К ВОПРОСУ О ПРИРОДНЫХ УСЛОВИЯХ ЗАПАДНОЙ СИБИРИ В МАКСИМУМ ПОСЛЕДНЕГО (САРТАНСКОГО) ОЛЕДЕНЕНИЯ

• Main Authors: КУЗЬМИН Я.В., ЗОЛЬНИКОВ И.Д., ОРЛОВА Л.А., ЗЕНИН В.Н.
• Format: Text
• Language: unknown
• Published: Федеральное государственное бюджетное образовательное учреждение высшего образования «Иркутский национальный исследовательский технический университет» 2006
• Subjects: Arctic; Arctic Ocean; Ice Sheet; ob river; Mansi; Siberia
• Online Access: http://cyberleninka.ru/article/n/k-voprosu-o-prirodnyh-usloviyah-zapadnoy-sibiri-v-maksimum-poslednego-sartanskogo-oledeneniya; http://cyberleninka.ru/article_covers/16962776.png

The problem of reconstructing natural conditions during the Saltan (Late Weichselian) glacial maximum (20000-18000 BP) in West Siberia is one of the most important issues in the Late Pleistocene geography of this region. Since the 1960s, several researchers have believed that formation of an continental ice sheet in the northern West Siberia served as barrier, which impeded the flow of Ob and Yenisei rivers to the Arctic Ocean and caused the emergence of giant ice dammed reservoir with an absolute height of + 130 m, called Mansi Lake (Sea). However, new data obtained during the last 10-15 years do not support the concept of the existence of this water basin. No traces of Sartan continental ice sheets were found in the lower course of the Ob River. Of special importance are findings of mammoths in the lowermost part of the West Siberian Plain at elevation marks not exceeding + 80 m. The 14C ages for most of these localities (Lyzhin Mys, Evalga, Lugovskoe, Rychkovo, and Kulachye) correspond to the time of the existence of the Mansi Sea, ca. 21000-15000 BP. Also, there are several Late Paleolithic sites in the territory of the West Siberian Plain (Mogochino 1, Tomsk, and Shikaevka 2) mat have been 14C-dated to 20000-18000 BP. Thus, the available information concerning the distribution of mammoths and Paleolithic sites on the plain with absolute heights below +100 m contradict the concept of a glacial Mansi Sea. The in situ position of the dated mammoth fossils is confirmed by available tapho-nomic data (mammoth skeleton parts found in the anatomical order at the Shikaevka 2, Tomsk, Lugovskoe, and Kulachye sites). The location of the Shikaevka 2 site in the Ubagan-Turgai depression, through which the waters of the Mansi Sea might have flown to the south, is an essential point in our discussion. Since the Shikaevka 2 site corresponds to about 18000 BP, it is evident that no intense southward water flow existed at that time at the level of about +120-130 m and even at a lower level, up to +70 m. The formation of ice-dammed lakes took part in northern and central parts of West Siberia at about 90000-60000 years ago, as results of resent studies have shown. The Last Glacial Maximum environment in West Siberia was of subaerial type, with ephemeral shallow lakes. The problem of reconstructing natural conditions during the Saltan (Late Weichselian) glacial maximum (20000-18000 BP) in West Siberia is one of the most important issues in the Late Pleistocene geography of this region. Since the 1960s, several researchers have believed that formation of an continental ice sheet in the northern West Siberia served as barrier, which impeded the flow of Ob and Yenisei rivers to the Arctic Ocean and caused the emergence of giant ice dammed reservoir with an absolute height of + 130 m, called Mansi Lake (Sea). However, new data obtained during the last 10-15 years do not support the concept of the existence of this water basin. No traces of Sartan continental ice sheets were found in the lower course of the Ob River. Of special importance are findings of mammoths in the lowermost part of the West Siberian Plain at elevation marks not exceeding + 80 m. The 14C ages for most of these localities (Lyzhin Mys, Evalga, Lugovskoe, Rychkovo, and Kulachye) correspond to the time of the existence of the Mansi Sea, ca. 21000-15000 BP. Also, there are several Late Paleolithic sites in the territory of the West Siberian Plain (Mogochino 1, Tomsk, and Shikaevka 2) mat have been 14C-dated to 20000-18000 BP. Thus, the available information concerning the distribution of mammoths and Paleolithic sites on the plain with absolute heights below +100 m contradict the concept of a glacial Mansi Sea. The in situ position of the dated mammoth fossils is confirmed by available tapho-nomic data (mammoth skeleton parts found in the anatomical order at the Shikaevka 2, Tomsk, Lugovskoe, and Kulachye sites). The location of the Shikaevka 2 site in the Ubagan-Turgai depression, through which the waters of the Mansi Sea might have flown to the south, is an essential point in our discussion. Since the Shikaevka 2 site corresponds to about 18000 BP, it is evident that no intense southward water flow existed at that time at the level of about +120-130 m and even at a lower level, up to +70 m. The formation of ice-dammed lakes took part in northern and central parts of West Siberia at about 90000-60000 years ago, as results of resent studies have shown. The Last Glacial Maximum environment in West Siberia was of subaerial type, with ephemeral shallow lakes.