The stratigraphic framework for the Upper Pleistocene of the glaciated Russian Arctic: changing paradigms

The development of stratigraphic ideas and terminology for the area of Late Pleistocene glaciation beyond the limit of the Fermoscandian ice sheet is discussed. The original meaning and subsequent distortions of the Siberian stratigraphic terms Zyryanka, Karginsky, Sartan and others are described. Stratigraphic schemes traditionally used in Siberia and in the Russian European Arctic contain similar mistakes due to poor sedimentology obtained from simplistic log descriptions. Indiscriminate use of radiocarbon dating, in disregard to the sedimentological complications, have eroded the value of the old stratigraphic terms and depleted their usefulness. Modem data on widespread glaciotectonic activity and redeposition of organics by shelf-based ice sheets, on retarded melting of buried glacial ice, on ubiquitous permafrost and aeolian processes, coupled with new geochronometric results make it impossible to employ the old framework based on the presumption of undisturbed stratification and slow unperturbed sedimentation. A more structurally complicated model, to which traditional stratigraphic labels are not applicable, is suggested for the uppermost sedimentary formations of arctic plains. It is derived from a wider view of the glacigenic complex by lateral tracing of study objects as a necessary complement to conventional log descriptions. The old Siberian stratigraphic scheme, being obsolete and misleading, is not recommended for further use. (C) 2001 Elsevier Science B.V. All rights reserved.