BATHOLITHS AND GEODYNAMICS OF BATHOLITH FORMATION IN THE CENTRAL ASIAN FOLD BELT
V.V. Yarmolyuk and V.I. Kovalenko
Institute of Geology of Ore Deposits, Petrography, Mineralogy and Geochemistry,
Russian Academy of Sciences, 35 Staromonetnyi per., Moscow, 109017, Russia
Keywords: Formation of batholiths, granitoids, Central Asian fold belt, mantle plumes, geodynamics
Pages: 1260-1274
Abstract
Three large batholiths were formed in the Central Asian fold belt in the period 310-190 Ma: Angara-Vitim, Hangayn, and Henteyn-Daurian. They are made up of granitoids of variable composition - from tonalites and plagiogranites to granosyenites and rare-metal granites, with a predominance of normal granites. The formation of each batholith lasted about 20-30 myr. For example, the Angara-Vitim batholith was formed in the period 320-290 Ma, the Hangayn one, 275-250 Ma, and the Henteyn batholith, 225-195 Ma. The batholiths are localized in zonal petrographic provinces and are framed by rifting zones with basaltic, bimodal, and peralkaline-granite magmatism.
According to isotope-geochemical data, the batholith granitoids have the same isotopic Nd composition as the host crust. The rocks of the Angara-Vitim and Hangayn batholiths, formed within terranes with
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