COMPOSITION AND ISOTOPIC EVOLUTION OF POTASSIC VOLCANIC ROCKS FROM THE SOUTHEASTERN GORNY ALTAI

Abstract

In the geodynamic evolution of the Gorny Altai, high-K magmatism was manifested repeatedly in several spatially limited areas. In the southeastern area of the region, the youngest rocks of this process are represented by the Early Jurassic association of Li–F granites at the Kalguty rare metal deposit and the Triassic mica lamprophyres (minettes) of the Chuya Complex comparable in age with traps of the Siberian Craton. The Middle Ordovician Edelveis Complex of K-alkaline basic rocks and carbonatites and the Devonian Aksai trachyandesite–dacite–rhyolite complex studied by the authors of this communication were formed in the Paleozoic. The derivatives of the latter complex are known in the closely located Aksai and Kalguty volcanotectonic depressions situated at the border with the Mongolian Altai.