Periglacial landscape evolution and environmental changes of Arctic lowland areas for the last 60 000 years (western Laptev Sea coast, Cape Mamontov Klyk)

Abstract

Non-glaciated Arctic lowlands in north-east Siberia were subjected to extensive landscape and environmental changes during the Late Quaternary. Coastal cliffs along the Arctic shelf seas expose terrestrial archives containing numerous palaeoenvironmental indicators (e.g., pollen, plant macro-fossils and mammal fossils) preserved in the permafrost. The presented sedimentological (grain size, magnetic susceptibility and biogeochemical parameters), cryolithological, geochronological (radiocarbon, accelerator mass spectrometry and infrared-stimulated luminescence), heavy mineral and palaeoecological records from Cape Mamontov Klyk record the environmental dynamics of an Arctic shelf lowland east of the Taymyr Peninsula, and thus, near the eastern edge of the Eurasian ice sheet, over the last 60 Ky. This region is also considered to be the westernmost part of Beringia, the non-glaciated landmass that lay between the Eurasian and the Laurentian ice caps during the Late Pleistocene. Several units and subunits of sand deposits, peat-sand alternations, ice-rich palaeocryosol sequences (Ice Complex) and peaty fillings of thermokarst depressions and valleys were presented. The recorded proxy data sets reflect cold stadial climate conditions between 60 and 50 Kya, moderate inderstadial conditions between 50 and 25 Kya and cold stadial conditions from 25 to 15 Kya. The Late Pleistocene to Holocene transition, including the Allerød warm period, the early to middle Holocene thermal optimum and the late Holocene cooling, are also recorded. Three phases of landscape dynamic (fluvial/alluvial, irregular slope run-off and thermokarst) were presented in a schematic model, and were subsequently correlated with the supraregional environmental history between the Early Weichselian and the Holocene.

Ground-ice stable isotopes and cryostratigraphy reflect late Quaternary palaeoclimate in the Northeast Siberian Arctic (Oyogos Yar coast, Dmitry Laptev Strait)

“…Even though the youngest age from Unit IV at Oyogos Yar is dated to 36.3 cal kyr b2k (Table 4) a longer Yedoma Ice Complex formation can be assumed as indicated by Bol'shoy Lyakhovsky Island, where ages of 33.5 to 32.5 cal kyr 2bk have been found for the Molotkov interstadial stratum of the Yedoma Ice Complex Wetterich et al, 2014) (Table 1). It remains unclear whether the Yedoma Ice Complex formation at Oyogos Yar continued further until the Sartan stadial (or even until the end of the Pleistocene as is known from Cape Mamontov Klyk (Schirrmeister et al, 2008a) and Bykovsky Peninsula ) or whether the accumulation regime has changed. On Bol'shoy Lyakhovsky Island the prevailing Yedoma Ice Complex formation moved from plain to erosional landforms such as river valleys where the Sartan stadial stratum of the Yedoma Ice Complex was formed at least between about 30 and 26.7 cal kyr b2k .…”

“…Selected stratigraphic units have been studied at Cape Mamontov Klyk (Boereboom et al, 2013), at Bol'shoy Lyakhovsky Island (Wetterich et al, , 2014, at the Oyogos Yar Coast , and in the Lena River delta (Schirrmeister et al, 2003b(Schirrmeister et al, , 2011aWetterich et al, 2008;Meyer et al, 2015). To verify the obtained palaeoclimate results on different timescales and to assess their spatial and temporal representativity, additional extensive groundice stable-isotope records are needed.…”

Last Glacial Maximum records in permafrost of the East Siberian Arctic

“…1; Schirrmeister et al, 2008b). This Ice Complex formed in the foreland plain north of the Pronchishchev Ridge, and comprises a continuous Sartan sequence up to 20 m thick and dated from 27.2 to 14.5 ka BP (Schirrmeister et al, 2008b). Yet unpublished data stable water isotope data from a syngenetic ice wedge 3.2 m wide) show mean values of À31& for d…”

“…6c, Table 4, personal communication H. Meyer, AWI Potsdam, Germany). The corresponding sediment unit was dated to about 22 ka BP (unit C, subprofile 15 in Schirrmeister et al, 2008b). These ice-rich Ice Complex sediments are badly sorted sandy silt Table 4 Stable water-isotope composition of ice wedges from regional Sartan stadial records where available according to Fig.…”

Late Quaternary environmental and landscape dynamics revealed by a pingo sequence on the northern Seward Peninsula, Alaska

“…Therefore, permafrost deposits are increasingly used as an archive of late-Quaternary environmental and climatic conditions in the high latitudes of the northern hemisphere (e.g. Matthews, 1974a;McDowell and Edwards, 2001;Murton, 2001;Schirrmeister et al, 2002Schirrmeister et al, , 2008Muhs et al, 2003;Hubberten et al, 2004;Sher et al, 2005;Froese et al, 2008;Kienast et al, 2008;Kuzmina et al, 2008;Wetterich et al, 2008;Meyer et al, 2010;Andreev et al, 2011).…”