Late Pleistocene in the southeastern White Sea and adjacent areas (Arkhangelsk region, Russia): Stratigraphy and palaeoenvironments

Abstract

An overview of the Late Pleistocene and Holocene stratigraphy of the southeastern White Sea region is presented in the paper, based upon the analysis of published data, new results, and correlation between marine and terrestrial archives. The Pleistocene stratigraphic record in the southeastern White Sea region begins with Mikulino Horizon, which comprises the whole MIS 5 and is composed of marine sediments – sands, sandy clays and clays – with Boreal, Arctic–Boreal and Lusitanean–Boreal microfauna and mollusc fauna, dated back at 161–77 ka. The Podporozhie Horizon in the southeastern White Sea region comprises the MIS 4 (71–57 ka) complex of marine mostly near-shore sediments. The glaciation during MIS 4 was localized, on one hand, within the Kola Peninsula. On the other hand, the glacier probably overlapped the Kanin Peninsula and the Mezen Bay, however the Gorlo Strait was not blocked and the northward river outflow was preserved. The Leningrad Horizon had been formed also in the marine sedimentation pattern during the MIS 3 (57–29 ka). However, the lack of data in the region allows us to make only the comparative analysis. The Ostashkov Horizon (MIS 2, 29–11.7 ka) is composed of the deposits of glacial paragenetic series: tills, glaciofluvial, glaciomarine, and glaciolacustrine deposits, but also comprises the deglaciation (Late Glacial) sedimentary complex including marginal tills. The Holocene stratigraphic record is subdivided into three stages – 11.7–9.5, 9.5–3.5 and 3.5–0 ka BP, and do not match with new formal stratigraphic subdivision of the Holocene series.