A regional Upper Cretaceous magnetostratigraphic section of southern West Siberia (Omsk depression)

Abstract

1107 Construction of regional magnetostratigraphic sections and scales for different geological provinces of continents is an important element of investigations aimed at development of the standard geomagnetic scale, which is widely used in geochronological, strati� graphic, and geodynamic studies, as well as in theoret� ical and applied geophysics. Recent investigations have yielded extensive data on the paleomagnetic properties of Cretaceous sections in the former Soviet Union and around the world. At the same time, the progress in development of the Cretaceous paleomag� netic scale has been determined by the results of pale� omagnetic investigations in the most important geo� logical provinces of continents, such as, for example, the West Siberian Basin (WSB). Paleomagnetic data on Cretaceous sections are practically missing from this region, which represents one of the largest petroliferous basins in the world, except for some information in [1–3]. We have studied and analyzed paleomagnetic and paleontological data on Upper Cretaceous sections of the Omsk depression located in the southwestern mar� ginal part of West Siberia. The geological section of the region in question (Russkaya Polyana area) is represented by Mesozoic– Cenozoic marine and terrestrial sediments that form the platformal cover resting upon the eroded surface of