Geological, geomorphological, and paleontological indicators for detecting Paleolithic sites in the Lower Ob region

Paleontological findings and absence of geological obstacles continue to be the main indicators for the possibility of human settlement in the north of Western Siberia after 90,000 BP. During the field survey on the right bank of the Ob River (from the village of Lopkhari to the village of Pitlyar) in 2019, a representative collection of mammoth fauna was obtained, indicating that this area was favorable for large mammals in the Late Pleistocene. The finds included the bones of woolly mammoth, reindeer, woolly rhinoceros, horse, bison, musk ox, and elk. Composite section of Quaternary sediments compiled on the basis of authors’ data and information from the literature, constitutes the sequence of layers with the Tazov glaciocomplex at its base, which was cut by the Upper Quaternary alluvium and glacial-lake sediments, which in turn were covered by the subaerial complex, including aeolian sediments, deluvium, solifluxium, and paleosols. According to a new understanding of the genesis of the layer which included bone deposits in the section near the village of Lopkhari, it constituted a subaerial (rather than floodplain-alluvial) complex which started to emerge 50,000 BP. The latest geological observations significantly optimize the search for promising locations for detecting stratified Paleolithic sites. The finds of megafauna combined with Paleolithic artifacts found on the beach make it possible to predict the possibility that cultural layers may exist in situ in the sediments of coastal cliffs and in the layers of gravel and pebble perluvium buried in alluvium. At the same time, it has been established that high-altitude levels of coastal sites do not always serve an accurate indicator of the age of deposits discovered in coastal outcrops and accordingly do not always indicate good prospects for the search of Paleolithic sites in them.