Publishing House SB RAS:

Publishing House SB RAS:

Address of the Publishing House SB RAS:
Morskoy pr. 2, 630090 Novosibirsk, Russia



Advanced Search

Russian Geology and Geophysics

2013 year, number 10

PETROLOGY AND GEOCHEMISTRY OF GABBRO AND PICRITES FROM THE ALTAI COLLISIONAL SYSTEM OF HERCYNIDES: EVIDENCE FOR THE ACTIVITY OF THE TARIM PLUME

S.V. Khromykh, A.G. Vladimirov, A.E. Izokh, A.V. Travin, I.R. Prokop’ev, E. Azimbaev, S.S. Lobanov
Keywords: Gabbro–picrite associations of fold belts, mantle plumes, plume–lithosphere interaction

Abstract

We present petrological, isotopic, and geochronological data on gabbro–picrite plutons from the Altai collisional system of Hercynides (eastern Kazakhstan). The geological, geochemical, and geochronological data suggest that these rocks are indicators of the activity of the Tarim plume. The gabbro and picrites formed in two stages (~293 and 280 Ma) in an acid-to-basic succession, explained by a model for the interaction of thermochemical plumes with the lithosphere. Early igneous activity, which gave rise to subalkalic gabbro plutons, reflects the first interaction between the ascending plume and the lithosphere, with low-melting sublithospheric protoliths. Further interaction was characterized by the sublithospheric spread of the plume head with intense heating of the lithospheric base and possible intrusion of deep melts, which resulted in the formation of Cu–Ni–PGE gabbro–picrite plutons in the Altai collisional system and Northwest China.