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陈希节,舒良树. 2010. 新疆哈尔里克山后碰撞期构造-岩浆活动特征及年代学证据. 岩石学报, 26(10): 3057-3064
新疆哈尔里克山后碰撞期构造-岩浆活动特征及年代学证据
作者单位E-mail
陈希节 南京大学内生金属矿床成矿机制研究国家重点实验室,地球科学与工程学院,南京 210093  
舒良树 南京大学内生金属矿床成矿机制研究国家重点实验室,地球科学与工程学院,南京 210093 Lsshu2003@yahoo.com.cn 
基金项目:本文受国家重点基础研究发展计划"中亚造山带大陆动力学过程与成矿作用"(2007CB411301)资助.
摘要:
      新疆地区后碰撞期构造-岩浆活动非常活跃,其同位素年龄集中在290~270Ma。天山东段的后碰撞期构造-岩浆活动研究相对薄弱,高质量的定年数据较少。在野外地质调查的基础上,笔者选择东天山哈尔里克地区的小堡花岗岩体进行了锆石的LA-ICP-MS U-Pb定年,获得两组谐和年龄,分别为297±2Ma和295±2Ma,代表哈尔里克地区后碰撞早期岩浆作用的形成时代。小堡岩体矿物组合以斜长石、石英、钾长石、角闪石和黑云母为主,副矿物有锆石、磷灰石和磁铁矿,与I型高钾钙碱性花岗岩矿物组合基本一致。与小堡花岗岩体同时发育、空间并存的还有基性岩墙群和碱性花岗岩,构成后碰撞初始阶段三组合地质标志。结合区域地质资料,认为小堡早二叠世花岗岩体是后碰撞初期碰撞造山、地壳增厚引发下地壳物质部分熔融的产物,其构造属性为板内岩浆活动。
英文摘要:
      The post-collisional tectonic-magmatic activity in Xinjiang region is very intensive, and the isotopic age of the activity ranges mainly from 270 to 290Ma. The study on post-collisional tectonic-magmatic activity is limited and relatively weak in this region, due to the lacking of high quality chronological data. On the basis of field geological investigations, we analyze the Xiaopu granite mass of Harlik region in the eastern Tianshan. Zircons from these plutons are dated by LA-ICP-MS U-Pb method and yield weighted mean age of 297±2Ma and 295±2Ma respectively, which is considered representing early period of post-collisional magmatism. The Xiaopu granite mass mainly consists of plagioclase,quartz,K-feldspar,amphibole,biotite,and some accessory minerals such as zircon,apatite and magnetite,with a similar mineral assemblage with the typical I-type high-K calc-alkaline granite. The triplet of basic dyke swarms, kaligranites as well as alkaline granites could be regarded as a prominent indication of the initial stage of post-collision, and they occurred synchronously and coexisted in Harlik region. According to the regional geological data, we concluded that the Early Permian Xiaopu granite mass was formed by partial melting of lower crustal materials under the thickening crust during the early post-collisional extension, and the tectonic affinity of the granite mass belongs to intraplate magmatism.
关键词:花岗岩  锆石U-Pb定年  构造演化  哈尔里克山  天山东段
投稿时间:2009-05-20  修订日期:2009-08-20
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