Indexed on: 21 May '08Published on: 21 May '08Published in: Journal of Volcanology and Seismology
Based on published and new data, a new petrological model of the preorogenic Late Cretaceous-Paleogene intrusive rock association is suggested. The principle of plume geodynamics is the essential one: homodromous intrusion of dunite-clinopyroxenite-gabbro magmas into upper layers of the lithosphere results from melting of a nonuniform substratum of the upper mantle caused by an ascending fluid and containing a phosphorus-potassium component. Different rock series are of comagmatic character: basalt-trachybasalt-latite and gabbro-monzogabbro-syenite, evolving in the process of crystallization differentiation of the basalt magma influenced by transmagmatic fluid. We suggest a petrogenesis of high-potassic basalt series.