西准噶尔扎依尔山花岗岩类地球化学与构造环境  

The Geochemistry and Tectonic Setting of Granitoids in Zhayier Mountain, West Junggar

作　　者：王金荣[1,2] 宋春晖 黄华芳[1,2] 杨占龙 

机构地区：[1]兰州大学地质系 [2]中国科学院兰州地质所

出　　处：《兰州大学学报（自然科学版）》1996年第4期155-162,共8页Journal of Lanzhou University(Natural Sciences)

基　　金：中国科学院院长基金

摘　　要：西准噶尔扎依尔山海西期花岗岩类可分为两期：第一期花岗岩类（γａ４，巴什基尔早期）σ均值为２．０５，Ａ／ＣＮＫ值小于１，均值为０．９４，Ａ／ＮＫ值大于１，均值为１．５７，属强准铝质钙碱性系列，但偏钙性；第二期（γｂ４）σ均值为２．３７，Ａ／ＣＮＫ均值为０．９４，Ａ／ＮＫ均值为１．０７，属准铝质钙碱性系列，但碱性程度较第一期的强．两期花岗岩类岩石学、矿物学及地球化学分析结果表明，第一期花岗岩类形成于大洋弧环境，石炭系杂砂岩地球化学判别结果也支持了这个结论；第二期花岗岩类形成于巴什基尔中晚期，延续至海西晚期，为造山后构造环境的产物．The Variscan granitoids in Zhayier Mountain, West Junggar can be divided into two periods:the first granitoids(γ a 4, Early Bashkirian period) with σ=1.19～2.92, average value 2.05, A/CNK average value 0.94(less than 1), and A/NK mean value 1.57(greater than 1) are attributed to highly metaluminous calc alkaline series but biasing to calcic; the second has σ average value 2.37, A/CNK average value 0.94 and A/NK value 1.07,also belonging to metaluminous calc alkli, but closing to alkali. The analytic results of the petrology, mineralogy and geochemical diagrams of the granitoids show that the first formed in oceanic island arc setting, which is also supported by the geochemical discrimination of the graywacke of Carboniferous from Zhayier Mountain, and that the second formed in post orogenic setting from the Mid Late Bashkirian to Late Variscan period. The sedimentary environment of the Xibeikulasi formation should be a relict oceanic basin after the end of the oceanic oceanic subduction.

关 键 词：花岗岩类 地球化学 构造环境 浊积岩 

分 类 号：P588.121[天文地球—岩石学]