摘要
There are plenty types of granites around the Kalamaili structural belt in East Junggar of Xinjiang,mostly including granodiorite,monzonitic granite,alkali-feldspar granite and alkali granite.This paper studied the dating of the Aotawuke’erxi granodiorites in the west of principal structural belt and their geochemical compositions.The result shows that the granites are characterized by medium SiO2 contents,modicum K-feldspar,amphibole and blotite contents,comparative enrichment natrium,and dominated plagioclases among the feldspars.The ratio of A/CNK is varying from 0.93 to 0.99,showing characteristics of metaluminous and medium calc-alkalic rock series.The granites are characterized by enrichment in LREE,not obvious depletion in Eu.For the trace elements of granites,large-ion lithophile elements of Rb,Sr,Th etc.and high field strength elements of Zr,Hf etc.are rich obviously,but Nb,Ta,Ti appear strong depletion.The main body of granites are I-type granodiorite.The LA-ICP MS ages of zircon are(329.1±1.3) Ma and(305.7±1.5) Ma.Geochemical elementary and regional geology analysis indicated that the orogenic collision at east Junggar presented during the early late-carboniferous periods,and the orogenic movement ended at the teminal of late-carboniferous periods.