东篱科研大数据发现系统（DRDS）

位置：成果数据库 > 期刊 > 期刊详情页

U-Pb zircon dating constraints on formation time of Qilian high-grade metamorphic rock and its tectonic implications

ISSN号：0379-1726
期刊名称：《地球化学》
时间：0
分类：P597.3[天文地球—地球化学;天文地球—地质学] P588.3[天文地球—岩石学;天文地球—地质学]
作者机构：[1]State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan 430074, China, [2]Faculty of Earth Sciences, China University of Geosciences, Wuhan 430074, China, [3]State Key Laboratory of Continental Dynamics, Northwest University, Xi'an 710069, China
相关基金：Supported by die National Natural Science Foundation of China （Grant Nos. 40234052 and 40521001） and Program for Changjiang Scholars and Innovative Research Team in University （Grant No. IRT0441）.The authors thank Dr. Wu Yuanbao for helpful discussion and three anonymous reviewers for constructive suggestions.

作者： XU WangChun[1,2], ZHANG HongFei[1,2], LIU XiaoMing[3]

关键词：祁连山, 高级变质岩, 形成时间, U-Pb锆测年, 地质构造, zircon U-Pb age, high-grade metamorphic rock, geotectonic affinity, Qilian Mountains

中文摘要：

以便在 Qilian 山抑制高级变形岩石的形成时间， U-Pb 锆石标明日期被在 Qilian 山地下室系列为 Hualong 组的 aparagneiss 使用 LA-ICPMS 技术执行并且一弱 foliated 花岗石那 intruds 进 Hualong 组。从帕拉片麻岩的锆石与回合或亚回合形状由由岩屑形成的岩浆锆石主导地组成。他们有 Pb/~(206 ) Pb 主要变老的 ~(207 ) 从 880 ～ 900 妈，与一个加权的平均数 891 ±使 9 妈变老，它作为它的火的起源的岩浆结晶化年龄被解释并且能为 theHualong 作为更低的年龄限制被拿组。为弱有叶花岗石的岩浆结晶化年龄是 875 ± 8 妈，哪个上面的年龄为 Hualong 组限制的罐头去赴。因此， HualongGroup 的形成时间被抑制在某时在 875 和 891 妈之间。从两帕拉片麻岩的一些锆石有叶 andweak 的花岗石显示 1000 ～ 1700 妈的旧继承年龄和年轻变形年龄早古生代。锆石年龄分发模式证实 Qilian 山和 Qaidam 盆的北边缘有一个统一地下室，与与 YangtzeBlock 的大地构造的亲密关系。结果也表明 Hualong 组的沉积由于快速的外壳的高举侵蚀由快速的累积形成了。这进程可以源于集中的 Neoproterozoic orogenesisdue 到晚饭大陆 Rodinia 的汇编。

英文摘要：

In order to constrain the formation time of high-grade metamorphic rocks in the Qilian Mountains, U-Pb zircon dating was carried out by using LA-ICPMS technique for a paragneiss of the Hualong Group in the Qilian Mountains basement series and a weakly foliated granite that intruds into the Hualong Group. Zircons from the paragneiss consist dominantly of detrital magma zircons with round or sub-round shape. They have ^207Pb/^206Pb ages mostly ranging from 880 to 900 Ma, with a weighted mean age of 891 ±9 Ma, which is interpreted as the magma crystallization age of its igneous provenance and can be taken as a lower age limit for the Hualong Group. Magma crystallization age for the weak-foliated granire is 875±8 Ma, which can be taken as an upper age limit for the Hualong Group. Accordingly, the formation time of the Hualong Group is constrained at sometime between 875 and 891 Ma. A few zircons from both paragneiss and weak-foliated granite display old inherited ages of 1000 to 1700 Ma and young metamorphic ages of Early Paleozoic. The zircon age distribution pattern confirms that the Qilian Mountains and the northern margin of Qaidam Basin had a united basement, with geotectonic affinity to the Yangtze Block. The results also reveal that sediments of the Hualong Group formed by rapid accumulation due to rapid crustal uplift-erosion. This process may result from intensive Neoproterozoic orogenesis due to assembly of the suppercontinent Rodinia.

同期刊论文项目