西天山造山帶及古生代構(gòu)造演化與地殼增生：來自花崗(編輯修改稿)
2024-09-19 16:46 本頁面
【文章內(nèi)容簡介】 tic rocks in western Tianshan had been formed during two periods: the granitic gneiss with an age of 896Ma, possibly representing the forming age of the Precambrian basement。 the granitic rocks with ages varying from 470Ma to 247Ma, recording the Paleozoic orogenic process of western Tianshan.The granitoids in western Tianshan are posed of intermediatebasic rocks, intermediate rocks, intermediateacid rocks and acid rocks, mainly intermediateacid rocks and acid rocks. They are mostly granite, granodiorite, quartz syenite and monzodiorite. Different types of granitic rocks are exposed in different tectonic units. The granitoids on the northern margin of the Yili Plate mainly formed in late Paleozoic (413Ma ~ 281Ma), those with ages varying from 413Ma to 297Ma show continental arc affinities and the magnesian calcalkalic metaluminous diorite of 281Ma display the geochemical characteristics similar to those of granites formed during the postorogenic period. The granitiods on the southern margin of the Yili Plate include the adakite diorite of 470Ma which was formd by partial melting of thickened lower crust, the postcollisional alkalifeldspar granite of 430Ma, the volcanic arc granite of 348Ma and the Triassic postcollisional granite. The granitoids in the Central Tianshan Plate formed in 479Ma ~ 247Ma, mainly in 433Ma ~ 321Ma. The granitic rocks with ages of 479Ma ~ 321Ma are magnesian calcalkalic to alkalic rocks with continental arc affinities. A few
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鄂ICP備17016276號-1