THE STRUCTURE AND GLACIAL RELIEF OF THE GORODOK UPLAND (NORTH-EASTERN BELARUS)<a href="#FN1"><sup>1</sup></a>

Abstract

The article presents the results of the first comprehensive study of the structure and morphology of the glacial relief of the Gorodok Upland in the north-eastern Belarus. New data were obtained using lithological-stratigraphic, petrographic and morphometric methods. It has been established that the formation of the upland is predetermined by the uplift in the top of the Upper Devonian rocks. This uplift of the pre-Quaternary surface is overbuilt by Middle Pleistocene glacial deposits with glacial tectonics and erratic masses. The presence of an uplift led to the formation of the upland in the ice divide zone between the Chud and Ladoga Ice Streams during the last glaciation. As a result, during the maximum advance of the last ice sheet, a moraine plateau with kames began to form in the center of the upland. During the Lepel Stage (18–20 cal. ka BP, Edrovo in Russia, Gruda in Lithuania, and Poznan in Poland) the ice lobes of the Chud and Ladoga Ice Streams moved from the periphery to the moraine plateau. In total, there were six distinct oscillations of the glacial edge. As a result, chains of hummocky and ridge end-moraine landforms were formed. Later, during the Braslav Stage (16–18 cal. ka BP, Vepsa in Russia, Baltija in Lithuania and Pomeranian in Poland), hummocky end-moraine landforms were formed on the north-western and north-eastern slopes of the upland. At the same time, large runoff troughs crossing the upland from the north to the south were formed as a result of ice melting. The results of the study are important for the rational conduct of geological surveys and prospecting for mineral building materials within the ice-divide zones of the last glaciation.