both sun and rain as well as intense research/questionnement over

the nature of the controlled moraine-mounds record. Overall, I remember the numerous captivating field

discussions that we have had together with Benny, as well as the great shovel-based field trip activities.

The snow, during the very last few days of our stay only made the whole trip more memorable!

Although, the biggest challenge for me was faced when I had to learn the Swedish language and try to

assimilate the what and whatnot from the Scandinavian culture at the same time. I was living in

Stockholm (and studying as well as researching!) for the duration of my master and even a little bit more

afterwards; due to work opportunity. Academic English has also been a challenge for me, and I thus want

to say a big “tack” both to the administrative team for the master in Glaciers and Polar Environments,

Elisabeth Sturesson and Maria Damberg, as well as to Karin Persson. You allowed me to make small

modification and thereby improve my final report before publishing it online:

- Tack så mycket!

96

Shootout to the IT-desk as well and then especially you (the distance student in physical geography) when

you could help me with the SU template, word and PDF as well as other technical issues that were

enigmas for me before I could meet you (3D shading on word and office 360 were one of the issues).

Least but not last, a big thank you to the different people I met on the way and who are very important for

me! I will not mention them all since they are so many, from the jurisprudence department at SU down to

a beautiful church in the city center;

And 115 pages is already way too much text on the ambition level for a 45 credits masters, isn’t it!

97

Appendix

The following are table and figures in complement of the clast shape analysis.

Table 4: Clast shape analysis at site 1, landform A. The lithology is only granite.

a

b

c

roundess

lithology

1

8.4

6.8

3.1

sub-rounded

blue granite

2

6.1

4.4

3.1

sub-rounded

blue granite

3

7

5.8

3.7

rounded

blue granite

4

4.6

3.1

2.1

sub-rounded

blue granite

5

6.8

5.1

3.3

sub-rounded

blue granite

6

6.1

5.1

4.9

sub-rounded

blue granite

7

5.1

4.5

3.2

sub-rounded

blue granite

8

6.1

3.1

2.9

rounded

blue granite

9

6.2

4.6

2.4

sub-rounded

blue granite

10

7.6

6.6

4.9

sub-rounded

white granite

11

4.8

4.4

1.8

rounded

white granite

12

5

4.6

2.9

sub-rounded

white granite

13

5.1

4.8

2.2

sub-rounded

white granite

14

7.9

4.9

2.6

sub-rounded

white granite

15

5.2

3.4

2.9

sub-rounded

white granite

16

5

3.8

3.2

sub-rounded

white granite

17

5.6

4.1

0.9

sub-angular

white granite

18

10.9

8.5

5.9

sub-rounded

granite

19

5.4

4.8

2.8

sub-rounded

granite

20

8.2

5.5

4

sub-angular

21

5.1

3.5

1.3

sub-angular

22

7

4.5

2.7

sub-rounded

23

5

4.6

3.8

sub-rounded

24

7

5.8

5.6

sub-rounded

25

4.8

4.5

2.4

sub-rounded

26

6.9

5.9

4.1

sub-rounded

27

5.2

5

3.7

sub-rounded

28

4.9

4

sub-angular

29

5.8

4.6

3.2

sub-rounded

98

30

5.7

3.8

3.5

sub-rounded

31

6.1

3.7

3.5

sub-rounded

32

7.1

5.2

3.9

sub-rounded

33

5.6

4.8

2.9

sub-rounded

34

5.2

5

2

rounded

35

5.2

4.3

4.1

sub-rounded

35 5.2 4.3 4.1 sub-rounded

36

4.2

3.7

3

sub-rounded

37

5.7

4.7

4.6

sub-rounded

38

4.8

4.1

3

sub-rounded

39

6.6

3.7

2.4

sub-rounded

40

4.6

2.4

2

sub-rounded

41

6.4

6.3

4.6

sub-rounded

42

4.9

4.5

2.5

sub-rounded

43

4.4

3.3

2.5

sub-rounded

44

6.2

3.8

sub-rounded

45

4.6

3.7

2.9

sub-rounded

46

6.5

5.2

2.6

sub-rounded

47

5.9

5

3.3

sub-rounded

48

4.6

4.5

2.3

sub-rounded

49

4.8

4.5

3.5

sub-rounded

50

4.4

4

3

sub-rounded

51

5.2

4.4

3.7

sub-rounded

52

5.8

3.8

2.9

sub-rounded

99

53

3.1

2.9

2.2

sub-rounded

54

3.6

3.3

2.4

sub-rounded

55

3.6

3.4

1.6

sub-rounded

56

3.3

3

1.8

rounded

Figure 42: Frequency diagram of clast shapes for landform A at site 1. VA: Very Angular. A: Angular.

SA: Sub-Angular. SR: Sub-Rounded. R: Rounded. WR: Well Rounded.

Figure 43: Triangular diagram for the ratio of the axis for the landform A at site 1.

100

Table 5: Clast shape analysis at site 1, landform D. Lithology is granite.

a

b

c

roundness

12.7

11.4

4.2

sub-rounded

11.8

8.4

5.5

sub-rounded

8.7

7.4

5.9

sub-rounded

5.1

4.5

2.5

sub-rounded

6.1

4.8

4.6

sub-rounded

8.1

5.8

4.9

sub-angular

8.5

5

4.2

sub-rounded

7.5

6.8

2.8

sub-rounded

7

6.2

3.3

sub-angular

8.6

4.4

2.8

sub-rounded

4.2

3.8

3.6

sub-rounded

9.8

8.5

5.6

sub-rounded

4

3.1

2

sub-rounded

4.4

3.4

1.9

sub-angular

8.7

7

3.6

sub-angular

7.5

5.2

sub-rounded

10.2

8.1

6.8

sub-rounded

10.2 8.1 6.8 sub-rounded

5.2

5

3.7

well rounded

8.5

6.9

4.9

sub-angular

9

7.2

6

well rounded

6.8

5.9

3.2

sub-rounded

6.4

5.6

2.8

sub-rounded

7

5.6

4.2

sub-rounded

4.7

3.3

2.5

sub-rounded

8.1

7.5

3

sub-rounded

6.5

5

4.7

sub-rounded

5

4.4

3.5

sub-rounded

4.9

3.8

sub-rounded

4.3

4

3.1

sub-rounded

6.8

6.7

5.5

sub-rounded

5.3

4.5

2.4

sub-rounded

101

7.2

4.8

4.3

sub-angular

6.5

6.4

3.7

sub-rounded

5.9

5.5

3.3

sub-rounded

8.1

4.9

3.4

sub-rounded

3.7

3.5

2.5

sub-rounded

3.6

3.4

2.5

sub-rounded

6.1

5.1

3.8

sub-rounded

6.3

4

2.3

sub-rounded

4.6

4.4

2.6

sub-rounded

4.5

4.4

3.4

sub-rounded

7.6

5.4

2.8

sub-rounded

4.6

4.2

3.1

sub-rounded

3.7

3.3

2.7

rounded

5.6

4.9

4

sub-rounded

4.2

3.6

2.7

sub-rounded

5.5

5.3

3.2

sub-rounded

4.6

4.3

2.4

sub-rounded

4.9

4.3

2.9

sub-rounded

Figure 44: Frequency diagram of clast shapes for landform D at site 1. VA: Very Angular. A: Angular.

SA: Sub-Angular. SR: Sub-Rounded. R: Rounded. WR: Well Rounded.

102

Figure 45: Triangular diagram for the ratio of the axis for the landform D at site 1.

Table 6: Clast shape analysis at site 2, landform E, unit 1. Lithology is granite.

a

b

c

roundness

10.9

9.2

6

rounded

10.1

7.8

4.8

well rounded

6.6

5.6

3.8

rounded

4.3

3.8

2.1

rounded

4.5

4.4

3.3

sub-rounded

7.9

6.6

4.2

sub-rounded

4.1

2.9

1.8

sub-rounded

6.8

5.3

2.8

rounded

5.5

4

3

sub-rounded

5.2

3.9

sub-rounded

6.6

5.6

3.4

sub-rounded

5.3

4.6

2.6

rounded

8.4

6.7

5.5

sub-rounded

4.2

3.3

2.7

sub-rounded

4.4

3.1

1.5

sub-angular

3.8

3.6

2.2

sub-rounded

5.5

4.6

2.2

sub-rounded

4.6

4.4

3

sub-rounded

4.9

3.3

2.2

sub-rounded

5.8

5.3

4.5

sub-rounded

4.8

4

2.9

sub-rounded

5.5

4.6

2.2

sub-rounded

103

7.7

7.3

3.4

sub-rounded

7.6

6.8

4.4

sub-rounded

3.8

3.2

2.2

sub-rounded

5.6

5.2

3.6

sub-rounded

5.5

5.4

2.9

rounded

12.1

8.9

3.8

sub-rounded

8.9

6.7

sub-rounded

4.8

4.1

2.1

sub-rounded

5.8

4.8

3.9

sub-rounded

4.8

4.5

2.2

sub-rounded

4.3

3.9

3.4

sub-rounded

4.6

3.2

2.1

sub-rounded

3.4

3.3

2.4

sub-rounded

5.5

4.4

2.6

sub-rounded

5.2

4.6

4.2

sub-rounded

6.4

6.2

3.8

sub-rounded

3.9

3.6

2.6

sub-rounded

3.9 3.6 2.6 sub-rounded

4.4

3.8

2.5

sub-rounded

3.7

3

2.3

sub-rounded

5.7

5

3.6

sub-rounded

4.3

3.6

3.2

sub-rounded

3.8

3.2

2.4

sub-rounded

4.6

4.4

2.3

sub-rounded

4.8

4.5

3

sub-rounded

4

3.6

2.4

sub-rounded

4.5

3.5

2.3

sub-angular

3.4

2.6

2.3

sub-rounded

4

3.7

2.7

sub-rounded

3.4

3.3

1.6

sub-rounded

2.9

2.4

1.8

sub-rounded

2.9

2.8

2.5

sub-rounded

104

Figure 46: Frequency diagram of clast shapes for landform E, unit 1, at site 2. VA: Very Angular. A:

Angular. SA: Sub-Angular. SR: Sub-Rounded. R: Rounded. WR: Well Rounded.

Figure 47: Triangular diagram for the ratio of the axis for the landform E, unit 1, at site 2.

Table 7: Clast shape analysis at site 2, landform E, unit 3. Lithology is granite.

a

b

c

roundness

9.2

8.5

6.2

sub-rounded

9.9

7

5.6

sub-rounded

8.6

7.7

4

sub-angular

6.4

5.9

3.9

sub-rounded

8.1

6.2

4.4

sub-rounded

105

9.6

8.4

5.4

sub-rounded

6.5

6.1

5.1

sub-rounded

7

6.7

5.1

sub-rounded

7

5.9

3.5

sub-rounded

6.8

6.6

5.1

sub-rounded

7.1

6.8

4.9

sub-angular

7

6.3

4.4

sub-rounded

5.9

4.4

3.3

rounded

6.2

5.7

3

sub-rounded

4.8

3.8

2.9

sub-rounded

6.9

5.8

3.8

sub-angular

5.5

4.5

3.9

sub-rounded

5.4

3.2

1.5

angular

4.6

4.5

3.9

angular

4.6

4.5

4

sub-rounded

4.4

3.6

3.3

sub-angular

5.4

4.1

2.2

sub-rounded

5.4 4.1 2.2 sub-rounded

5.5

5

4.8

sub-rounded

6.6

3.8

3

sub-angular

5.6

3.8

2

sub-angular

5

4.8

4.1

sub-rounded

4.3

3.3

sub-angular

5.1

3.8

1.9

sub-rounded

4.6

4.3

2.6

sub-rounded

4.2

3.5

2.3

sub-angular

3.9

3.6

Different generation of controlled moraines in the glacier foreland of Midtdalsbreen, Norway

Abstract and Figures