青海德令哈石底泉地区牦牛山组火山岩LA-ICP-MS锆石U-Pb年龄及地质意义

发布时间：2018-05-25 18:32

本文选题：牦牛山组 + 锆石U-Pb年龄　；参考：《地质论评》2017年06期

【摘要】：本文对德令哈市石底泉地区牦牛山组火山岩进行了年代学、岩石学和地球化学研究,主量元素和微量元素分析结果显示岩石具有高钾高钠,贫铁镁的特征,属中酸性岩类,具有岛弧火山岩的地球化学特征。牦牛山组上部火山岩段的安山岩LA-ICP-MS锆石U-Pb年龄为395.7±2.7Ma,确定其形成时代不晚于早泥盆世,而不是传统认为的晚泥盆世,为柴达木盆地北缘早古生代的构造演化提供新的年代学依据。综合分析表明,石底泉地区牦牛山组火山岩为活动大陆边缘构造环境的产物,其形成与板块俯冲作用密切相关。
[Abstract]:In this paper, the geochronology, petrology and geochemistry of yak Niushan volcanic rocks in Shidiquan area of Delingha City have been studied. The main elements and trace elements show that the rocks are characterized by high potassium, high sodium, low iron and magnesium, and belong to intermediate-acid rocks. It has geochemical characteristics of island arc volcanic rocks. The LA-ICP-MS zircon U-Pb age of andesite in the upper volcanic member of Yaniushan formation is 395.7 卤2.7 Ma. it is determined that the age of its formation is not later than the early Devonian, rather than the traditional late Devonian, which provides a new chronological basis for the early Paleozoic tectonic evolution in the northern margin of Qaidam Basin. The comprehensive analysis shows that the volcanic rock of Yaniushan formation in Shidiquan area is the product of active continental margin tectonic environment and its formation is closely related to plate subduction.
【作者单位】：陕西地矿第一地质队;
【基金】：中国地质调查局地质调查项目(编号:DD20160012)的成果~~
【分类号】：P588.14;P597.3

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