青海东昆仑哈陇休玛辉石橄榄岩LA-ICP-MS锆石U-Pb测年及其地质意义

发布时间：2018-04-16 12:09

本文选题：东昆仑 + 锆石LA-ICP-MS　；参考：《地质科技情报》2017年01期

【摘要】：东昆仑地区是经历了多期次构造岩浆旋回后形成的一个复合型造山带,并包括多条蛇绿混杂岩带。近来,在东昆仑东段哈陇休玛一带进行地质调查过程中发现了辉石橄榄岩,其属于蛇绿岩的组成部分。利用LA-ICP-MS锆石U-Pb定年法,得到辉石橄榄岩加权平均年龄为(525.9±5.9)Ma(n=24,MSWD=0.02),确定其形成时代为早寒武世。该年龄与东昆中断裂附近的清水泉蛇绿岩的时代相近,可能都属于原特提斯洋打开时的产物,认为东昆仑造山带在早古生代早期存在一期明显的洋壳扩张事件,这为东昆仑地区东段早古生代的区域构造演化提供了新的年代学证据。
[Abstract]:The East Kunlun area is a complex orogenic belt formed after several periods of tectonic magma cycles and includes several ophiolite melange belts.Recently, pyroxene peridotite, which is a part of ophiolite, has been discovered in the geological survey of Halong Xiuma area of East Kunlun.Using the LA-ICP-MS zircon U-Pb dating method, the weighted mean age of pyroxene peridotite is 525.9 卤5.9 Ma ~ (2 +) ~ (24) MSWD ~ (2 +) ~ (0.02), which is determined to be an early Cambrian epoch.This age is close to the age of Qingshuiquan ophiolite near the middle fault of Dongkun, and may be the product of the opening of the original Tethys ocean. It is believed that there was an obvious oceanic crust spreading event in the East Kunlun orogenic belt in the early Paleozoic.This provides a new chronological evidence for the early Paleozoic regional tectonic evolution in the eastern segment of East Kunlun.
【作者单位】：中国地质调查局西安地质调查中心国土资源部岩浆作用成矿与找矿重点实验室;
【基金】：中国地质调查局地质调查项目(DD20160013;12120113029000;12120115022101)
【分类号】：P597.3;P588.125

【参考文献】