The Petrogenesis and Tectonic Environment of the Dongping Granite in South Frontier of the Altyn Mountains
TAO Jin-yu1, LI Jian-ming1,2, WANG Li-qun3, ZHANG Yong-shu3, WU Zhi-xiong3
1. School of Geosciences, Yangtze University, Wuhan 430100, China;
2. Hubei Cooperative Innovation Center of Unconventional Oil and Gas, Wuhan 430100, China;
3. Exploration and Development Research Institute of Qinghai Oilfield Company, PetroChina, Dunhuang Gansu 736202, China
Abstract：In order to probe the petrogenesis and tectonic setting of the Dongping granite batholith in south frontier of the Altyn Mountains, studies on petrological and elemental geochemical characteristics of the Dongping granite have been carried out in this paper. The results show that the Dongping granite is characterized with rich silica (average SiO2 content of 71.4%) and aluminum (average Al2O3 content of 13.57%), AR (alkalinity rate) values of 2.23-3.19, and high aluminum saturation indexes (A/CNK values >1.44), indicating that it belongs to peraluminous and high potassium calc-alkaline granite. It is enriched in LILEs and depleted in HFSEs, with moderate right-declined REE patterns, negative Eu anomalies (δEu of 0.44-0.61), and the characteristic of LREEs enrichment. The Dongping granite belongs to the S-type granite, which was derived from the re-melting of greywacke in crust, with involvement of none or little mantle material.It is assumed that the magmatic intrusion of the Dongping granite occurred in the island-arc setting in Late Caledonian period, indicating the existence of trench-arc-basin system in south frontier of the Altyn mountains. It is believed that the Dongping granite was formed in the evolution background of the subduction and collision of the Tarim terrain to the Qaidam terrain.
陶金雨, 李建明, 汪立群, 张永庶, 吴志雄. 阿尔金山前东坪花岗岩成因及其构造环境研究[J]. 矿物岩石地球化学通报, 2018, 37(3): 461-468.
TAO Jin-yu, LI Jian-ming, WANG Li-qun, ZHANG Yong-shu, WU Zhi-xiong. The Petrogenesis and Tectonic Environment of the Dongping Granite in South Frontier of the Altyn Mountains. Acta Metallurgica Sinica, 2018, 37(3): 461-468.
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