Geological Structure and Glacial Landforms of the Gorodok Upland (Northeastern Belarus).

A comprehensive study of the glacial relief structure and morphology has been carried out for the first time in the Gorodok Upland (northeastern Belarus). New data have been obtained using lithological–stratigraphic, petrographic, and morphometric methods. The upland formation was caused by uplifting at the top of the Upper Devonian rocks. This pre-Quaternary surface uplift was overbuilt by Middle Pleistocene glacial deposits with glaciodislocations and erratic masses. As a result, the upland was formed in the ice-divide zone between the Chud and Ladoga ice streams during the last glaciation. Under the maximum advance of the last ice sheet, a moraine plateau with kames began to be formed in the center of the upland. At 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, at the Braslav Stage (16–18 cal. ka BP, Vepsa in Russia, Baltija in Lithuania, and Pomeranian in Poland), hummocky end-moraine landforms appeared on northwestern and northeastern slopes of the upland. At the same time, the ice melting process resulted in large runoff troughs crossing the upland from north to south. The study results are important for reasonable geological survey and prospecting for mineral building materials within the ice-divide zones of the last glaciation. [ABSTRACT FROM AUTHOR]