地质通报2017，Vol.36Issue(9)：1569-1582,14.
中天山地块尾亚地区早古生代构造格架——来自野外地质和锆石U-Pb年代学的证据
The Early Paleozoic tectonic framework in Weiya area of Central Tianshan Block-Evidence from field geological investigation and zircon U-Pb chronology
摘要
Abstract
Through detailed field work in Weiya area, the authors hold that the main rock assemblage there consists of arc complexes including some metamorphic rocks intruded by post-tectonic granites such as K-feldspar granite. Moreover, these arc complexes were partly metamorphosed and deformed due to the CAOB orogenesis there. Thus, the distribution of metamorphic rocks is limit-ed, and their metamorphic degree has reached greenschist facies with strong cleavage. Sample YM01, YM02 are respectively biotite plagioclase leptynite and amphibolite plagioclase leptynite, and their original rocks are acidic volcanoclastic rocks and diorite, respec-tively. Both zircons of these two samples have recorded the arc magmatic events in northern Central Tianshan Block, suggesting large-scale southward subduction of Tianshan Ocean (part of Paleo-Asian Ocean) between the Ordovician and Devonian. The earli-est subductive processes of Tianshan Ocean from the Late Cambrian indicate that the tectonic transformation occurred in Central Tianshan Block from passive continental margin to active continental margin at that time. Moreover, there are no Precambrian age re-cord in arc complex there. Combined with previous work, the authors hold that at least in Weiya area there must have existed limited Precambrian materials and metamorphic rocks with strong foliations and cleavages, which were probably connected with the orogenic tectonics.关键词
中天山地块/岛弧岩浆增生作用/奥陶纪—泥盆纪/尾亚地区Key words
Central Tianshan Block/arc magmatic accretionary process/Ordovician to Devonian/Weiya area分类
天文与地球科学引用本文复制引用
周海,陈亮,孙勇..中天山地块尾亚地区早古生代构造格架——来自野外地质和锆石U-Pb年代学的证据[J].地质通报,2017,36(9):1569-1582,14.基金项目
中国地质调查局项目《北山-东天山及邻区前寒武纪陆块组成及对比》(编号:1212011121137)和国家自然科学基金项目《固阳花岗-绿岩地体的成因及晚太古代地壳生长机制》(批准号:40602023)、《鱼洞子杂岩的成因与扬子克拉通晚太古代地壳增生》(批准号:41072147) （编号:1212011121137）
