GEOCHRONOLOGY OF BASALTS FROM THE VALLEY OF LAKES, MONGOLIA, AND THEIR CORRELATION WITH THE CENOZOIC SEDIMENTARY SEQUENCE

Abstract

The Valley of Lakes, Mongolia, is a key region in which to elaborate the geochronology of biostratigraphic horizons of the continental Paleogene and Neogene. Here, basaltic volcanism is developed widely. Basalt flow units are found alternating with and overlying sedimentary strata, while dikes and bosses cut through Paleocene, Oligocene, and Miocene faunal horizons. Analyzing biostratigraphic material in combination with K-Ar dating affords upgrading the biogeochronological subdivision and correlating some of the horizons with the mammalian zonation of Europe. The Valley of Lakes thus becomes the stratotype locality for Cenozoic continental sections in Inner Asia.