地质论评2012，Vol.58Issue(6)：1023-1037,15.
阿尔泰南缘冲乎尔盆地康布铁堡组变质酸性火山岩年龄及岩石成因
Geochronology and Genesis of Meta-felsic Volcanic Rocks from the Kangbutiebao Formation in Chonghuer Basin on Southern Margin of Altay, Xinjiang
摘要
Abstract
The Chonghuer basin is one of the fault-bounded volcano-sedimentary basins on the southern margin of the Altay orogenic belt, where the Kangbutiebao Formation ( Fm. ) stratigraphic unithosted many economic deposits outcrops. LA-ICP-MS U-Pb zircon analyses from two meta-rhyolites and one meta-tuff of the Kangbutiebao Fm. in the Chonghuer Basin yield weighted mean 206Pb/238U ages of 385. 3 ± 1. 2Ma,398. 1 ± 1. 8Ma and 405. 6 ± 2. 2Ma, respectively, which can be interpreted as the eruption age of the Kangbutiebao silicic volcanic rocks in the Chonghuer Basin. The meta-rhyolites have similar geochemical features to meta-rhyolites in Kelang Basin and Maizi Basin, which are low-Ti rhyolite with obvious negative anomaly of Ti, P, Sr, Ba, Nb, Ta and Eu (δEu =0.25 ~ 0. 54) , obvious enrichment of Th, U, Pb, Zr, Hf and LREE. These features, together with the regional geological characteristics, indicate that these felsic volcanic rocks were generated by partial melting of lower crust on an active continental margin. These volcano-sedimentary basins are down-faulted Basin formed in compression tectonic environment of Early-Middle Devonian period.关键词
变质酸性火山岩/地球化学/LA-ICP-MS锆石U-Pb定年/新疆阿尔泰南缘Key words
Meta-felsic-volcanic rocks/ geochemistry/ LA-ICP-MS Zircon U-Pb dating/ southern margin of the Altay orogenic belt引用本文复制引用
柴凤梅,杨富全,刘锋,耿新霞,姜丽萍,吕书君,郭旭吉,陈斌..阿尔泰南缘冲乎尔盆地康布铁堡组变质酸性火山岩年龄及岩石成因[J].地质论评,2012,58(6):1023-1037,15.基金项目
本文为国土资源部公益性行业科研专项经费项目(编号200911007-06)、国家科技支撑计划项目(编号2011BAB06B03-02)和新疆大学"天山学者"特聘教授启动经费联合资助成果. （编号200911007-06）
