Ice-Marginal and Periglacial Processes and Sediments ppt

[...]... The islands of Hopen (SE from the Svalbard archipelago) and Bjørnøya (midway between Norwegian mainland and Spitsbergen) are not on the map full-glacial mode leaves pronounced fingerprints on the continental shelf margins and slopes, and during deglaciation sediments and landforms are deposited on the continental shelf and in fjords around Svalbard Most sedimentation occurs subglacially in fjords and on... oblique aerial view of northwest Banks Island showing: the current fluvial dissection; the asymmetrical nature of the valleys; large-scale thermal-contraction crack polygons on the upland surface; and snow remaining on lee slopes and in valley bottoms and small gullies The photograph was taken in early July both terrestrial and marine glacial processes, landforms and sediments It is followed by two papers... examples of periglacial landscapes currently being fashioned by frost action and mass wasting (gelifluction) processes in conjunction with the operation of the azonal processes of wind, snow and fluvial activity It is this sort of environment and the associated processes and sediments that are central to Part Two of the volume Contributions in this volume Much is now known about glaciers and cold-climate environments... assemblage of sediments and landforms that can be used to infer the flow and dynamics of the last ice sheet on Svalbard (Fig 3) They distinguished between inter-ice-stream and ice-stream glacial landform assemblages, which reflect different glacial dynamics associated with ice streams in fjords and troughs and slower moving ice between the troughs and ice streams They identified five subsets of landforms that... Svalbard ice caps and glaciers cover about 36 600 km2, with an estimated total volume of c 7000 km3 (Hagen et al 1993) Most of the ice volume is contained in the highland ice fields and ice caps on Spitsbergen and Nordaustlandet, but large valley glaciers and cirque glaciers are frequent along both the west and east coasts of Spitsbergen Small ice caps also exist on the eastern islands, Edgeøya and Barentsøya... contains H2O in the form of buried icy bodies (Mellon & Jakowsky 1995) and there is morphological evidence that suggests the ephemeral occurrence of surface water in the geological past (Baker 2001) The weathering and 4 I P MARTINI ET AL landscape models associated with traditional (Earthbased) ice-marginal and periglacial processes and sediments are therefore uniquely challenged when totally cryotic environments... specifically identify a cold-climate origin or specific periglacial processes Indeed, large quantities of fines generated by glacial abrasion glacier are stored temporarily in proglacial /periglacial settings and are partly eroded and redistributed continent-wide by wind, both in periglacial and non -periglacial settings (Derbyshire & Owen 1996) The existence of periglacial settings is indicated primarily by post-depositional... Landforms of ice retreat from fjord mouths to fjord heads These are arcuate moraines (suggesting possible glacial re-advance to fjord mouths and/ or stillstands during deglaciation), crag -and- tail features and small transverse ridges (suggesting active ice in fjords prior to deglaciation) The crag -and- tail landforms (3 on Fig 3a) are streamlined features with an upstream core of bedrock and glacial sediments. .. northwest Banks Island, N.W.T., Canada Canadian Journal of Earth Sciences, 8, 717–731 French, H M 1972 Proglacial drainage of northwest Banks Island, District of Franklin, NWT The Musk-Ox, 10, 26–31 French, H M 2000 Does Lozinski’s periglacial realm exist today? A discussion relevant to modern usage of the term periglacial Permafrost and Periglacial Processes, 11, 35–42 French, H M 2007 The Periglacial. .. 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 . desert landforms and sedimentary processes during recent Martian geological history. In:Martini, I. P., French,H.M.&Pe ´ rez Alberti, A. (eds) Ice-Marginal and Periglacial Processes and Sediments. . time and alternating cold and warm periods (modified from Scotese 2008). INTRODUCTION 3 landscape models associated with traditional (Earth- based) ice-marginal and periglacial processes and sediments. 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