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Karst caverns in the Upper Triassic dolostones of the Rusinovdel Formation are filled with allochthonous clastics (brecciaconglomerates with maximum boulder size) and locally with speleothems (flowstones). Deposition of the former (diamicton facies) by debris flows resulted from extreme flood events along the upper reaches of Struma river. The polymict material reflects erosion of various rock types in the source area but is dominated by resedimented Lower Triassic red beds. The diamictons are more or less similar to the few known examples from Quaternary karst caves.

The study presents three sedimentary profiles from Tarimba cave in central Brazil. The data allow constraining the late Quaternary sedimentary evolution of cave systems in the region. A multi-techniques approach was used to characterize sediment texture (grain size and circularity index), mineralogical composition (X-Ray Diffraction), chemical composition (ICP-OES) and deposition ages (Optically Stimulated Luminescence and radiocarbon). Eight sedimentary facies were identified, including a facies formed by autochthonous sediments (Guano) and seven facies formed by allochthonous siliciclastic sediments. The siliciclastic facies range from clayey to gravelly deposits that correspond to high-density gravity flows (Diamicton) and water laid traction process of varied deposition energy (Channel, Backswamp, and Slackwater). The studied deposits reflect an intense cave filing from the Middle to Late Pleistocene in the last 200 Ka. Subsequent depositional events formed three sedimentation phases: the first before 200 Ka corresponding to a larger granulometric interval, clay to gravel, identified through erosive surfaces; the second, after 197 Ka, is composed of sandy sediments and oscillations in the water flow energy. The third phase between 87 and 52 Ka (which covered the other stages) was responsible for the last fluvial deposition.

We reconstruct patterns of subglacial processes on a hard bedrock and a soft bed under the southern sector of Scandinavian Ice Sheet (SIS) occurring in the basal till of the Late Saalian Glaciation at the Wapienno, Barcin and Młodocin sites (north-central Poland). Based on detailed sedimentological studies, two phases of SIS transgression were recognised. In the initial phase of the transgression, the SIS advanced onto a frozen substrate (continuous permafrost). The low permeability of the substratum led to a high subglacial water pressure (SWP) and increased basal sliding. The local increase of SWP led to the development of different types of structures and sediments. On a hard bedrock, with low SWP, abrasion predominated and linear structures were developing, while in the case of high SWP, the ice was decoupled from the hard substrate, pressurised liquefied sediment flowed, and structures of the p-form and s-form type developed. On a soft bed, the ice-bed contact was of a mosaic type and the ice movement had an ice-stream character. The ice-stream developed towards the east in the marginal zone of the SIS and used a W-E oriented valley filled by the Wapienno Formation fluvial complex. During a later phase, the ice movement was slower and did not have a stream character. Its direction changed to SE. The deposition of the main part of the diamicton occurred mainly as a result of the lodgement process.

This article continues the discussion on quaternary geology and paleogeography of the vast and well-studied shelf of the Barents Sea. The object this research is the relief and quaternary formations of the Barents shelf. The data of seismic-acoustic profiling and materials of engineering-geological drilling were used. Since the Barents shelf is a high-latitude area of Holocene sedimentation, the author analyzes various aspects of the quaternary sediments genesis, taking into account the geographic zoning of marine sedimentation processes and an increase in the gravitational consolidation of sediments down through the section. The genetic link between the microstructure and the degree of consolidation of clayey sediments with their seismic image was revealed, which was considered in interpretation of seismic profiling materials. Over the Barents shelf, the cover of weakly consolidated sediments of the last marine transgression is separated from the underlying morainelike or pre-quaternary sediments by a diachronous boundary of stratigraphic and sometimes angular unconformity. The transgression is not of glacioeustatic, but of tectonic nature. During the hiatus that preceded it, an erosional relief with river valleys and their tributaries was formed, the main features of which have been preserved in the northern deep-water part of the sea. The conclusion is argued that approbation of the glacial theory on the example of high-latitude Arctic shelf contradicts the facts and main provisions of glaciology, reflecting the overall crisis of this theory.

In the region of the Serteyka River, an extensive accumulative fan was studied. The main goal of the research is an attempt to reconstruct the palaeogeographic development of erosive cuts in Western Russia. The geological structure of the fan and its surroundings was recognized. The fan is built by deluvium sediments, which can be divided into: lower diluvium unit, middle diluvium unit and upper diluvium unit. The top of the fan is built by tillage diamicton. The fan was formed at the earliest from the 2nd half of the 17th century (during the Little Ice Age pessimum). Samples were taken for AMS, OSL, Pb210 dating to determine the phases of fans development. The AMS dating produced mixed results. This was due to the redeposition of the material. Using the OSL method, two samples were dated from the bottom of the clastic fan deposits. Dates from the Neolithic period were obtained, additionally in inversion. It was caused by inaccurate bleaching of the quartz grains. The top part of the fan was dated using the Pb210 method. Slope sediments can be extremely difficult to dating. This may be due to the redeposition of the material, the presence of hiatuses and inaccurate bleaching of samples. The individual units of deluvium sediments differ in colour, structural and textural features.

The geomorphology and stratigraphy of the South Fork Hoh River (SF Hoh), Olympic Mountains, Washington, allow for greater understanding of Marine Oxygen Isotope Stage 2 (MIS 2) ice fluctuations, glacial dynamics, and sedimentation. Age control from optically stimulated luminescence and radiocarbon dating constrains deposited sediments associated with four Late Pleistocene ice-marginal positions that formed under reduced ice volume conditions compared with MIS 3–5 glaciers in the same drainage. The earliest MIS 2 ice margin extended into the main Hoh River valley (pre–SF 1, 28 ka to >23.0 ka). After retreat, the ice occupied three closely spaced ice-marginal positions (SF 1–3) that range in age from 22.0 ka to shortly after 18.7 ka. While the SF 1 and SF 3 positions were previously identified as the Twin Creeks I and II positions, the intermediate SF 2 position had not been recognized. Moraines are composed of poorly sorted, but stratified, sediment and few tills. Diamicton units show evidence of water reworking. This research documents a detailed record of MIS 2 glaciation in a maritime setting in western North America and provides evidence of rapid MIS 2 ice-marginal fluctuations that likely reflect responses to millennial-scale climatic fluctuations and may be relevant to understanding other complex MIS 2 moraine sequences.

The results from the analysis of a relatively deep stratigraphic sequence from a formerly glaciated plateau in the Upper Badia valley (Dolomites, Italy) are discussed, and the first insight on Late Pleistocene sedimentary records and geomorphological evolution of the area are provided. The investigated sequence comprises: i) cohesive sediments interpreted as colluvial-eluvial in origin or as stagnant water deposits; ii) sandy diamicton and dolostone monolithic sediments interpreted as gravity-induced deposits, possibly owing to debris flows or wash out/reworking of rock avalanche deposits from the surrounding dolomite ridges; iii) silty diamicton interpreted as lodgement till, possibly attributed to the Last Glacial Maximum (LGM). Radiocarbon dating results and interpretation of stratigraphic data, supported by geomorphological field surveys, remote sensing data analyses and palaeo-climatic and palaeo-environmental data from literature, enabled us to conclude that the investigated plateau (Pralongia, ca. 2000 m a.s.l.) was likely ice-free for most of Marine Isotope Stage 3. In particular, between 38 ka BP and the inset of full-glacial conditions (LGM ~ 27 ka BP) clastic gravity-induced sediments were deposited within the study site. Supraglacial transport is supposed to have played a role in the emplacement of gravity-induced deposits from the surrounding dolomite cliffs to the plateau. This study resulted in the first Pre-LGM record of sedimentation and palaeo-environmental conditions inside the Eastern Dolomites in the 46 to 38 ka BP period.

We present 14 new 10Be cosmogenic nuclide exposure ages quantifying asynchronous readvances during the Antarctic Cold Reversal from glaciers in the Baker Valley region of central Patagonia. We constrain glacier and ice-dammed palaeolake dynamics using a landsystems approach, concentrating on outlet glaciers from the eastern Northern Patagonian Icefield (NPI) and Monte San Lorenzo (MSL). Soler Glacier (NPI) produced lateral moraines above Lago Bertrand from 15.1 ± 0.7 to 14.0 ± 0.6 ka, when it dammed the drainage of Lago General Carrera/Buenos Aires through Rio Baker at a bedrock pinning point. At this time, Soler Glacier terminated into the 400 m “Deseado” level of the ice-dammed palaeolake. Later, Calluqueo Glacier (MSL) deposited subaerial and subaqueous moraines in the Salto Valley near Cochrane at 13.0 ± 0.6 ka. These moraines were deposited in an ice-dammed palaeolake unified through the Baker Valley (Lago Chalenko; 350 m asl). The Salto Valley glaciolacustrine landsystem includes subaqueous morainal banks, ice-scoured bedrock, glacial diamicton plastered onto valley sides, perched delta terraces, kame terraces, ice-contact fans, palaeoshorelines and subaerial push and lateral moraines. Boulders from the subaqueous Salto Moraine became exposed at 12.1 ± 0.6 years, indicating palaeolake drainage. These data show an asynchronous advance of outlet glaciers from the Northern Patagonian Icefield and Monte San Lorenzo during the Antarctic Cold Reversal. These advances occurred during a period of regional climatic cooling, but differential moraine extent and timing of advance was controlled by topography and calving processes.

Twelve piston cores were used to characterize late Quaternary lithofacies, depositional processes and deglacial history along the Baffin Bay slope between Lancaster Sound and Home Bay. Core investigations show four distinct laterally correlatable lithofacies along the slope – basal and upper diamicton, laminated red brown mud, tan carbonate gravelly, sandy mud and bioturbated brown mud. Basal diamicton largely represents glacigenic debris flow deposits during a glacial advance from Baffin Island at ~25 cal ka. The distribution and character of laminated red brown mud suggests a lateral supply to Baffin Bay slope from ice-proximal meltwater plumes and turbidity currents sourced in glacial ice from both Baffin Bay shelf and Home Bay between 41.5 cal ka to ~14.2 cal ka. An upper diamicton records a lesser, localized glacial advance that ended at about 14.2 cal ka. Tan carbonate mud events represent ice-rafted, enhanced detrital carbonate delivery to the slope between ~25 cal ka and ~11 cal ka. A gradual thinning of these events, from northern to southern Baffin Bay, corroborates a northern Baffin Bay, Lancaster Sound or Nares Strait iceberg source. Proglacial facies seaward of Home Bay contain beds with slightly elevated detrital carbonate that may represent the distal edge of carbonate ice-rafted from Lancaster Sound. Baffin Bay is a type example of a polar glacial basin in which direct glacial supply predominates over the effects of glacial meltwater. As a result, axial supply from the large ice streams north of Baffin Bay (particularly Lancaster Sound) is dominant in the Baffin Bay basin and lateral supply from smaller ice streams on Baffin Island predominates on the NE Baffin Slope.

The Quaternary Geology of the eastern South Bend 30- x 60-Minute Quadrangle in Indiana represents landforms and near-surface sediments deposited during the Wisconsin Episode, Late Pleistocene. Sediments and landforms reflect the interplay between the Saginaw and Michigan Lobes of the Laurentide Ice Sheet. A relatively shallow, buried pre-Wisconsin and mid-Wisconsin morphology has been overridden by advances leading to the Last Glacial Maximum (LGM), ca. 24 ka. Between 24 and 17 ka, retreating ice fronts from the Michigan Lobe left a succession of ice-contact sediment ramps and associated pitted and collapsed fan-moraine complexes throughout the south and west of the map area. A sequence of stacked diamicton and sand and gravel fan heads appears at the hinged interlobate area north and northeast of South Bend. Ice margin positions are marked by distinct features like fans, kames and ice-walled lake plains, which are well developed on Michigan Lobe margins. The thicker glaciofluvial sand and gravel packages appear mostly interbedded with diamicton beds along fan heads, with relatively minor deposits in valley train units. Lowlands are mostly occupied by post-LGM (ca. 18 ka) valley-train outwash deposits, with interpreted flow toward the south and west, derived from an ice margin retreating first from south to north, near Mishawaka, then from southeast to northwest across the Kankakee valley. Sand and gravel colluvial and alluvial fans developed in a short span after ice retreated, along with incision of the ice-sculpted morphology. Late-glacial aeolian sand dunes sealed the landscape. Relatively minor modification of the landscape during the Holocene is indicated by alluvial and palustrine deposits.

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 moutonees develop on gneiss, compound bedrock-sediment bedforms (crag and tail structures), flutes, and small diamicton ridges. The glacial sediments and landforms are undergoing incision and terrace development by meltwater streams. Glacial geomorphological and surface geological maps, in concert with elevation models of difference between July 2019 and July 2020 highlight considerable changes to the forefield over a 12-month time period. Till exposed within the last 20 years has undergone substantial mass wasting and re-deposition as subaerial mass flows, or reworked into stream deposits. The lee sides of many roches moutonees completely lack subglacial sediment, and instead contain a sand and gravel deposit interpreted to result from glaciofluvial deposition. Thus, insights into the rates of erosion and deposition in a complex, proglacial setting, allow some of these processes to be quantified for the first time. Repeated monitoring of glacier forefields is expected to yield a better understanding of the preservation potential of proglacial sedimentary facies, and hence their preservation potential in Earth9s sedimentary record. Supplementary material: A comparison of 3D model parameters for 2019 and 2020 data is available at https://doi.org/10.6084/m9.figshare.c.5664299

Ancient remains have been discovered in Rennaz-Noville, in southwestern Switzerland, where the Rhône Valley opens onto Lake Geneva. The stratigraphic sections documented during the construction of a canal revealed that the sedimentary sequence consists of a deformed and compartmentalized diamicton based, according to a thrust plane, on limnic deposits. Paleosols containing artifacts included in the transported mass have been deformed to varying degrees. About one hundred archaeological structures have been discovered in one of these with, in addition, masonry in a secondary position. The collected artifacts and 14C dates converge towards an occupation between the 1st and the end of the IVth century AD. Ground movements also affect a Late Iron Age occupation, largely obliterated by the gallo-roman settlement. These facts are compatible with a thrusting triggered in the middle of the VIth century, relating to the so-called Tauredunum event in 563 AD. In addition to unpublished chronological elements, the discoveries at Rennaz-Noville thus provide new evidence on the effects of the disaster on the terrestrial environment., Des vestiges antiques ont été découverts à Rennaz-Noville, dans le sud-ouest de la Suisse, au débouché de la vallée du Rhône dans le lac Léman. Les coupes dégagées lors de la construction d’un canal ont révélé que le sommet de l’accumulation sédimentaire se compose d’un diamicton déformé et compartimenté reposant, selon une surface de cisaillement, sur des dépôts limniques. Inclus à la masse transportée, des paléosols renfermant des artefacts ont subi une déformation d’amplitude variable. Une centaine de structures archéologiques ont été mises au jour dans l’un d’entre eux, auxquelles s’ajoutent des maçonneries en position secondaire. Le mobilier collecté et les datations 14C convergent vers une occupation comprise entre le Ier et la fin du IVe siècle ap. J.-C. Une occupation du Second âge du Fer, oblitérée par l’occupation antique, est également concernée par les mouvements de terrain. Tous les éléments de datation obtenus sont compatibles avec un glissement déclenché vers le milieu du VIe siècle par l’écroulement dit du Tauredunum, en 563 ap. J.-C. Outre des éléments de chronologie inédits, les découvertes à Rennaz-Noville fournissent ainsi une nouvelle argumentation sur les effets de cette catastrophe en milieu terrestre.

The glaciers act as an important proxy of climate changes; however, little is known about the glacial activities in Ny-Alesund during the Little Ice Age (LIA). In the present study, we studied a 118-cm-high palaeo-notch sediment profile YN in Ny-Alesund which is divided into three units: upper unit (0–10 cm), middle unit (10–70 cm) and lower unit (70–118 cm). The middle unit contains many gravels and lacks regular lamination, and most of the gravels have striations and extrusion pits on the surface. The middle unit has the grain size characteristics and origin of organic matter distinct from other units, and it is likely the glacial till. The LIA in Svalbard took place between 1500 and 1900 AD, the middle unit is deposited between 2219 yr BP and AD 1900, and thus the middle unit is most likely caused by glacier advance during the LIA. Glaciers during the LIA likely overran the sampling site, removed part of the pre-existing sediments, and contributed to the formation of diamicton in the middle unit. This study provides evidence for glacial deposits during the LIA in Ny-Alesund and improves our understanding about historical glacier dynamics and ice-sheet margins during the LIA in western Spitsbergen.

Proglacial Lake Humber formed in the Vale of York and Ancholme Valley during the Late Devensian (Weichselian) glaciation, but its lake levels and their precise ages are uncertain. Three-dimensional geological modelling, based on 193 borehole sediment logs from the eastern part of the Vale of York, indicates that glaciolacustrine sediments extend no higher than 10 m O.D. By contrast, recent palaeoenvironmental reconstructions for the region that suggest Lake Humber had eight recessional shorelines, extending from 42 m to 5 m O.D. Above 10 m O.D., the sediments become more discontinuous, and comprise clay with occasional chalk and flint gravel, and matrix-rich diamicton interdigitated with sands and gravels. Sedimentary and geochemical analyses of sands and gravels from one of the putative shorelines, at 25 m O.D., indicate an easterly provenance for these sediments. They are interpreted here as colluvial deposits, sourced largely by periglacial weathering of Jurassic and chalk bedrock. Collectively, the geological evidence suggests that the highest level of Lake Humber during the Late Devensian did not exceed 10 m O.D., and therefore reconstructions invoking higher lake levels are thought to be unlikely.

Detailed studies of coastal cliff exposures through two end moraines form the basis for a model of ice-marginal sedimentation in large ice-contact glacier-fed lakes. The input to the ice-marginal environment directly from the glacier included subglacial till and subaquatic flow tills. The subaquatic flow till (thinly bedded diamicton) was deposited in an apron (up to 1 km wide) along the ice margin. An upward gradient of pore-water pressure immediately beyond the ice margin, causing heaving and dilation of the sediments, initiated debris flows of glacially derived debris (subaquatic flow tills). Most of the stratified sediments in the ice-marginal zone entered the lake by way of a large proglacial stream. Sedimentation was dominated by quasi- or near-continuous density underflows that resulted in the deposition of a sequence of thick rhythmites. The glacier in the Lake Erie basin most likely behaved like an ice stream, with its movement controlled predominantly by a deforming bed of glacial debris, separating the glacier sole from underlying predeposited sediments. The deforming bed is preserved as a massive diamicton layer, interpreted here as subglacially deposited till.

Litho- and chronostratigraphy of the Early Weichselian time period, or Marine Isotope Stages (MIS) 5e-5a, is insufficiently established in Northern Fennoscandia and still more ambiguous is the regional-scale distribution of the corresponding end moraines. We applied Light Detection And Ranging Digital Elevation Models (LiDAR DEMs), electromagnetic (EM) sedimentary anisotropy (orientation) and ground penetrating radar (GPR) to reveal till-covered landforms diagnostic to the Early Weichselian phase(s) in Finnish Lapland. Morphometric and geophysical data revealed that sands and gravels of the Porttipahta end moraine were deposited from the north-northwest and are overlain by one diamicton (till) unit deposited from the southwest and most likely being correlative to the Late Weichselian (MIS 2). Sub-till OSL-ages yielded 91 ± 19, 96 ± 14, 100 ± 16 and 120 ± 26 ka, thus correlative with the MIS 5c interstadial (Brorup). The Porttipahta end moraine deposited during the deglaciation of the Early Weichselian 5d stadial (Herning). The NW-SE oriented till-covered eskers and rock drumlins in the area suggest Late Saalian (MIS 6) phase. Southwest of the Porttipahta area the end moraine complex is deformed by earthquake(s) attributable to glacial isostatic adjustment (GIA) probably during the MIS 5d phase. The morphological appearance is similar to Veiki moraine in Norrbotten, Sweden, and high-resolution LiDAR DEMs emphasize that both landforms exhibit a minute erosion by the later stadials. It remains unresolved, if the Porttipahta end moraine represents the maximum extent of the MIS 5d or if it represents a recessional stage.

Stratigraphy, geomorphology, and luminescence dating of ice-proximal sediments document extensive MIS 3 Rakaia valley glaciation. Basal outwash contains ice-meltout depressions filled with upward-coarsening and progressively deformed outwash, overlain by undeformed ice-proximal diamicton and outwash. The most reliable luminescence date from basal outwash is 35.2 ± 0.7 ka, consistent with site stratigraphic evolution and overlying exposure ages. The site thus indicates MIS 3 ice of similar extent as the main MIS 3/2 advance and demonstrates that ice retreated at least a short distance up-valley between the two advances. The results correlate with similar ages on ice-proximal lake sediments 10 km up-valley, on distal outwash 65 km down-valley, and with cosmogenic radionuclide dates elsewhere in the Southern Alps. This study thus confirms independently that MIS 3 glaciation was nearly as extensive as the main LGM advances in central South Island, New Zealand.

The name “Steepbank Formation” is proposed for a paleokarst diamictite deposit that is present along the margins of the Middle Devonian Prairie Evaporite Formation in the Western Canada and Williston sedimentary basins, including the eastern portion of the Athabasca Oil Sands region. This poorly lithified diamictite forms a mappable unit that is distinct in both age and lithology from all contiguous formations. The Steepbank consists of clasts of dolostone, limestone, and siltstone up to the size of boulders with a matrix of silty to sandy calcareous mudstone. The material shows little or no evidence of bedding or sorting. Most clasts are angular and their orientation is commonly random. The diamictite formed in response to the dissolution of thick (up to 300 m) sequences of halite, anhydrite, and gypsum in the Prairie Evaporite Formation and the subsequent failure and collapse of interbedded and overlying insoluble strata. The top contact occurs where the intact strata of an overlying formation can be identified and is commonly gradational. The basal contact with the underlying Keg River Formation is sharp. Both contacts are unconformable. Evaporite dissolution and diamicton deposition likely began in late Middle Devonian time, moving down dip toward the west, and are continuing today near the Athabasca River.

Over the past 200 years significant research effort has gone into explaining the origin of the obvious former shorelines in Glen Roy (the so-called “Parallel Roads”). The large gravel deposit at the mouth of Glen Turret has attracted similar interest, but a solution to its origin and age remains contested: the same applies to the associated gravel fans in upper Glen Roy. This paper presents the results of systematic mapping and instrumental levelling of these features and new evidence from two previously unrecorded gravel fans in the nearby Allt Chonnal valley. Interpretation of altitudinal and lithofacies data indicates that all the fans (including the one at the mouth of Glen Turret) were deposited in a series of ice-dammed lakes during the Loch Lomond Stadial (Younger Dryas). The largest gravel fans were deposited in the shallow lake heads of the 260 m, 325 m and 350 m lakes in upper Glen Roy, infilling these areas to the extent that deposition was in part subaerial. The absence of foreset bedding from the deposits is explained by the relatively shallow depth of lake waters, which inhibited development of classic Gilbert-type deltas and encouraged Hjulstrom-type fans. The previous assumption that gravel deposition into the 325 m and 350 m lakes was relatively limited is shown to be erroneous. The Allt Chonnal gravel fans, deposited into these lakes, have an estimated combined volume of 6,000,000 m 3 deposited in about 200 years. Significant gravel deposition into these former lakes continued at least until glaciers started to retreat in Glen Roy. When glacier retreat began, gravel deposition was reduced by over 85%. This research also concludes that the glacier which deposited the Turret fan emanated from Glen Gloy, supplied not only by ice from the south but also from ice that spilled into Glen Gloy from the adjacent Great Glen. The Loch Lomond Stadial (LLS) ice cap mapped in the Monadhliath Mountains was connected to the west Highland ice cap, which at the time filled the Great Glen. Regional equilibrium line altitude (ELA) estimates, based solely on the Monadhliath LLS ice cap evidence, may therefore be altitudinally too high.

Diamicton deposits (up to 6.90 m thick) in the Vale of Pickering and the Tabular Hills (North York Moors) have been confirmed by cored boreholes. The diamicton is interpreted as glacial till with a matrix consisting predominantly of grey-brown, yellow-brown and dark grey, stiff to very stiff clay and sandy clay with occasional thin beds of laminated sand and clay. Sub-rounded to sub-angular erratic clasts were sourced predominantly from local Upper Jurassic Corallian Group bedrock exposed in the southern part of the North York Moors. Clasts include well-rounded, pebbles of Jurassic sandstone, mudstone and sparse Jurassic coal derived from outcrops on the North York Moors. Fragments of underlying Upper Jurassic mudstone bedrock form the predominant clasts in the lower part of the till. The paucity of exotic clasts and a local derivation suggests a relatively small glacier – perhaps a temperate-plateau ice-field, was established on the Tabular Hills. The glacier subsequently advanced southwards to the Vale of Pickering depositing locally derived subglacial traction till at the base, passing up to lodgement till. Local preservation of the degraded till outcrops in the Vale of Pickering, the overconsolidated nature of the clay till matrix, striated pebbles and the presence of sub-rounded pebbles suggests deposition during a glacial cold stage post-MIS 12 (Anglian) and pre-MIS 2 (Devensian). A tentative Middle Pleistocene MIS8 age is proposed, possibly coeval, but not coincident, with the Basement Till (Bridlington Member) of the Holderness coast and the Wragby Till of central and eastern England.

Icebergs are important as agents of deposition and seafloor reworking on glacier-influenced continental margins. When the keel of an iceberg exceeds water depth it ploughs through soft sediments producing scours/ploughmarks that can be kilometres long, hundreds of metres wide and sometimes tens of metres deep. Because the influence of iceberg keels on sediment is a critical factor when offshore structures (e.g. pipelines, power cables) are installed, the surface morphology of iceberg scours on the seafloor is relatively well-documented. Less however, is known about sub-scour deformation below the seafloor. This is particularly true of iceberg scoured diamicton (poorly sorted sediment comprising a variety of particle sizes), which is present in many high-latitude fjords and continental shelves. The aim of this research is to examine directly (macroscopically and microscopically, with thin sections) the style and intensity of deformation caused by the scouring action of iceberg keels in diamicton offshore of East Greenland. Results show that a distinctive suite of deformation structures (individual structures and overprinted structural patterns) dominated by planar shear, sediment mixing and high porewater, and dropstones characterises iceberg scoured diamicton. In addition, diamicton from areas of high-intensity iceberg scouring tends to show a wider variety, higher frequency and distribution, more abundant and better-developed deformation structures than diamicton from areas of intermediate- and low-intensity iceberg scouring. Characterising the effects of iceberg scour in diamicton is important more widely to inform: i) reconstruction of the geometry and dynamics of former ice sheets; and ii) installation and protection of offshore engineering structures in diamicton where iceberg scouring presents a geohazard. The value of micromorphology is significant especially in the absence of macroscopic sediment exposures/outcrops where the study of cores is necessary instead.

Ravine slopes at the recently discovered Nesseltalgraben site in southeastern Germany provide a unique last glacial sediment record for the Northern Calcareous Alps. The 21 m-long profile is dominated by fine-grained lacustrine-palustrine sediments overlain by several metres of glacifiuvial gravels and lodgement tills of the Last Glacial Maximum and underlain by a diamicton. The age model includes 29 radiocarbon analyses and one paleomagnetic anomaly (Laschamp event) together providing a modelled age range from c. 59 to 29.6 ka cal BP, i.e. Marine Isotope Stage (MIS) 3. Apart from a description of the lithofacies, X-ray-fluorescence (XRF) scanning and elemental analyses provide high-resolution records of the geochemical composition. Multivariate analyses of XRF data separate Ca from other major elements. Carbonate contents, represented by Ca and total inorganic carbon, reach maxima in repeatedly occurring calcareous silty to sandy layers and are related to glacigenic origin. These indicate repeated inner-alpine local glaciations during stadials of MIS 3. Scanning electron microscopy and XRF data confirm the detrital origin of these layers. In contrast, organic matter and elements more resistant to chemical weathering (Si, Ti, Zr) accumulated during interstadials and concurrently elevated Rb/Sr ratios indicate intensified weathering. The high-frequency proxy variations determined for Nesseltalgraben reflect interstadialstadial climate variability comparable with oxygen-isotope records from Greenland ice cores and Alpine speleothems. Thus, Nesseltalgraben is among the very few independently dated sediment records from continental Europe covering the entire MIS 3 and reflecting the full Dansgaard-Oeschger climate variability. (C) 2019 Elsevier Ltd. All rights reserved.

Geomorphological studies have been carried out in rapidly evolving salt caves related to small watersheds in the San Pedro de Atacama area, Chile. Radiocarbon ages of bones and wood from cave deposits, combined with the presence of large salt caves, geomorphological and sedimentological observations, and the results of micrometer measurements outside and in some of the caves, suggest a period of speleogenesis in the Cordillera de la Sal during the onset of the Holocene, during which the large halite cave systems developed, followed by an early Holocene hyperarid period. Most smaller caves (i.e. Lechuza del Campanario) most probably formed at the start of the wetter mid-Holocene period (5–4.4 ka), when precipitation was never intense enough to entrain large amounts of sediments, but enough to trigger cave development. A diamicton in Lechuza del Campanario Cave radiocarbon dated at ca. 4.4 ka shows that at least one high intensity rainfall event occurred in this recharge basin during the mid-Holocene wet interval. A wet period with lower intensity rainfall events followed between 4.0 and 2.5 ka, causing the 4.4 kyrs old diamicton in Lechuza del Campanario Cave to be entrenched, and the alluvial fan at the downstream end of Palacio del Sal Cave to be covered with windborne sediments dated by OSL at around 3.6 ka. At ca. 2 ka there was a high-intensity rainfall event documented by the age of a twig stuck in the ceiling of the Palacio del Sal Cave, followed by a period with lower intensity rain events until ca. 1.3 ka, when another intense flood produced a mudflow that deposited a second diamicton in Lechuza del Campanario Cave. From then on clustering of radiocarbon ages for wood and bone recovered from caves indicates increased rainfall intensity in the period ca. 0.9–0.5 ka, followed by no registered events until a minor flood at ca. 0.13 ka. The four-centuries long wetter time interval (0.9–0.5 ka), corresponding to the Medieval Climate Anomaly, has been an archeologically important period in the Atacama Desert (Tiwanaku culture). The observations and a detailed review of paleoclimate literature from this key area have allowed the development of a landscape evolution model related to changing climate conditions during the Late Holocene.

Blomvag, on the western coast of Norway north of Bergen, is a classical site in Norwegian Quaternary science. Foreshore marine sediments, named the Blomvag Beds and now dated to the Bolling-Allerod from 14.8 to 13.3 cal. ka BP, contain the richest Lateglacial bone fauna in Norway, numerous mollusc shells, driftwood, and flint that some archaeologists consider as the oldest traces of humans in Norway. The main theme of this paper is that the Blomvag Beds are overlain by a compact diamicton, named the Ulvoy Diamicton, which was interpreted previously as a basal till deposited during a glacial re-advance into the ocean during the Older Dryas (c. 14 cal. ka BP). Sediment sections of the Blomvag Beds and the Ulvoy Diamicton were exposed in ditches in a cemetery that was constructed in 1941–42 and have subsequently not been accessible. A number of radiocarbon and cosmogenic 10Be exposure ages demonstrate that the diamicton is not likely to be a till because minimum deglaciation ages (14.8–14.5 cal. ka BP) from the vicinity pre-date the Ulvoy Diamicton. We now consider that sea ice and icebergs formed the Ulvoy Diamicton during the Younger Dryas. The Scandinavian Ice Sheet margin was located on the outermost coastal islands between at least c. 18.5 and 14.8 cal. ka BP; however, no ice-marginal deposits have been found offshore from this long period. The Older Dryas ice margin in this area was located slightly inside the Younger Dryas margin, whereas farther south it was located slightly beyond the Younger Dryas margin.

The Kapp Ekholm site, in central Spitsbergen, shows alternating units of glaciomarine sandy silt and diamicton representing three glacial cycles and is key in reconstructing the Late Pleistocene glacial history of Svalbard. Part of the site is reinvestigated here by focusing on re-dating two units (B and F) interpreted as interglacial/interstadial glaciomarine deposits, in order to constrain the controversial chronology. A combination of Optical Stimulated Luminescence (OSL) on quartz, infrared stimulated luminescence with a 50 °C readout temperature (IRSL50) and post infrared-infrared stimulated luminescence (pIR), both on feldspar, was applied. While Formation B was beyond the dateable range of OSL, IRSL50 and pIR ages lead to the conclusion that this unit represents the Last Interglacial, Marine Isotope Stage (MIS) 5e, and the underlying diamicton the MIS 6 glacial. Formation F yielded ages implying that the formation represents the MIS 5a interstadial and the underlying diamicton is interpreted to represent the MIS 5b stadial. This agrees with conclusions drawn concerning the Pleistocene glaciations elsewhere on Svalbard.

Large volcanic debris avalanches are triggered by failure of the steep flanks of long-lived composite cones. Their huge deposits change the landscape and drainage pattern surrounding stratovolcanoes for thousands of years. At Mt. Ruapehu, New Zealand, we identified seven major flank-collapse events that produced debris avalanches travelling down pre-existing river catchments for up to 90 km from source. In two cases the extreme mass flux into the river valleys led to their complete truncation from the volcano, while four drainage systems were subsequently re-established along similar pathways influenced by regional strike-slip faulting, which caused localized graben formation. In all cases the volcanic debris-avalanche deposits currently form distinctive plateaus at or near the highest topographic elevations of each river valley margin. The timing of the flank failures indicate that inter-eruptive cone destabilization of Mt. Ruapehu is affected by climate change and occurs most commonly during interstadials when glaciers on the cone are in retreat, whereas syn-eruptive collapses are most prominent during cold stages. Dated debris-avalanche deposit levels, along with those of up to four stadial-related aggradational gravel terraces between c. 125 and 18 ka, were used to calculate regional uplift rates in this area. Rates of between 0.2 ± 0.1 mm yr− 1 to 3.8 ± 0.8 mm yr− 1 are found for four river systems dissecting the central North Island of New Zealand. In three cases incision below the diamicton sequences and into the basement, allowed quantification of sediment-flux rates into the Tasman Sea of 107,000 ± 1,200 m3 yr− 1 to 177,000 ± 3,500 m3 yr− 1 since debris-avalanche emplacement.

The Wissower Bach Syncline on the Jasmund Peninsula (NE Germany) has been examined to understand the complicated glacitectonic environment in the southern Baltic Sea region, comprising folds and thrust faults from the Weichselian–Pleniglacial. Soft-sediment thin sections from a SW-dipping thrust fault at the south-western limb of the syncline between Cretaceous chalk (hangingwall) and Pleistocene deposits (footwall) were analysed using micromorphology and microstructural mapping. Within the diamicton bounding the fault, three different clast microfabrics were distinguished: an older, but dominant S1 fabric; a second S2 foliation orientated perpendicular to S1; and a younger subvertical S3 fabric. These fabrics developed during large-scale folding and thrusting, subsequent fabric rotation adjacent to the thrust fault accompanied by dewatering of the diamicton and extension; the extension implies late-stage reactivation and gravitational relaxation at the south-western limb of the syncline as the ice retreated. The combination of a 3D microstructural model and the macroscale information has led to the development of a detailed model for the evolution of the Wissower Bach Syncline during glacitectonism and the localized reactivation of the associated thrusts in response to ice retreat. Moreover, this methodology provides a robust dataset on which to interpret the structural evolution of glacitectonic complexes.