REMARKS ON THE OLIGOCENE-MIOCENE MAMMAL PALEONTOLOGY AND SEQUENCE STRATIGRAPHY OF SOUTH-WESTERN BETPAKDALA STEPPE, SOUTH KAZAKHSTAN

Abstract

Tertiary vertebrates collected in 1995 in the Askazansor Fm. (Southwestern Betpakdala, South Kazakhstan) provide new data for systematics and the age of the fossiliferous deposits. The lower part of the Askazansor Fm. contains a Late Oligocene mammalian fauna with remnants of rodents, chalicotheriids, indricotheriids, rhinocerotoids and tragulids found on the left bank of the Baktykaryn River, while the upper one produces a rich bone concentration with amphicyonids, chalicotheriids, rhinocerotids, anthracotheriids, cervoids, etc. found to the south of the Askazansor Salt Lake. The age of the upper part of the formation appears to be Early Miocene and corresponds to MN2-MN3 of the European Zonation.