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The Physical Characteristics of Limestone Shore Platforms on the Maltese Islands and Their Neglected Contribution to Coastal Land Use Development

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The shore platforms of the Maltese Islands, as both conspicuous landforms and participants in the coastal land use development on the islands, have never been properly investigated in order to provide a clearer understanding of their role in the built-up development of the Maltese foreshore. This chapter details the physical characteristics of these landforms, their spatial distribution, lithological controls and process-based interactions within a micro-tidal Mediterranean coastal regime. In discussing the historical development of coastal land use of the Maltese Islands, this chapter aims to illustrate how various local aspects of foreshore development have both been driven by and impacted on shore platforms. Archaeological and historical evidences point to a long history of platform use which dates back to millennia. However, pressures to develop and encroach on these landforms with further land use are ever present, in a relentless drive to maximise the amenity value of the coast and address the pressures imposed by a growing population and expanding tourism-based economy.
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27
The Physical Characteristics of Limestone
Shore Platforms on the Maltese Islands
and Their Neglected Contribution to Coastal
Land Use Development
Ritienne Gauci and Robert Inkpen
Abstract
The shore platforms of the Maltese Islands, as both
conspicuous landforms and participants in the coastal
land use development on the islands, have never been
properly investigated in order to provide a clearer
understanding of their role in the built-up development
of the Maltese foreshore. This chapter details the physical
characteristics of these landforms, their spatial distribu-
tion, lithological controls and process-based interactions
within a micro-tidal Mediterranean coastal regime. In
discussing the historical development of coastal land use
of the Maltese Islands, this chapter aims to illustrate how
various local aspects of foreshore development have both
been driven by and impacted on shore platforms.
Archaeological and historical evidences point to a long
history of platform use which dates back to millennia.
However, pressures to develop and encroach on these
landforms with further land use are ever present, in a
relentless drive to maximise the amenity value of the
coast and address the pressures imposed by a growing
population and expanding tourism-based economy.
Keywords
Shore platforms Globigerina Limestone Coastal
development Foreshore
27.1 Introduction
The geomorphology of shore platforms is considered to be
mainly a product of local geology, tidal regime, wave cli-
mate and weathering environment (Trenhaile 2002;
Stephenson et al. 2013). Shore platforms are conspicuous
landforms along much of the worlds coastline (including
lake shorelines) and across various latitudes. They do not
exist in isolation but are associated with a variety of mor-
phological features, such as backing cliffs, sea caves, ramps,
notches, potholes, ramparts, solution pools, boulder elds
and low-tide cliffs. Shore platforms form an essential com-
ponent of an assemblage of landforms that creates distinct
accessible coastlines.
In attempting to understand the processes responsible for
rock coast development, shore platforms were amongst the
rst landforms to be studied worldwide. Despite this, the
total percentage of worlds coastline composed of shore
platforms is still unknown and thus they remain as an
unquantied component of rocky shore environments
(Stephenson and Kirk 2006), which is a key issue when
trying to assess the potential impact of environmental change
on the worlds coasts.
27.2 The Context: Definition
and Development
Many workers agree that there is an inherent complexity in
dening how shore platforms are formed (Trenhaile 2006).
Most workers dene shore platforms as a resultant product
of cliff recession. Trenhaile (2006)denes them as rock
surfaces created by the erosion and retreat of coastal cliffs
(Trenhaile 2006: 956), whilst Stephenson and Kirk (2006)
are more specic in terms of gradient and lithology and
describe them as horizontal or gently sloping surfaces
backed by a cliff, eroded in bedrock at the shore
(Stephenson and Kirk 2006, p. 873). However, there is no
R. Gauci (&)
Department of Geography, University of Malta, Tal-Qroqq,
Msida, MSD 2080, Malta
e-mail: ritienne.gauci@um.edu.mt
R. Inkpen
Department of Geography, University of Portsmouth, Lion
Terrace, Portsmouth, PO1 3HE, UK
e-mail: robert.inkpen@port.ac.uk
©Springer Nature Switzerland AG 2019
R. Gauci and J. A. Schembri (eds.), Landscapes and Landforms
of the Maltese Islands, World Geomorphological Landscapes,
https://doi.org/10.1007/978-3-030-15456-1_27
343
overall consensus with regards to the denition parameters.
In his IAG glossary for geological terms, Goudie (2014)
denes them as aat or gently sloping smooth or relatively
smooth rock surface formed in the zone between high and
low tide levels(Goudie 2014, p. 68).
In micro-tidal settings, the vertical extent of the intertidal
zone is narrow and this favours the development of
near-horizontal shore platforms, with a seaward terminus
present at the edge of the platform (Trenhaile and Layzell
1981). Their width and elevation from sea level may vary
considerably: from a few metres to hundreds of metres in
width and formed at either low-tide, intertidal elevations or
at a range of supratidal elevations up to several metres above
high tide (Stephenson et al. 2013). They are considered as
typical of the micro-tidal regime of Australasia (Japan,
Korea [East Coast] and New Zealand [Kaikoura Peninsula])
and in much of the tropical and subtropical world (Sunamura
1992; Sunamura et al. 2014; Choi and Seong 2014; Dickson
and Stephenson 2014).
Recently, researchers have undertaken work on the
micro-tidal platforms of the Mediterranean region (such as
Chelli et al. 2010,2012; Pappalardo 2017; Gauci 2018).
These works aim to widen the debate on the development of
sub-horizontal platforms in environmental settings different
from those examined in previous research. In fact, previous
works on micro-tidal regions have argued that sub-horizontal
platforms were shaped by former sea-level high stands
during the Holocene changes in sea level (especially over
much of the Southern Hemisphere) (Trenhaile 2010). Other
coastal geomorphologists, such as Kirk (1977), postulated
that these platforms are indicative of recent emergence such
as those in southern New Zealand. These two arguments do
not explain the presence of sub-horizontal platforms around
the Mediterranean, when Holocene sea level rose to the
present levels around the Maltese Islands (Furlani et al.
2013; Micallef et al. 2013). In representing micro-tidal,
sub-horizontal platforms within a Mediterranean context, the
Maltese shore platforms have therefore much to offer as
avenues for new investigation in platform studies (Gauci
2018).
27.3 Spatial Distribution of Maltese Shore
Platforms
The identication and quantication of the physical extent of
shore platforms along the Maltese coasts as a separate geo-
morphological unit remains relatively understudied (Paskoff
and Sanlaville 1978; Ellenberg 1983; Buttiġieġet al. 1997;
Magri 2006; Said and Schembri 2010). In one of the earliest
works specically dedicated to Maltese shore platforms,
Buttiġieġet al. (1997) identied the areas along the east
coast of Malta having shore platforms features, mainly the
Grand Harbour, Marsamxett Harbour, Sliema, Mellieħa Bay,
St Pauls Bay and Salini Bay. In Gozo, parts of the southern
coast were identied as well as the eastern side of Daħlet
Qorrot, Marsalforn and Xwejni (Fig. 27.1).
In review studies about the coastal geomorphology of the
Maltese Islands, the genesis and morphology of Maltese
shore platforms were described on a generic level, whereas
their spatial distribution remains unquantied and classied
within a larger category of coast dened as low-lying rock
coast. To establish a proper inventory of Maltese shore
platforms, it is necessary to quantify their spatial distribution
along the Maltese coasts. Only two studies to date attempted
to present a separate representative gure. The rst of these
two studies was a cartographic study carried out by
Schembri (2003) in which, amongst other things, he
undertook area calculations of the Maltese coasts from
1:2500 survey sheets based on the subdivision of the Maltese
coasts in sixteen coastal segments to identify the spatial
distribution of their physical and anthropogenic features.
Schembri (2003)dened low-lying rock coast as predom-
inantly Coralline Limestone shoreline with pitted surface,
sparse garigue vegetation(Schembri 2003, p. 141) and
distinguished it from shore platform, which he denes as
predominantly Globigerina Limestone shoreline with
smooth surface, unvegetated(Schembri 2003, p. 141). The
landward boundary of the coastal area was demarcated by
Schembri (2003) in two ways and expressed in km
2
as fol-
lows: i. by the rst break of slope or presence of halophytic
vegetation running parallel in coastal rural areas; and ii. by
the landward extent of coast-dependent (or coast-related)
activities in the urban areas.
The cartometric measurements by Schembri (2003) pro-
vided the following calculations:
a. A shore platform surface area occupies 3.3% (i.e. 63.4 ha
or 0.634 km
2
) out of the total coastal area of the Maltese
archipelago of 19.28 km
2
.
b. The largest representation of shore platform area for the
whole archipelago, i.e. 55.6% (3.53 km
2
) was measured
along the low-lying eastern coast of mainland Malta,
stretching from Ponta tal-Aħrax to Delimara.
c. The northern and eastern coast of Gozo, extending from
il-Ponta ta` San Dimitri to Ras il-Qala, are characterised
by the largest section for Gozo, i.e. 19.7% (0.125 km
2
)of
the total shore platform area.
344 R. Gauci and R. Inkpen
A subsequent study was undertaken by Biolchi et al.
(2016) and consisted of a coastal geomorphological inves-
tigation of mainland Malta in order to provide a detailed
classication of the diverse coastal geomorphotypes present
on the island (Fig. 27.1). Through GIS mapping, the authors
calculated that 15% of the Maltas coastal length is made up
of shore platforms, third in spatial extent after plunging cliffs
(22%) and sloping coast (21%). Biolchi et al. (2016) iden-
tied shore platforms at following sites: Qammieħ, Selmun,
Ġnejna, Qawra, Sliema, Gżira, the outer parts of Marsamxett
Harbour and Grand Harbour, the south-east stretch from
Kalkara to Żonqor Point, Marsaskala, St. Thomas Bay,
Xrobb l-Għaġin, Delimara Peninsula and Birżebbuġa
(Fig. 27.1). Though different measurement techniques and
cartographic scales were used, Schembris calculation of
31% for Maltas lowland coastline (including shore plat-
forms) was a close estimate to that produced by Biolchis
(2016) with 36% for the same geomorphotype.
27.4 Physical Characteristics of Maltese
Shore Platforms: Geology
and Geomorphology
The physical characteristics of Maltese shore platforms align
well with those of a shore platform morphology having
horizontal to sub-horizontal rock surface (0°5°), produced
along a shore by the action of marine processes (wave ero-
sion, biogeochemical dissolution and other weathering pro-
cesses) and usually backed by retreating soft rock cliffs in
the upper intertidal or supratidal zone (Trenhaile 1987,2002,
2008). At the foreshore, most of the platforms also end with
abrupt low seaward terminus and deeply carved abrasional
notches at mean sea level (Fig. 27.2).
Several review studies on Maltese coastal landforms
describe how most of the shore platforms can be observed at
510 m above sea level (asl), and these are considered as
Fig. 27.1 Location of shore platforms as identied by Buttiġieġet al. (1997) and Biolchi et al. (2016). Source Google Earth ©2016, Terra
Metrics
27 The Physical Characteristics of Limestone Shore Platforms 345
contemporaryshore platforms, i.e. platforms that were
probably initiated at the beginning of the Holocene stillstand
and thus have developed since the sea reached its present
level about 60007000 years BP (Said and Schembri 2010;
Biolchi et al. 2016).
As evidenced by Schembri (2003), platforms occur
mostly on low-lying sectors of the coast exposed to strong
wave action and develop where the horizontal or gently
dipping rock formation of Globigerina Limestone outcrops
at sea level (Fig. 27.2). Given the micro-tidal conditions of
the Maltese Islands, these landforms are never submerged
and are mostly affected by wave action and/or marine spray
(Schembri 2003; Said and Schembri 2010; Biolchi et al.
2016; Gauci 2018; Gauci and Scerri 2019, Chap. 5).
Their genesis is generally attributed to differential erosion
produced by wave action at the contact zone between dif-
ferent limestone lithologies. Paskoff and Sanlaville (1978)
were amongst the rst to suggest the genesis of stepped
shore platforms in Malta as a consequence of variance in
resistance to marine erosion (mainly controlled by the Glo-
bigerina Limestone geological sub-divisions) that would
lead to the stripping of the less resistant layers and leave a
harder surface as a shore platform. Micallef and Williams
(2009) identied a stepped sequence of shore platforms at
Ġnejna and Delimara as a result of different lithological
resistance in the Globigerina Limestone to sea erosion. Said
and Schembri (2010) classied shore platforms on the
Maltese Islands into three sub-types according to their
location, degree of exposure and rock type, as follows:
a. Seaward sloping intertidal platforms, produced mainly by
abrasion.
b. Horizontal or low sloping structural platforms, with
ledges related to resistant and/or gently dipped rock
outcrops.
c. Solution platforms which tend to be sub-horizontal at low
tide.
Said and Schembri (2010) attribute the formation of
seaward sloping intertidal platforms to wave quarrying and
abrasion, given their location in high-wave energy coastal
areas such as the north and north-eastern coasts of Malta and
Fig. 27.2 Shore platforms in Lower Globigerina Limestone Member
at Ponta tal-Miġnuna in Marsaskala, Malta (left) and shore platforms in
Upper Globigerina Limestone Member at Għar Qawqla in Marsalforn,
Gozo (right). Top prole drawings describe the respective landform
structure and stratigraphy for each platform site and resultant processes
close to sea level
346 R. Gauci and R. Inkpen
Gozo. It is important to note that dening this sub-type as
intertidalmay be debatable in view of the micro-tidal
conditions present in the Maltese marine environment and
which leave a very narrow intertidal space along which
platforms can develop. Structural platforms have been linked
by the authors to horizontal or gently dipped resistant rock
formation outcrops at sea level, already amply described by
Paskoff and Sanlaville (1978) as a consequence of variance
in lithological resistance to erosion. The third type of plat-
formthe solution platformis described as characterised
by repeated wetting and drying of its irregular limestone
surfaces and the authors provide Dwejra shores as an
example.
Said and Schembris three main observationsthat the
seaward sloping platforms are driven by marine-dominated
processes, that so-called structural platforms are mostly
geologically controlled and that the wetting and drying
effects contribute to limestone dissolution on Maltese plat-
formsare inferred mainly from observations of the plat-
form morphology. Though the processes involved may be
suggested to a certain extent by the general morphology of
the landform, to what extent and how they are driving the
evolution of the platform development is still not clearly
investigated.
Maltese shore platforms have mostly been cut out at the
foot of cliff lines in Globigerina Limestone (GL) (Gauci
2018). Most of the platforms in Lower Globigerina Lime-
stone Member (LGLM) are cliff-backed by the retreating
cliffs in Middle Globigerina Limestone Member (MGLM)
and present stepped proles wherever there are outcrops of
hardground and/or conglomerate phosphorite beds between
the Middle and Lower Globigerina Members (Fig. 27.2). On
the south-east coast of Malta, between St. Thomas Bay and
Marsaxlokk Bay, the MGLM lies exposed as near-vertical
cliffs, which reach heights of more than 50 m with
sub-horizontal shore platform surfaces composed of a
sequence of more resistant layers made up of the C1 con-
glomerate bed, the underlying Terminal Lower Globigerina
Hardground (TLGHg) and nally, the massive bedded pale
yellow limestones of the LGLM which is relatively more
resistant than MGLM upon exposure. Similar platform-cliff
morphology exists at Qammieħ(Malta) and Xwejni in Gozo.
The development of platforms in Upper Globigerina
Limestone Member is less well documented (UGLM; Gauci
2018). As explained in Chapter 4in this volume, the UGLM
is subdivided in four members (Felix 1973): i. a C
2
phos-
phorite pebble bed at the base; ii. a yellow to orange hard
and compact limestone; iii. A calcareous grey marly middle
bed (mudstone) and iv. yellow to orange hard and compact
limestone at the top. In situations when the C
2
and the
overlying compact yellow bed are located at sea level, they
offer relatively more resistance to erosion by marine action
than the grey marly middle bed (Fig. 27.2).
This alternating limestone stratigraphy leads to differen-
tial erosion behaviour similar to that of the LGLM platform
MGLM cliff system, in which the grey marly middle bed of
the UGLM will retreat faster in a cliff-form manner and
undermine the overlying top yellow bed of the same member
(Fig. 27.2). Such a retreat would leave exposed the relatively
more resistant C
2
phosphorite pebble bed and/or underlying
hardgrounds at the base and the overlying yellow to orange
hard and compact bed. Such platforms are not as numerous
as the LGLM platforms, given that the positioning of UGLM
at sea level is far less common and can be developed mostly
Fig. 27.3 Narrow shore platforms in Lower Coralline Limestone in Malta: aShore platform at Ġebel Ciantar, Ħad-Dingli. bShore platform at
Xgħajra. Photo J Causon Deguara
27 The Physical Characteristics of Limestone Shore Platforms 347
when there is a gentle dipping rock exposure in UGLM. The
three best developed sites are the Blata l-Bajda platform at
Selmun (see Sammut et al. 2019; Chap. 26), Ras il-Fenek
platform at Delimara (Gauci 2018) and at Għar Qawqla in
Marsalforn (Fig. 27.2).
Even though the GL is commonly associated with smooth
and unvegetated coastal platforms and considered far more
erodible than the Coralline Limestone formations, shore
platforms at the foot of high coastal cliffs in the Lower Cor-
alline Limestone (LCL) are not totally absent, albeit relatively
uncommon. Examples of LCL platforms may be observed at
Maddalena and Ġebel Ciantar at Ħad-Dingli (Fig. 27.3a) and
Xgħajra coast (Causon Deguara and Scerri 2019, Chap. 19).
Gauci and Scerri (2019, Chap. 5) associate the formation of
these platforms with a gently dipping softer bed of LCL at sea
level. Wave action along this bed easily induces undermining
and collapse of the overlying rock layers, producing shore
platform as the cliff face recedes (Fig. 27.3b)
In the case of Xgħajra, a soft marl bed is situated close to
sea level between the Lower Globigerina Limestone Member
and il-Mara Member of the Lower Coralline Limestone.
Marine erosion undermines this fragile bed and destabilizes
the overlying thickly bedded LGLM. Successive undercutting
and resultant rock falls from LGLM, led to progressive epi-
sodes of cliff retreat and the exposure of the underlying LCL
as a shore platform (Causon Deguara and Scerri 2019,
Chap. 19)
LCL platforms extend to supratidal levels where the soft
bed is high enough and no longer within reach of storm
waves. Beyond this point, there is no undermining and shore
platform development ends. At Maddalena (Dingli), the
platform terminates along a fault.
27.5 Connection with Coastal Land Use
Development
There are various important connections between the his-
torical development of coastal land use on the Maltese
Islands and the presence of shore platforms skirting along its
shores (Table 27.1). Whilst for many years they were just
considered as atrocky outcrops of no particular utility,
their strategic presence at the landsea interface, especially
in sheltered bays, provided efciency of access for maritime
and recreational purposes (Buttiġieġet al. 1997).
The accessible nature from both land and sea and
sub-horizontal morphology of shore platforms on the Maltese
Islands attracted various forms of recreational and sports
activities all year round such as bathing, barbecuing, shing,
diving, outdoor strolling and tness workouts. In addition,
intense coastal infrastructure has also been built close or onto
these platforms in the hope to maximise defensive military
operations, recreational and property revenue. All this occurred
during times in which minimal consideration was given to the
exposure pressures impacting on this development.
In the next few sections, the role of shore platforms
within the history of coastal land use development on the
Maltese Islands is identied and discussed, in order to offer a
context in which the past and present utility of shore plat-
forms can be better understood.
Table 27.1 Growth of shore platform use though the ages. Source Compiled by Authors
Period Date Platform uses
Neolithic No date Historic cart ruts
Bronze Age 1500900 BC Cisterns, dye pits (?)
Roman 218533 Cisterns, small port operations
Norman 11941530 Salinas
Knights of St John 15301798 Military operations
Coastal defences
Salinas, shing
British Empire 18001964 Consolidation of maritime operations, including slipways for seaplane operation,
barbed wire lines in World War II and construction of pill boxes.
Recreational uses such as the Victorian baths
Post-independence 1964present Growth of mass tourism
Development of open public spaces and small pools
Intensication of retail facilities
Access services such as promenades, stairs, ramps
Other outdoor sports activities such as tness training, yoga
Use for lming industries and music video productions
Salinas as ecotourism product
348 R. Gauci and R. Inkpen
27.5.1 Early Settlers: From Neolithic to Late
Medieval Period (5000BC1530AD)
Strategically located in the centre of the Mediterranean Sea,
the Maltese Islands have long served as an important
waterway outpost for various Mediterranean and European
maritime powers (Table 27.1). As a result, they hold a long
millennial history of human occupancy and colonisation
dating back to Neolithic times (5000 BC). For early settlers,
the coast served as the main survival link with nearby lands
(such as with Sicily) for the supply and trading of goods.
Yet, the convenience of having accessible coasts with
low-lying topography and shore platforms in deep sheltered
creeks was overshadowed by the constant fear of threatening
landings for violent incursions and frequent pirate raids. In
fact, by the medieval period, a military set-up of coastal
roster watch (Maltese: dejma) was already in place to
watch over the marine approaches (Wettinger 1979).
Nonetheless, early human settlements developed as agrarian
clustered communities located mostly away from these
accessible but dangerous shores (Schembri 2003).
Though shore platforms themselves are not favourable
locations for preserving traces of the past, a few archaeo-
logical remains are still visible on shore platforms, indicating
other uses by early settlers, apart from that as access points
to the sea (Table 27.1). Amongst these, there is a group of
bell-shaped cisterns (Fig. 27.4), dating from the Bronze Age
period (1500900 BC), which are located on one of the very
few shore platforms in the sheltered bay of St Georges Bay,
Birżebbuġa (Malta). The function of these pits is still not
completely clear (Abela 1999; Furlani et al. 2013). A
number of theories were put forward: hideouts from pirates
during the Middle Ages, used for storage of oil by the local
people (Adams 1870), silos (i.e. storage tanks) for grain and
drinking water (Trump 1990,2002), dyeing vats servicing
the Phoenician textile trade (Sagona 1999) or the retting of
ax (Furlani et al. 2013).
Adams (1870) estimated the presence of seventy to eighty
pits that extended from this shore platform to the inland
Bronze Age settlement of Borġin-Nadur. Twenty-six of
these pits have been identied by Sagona (1999), whilst the
rest of the pits located in the intervening area between Borġ
in-Nadur and the shore platform have been destroyed due to
building development and coast road construction leading to
the British seaplane base and the fuel installation tank
facilities, the latter both located at Kalafrana. Some of the
extant pits have been partially submerged below present-day
sea level. Regardless of what functions these pits may have
served, they surely were meant to be used above the upper
limit of sea level. Sea-level change measurements carried out
by Furlani et al. (2013) conrmed that the rates of sea-level
rise responsible for this partial submergence coincide with
the estimations of sea-level change in the Mediterranean
region during the Holocene period. In this particular case,
this work also showed the importance of shore platforms in
shedding light on past palaeo-shorelines for the Mediter-
ranean region.
On the same platform, a pair of prehistoric cart-ruts is
deeply grooved at the extreme end of the platform and enters
into the sea at a slope inclination of 12° (Fig. 27.4). Coastal
encroachment at the back of the platform has left only two
metres visible on the platform at a few centimetres above the
present-day sea level. In a study by Zammit (1928), it was
suggested that they were meant to carry loaded carts across
the bay (above the sea level of the time) with the ruts skirting
landwards along the shoreline of the bay in a westerly
direction and emerging on the north-eastern side of the bay.
The end of these ruts could not be veried given that the
urban development on the other side of the bay had oblit-
erated any possible evidence. Similar to the pits, the sub-
merged cart ruts reveal interesting aspects of
palaeo-shorelines with the submerged part at about two
metres below the present mean sea level (Furlani et al.
2013). In conclusion, there is clear evidence of forms of
activity on shore platforms in prehistory.
27.5.2 Uses During the Ruling Times
of the Knights of St John (15301798)
The maritime role of the islands gained strength through the
ages, culminating with the arrival of the Knights of St John
in 1530, who established the Grand Harbour area as the main
seat of their operations (Table 27.1). Experienced in their
maritime prowess, the Knights quickly recognised the value
of optimising the physical features provided by accessible
coasts and deep sheltered harbours for maritime operations.
They embarked on a series of projects which saw the
building of a large number of coastal defences around Grand
Harbour (and beyond) and subsequently the building of
Valletta as their capital and administrative city.
Coastal areas with low-lying topography and sheltered
bays with shore platforms were not feared anymore but rather
defended and watched over by ne examples of military
defensive architecture throughout the ruling period of the
Knights of St John (15301798). These coastal protection
projects extinguished forever the long-standing medieval
fears of the accessible coasts as vulnerable and dangerous
places. The foreshore was slowly transformed into an area of
economic opportunities and industrial enterprise, and as a
result, it magnetised local population shifts towards the har-
bour areas seeking occupation and nearby residential areas.
27 The Physical Characteristics of Limestone Shore Platforms 349
Fig. 27.4 Historical land uses of Maltese shore platforms: aBronze
Age pits at St Georges Bay, Birżebbuġa. bCart ruts at St Georges Bay
Birżebbuġa. cSalinas of the Darmanin family, Marsaskala. dValletta
fortications at St Elmo, with further contemporary land use
encroachment in front of the bastion lines. eUndated salinas hewn
out of plates formes a vasqueson a Sliema shore platform. fVictorian
baths on a Sliema shore platform
350 R. Gauci and R. Inkpen
Shore platforms held not only a fundamental role in
easing landings in sheltered bays but also in placing coastal
defences in the most strategic and accessible parts of the
Maltese coasts. They acted as strong foundations for
important bastion lines and curtain walls erected along the
platforms backing cliff lines, whilst still retaining strategic
access points for maritime operations. The long network of
fortications lining the Grand Harbours rocky coast, for
example, was in fact built along pre-existing high Glo-
bigerina Limestone cliffs and rested on the underlying Lower
Globigerina shore platform (Schembri 2003; Schembri and
Spiteri 2019, Chap. 6). The cliff heights also provided an
ideal high advantage point over which to build the rest of the
military fortications (forts, cavaliers and sentinel posts) to
complete the strategic defence of the whole harbour. With
the intensication of maritime operations in the Grand
Harbour over the centuries, much of the original platforms
were built over with additional articial structures, pave-
ments and walkways, leaving very few outcrops as a
remembrance of the original Globigerina cliffplatform
landscape that once dominated the Grand Harbour
(Fig. 27.4).
With more coastal protection in place, another important
industrial activity was carried out on shore platforms during
the ruling period of the Knights of St John, i.e. the salinas
industry (Table 27.1). With limited natural resources avail-
able on the Maltese Islands, the extraction of salt through sea
water insolation and intensive manual labour offered
numerous economic advantages (Gauci et al. 2017). For
millennia, salt has been an important mineral for a range of
uses from preserving edible foods to cooking, cleaning and
for medicinal uses in dilute solutions. The local manufacture
of salt was so important that it became a royal monopoly of
the Sicilian kingdom during the Norman rule of the islands
(11941530). On the Maltese Islands, this traditional activity
is mostly (but not only) carried out on the sub-horizontal
morphology on the shore platforms in relative soft Lower
and Upper Globigerina Members (Fig. 27.4).
In many cases, the initial presence of naturally forming
shallow solution pools with at bottoms on Globigerina
Limestone shore platforms, known as plates formes a`
vasques(Viles and Spencer 2014; Gauci et al. 2017), would
have easily accommodated the salt requirements of a small
population, which was estimated to be around 15,000 people
upon the arrival of the Knights of St John in 1530 (Camilleri
2005). The rise in population during the rule of the Knights
and the constant fear of a siege by the Ottoman Turks (which
could severely restrict the possibility of food preservation
reaching the strongholds) brought an increase in the demand
for salt and consequently further hewing of humanly pro-
duced salinas by widening and enlarging of these vasques
(Fig. 27.4). With the profound changes experienced in the
salt production by the world salt market over the last
century, this extractive practice declined as an industry and
acquired more a status of an artisanal practice (Gauci et al.
2017). The cultural attraction of traditional salt making
continues to transform the Maltese shore platforms into a
prime site for geotourism in which the salt harvesting work
becomes a unique daily re-enactment of local traditional
practices (See Case study and Fig. 27.5).
Case study: Promoting the geoheritage of arti-
sanal salinas on limestone shore platforms
The salinas of the Darmanin family are located on a
Globigerina shore platform in the area of Żonqor,
Marsaskala (Malta). The salinas have been a property
of the family for more than two centuries and are
currently worked by octogenarian Nazzareno Żaren
Darmanin (Fig. 27.5a), his wife Nina and their son,
Mario. Salt harvesting is an artisanal practice that has
been passing down from generation to generation on
the Maltese Islands, but it is only recently that local
companies have started to market sea salt as a gourmet
product. The Darmanin Salt Pans
®
are one of the few
salinas still in operation on the Maltese Islands.
Additionally, the Darmanin family are the only salt
harvesters forming part of the Merill Rural Network
®
-a
cooperative initiative which brings together farmers
and local produce artisans from all over the Maltese
Islands to create awareness about local produce, revive
long-standing traditions and empower the rural com-
munity.With the support of the Merill Rural Network,
organised visits and hands-on salt harvesting work-
shops are offered to the public in order not only to
market local salt produce, but also to promote the
artisanal skills of the salt harvesters and their familial
relationship with the coastal landscape. This organised
outreach gives a unique experience to locals and
tourists alike to appreciate the physical landscape set-
ting in which sea salt is harvested and to discover
the geoheritage value of shore platforms for the pro-
duction of genuine ingredients and authentic condi-
ment to Mediterranean food. Hands-on workshops
organised by the Merill Eco Tours are scheduled
during summer, when salt harvesting is in peak pro-
duction (Fig. 27.5). The salinas of the Darmanin
family have all been manually etched out of the plat-
form surface with a pick axe. Salt is harvested between
June and the rst rains of September. Prior to the
harvesting season, repair works are done in order to
restore the salinas from the winter storm damages.
Following repair works, sea water is then pumped into
the larger reservoirs and left for two weeks to reach
hypersaline conditions before it is own down by
27 The Physical Characteristics of Limestone Shore Platforms 351
gravity (or articially pumped) into the smaller
evaporation pans. After an evaporation period of six
days, salt is then collected manually from these pans by
using soft tools (such as soft-brush brooms and plastic
hand spades) (Fig. 27.5). Two kilograms of salt is
estimated to be collected from each pan. The collected
condiment is then piled into one single large harvest
heap and left two dry for another three days (Fig. 27.5).
The entire harvesting process is repeated for ca.
15 weeks throughout summer. Dried salt is then trans-
ferred to the packaging stores and packaged under the
trademark of Merill produce.The duration of the
hands-on harvesting workshop takes over two hours. It
ends with the Merill network representative showcasing
the benets of Maltese salt produce in a variety of
typical Mediterranean cuisine, the latter prepared for
their workshop guests to feast upon.
27.5.3 Uses from the British Colonial Period
(18001964) to Contemporary Times
The British period (18001964) continued to see a consol-
idation of the maritime and coastal activities (Table 27.1).
Worth of mention are the following activities during the
British period:
a. Further intensication of maritime industries (including
ship repair) around the Grand Harbour.
b. Patrolling of inland coastal waters through the set-up of
military establishments, with sea planes and sea rescue
squad at Hal-Far and Kalafrana.
c. The spread of coastal settlements as housing and married
quarters for the British forces (such as along Pieta to St
Julians seafront, Pembroke and Kalafrana).
Towards the end of the nineteenth century and the start of
the twentieth century, shore platforms acquired also a popular
Fig. 27.5 Artisanal work at Darmanin Salt Pans
®
in Marsaskala:
aSalt harvester, Nazzareno Darmanin, working on his salinas.
bParticipants in a public hands-on salt harvesting workshop held in
August 2017. cNazzareno Darmanin piling up the collected salt
crystals into individual heaps. dExamples of soft tools used to collect
the salt crystals from the evaporation pans
352 R. Gauci and R. Inkpen
recreational status amongst the middle and upper class and
various swimming bath complexes were hewn into various
shore platforms to accommodate safe and shallow waters for
bathers (Fig. 27.4). They came to be known as Victorian
baths and in general were rectangular in shape, with dimen-
sions of approximately two by three metres. They were cut
out from the front edge of the platform at a shallow depth of
not more than 1.3 m to facilitate access and safe bathing.
Steps were carved down in the rock until sea water level, with
the latter owing in the baths from open channels connecting
the baths to the open sea (Furlani et al. 2013).
During the twentieth century and especially after inde-
pendence (from the British), the tourism sector, and in par-
ticular mass tourism, was viewed as the alternative key to
income, with annual tourist arrivals soaring from 28,000
(1960) to over 1.1 million in 2000 (Boissevain 2004) and 2.3
million in 2017 (National Statistics Ofce 2018). The rise of
mass tourism had a profound effect on the coastal landscape,
with the growth of many coastal localities and the absence of
proper planning legislations prior to the nineties. The fore-
shore was mostly seen as a way to maximise economic
revenue from tourists, restricting most of Maltas accessible
coast and maximising capital to satisfy the demands of for-
eign consumers at the expense of local residents (Boissevain
and Selwyn 2004).
Coastal stretches and embayments with shore platforms
could not escape from a similar fate in frenzied development
(Buttiġieġet al. 1997). With smooth surfaces and backed by
a low cliff line, they presented a high level of accessibility.
These physical factors attracted development, especially in
areas sheltered from sea swell in the inner recesses of bays,
or where jetties provided physical protection. They were
transformed into extensions of marine recreational activities,
with slipways cutting through the cliffs and concrete walk-
ways built over the platform to facilitate access to the sea
(Fig. 27.4). The onset of more recreational ventures along
the foreshore led to more intensive land use spread and
further encroachment on and around these landforms
(Table 27.1).
Coast roads, anked with side promenades, were built on
top of the cliffs backing the platforms, with buttressing walls
and their base covering the cliff facade and the cliffplatform
junctions, respectively (Fig. 27.6). Stairs and ramps facili-
tated access from the promenades to the platforms, in order
to maximise the growing recreational role of these platforms
for activities such as swimming, shing and diving. As
evidenced by the shore platform in Sliema, various levels of
accessibility developed through time, which Buttiġieġet al.
(1997) identied in three categories:
a. Promenade to platform links: through stairways, ramps
and car park spaces.
b. Platform to platform links: through footpaths, steps,
bridged pathways and patches of concrete.
c. Sea to platform links: through ladders, slipways,
hewn-in-rock steps and swimming bath complexes
(Fig. 27.4).
27.6 Current Issues of Encroachment
and Space Maximisation for Economic
Revenue
The presence of these shore platforms was crucial for the
eventual proliferation of ancillary nearby land uses aimed to
maximise economic revenue from the visits of bathers to
these platforms such as restaurants, retail outlets, public
gardens, bars, hotels; all constructed within walking distance
from these platforms. Today, most of the shore platforms
within recreational areas like Sliema (Fig. 27.6), Buġibba,
Qawra, St Pauls Bay, Baħar iċ-Ċagħaq, Marsaskala, Mar-
saxlokk and Birżebbuġa are heavily encroached with retail
facilities and services to accommodate the capitalistic
demand of the tourism sector.
A more encouraging note is the increase in public sen-
sitivity to building development permits on the foreshore,
especially if these cut access to the sea or are in outside
development zones (ODZ). Crucial was the rapidly
expanding network of several environmental NGOs (such as
Nature Trust and Friends of the Earth) who over the years
have become more successful in monitoring development,
sensitising civil society (becoming more effective nowadays
through social media outreach) and gaining stature in the
public eye (Boissevain 2004).
The key issue is one where shore platforms provide a
potential for expanding the space used by businesses but that
using this space is complex. It requires signicant invest-
ment which is unlikely to be available to small businesses
and has a set of opportunity costs associated with it, as
alteration of the shore platform is often irreversible and can
impact on future environmental condition of the shoreline as
well as protection against climate change.
27.7 Hazards and Erosion Management
The implications of erosion and weathering of Globigerina
shore platforms on the functioning of the wider coastal
system have largely been ignored to date and much remain
to be done also in the context on scientic work on coastal
erosion and related hazard management on the Maltese
Islands (Gauci 2018; Main et al. 2018). The following issues
are considered as highly critical in justifying the scope for
27 The Physical Characteristics of Limestone Shore Platforms 353
specic management actions on the protection and conser-
vation of Maltese shore platforms:
a. Disruption of platform morphological equilibrium with
articial lowering of platform surfaces and resultant
decline in the abilities of the platform geometry to reg-
ulate the backing cliffs from erosion.
b. More incidents of ooding and inundation due to pro-
jected increase in sea-level rise (with waves breaking
further inshore due to increase in water depth) and
increasing incidence of storminess related to climate
change.
c. Loss of land through cliff recession, also due to the rel-
atively short distances between the platform edge and the
cliff line.
d. Dangers to or loss of life due to exposure risks related to
platform surface collapse, block detachment from
platform edges, rock falls from cliff faces or onshore
wave breaking.
e. Loss or damage to geological properties of the shore
platforms, with resultant devaluation of their aesthetic
qualities as well.
f. Loss of recreational space for local and international
community.
g. Damage to or loss of infrastructure amenities built close
or upon shore platforms.
h. Damage to or loss of archaeological and historical sites.
i. Damage to or loss of artisanal practices such as salinas
works.
j. Disruption or loss of supratidal habitats.
k. Loss of recreational revenue for tourism activities.
More scientic research is also necessary to examine the
inuence of wave exposure and how platform elevation and
Fig. 27.6 Shore platform in Lower Globigerina Limestone, backed by buttressing walls along the coastal promenade of the highly touristic
Sliema front
354 R. Gauci and R. Inkpen
sub-tidal morphology is inuencing the extent of onshore
wave breaking across Maltese shore platforms. In a recent
work by Micallef et al. (2018) on erosion hazard assessment
of the Maltese coasts, outcrops in Globigerina Limestone
coasts scored very high in terms of hazard levels of erosion
according to parameters such as wave exposure, geological
layout and storm climate. They were termed as softer
geological strata(2018, p. 9) and assigned a high index of
erosion hazard level. No distinction is however provided for
the different members. Additionally, narrow platforms with
soft backshores are recommended as priority areas of coastal
erosion management. These recommendations emphasise all
the more the need to monitor changes on Maltese shore
platforms on a long-term basis in order to scientically feed
future policies of coastal management and land use
development.
27.8 Conclusion
This chapter addressed a theme that is seldom discussed in
shore platform literature, i.e. the role of shore platforms in
coastal land use development. With its strategic position in
the centre of the Mediterranean, the Maltese Islands served
as an important maritime hub from prehistoric times and this
proliferated a wide and intensive use of the coast. Such
development was facilitated by the presence of shore plat-
forms, to the extent that it militated against their natural
preservation in the most highly urbanised coasts. In one of
the most densely populated countries in Europe, natural
landforms such as shore platforms need to be recognised not
just for their coastal function but also for their geoheritage
signicance.
Acknowledgements The authors would like to thank Ms Sandra
Mather for her help to create Figs. 27.1 and 27.2.
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... A small-scale example of adaptation of natural landforms to serve economic purposes is offered by rocky shore platforms, modified into patterns of interconnected shallow pans to allow for salt harvesting [110][111][112]. Locally, salt pans were also developed in inland sites ( Figure 3d) [113]. ...
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... Regarding MSPs, we found them only along short sectors of the Maltese coast, which has already been reported in [28] and discussed in [91,92]. MSPs are near-horizontal, with a gradient of about 1 • or less, following the features described in [60] for microtidal environments. ...
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The geomorphological character of Selmun is primarily defined by the tectonic structure, geological outcrops and the supply of sediments to the coastal zone. The geomorphology becomes remarkably varied within hundreds of metres and displays diverse inland and coastal landforms. Contrasting topography—with high plateaux and valleys—offers an outstanding scenery with various strategic viewpoints such as islets, rocky headlands, narrow bays, pocket beaches, shore platforms, ‘rdum’ (scree slopes), valleys and subsidence structures. Located on the north-eastern part of Malta, Selmun also offers shelter to a variety of protected endemic habitats from coastal vegetated sea cliffs to Holm Oak woodlands, through the provision of three Special Areas of Conservation (SAC). Against this natural backdrop, this rural site also represents a long history of anthropogenic land uses which aimed to maximise the possibilities offered by the diverse landforms such as historical military defence at strategic heights and viewpoints to guard numerous embayments, agricultural terracing on fertile sloping hills and valleys, and salt harvesting on shore platforms. With the presence of St Paul’s Islands, this area is also mentioned in an important biblical narrative which is related to the early conversion of the Maltese to Christianity. Selmun can thus be truly considered as a representative niche of diversity in the Maltese rural geomorphological landscape and demonstrates how both the land use and history unfold through the opportunities offered by such a natural landscape.
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This paper investigates whether waves are active morphologic agents capable of shaping the small shore platforms that characterize the rocky coast of NW Italy. Two study areas have been selected along this coastal tract: Calafuria (Livorno) and Lerici-Tellaro (La Spezia), located ca. 120 km apart, the first being shaped in sandstone and the second in dolomite bedrock. Propagation of waves in the nearshore has been simulated by numerical modeling. From wave model results, validated with data from an offshore wave meter buoy, it is inferred that waves break directly on the coast or very close to it at Calafuria, whereas for Lerici-Tellaro shores, waves mostly break up to 150 m seaward of the shore platform. This implies that the amount of energy delivered on the platform is much greater in the first case than in the second case. Given breaking depths and the height of breakers, maximum pressure and shear stress released at the breaking point were calculated for both areas. The results showed that wave forces released onto the shore platforms both at Calafuria and at Lerici-Tellaro never exceeded the compressive strength of the platform rocks, assessed using the Schmidt hammer test. It is concluded that, in the study area and with the present oceanographic conditions, wave forces are not directly capable of causing erosion on shore platforms.
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Shore platforms and salinas in the Mediterranean region have a long-standing relationship, rooted in the traditional practice of salt making. On small islands with limited natural resources, the production of salt from seawater, through insolation and intense human endeavour, offered numerous economic benefits. Salt has been a foremost natural resource for millennia with a range of uses from preserving edible foods to cooking, cleaning, laundry, and hygiene, and for medicinal uses in dilute solutions. Within the Maltese Islands, this traditional activity was developed primarily on the soft limestone shore platforms situated along low-lying rocky coasts. Although coastal production has declined in number over the years, a few salinas have persisted in their artisanal practice and are becoming a cultural geo-heritage attraction. The aim of this article is to explore the multiple geographies of this industry on two shore platforms by examining the complicated relationships that have emerged and molded between the physical landscape and human culture. Mapping out these relations through the traditional but complex management systems at two salinas, that is, the salinas at Delimara Point (Malta) and those at Xwejni Bay (Gozo), highlights the delicate nature of these relations as well as the need to support them in order to continually reproduce the cultural micro-landscape. The resultant micro-landscape is becoming an increasingly important living expression of the cultural geo-heritage of the Maltese Islands, which requires careful understanding and management of these relations if it is to be maintained as a vibrant geo-tourist attraction.
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Ras il-Ġebel is a small headland on the south-east coast of the Maltese Islands which faces the open sea. The morphology of the coastline is dominated by a wide shore platform and a high volume of boulders that form a small boulder beach. The evolution of these coastal landforms is controlled by geological structure and may be attributed to high energy waves acting upon regular discontinuities in the bedrock. These take the form of a conjugate set of joints and weak interbedding layers which facilitate erosional processes such as block detachment. These processes are enhanced by the different limestone stratigraphic units that occur within the zone of storm wave impact.
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Ria coastal landforms are important geomorphological features because they provide a highly irregular coastline and, if sited on important channels and waterways, can be transformed from harbours, due to their features, to ports, as a result of human activities. Thus, their landscape is a reflection of two geographies: the natural indentation into the landmass and the human changes made especially to their littoral. This chapter first gives a brief account of the importance of coastal classification within geomorphology; and, secondly, a detailed definition of rias together with an account showing their importance to the Maltese Islands. The highly indented coast gives the Maltese Islands a relatively long coastline with respect to its landmass thus allowing the possibility of intense human interaction along the littoral. The second part of the chapter integrates the geographical features of the Harbours’ ria coastline with the building of the fortifications by the Order of St. John for the defence of the islands. By the end of their rule, which lasted more than two centuries, the Knights finally succeeded in defending the whole shoreline with structural changes along all the promontories of the harbours and the rectilinear parts of the coast.
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This study provides an assessment of erosion hazard on the Maltese coast via application of the Coastal Hazard Wheel, a tool that also facilitated analysis of a number of other inherent coastal hazards including ecosystem disruption, gradual inundation, salt water intrusion, and flooding. The CHW characterises the coastal environment by considering geological layout, wave exposure, tidal range, flora and fauna, sediment balance and storm climate. Application of the CHW identified coastal erosion to present a high to very high influence on the Maltese coastline, with 45.7% of the coast exhibiting a low level of erosion hazard, 12.1% a moderate level, 12.6% a high level and 18.4%, a very high level of erosion hazard. Application of the CHW suggested somewhat higher erosion hazard levels than prior studies using different methodologies; it also confirmed the ease of application of this climate change sensitive coastal hazard identification tool. Management considerations identified a wide range of options the applicability of which is highly dependent on specific coastal configuration and that characterisation of the latter is crucial to allow appropriate management. The study generated management-useful maps describing coastal susceptibility to various hazards and hazard levels. It further provided a description of the entire Maltese coast in terms of ten different coastal configurations that infer management considerations of six coastal characteristics and five hazards. The study outputs are presented as a contribution to more effective management and decision-making by civil protection and planning agencies and as a key first step in the risk analysis process.