Geochemistry,origin, and nature of metamorphic rocks of the Batomga granite-greenstone terrane (Aldan Shield) |
| |
Authors: | G. M. Vovna M. A. Mishkin A. M. Lennikov R. A. Oktyabrsky V. F. Polin Z. G. Badredinov T. A. Yasnygina |
| |
Affiliation: | 1. Far East Geological Institute, Far East Branch, Russian Academy of Sciences, pr. 100 let Vladivostoku 159, Vladivostok, 690022, Russia 2. Institute of the Earth’s Crust, Siberian Branch, Russian Academy of Sciences, ul. Lermontova 128, Irkutsk, 664033, Russia
|
| |
Abstract: | Two series of volcanic rocks with different petrochemical affinities-calc-alkaline and komatiitetholeiitic series-were identified as protoliths for the Early Proterozoic metamorphic rocks of the Batomga granite-greenstone terrane. The metavolcanic rocks of the calc-alkaline series comprise metabasalts, metaandesites, metadacites, and metarhyolites. The distribution of the trace element abundances in the felsic metavolcanic rocks is similar to that of the Archean grey gneisses from the platform basements, thus suggesting a similar petrological mechanism for the formation of their protoliths. The protoliths for the komatiite-tholeiitic metavolcanic rocks include komatiite and tholeiite basalts. The chemical behavior of the tholeiites tends to support the fractionation of primary high-Mg basaltic magmas in a transient magma chamber at low pressures. The variations in the Nb, Y, and Zr contents of the metatoleiites indicate the derivation of their parental magmas from a plume-related source. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|