CHRONOLOGY OF QUATERNARY VOLCANISM OF THE KELI HIGHLAND, GREATER CAUCASUS: EVIDENCE FROM K-AR ISOTOPIC DATING

Abstract

The specified on the basis of K-Ar data magmatic activity phases in manifestation time coincide with certain activity phases of other large latest-volcanism centers at Greater Caucasus - Elbrus and Kazbek. The initial volcanic activity phase (225-175 thousand years ago) was marked by extrusion bodies formation in different parts of the region. In the Late neo-Pleistocene (130-60 t.y.a.) the activity had reached its maximum, at that stage predominantly lava volcanoes erupted and thus lavatic plateaus and valley streams were formed. The youngest geologic formations in the western part of Keli highland are the volcano Sev. Shadilkhokh and associated with it Hodzh stream; however, strict proof of their Holocene age requires additional data.