On formation of contrast effusive complexes from basaltoid abyssal melts

On the basis of studying geological sections, petrographic thin sections and also recalculation for the petrological indexes-diagrams of chemical analyses of Triassic basalts and liparites of the Middle Transural, the conclusion about fractioning acidic melts magma from initial tholeitic bаsalt magmas has been made. Similar processes are supposed in oceanic lavas of Iceland, Easter Island and Hawaian Islands as well.