A wide variety of environmental records is necessary for analysing and understanding the complex Late Quaternary dynamics of permafrost-dominated Arctic landscapes. A ne siberian periglacial region with a rich history of previous paleo-environmental research was studied in detail using sediment records, remote sensing data, and terrain modelling, all incorporated in geographical information systems (gis). the study area consists of the Bykovsky Peninsula and the adjacent Khorogor valley in the Kharaulakh ridge situated a few kilometres southeast from the Lena delta. in this study a comprehensive cryolithological database containing information from 76 sites was compiled. the information from these sites is based on the review of previously published borehole data, outcrop profiles, surface samples, and our own field data. these archives cover depositional records of three periods: from Pliocene to early Pleistocene, the Late Pleistocene, and the Holocene. the main sediment sequences on the Bykovsky Peninsula consist of up to 50 m thick ice-rich permafrost deposits (ice complex) that were accumulated during the Late Pleistocene. they were formed as a result of nival processes around extensive snowfields in the Kharaulakh ridge, slope processes (e.g., in the Khorogor valley), and alluvial/proluvial sedimentation in a flat accumulation plain dominated by polygonal tundra in the mountain foreland (Bykovsky Peninsula). during the early to middle Holocene warming, a general landscape transformation occurred from an extensive Late Pleistocene accumulation plain to a strongly thermokarst-dominated relief dissected by numerous depressions. thermokarst subsidence had a large influence on the periglacial hydrological patterns, the sediment deposition, and on the composition and distribution of habitats. climate deterioration, lake drainage, and talik refreezing occurred during the middle to late Holocene. Because of the post-glacial sea level rise, the sea reached the region during the middle Holocene, triggering thermo-abrasion of ice-rich coasts and the marine inundation of thermokarst depressions in the investigated area.
Helmholtz Research Programs > MARCOPOLI (2004-2008) > POL6-Earth climate variability since the Pliocene