Daniel Le Heron

University of Vienna | UniWien · Department of Geodynamics and Sedimentology

The rapid retreat and fragmentation of Alpine glaciers is widely reported as humanity faces dramatic climate change in mountainous regions. This rapid change leads to changes in sedimentary processes, which are exposed in recently deglaciated regions. These Alpine glacier forefields offer a wide spectrum of settings through which the ancient sedime...

Namibia is remarkable in terms of its network of approximately 300-million-year-old fjords, cut by Gondwanan glaciers at high palaeolatitudes during the Late Palaeozoic Ice Age (LPIA). A classic suite of structures is preserved on Proterozoic bedrock, including striations, roches moutonnées and other subglacial features within many of these palaeov...

The investigation area is located in the western mountainous area of Henan Province. It is midsummer in late August, with an average temperature of about 21–33 ℃. During this period, it is mostly sunny with thunderstorms. We recommend wearing thinner clothes and long shirts, and to come equipped with sunscreen and rainwear. The routes are generally...

The modern relief of Southern Africa is characterised by stepped plateaus bordered by escarpments. This morphology is thought to result from stepwise uplift and ensuing continental-scale erosion of the region as it rode over Africa’s mantle ‘superplume’ following the break-up of Gondwana, i.e. since the mid-Mesozoic. We demonstrate in this contribu...

On three occasions, during the Cryogenian, Ordovician and early Carboniferous, the present-day Sahara was glaciated. The first of these glaciations left glacial landforms and deposits in the western part of the desert. Much more widely, expansion of large ice masses towards the present north took place multiple times during the late Ordovician and...

Although the retreat process of glaciers from the Late Glacial Maximum (LGM) is well documented, high-resolution insight into conditions prior to the maximum is lacking in the eastern European Alps, resulting in a gap in our understanding about the processes associated with this important climatic tipping point. We describe an outstanding sand and...

The Ennedi Plateau in Chad, Africa, shows glacial landforms originating from an LPIA ice sheet as an outstandingly well-preserved analogue to Quaternary deglaciated areas. The assemblage of palaeo-glacial structures tells the story of a marine-terminating ice sheet.

The Cryogenian interval (720–635 Ma) is famous for a rich archive of diamictites, many of which were deposited during glaciations. Classic examples are exposed in the Kingston Peak Formation of the Valjean Hills, near Death Valley (United States), with previous work pointing to multiple glacial cycles in other outcrop belts. Within any glacial peri...

Icehouse climate systems occur across an abbreviated portion of Earth history, comprising ∼25% of the Phanerozoic record. The Late Paleozoic Ice Age (LPIA) was the most extreme and longest lasting glaciation of the Phanerozoic and is characterized by periods of acute continental scale glaciation, separated by periods of ice minima or ice-free condi...

The Ediacaran–Cambrian transition (approx. 580–520 million years ago), one of the most critical intervals in Earth's history, witnessed physical environment change and climate fluctuations coupled with extraordinary radiations of metazoan life. Up to now, there are insufficient data to evaluate the true nature of the Ediacaran–Cambrian transition c...

While Ediacaran cap dolostones research is a hot topic, detailed sedimentological analysis of barite-bearing cap dolostones remains scarce. Here, new data are presented from Xiangerwan in northern Three Gorges, South China, to illustrate the sedimentary characteristics, depositional environment and formation mechanism of the barite-bearing cap dolo...

The Makganyene Formation is a Siderian (2.45–2.22 Ga) diamictite-dominated succession, with both outcrop and subcrop in the Griqualand West Basin of the Transvaal Group of South Africa. We provide new outcrop and core descriptions from this succession, supplemented by microscopic analyses, to present an updated depositional model for a classic Pala...

The Pasterze is Austria’s largest glacier, and it is experiencing rapid downwasting and retreat. A mosaic of complex sedimentary deposits has been produced in recent years which have not hitherto been studied, yet provide excellent lessons into the facies distribution expected from a dying valley glacier. In this paper, a new glaciological‐geomorph...

The deep time (pre-Quaternary) glacial record is an important means to understand the growth, development, and recession of the global cryosphere on very long timescales (10⁶–10⁸ Myr). Sedimentological description and interpretation of outcrops has traditionally played an important role. Whilst such data remain vital, new insights are now possible...

The sedimentary record of the Pahrump Group in Death Valley comprises well‐exposed successions of mixed carbonate and siliciclastic deposits. Despite the abundance of studies focussing on the depositional dynamics of mixed carbonate – siliciclastic deposition in the Phanerozoic, the record of similar Proterozoic examples is comparatively sparse. Us...

Ediacaran cap dolomites are strong evidence for the glaciation during the Neoproterozoic. Stratigraphic-sedimentological studies combined with δ¹³C and δ¹⁸O isotope analyses are used for defining the processes of post-glacier environmental changes and sea-level rise caused by glacier melting and the reconstruction of the depositional environments f...

Northwestern Namibia is not your typical desert landscape. Valleys dissect plateaus, creating striking vistas across the hot, dry region in southwest Africa. While these valleys are extremely old—with origins dating back hundreds of millions of years—they are remarkably well preserved.

The Gepatsch Glacier in Tirol (Austria) is a rapidly retreating valley glacier whose host valley and forefield reveal subglacial, proglacial, and reworked sediment-landform assemblages. Structures include roches moutonées develop on gneiss, compound bedrock-sediment bedforms (crag and tail structures), flutes, and small diamicton ridges. The glacia...

The expansion of ice masses across southern Africa during the Late Palaeozoic Ice Age has been known for 150 years, including the distribution of upland areas in controlling the configuration of glaciation. In Namibia, increasing attention has focussed on long and deep palaeovalley networks in the Kaokoland region in the north, but comparatively li...

Determining the extent and nature of ancient glacial deposits is fundamental to understanding Earth’s climate in the Cryogenian Period. Although the detailed study of sedimentary facies has allowed significant insights, it typically fails to produce high confidence interpretations for the past position of grounded ice, its thermal regime and flow d...

Fjords are glacially carved estuaries that profoundly influence ice-sheet stability by draining and ablating ice. Although abundant on modern high-latitude continental shelves, fjord-network morphologies have never been identified in Earth’s pre-Cenozoic glacial epochs, hindering our ability to constrain ancient ice-sheet dynamics. We show that U-s...

The response of sediment routing to climatic changes across icehouse-to-greenhouse turnovers is not well documented in Earth’s pre-Cenozoic sedimentary record. Southwest Gondwana hosts one of the thickest and most laterally extensive records of Earth’s penultimate icehouse, the late Paleozoic ice age. We present the first high-resolution U-Pb zirco...

Increasing sedimentary records and non-glacial facies reported from various regional glaciations suggest diverse interpretation against the ‘hard’ snowball Earth. At Shennongjia, in northern Yangtze Craton, glaciogenic strata of the Nantuo Formation (~649-635 Ma) are widely outcropped, which represents the Marinoan glacial record. In this study, se...

This poster belongs to the abstract with the same name and was presented at the online EGU General Assembly 2020

Upper-flow-regime bedforms, including upper-stage-plane beds, antidunes, chutes-and-pools and cyclic steps, are ubiquitous in glacigenic depositional environments characterized by abundant meltwater discharge and sediment supply. In this study, the depositional record of Froude near-critical and supercritical flows in glacigenic settings is reviewe...

Dropstones of ice-rafted origin are typically cited as key cold-climate evidence in Cryogenian strata and, according to conventional wisdom, should not occur in postglacial, warm-water carbonates. In Namibia, the Chuos Formation (early Cryogenian) contains abundant dropstone-bearing intervals and striated clasts. It is capped by the Rasthof Formati...

The expansion of ice sheets over soft, sandy substrates was widespread in the Early Palaeozoic, during the Late Ordovician glaciation of North Africa and Arabia. Similarly, large parts of southern Africa were glaciated by soft bedded ice sheets in the Late Palaeozoic Ice Age. An unanswered question is the extent to which subglacial deformation invo...

One of the major issues in Neoproterozoic geology is the extent to which glaciations in the Cryogenian and Ediacaran periods were global in extent and synchronous or regional in extent and diachronous. A similarly outstanding concern is determining whether deposits are truly glacial, as opposed to gravitationally initiated mass flow deposits in the...

Upper‐flow‐regime bedforms, including upper‐stage‐plane beds, antidunes, chutes‐and‐pools and cyclic steps, are ubiquitous in glacigenic depositional environments characterized by abundant meltwater discharge and sediment supply. In this study, the depositional record of Froude near‐critical and supercritical flows in glacigenic settings is reviewe...

The “Great Unconformity” across the Proterozoic-Phanerozoic boundary has long been recognised as a critical moment for the Cambrian Explosion and changes in sediment preservation. However in many parts of the Earth no rock strata are preserved for hundreds of millions of years leading up to the Cambrian Period. This study reports detrital zircon ag...

Field observations in conjunction with aerial images from an unmanned aerial vehicle were used to create the first map of a glacial unconformity underlying the late Carboniferous Dwyka Group of South Africa. Crosscutting relationships reveal that the glacial unconformity at Oorlogskloof, in which flutes, grooves, and striae were ploughed into uncon...

Depositional evidence for glaciation (dropstones, diamictites) is common in Neoproterozoic strata, and often debated, but erosional evidence (e.g., unconformities cut directly by ice) is rare. Only two such unconformities are known to have been well preserved globally from the Ediacaran Period (in western Australia and central China). This paper pr...

Ubiquitous glaciation was the hallmark of the Cryogenian Period (ca. 720 – 635 Ma), therefore understanding the character, behaviour, extent and configuration of Cryogenian ice bodies is a fundamental requirement in reconstructing climates and environments from the period. Unfortunately, despite abundant evidence for glaciation, there is a strong p...

The Death Valley region has previously been claimed to preserve the sedimentary records of both the Sturtian and Marinoan snowball Earth events within the Kingston Peak Formation, which outcrops in a number of disconnected mountain ranges. In this context, new sedimentary logs are presented together with detailed clast textural analyses which allow...

The Kingston Peak Formation of Death Valley, California, provides an exceptional archive of Cryogenian glaciation and concomitant rifting of Rodinia. In the Saratoga Hills, an 800 m thick succession of diamictite-dominated strata is exposed, allowing lithofacies and clast compositions to be studied in detail, and for the relative influence of glaci...

Major glaciations or ‘ice ages’ are known to have affected the Earth's surface over the past three billion years. The best preserved records of these glaciations are often found in high-latitude continental margin settings where sediment has been delivered to, and then accumulated at, the edge of the ice sheet in thick glacier-influenced marine seq...

The Luoquan Formation provides a record of the Ediacaran‐Cambrian glaciation in the North China Craton. The sedimentary record is well expressed in the Henan Province along the central China orogen, and includes a rich archive of striated pavements, diamictites, and dropstone‐bearing laminites. A reappraisal of the sedimentological evolution of the...

The Death Valley area of California, USA, exposes an outstanding record of a Neoproterozoic (Cryogenian) glaciated margin: the Kingston Peak Formation. Despite the quality of exposure, however, the outcrops of glaciogenic strata are fragmentary, forming isolated, laterally offset outcrop belts at the western extremity of the Basin and Range provinc...

Late Ordovician glacial deposits are of great importance in North Africa and the Middle East as a result of their significance as reservoirs for hydrocarbons and groundwater. The sedimentary record of this glaciations inNWSaudi Arabia (the Sarah Formation) is generally preserved in meridionally oriented palaeovalleys cut beneath northward-flowing i...

Micromorphology is a well-established technique adopted by Quaternary scientists which has received wide application in the study of glacial sediments and in soil science. One area where the approach is far less developed is in the analysis of ancient successions and, in particular, rocks of Cryogenian age that are purported to have been deposited...

Unravelling the origins of Cryogenian diamictites is vital in determining their significance in a snowball Earth context and their relationship to environmental processes. Here, we present new sedimentological and geochemical data for the Cryogenian sedimentary rocks from the Tarim Craton, NW China. The diamictite member of the East Qiaoenbrak Form...

Olistolith production and magmatism are processes commonly associated with extensional tectonic settings, such as rift basins. We present a cautionary exemplar from one such Precambrian basin, in which we reinterpret metabasite bodies, previously documented as sills, to be olistoliths. We nevertheless demonstrate that, on the basis of field observa...

The Port Askaig Formation (PAF) is a diamictite-bearing succession in the Dalradian Supergroup of Scotland that provides an excellent archive of a Cryogenian glaciation in the Garvellach Islands and Islay, Argyll. The formation is ?1100 m thick, comprises 5 members and includes 47 diamictite beds, interbedded with siltstones, dolostones and sandsto...

In northern Chad, an outcrop belt of Paleozoic rocks occurs in the Ennedi-Bourkou range. There, satellite image interpretation reveals a series of clearly expressed paleo-ice stream pathways, which are encased in sandstone plateaux. At least five paleo-ice stream pathways are recognized, measuring 5-12 km wide. Each contains well-expressed belts of...

The Kingston Peak Formation of the Death Valley area, California, allows valuable insight into both regional Cordilleran stratigraphy and the number of glacial cycles preserved in the Cryogenian record. In the Kingston Range, the eponymous strata have been previously interpreted to record both Sturtian and Marinoan pan-glacial events. In the contex...

Multiple intercalations of glacially derived and slope-derived diamictites testify to the drawbacks of correlating Neoproterozoic diamictites more widely, but shed new light on the close interrelationship of these processes in the Cryogenian world. In the Neoproterozoic of Death Valley, California (USA), rifting of Rodinia occurred concomitantly wi...

Across the Saharan platform, mudrocks of latest Ordovician–Silurian age (the Tanezzuft Formation) are a major source rock interval for Palaeozoic petroleum systems, but source rock quality is variable and difficult to predict. In the Kufra Basin of southern Libya, evidence for organic enrichment in this formation is scarce. This paper presents the...

A glaciated margin is a continental margin that has been occupied by a large ice mass, such that glacial processes and slope processes conspire to produce a thick sedimentary record. Ice masses take an active role in sculpting, redistributing and reorganising the sediment that they erode on the continental shelf, and act as a supply route to large...

Composite hematite–silica structures recovered from a siltstone bed in the Elatina Formation of South Australia include (1) sub-circular to whorl-shaped forms, (2) elongate to half-moon-shaped forms and (3) and lozenge-shaped forms locally linked into chains. They range from 200 to 500 µm in diameter and are interpreted as eukaryote tests. Evidence...

Sedimentological insights underpin many of the important recent advances in understanding of Earth system behaviour in the Neoproterozoic Era. This article reviews three main areas: (i) chemical proxies and their preservation, with emphasis on carbonate facies; (ii) glacial and post-glacial facies, including their age constraints; III) sedimentary...

The Vorogovka Basin records the establishment and infilling of a rift-related basin during Cryogenian time. Its infill records the whole spectrum of continental clastic and carbonate shelfal to deep marine systems. Initiation of the Vorogovka trough as a sedimentary basin was accompanied by subsidence, and the accumulation of diamictites and conglo...

The Kingston Peak Formation is a Cryogenian sedimentary succession that crops out in the Death Valley area, California. It is widely accepted to record pre-glacial conditions (KP1), followed by two glaciations of pan-global extent, the older Sturtian (KP2 to KP3) and younger Marinoan glaciation (KP4). In the type area (the Kingston Range), detailed...

Outstanding exposures of Ediacaran-aged thrombolite-stromatolite bioherms and biostromes crop out in the Nama Basin, SW Namibia. Fieldwork, dovetailed with remote sensing and a terrestrial laser scanning (LiDAR) survey, allow the fracture network of this succession to be characterized, and the relative age of fracture sets and families to be determ...

The Rasthof Formation is a mid-Cryogenian cap carbonate succession deposited in Namibia following the Sturtian glaciation. It includes a microbial member, typically.100 m thick. This member exhibits contorted intervals, and is divisible into two informally defined units. The lower unit (microbial member 1: MM1) comprises thickly laminated microbial...

Extract Microbial carbonates (microbialites) are remarkable sedimentary deposits for four good reasons: they have the longest geological range of any type of biogenic limestones; they form in the greatest range of different sedimentary environments; they oxygenated the Earth's atmosphere; and they produce and store large volumes of hydrocarbons. Ho...

Globally, Sturtian (early Cryogenian) glacial deposits are well expressed, and belong to the oldest Neoproterozoic icehouse Earth event. The evidence for glaciation typically includes phenomena such as striated pavements, striated clasts in diamictites, and abundant dropstones. More problematic, and potentially more significant, are intercalated de...

The Kingston Peak Formation is an archetypal Cryogenian succession that crops out across the Death Valley region of eastern California. Above pre-glacial strata (KP1), two distinct glacial phases have been recognized and are interpreted to be allied to the panglacial Sturtian (KP2 and KP3) and Marinoan (KP4) icehouse events. The thickest and most e...

This paper presents new stratigraphic and sedimentological data of the Ordovician, Silurian, and Mesozoic succession exposed on the western flank of Al Kufrah Basin. Field data (logged sections, photographs, palaeocurrent analyses) are presented from the Jabal Eghei region. This region lies approximately 200 km E of the closest stratigraphic tie po...

The Kingston Peak Formation is a diamictite-bearing succession that crops out in the Death Valley region, California, USA. An exceptionally thick (>1.5 km) outcrop belt in its type area (the Kingston Range) provides clear insights into the dynamics of mid-Cryogenian ('Sturtian') ice sheets in Laurentia. Seven detailed logs allow the lateral and ver...

The Cryogenian record of South Australia includes the type region of the Sturtian glaciation, the oldest of three pan-global icehouse intervals during the Neoproterozoic. Data are presented from previously little described sections at Holowilena Creek, Oladdie Creek and Hillpara Creek in the central and southern Flinders Ranges, where five facies...

The Bolla Bollana Formation is an exceptionally thick (ca 1500 m), rift-related sedimentary succession cropping out in the northern Flinders Ranges, South Australia, which was deposited during the Sturtian (mid Cryogenian) glaciation. Lithofacies analysis reveals three distinct facies associations which chart changing depositional styles on an ice-...

The Chuos Formation is a diamictite-dominated succession of Cryogenian age, variously interpreted as the product of glaciomarine deposition, glacially related mass movement, or rift-related sediment remobilisation in a non-glacial environment. These interpretations have wide ranging implications for the extent of ice cover during the supposedly pan...