Continuous Late Quaternary proxy climate records from loess in Beringia

Abstract

Loess deposits in eastern Beringia contain continuous proxy records of the effects of past climatic change on terrestrial landscapes at high latitudes. Variations of environmental magnetism and sedimentology of high-latitude loess deposits indicate that the timing and pattern of responses to local variations in wind intensity, storminess, and pedogenesis in eastern Beringia closely resemble the pattern of global climate change during the Late Quaternary deduced from studies of marine and ice core records. The age of paleoclimatic fluctuations, permafrost features, volcanic ash horizons, buried forest layers and paleosols, and other features of the eastern Beringian loess record can be determined using a variety of Quaternary dating methods. Tephrochronologic correlations between the loess record and the glacial history of eastern Beringia indicate the Delta Glaciation occurred during marine isotope stage 6. Several other middle and Late Quaternary glaciations across eastern Beringia can be tephrochronologically tied to the loess record, and appear to have been in phase with episodes of global cooling recorded in deep-sea records.