摘要
天山早古生代花岗岩普遍发育片麻状构造或者发生糜棱岩化，主要是由于受到后来构造——变形热事件影响的结果．锆石U-Pb定年结果显示．天山早古生代花岗岩形成于380-490Ma,目前主要产出在具有元古代基底的中天山构造带中，在霍拉山一带也应该具有一定的规模．它们的岩石地球化学不显示活动大陆边缘花岗岩的特点，而是具有铝质A型花岗岩的特征．它们的形成可能与南天山洋南支的扩张过程有关，或者与早古生代的一次造山过程的晚期伸展阶段有关．
In the Chinese Tianshan, the early Paleozoic granites are often characterized by gneissic and mylonitic structures that were produced by late tectonics and deformation or thermal events. In this paper, we present the results of zircon U-Pb dating on the granites. In combination with geochronological data from the literature, it has been revealed that the early Paleozoic granites in the Chinese Tianshan were emplaced in the Proterozoic basement which mainly occur in middle Tianshan and the Huolashan during a period from 490 to 380 Ma. Their geochemistry shows the typical features of the so-called aluminous A-type granites. We can speculated about that the formation of the early Paleozoic granites in the Chinese Tianshan could be related to either the extension of the southern branch of the Southern Tianshan Ocean or a late extensional process of an orogenic cycle in the early Paleozoic.
出处
《新疆地质》
CAS
CSCD
2004年第1期4-11,共8页
Xinjiang Geology
基金
国家重大基础研究项目(2001CB409802)子项目资助
