Abstract Understanding the sediments deposited by glaciers or other cold-climate processes assumes enhanced significance in the context of current global warming and the predicted melt and retreat of glaciers and ice sheets. This volume analyses glacial, proglacial and periglacial settings focusing, among others, on sedimentation at termini of tidewater glaciers, on hitherto not-well-understood high-mountain features, and on sediments such as slope and aeolian deposits whose clasts were sourced in glacial and periglacial regions, but have been transported and deposited by azonal processes. Difficulties are thus often encountered in inferring Pleistocene and pre-Pleistocene cold-climate conditions when the sedimentary record lacks many of the specific diagnostic indicators. The main objective of this volume is to establish the validity and limitations of the evidence that can be obtained from widely distributed clastic deposits, in order to achieve reliable palaeogeographic and palaeoclimatic reconstructions. At a more general level and on the much longer geological timescale, an understanding of ice-marginal and periglacial environments may better prepare us for the unavoidable reversal towards cooler and perhaps even glacial times in the future.

Abstract The volume focuses on the analysis of glacial clastic sedimentary deposits, both ancient and recent. The papers range from reviews of glacial systems and cold-climate weathering products and processes to conceptual and field studies of specific ice-marginal and cold-climate sediments. Papers are included that deal with tidewater glaciers, mountain settings on Earth, permafrost areas on both Earth and Mars and detailed regional analyses of cold-climate sediments of Late Pleistocene and Holocene age. The identification of sedimentary facies allows an accurate reconstruction of many of the developmental processes that are involved in ice-marginal and periglacial environments. Lithostratigraphic characteristics of clastic deposits also constitute circumstantial evidence for the previous existence of ancient, and certainly pre-Quaternary, cold-climate systems. This is demonstrated by a study on putative Palaeozoic glacial deposits in Saudi Arabia.

Abstract Marine and terrestrial archives can be used to reconstruct the development of glacially influenced depositional environments on Svalbard in time and space during the late Cenozoic. The marine archives document sedimentary environments, deposits and landforms associated with the Last Glacial Maximum (LGM) when Svalbard and the Barents Sea were covered by continental-scale marine-based ice sheet, the last deglaciation and the work of tidewater glaciers in interglacial setting as today. The terrestrial archives record large-scale Quaternary glacial sculpturing and repeated build-up and decay of the Svalbard–Barents Sea ice sheet. The fingerprinting of Quaternary glaciations on Svalbard reflects the transition from a full-glacial mode, with very extensive coverage by the Svalbard–Barents Sea ice sheet and subsequent deglaciation, to an interglacial mode with valley, cirque and tidewater glaciers as active agents of erosion and deposition. Conceptual models for Svalbard glacial environments are useful for understanding developments of glacial landforms and sediments in formerly glaciated areas. Svalbard glacial environments, past and present, may serve as analogues for interpreting geological records of marine-terminating and marine-based ice sheets in the past.

Abstract The study focuses on the terminal moraine of a fast-flowing, temperate tidewater glacier that protruded in Oslofjorden trough, southern Norway, during one of the re-advances of the receding Fennoscandian Ice Sheet in the Younger Dryas time. Allostratigraphic mapping is used to reconstruct the moraine's morphodynamic development, showing how information on the dynamics of ancient glaciers can be derived from their grounding-line deposits. The Storsand moraine commenced its development in the latest phases of ice-margin advance and continued to grow during the stillstand phase, as long as the ice flux persisted. The thick moraine (>100 m) formed in a few decades, to be rapidly abandoned and later emerged by regional uplift. The study concludes that: (a) both meltwater and ice flow invariably supply sediment to the grounding line, and it is the varied preservation potential of ice-derived diamicton that results in misleading differences between moraines; (b) the glacier-front kinematics is asymmetrical with slow advances and rapid retreats; (c) no moraines can form during glacier retreat; (d) the front of an outlet glacier may stabilize while the adjacent ice margin is oscillating or virtually retreating; and (e) marine moraines are an important source of information about ancient ice margins and glacier dynamics.

Abstract Modern studies indicate that the kinematic behaviour of tidewater glaciers is a crucial part of ice-sheet dynamics. A similar relationship may be expected for ancient ice sheets, but can the kinematics of ancient tidewater ice margins be recognized? The paper addresses this methodological issue by pointing to the high-resolution stratigraphic record of marine moraines, thus far little explored. On the basis of a series of case studies, a range of field criteria are proposed for the recognition of short-term grounding-line movement and possible oscillations in moraine outcrop sections. The method combines allostratigraphic mapping and architectural facies analysis of the moraine sedimentary units formed during glacier advance, subaqueous stillstand and eventual subaerial stillstand, with recognition of the successive ice-contact surfaces. The stacking architecture of the sedimentary units and their ice-contact bounding surfaces reveal the time–distance trajectory of the grounding-line positions. It is also possible to recognize changes in the mode and rate of subglacial sediment delivery, as well as fluctuations in the ice flux and meltwater discharge. This methodology invites detailed studies of marine moraines. Systematic case studies on a regional scale may provide new information on the behaviour of tidewater ice margins and lead to unprecedented insights into the dynamics of ancient ice sheets.

Abstract Studies on the formation of alpine lateral moraines are rare; consequently, their internal structure and their modes of formation are relatively poorly understood. We present here sedimentological and ground-penetrating radar (GPR) data from a lateral moraine complex where an exposure allows radar facies to be compared to the field evidence. The moraine, which is slightly asymmetric with a slightly steeper distal slope, consists of alternating clast- and matrix-supported stratified diamicts and intercalated sorted sediment units which are all subparallel to the moraine surface. They are interpreted as subaerial debris flows and fluvial sediments, respectively. The GPR, using frequencies of 50, 100 and 200 MHz, allows tracing of very similar subparallel reflectors to c. 10 m into the subsurface. These are interpreted to represent the diamict units while the thickness of the sorted sediment units is below GPR resolution. Our data suggests that a two or three frequency approach supplemented by common-midpoint (CMP) measurements works well in glaciated high-mountain environments. Based on our sedimentological and GPR data we develop a conceptual framework for the formation of successive lateral moraines which involves ice-contact fan sedimentation, followed by collapse and incremental reworking of the proximal side during glacier retreat.

Abstract Sediments at Pias (Galicia) provide evidence of Upper Pleistocene glacial activities at a valley junction in the north-western mountains of Spain. The sedimentary sequence consists of lower, predominately fine-grained lacustrine deposits with few lonestones, overlain by poorly sorted, sandy gravels interstratified with massive diamicton deposited during mid-Weichselian times (MIS 3) (marine isotope stage 3). The lacustrine sediments were deposited in a glacial valley temporarily dammed by a confluent glacier. The presence of active ice is suggested by massive diamicton layers best interpreted as till, rafted sediments in lacustrine deposits and deformation structures indicative of loading and kettle formation. Frozen ground conditions are suggested by a few involution-like structures. The Pias area contains one of the few western-Spain sedimentary records of Upper Pleistocene glaciation at relatively low latitude (about 42°N) and low altitude (less than 1000 m a.s.l.). A southern dip of the Polar front to 40–45°N latitudes, as occurred during Last Glacial Maximum, could have cut moisture to the northern Fennoscandinavian ice sheets. At the same time, however, sufficient precipitations would have persisted in north-western Spain to sustain extensive ice caps and their outlets to elevations as low as c. 900 m a.s.l.

Abstract Glacial lake Kuray–Chuja which occupied the Kuray and Chuja Basins during the Quaternary Period (Marine Isotope Stages 2 and 3) left distinct shoreline features around the basin margins. At the greatest extent the lake had a surface area of 2951 km 2 with wind fetches up to 70 km. Wind waves constructed erosional, erosional-accumulative and accumulative strandlines, the latter including spits, tombolos, barrier beaches and offshore bars. Strandlines range in altitude between c . 1600 and 2100 m, the range in altitudes demonstrating lake level variations through time. The shoreline forms and stratigraphy are detailed. Particular attention is given to the presence of pocket beaches on rock-coasts, the alluvial strandlines of which have distinctive alongshore gradients. Although reasonably ascribed to regional differential tectonic uplift, the possibility that the local alongshore gradients are augmented as a process response to alongshore drift of sediment in a sediment-starved system of closed coastal cells is explored using a simple numerical model.

Abstract Saudi Arabia is one of the few places in Gondwana where deposits of two Palaeozoic glaciations are well preserved. They were formed under similar conditions in a tectonically stable shelf setting. We studied the sedimentary facies and architectural geometries of Upper Ordovician and Permo-Carboniferous glaciogenic deposits in the Wajid Sandstone and developed a genetic model for both units. Common features and of both glacial episodes are (a) incision of glacial (tunnel?) valleys, (b) subsequent valley fill by proglacial deposits in front of an oscillating, polythermal ice shield; (c) intra-formational erosional events through repeated ice advance, (d) widespread and large-scale soft deformation due to glacial surge during deglaciation, and (e) marine transgression most probably due to eustatic sea-level rise following deglaciation. The general patterns and observations fit well with recently published observations on Upper Ordovician deposits in northern Africa, pointing to closely coupled glaciological processes of the North African–Arabian ice shield. Although the same general patterns apply for the Permo-Carboniferous glaciation, sedimentary styles and petrographical properties differ, probably due to a more heterogeneous ice-flow pattern controlled by a more pronounced topography after the Hercynian tectonic event.

Abstract Frozen surficial sediments that are otherwise unconsolidated contain structures and characteristics that are different from those of the same sediments when in an unfrozen state. These differences are usually related to either the nature of the ice contained within the frozen sediment or to weathering processes and chemical precipitates that are associated with freezing and thawing. This paper summarizes (a) the manner in which ground freezes when a landscape experiences the onset of cold-climate conditions and (b) what happens when newly transported sediments freeze following deposition in that environment. In the absence of obvious morphological evidence, the recognition of previously-frozen sediments is problematic. Less well-understood evidence includes secondary precipitates, neoformed clay minerals, seasonal frost cracks and fragipans.

Abstract A range of cold desert landforms are found on the Martian surface that have been interpreted to indicate prevailing frozen and hyper-arid conditions for at least the past several million years. These cold desert conditions are punctuated by brief periods of localized surficial liquid water flow. Sediment transport pathways operate under these conditions of extreme cold and aridity and the processes involved generate permafrost landforms that are recognizable from spacecraft at local, regional and global scales. Thermal-contraction-crack polygons are associated with hemisphere-spanning mantle units that contain excess ice in the immediate subsurface. Sublimation is the dominant phase transition rather than melting under present Martian conditions. Evidence is presented for melting of near-surface snow, frost and/or ground ice in protected gully alcove microclimates during the most recent several million years.

Abstract Research in the Arctic and alpine regions of NW Sweden and south-central Norway reveals an active chemical-weathering regime: in Kärkevagge, Swedish Lapland, pyrite weathers to produce an acidic environment with vigorous chemical weathering and active pedogenesis as indicated by locally well-developed Spodosols; in the Jotunheimen Mountains of Norway, soil horizons form slowly but cobbles develop weathering rinds within c . 250 years. Such results indicate that chemical weathering and pedogenesis may be quite advanced in alpine periglacial regions and is just one illustration that such regions may be profitably scrutinized using geomorphological and pedological conceptual frameworks other than the traditional periglacial framework.

Abstract The mechanical and chemical effects of lichens on the outer and inner surfaces of tafoni features were investigated through a multidisciplinary approach at two locations (Oasi 74°42′S, 164°07′E, 40–250 m a.s.l.; Mount Keinath, 74°32′S; 163°58′E; 850 m a.s.l.) close to the Italian Antarctic station (Mario Zucchelli). Outer tafoni roof surfaces show low values of effective porosity coupled with pervasive hyphal penetration and an extensive reddish-brown weathering rind. Inner tafoni surfaces show higher values of effective porosity, which correspond with an almost absent weathering rind and low hyphal penetration. Our observations indicate that: (a) iron oxy-hydroxides, particularly concentrated where hyphal patches and bundles contact biotite, consist of hematite; (b) the microcosms of lichen hyphae and their precipitates fill voids to form case hardening on outer surfaces; and (c) on inner surfaces biological action is less active, most likely because of more intense thermal stress and salt action.

Abstract ‘Periglacial deposits’ have often been reported in the Quaternary geological literature. Sometimes their identity has been confused with the periglacial processes, landforms and environments with which these deposits are linked. However, the question arises: what are the diagnostic characteristics of such ‘periglacial’ deposits? A number of examples illustrate that ‘periglacial deposition’ follows the general geomorphological and sedimentological laws, although it may be influenced by specific conditions of vegetation and sediment availability. These may be completely or partly dependent on periglacial climatic conditions. Some marginal conditions are specific to cold environments, for instance the scarcity of vegetation that has a clear effect on transport and deposition of aeolian sediments. In addition, the intensity of some processes is governed by climate-derived conditions, for instance in the case of fluvial and slope processes. In this sense, the answer to the question in the title is negative. ‘Periglacial deposits’ do not correspond to any particular sedimentary process. This conclusion is, however, only valid when post-depositional weathering and deformations at micro- and macro-scale are excluded.

Abstract Stratified slope deposits occur on or at the base of slopes within a wide range of hilly or mountainous environments. Gelifraction, a lack of vegetation, and snowmelt-derived slopewash are thought to be important factors in their development. The relatively fine-grained grèzes litées found at many sites within the French Charente region are the prototype of this kind of deposit. The original, strictly limited and genetically intended definition has been enlarged by mainly non-French authors causing considerable confusion. Other assemblages of cold-climate slope deposits are more heterogeneous, sometimes less clearly stratified, and show much larger variation in grain sizes and sedimentary structures than grèzes litées . The most important of these are stone-banked solifluction (sheets or lobes), rock fall, (dry) grain flow, frost-coated clast flow, debris flow, snow avalanching and, to a lesser degree, rain-generated overland flow and (niveo-) aeolian activity. Many of these processes are azonal and occur under a wide range of environmental conditions. A periglacial context may nevertheless influence process activity in these cases, for instance with regard to their magnitude and/or frequency.

Abstract The activity of geomorphic processes in the current periglacial belt of Sierra Nevada during the Holocene has been strongly controlled by climate variability. We examined two sedimentary records showing several cycles with varying intensity of slope processes in the massif. Chronostratigraphic studies of solifluction landforms have revealed seven cycles of enhanced slope activity in Sierra Nevada during the last 7 ka. Lake sediments show eight periods with increased slope activity over the last 6 ka. Depending on temperature and moisture regime, erosion or conditions of slope stability prevailed. Cold and wet periods triggered slope processes and favoured deposition of coarse-grained sediments into the lakes, whereas warm phases were prone to soil development and fine-grained sedimentation in the lakes. The lake sediments also show evidence for an increasing aridity trend since the Holocene Optimum Warm Period in Sierra Nevada, which induced a shift of solifluction processes to higher elevations accompanying late-lying snow patches.

Abstract This review concentrates on the characteristics of wind processes and products in cold lowland deserts. Its main aims are: to show how difficult it can be to separate wind-generated from water-generated processes and features without detailed study of lamination types; to suggest cold aeolian interpretations for some ancient pre-Quaternary rocks; and to encourage students to revisit many ancient deposits with such interpretations in mind. Although upper Quaternary and Recent cold-climate aeolian deposits have been studied for many years there are very few older examples described. Martian features are included since Mars is now one of the most exciting areas of study for geologists.

Abstract The effects of Pleistocene cold-climate geomorphology are distributed across the weathered and eroded Mid-Atlantic Coastal Plain uplands from the Wisconsinan terminal moraine south to Tidewater Virginia. Cold-climate deposits and landscape modifications are superimposed on antecedent landscapes of old, weathered Neogene upland gravels and Pleistocene marine terraces that had been built during warm periods and sea-level highstands. In New Jersey, sequences of surficial deposits define a long history of repeating climate change events. To the south across the Delmarva Peninsula and southern Maryland, most antecedent topography has been obscured by Late Pleistocene surficial deposits. These are spatially variable and are collectively described as a cold-climate alloformation. The cold-climate alloformation includes time-transgressive details of climate deterioration from at least marine isotope stage (MIS) 4 through the end of MIS 2. Some deposits and landforms within the alloformation may be as young as the Younger Dryas. Southwards along the trend of the Potomac River, these deposits and their climatic affinities become diffused. In Virginia, a continuum of erosion and surficial deposits appears to be the product of ‘normal’ temperate, climate-forced processes. The cold-climate alloformation and more temperate deposits in Virginia are being partly covered by Holocene alluvium and bay mud.