石油实验地质2017，Vol.39Issue(3)：362-369,8.DOI:10.11781/sysydz201703362
西天山巴尔盖提花岗岩体年龄、地球化学特征与构造意义
Geochronology, geochemical properties and tectonic significance of Baergaiti granitoid in western Tianshan Mountain, NW China
摘要
Abstract
The Baergaiti granitoid is located in the Boluohuoluo tectonic belt in the western Tianshan Mountain of the Yili Basin.LA-ICP-MS zircon U-Pb shows age of 374±7.0 Ma, corresponding to the Late Devonian.Petrogeochemical analyses suggest that the intrusion belong to calc-alkaline metaliferous rocks characterized with high silica, potassium, and alkalinity, low magnesium and titanium.The contents of SiO2, Al2O3, K2O, Na2O range 70.72%-79.12%, 9.87%-14.51%, 4.13%-5.54%, 2.87%-4.35%, respectively.Meanwhile, the REE contents show an obvious rich LREE pattern ((La/Yb)N ranges 7.61-16.31) with negative Eu anomalies.Large ion lithophile elements such as Rb, Th and U are relatively enriched, whereas high strength field elements such as Nb, Ta and Ti are relatively depleted.Geochemical and isotope characteristics show a transition feature of high-K calc-alkaline I-A type granite.The analyses of a regional angular unconformity and sedimentary features suggest that the Baergaiti granitoid was deposited under a post-orogenic intra-continental extensional tectonic setting during the Late Devonian, and formed a complete tectonic evolution cycle coupling with the Carboniferous volcanic-sedimentary strata.关键词
巴尔盖提花岗岩体/锆石U-Pb年龄/I-A型花岗岩/造山后伸展/西天山Key words
Baergaiti granitoid/zircon U-Pb dating/I-A type granite/post-orogenic extension/western Tianshan分类
能源科技引用本文复制引用
高山林..西天山巴尔盖提花岗岩体年龄、地球化学特征与构造意义[J].石油实验地质,2017,39(3):362-369,8.基金项目
国家科技重大专项(2011ZX05005-004) 资助. （2011ZX05005-004）
