Landscape development history of the Zabolotsky peat bog in the context of initial settlement of the Dubna River lowland (Upper Volga basin)

Abstract

Zabolotsky peat bog is a unique biospheric and cultural-historical archive located in the north of the Moscow Region on the territory of the Dubna River lowland. Despite the advances in studying the Zabolotsky region, the question of reconstruction of the primitive population habitat remains unresolved. Until recently, it has been be-lieved that in the Late Valdai period, the Dubna River lowland was covered by the waters of an extensive glacier-dammed Tver paleolake, drained only at the turn of the Pleistocene and Holocene. It was assumed that the lake's existence prevented the settlement of the territory, whereas after its drainage, the shallow residual water pools were actively exploited in the economic activities of the primitive population. However, paleogeographic and ar-chaeological materials have been accumulated during the last two decades that questioned the existence of large dammed lakes in the Upper Volga basin in the Late Valdai time. This paper presents the results of three years (2018–2020) of research, allowing revision of the ideas about the Quaternary geology and development of the geomorphic conditions of this area. A program of research, comprising topographic and geodetic surveys, drilling using a portable boring rig, lithologic description of the core, radiocarbon (AMS) dating, paleo-soil studies, biologi-cal analysis of organic macrofossils, and ground-penetrating radar, has been carried out aimed at reconstruction of the paleogeographic setting and landscape development. Drilling data were used to build the profile across the left bank of the Dubna River floodplain with extension to the low terrace. The lithofacial analysis of samples and AMS dating allowed identifying three generations of ancient riverbeds, the deepest of which (with the bottom at 12 m below the water edge) is more than 30 thousand years old. The biological residues from the dark-coloured loams directly below the peat bottom belong almost exclusively to higher plants, both arboraceous and wetland, which may have been brought in by the floodwaters. The ground-penetrating radar profiles clearly show the boundaries of three electromagnetically homogeneous sedimental layers — the peat, silted peat, and loam. The paleo-geographic data, in conjunction with the geophysical profiling data, indicate the existence of a copious waterway in the lowland (the ancient Dubna River) no later than 15,000–16,000 years ago which formed a floodplain with large features of fluvial paleorelief available for settlement. These data agree well with the new serial AMS-dates for the resin from the grooves of the bone and horn artifacts, which permit extension of the time of the initial de-velopment of the Zabolotsky peat bog by the bearers of the Resseta Culture to 15,500 years ago. The conclu-sions drawn have major significance for the development of an evidence-based chronology of the events and dynamics of the settlement strategy of the population during the transition from the Pleistocene to the Holocene. The new data not only are consistent with the system of global paleoecologic events and history of the develop-ment of the outwash plain zone in Eastern Europe, but also provide the basis for refinement, and, possibly, revi-sion of a range of current concepts.