中国地质2016，Vol.43Issue(5)：1545-1557,13.DOI:10.12029/gc20160505
新疆中天山干沟一带晚石炭世花岗岩的岩石成因及其地质意义
Petrogenesis and geological significance of the Late Carboniferous granites from Gangou, Central Tianshan Mountains, Xinjiang
摘要
Abstract
Granitoid plutons are widespread in Gangou of Central Tianshan orogen. Previous studies of the augen granite and the fine-grained granite from north Gangou revealed that their SHRIMP U-Pb dating ages were 428 Ma and 361-368 Ma, respectively. Comparatively, zircon LA-ICP-MS U-Pb dating of the south granitoid pluton in this study yielded the 206Pb/238U age of 301±1.0 Ma. Major and trace elements show that the granites belong to high-K calc-alkaline series, and theirσ=2.67-3.22. In addition, they are enriched in LREE, Rb, K, Th, La, Zr and Hf, and depleted in Ba, Sr, Nb, Ta, P and Ti. They show a transitional features from I-type to A-type. Compared with the Silurian-Devonian granites, late-Carboniferous granits are characterized by lower ISr values (0.704771-0.705451), higherεNd(t) (2.14-2.51) and younger TDM2 (861-891 Ma), suggesting that more new depleted mantel-derived materials contributed to the generation of the granites during post orogen. It is therefore held that the petrogenesis of the late-Carboniferous granites was related to the underplating of the mantle-derived magmas. This study also provides new evidence for Phanerozoic vertical continental crustal growth in the Central Asian orogenic belt.关键词
干沟/晚石炭世/花岗岩/幔源岩浆底侵/地壳增生Key words
Gangou/late Carboniferous/granites/mantle-derived magma underplating/crustal growth分类
天文与地球科学引用本文复制引用
冯光英,杨经绥,刘飞,牛晓露,高健..新疆中天山干沟一带晚石炭世花岗岩的岩石成因及其地质意义[J].中国地质,2016,43(5):1545-1557,13.基金项目
中国地质调查局工作项目（DD20160023-01，DD20160022-01）、公益性行业科研专项（201511022）、国家行业专项（SinoProbe-05-02）、自然科学青年基金项目NSFC（41303019）、中国地质科学院地质研究所基本科研业务（J1321）联合资助。 （）
