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华北地台中生代热液成矿的构造环境

胡受奚 叶瑛 赵懿英 刘红樱   

  1. 南京大学地球科学系
  • 收稿日期:1995-03-20 修回日期:1995-03-20 出版日期:1995-09-20 发布日期:1995-09-20

THE MESOZOIC TECTONIC SETTING OF NORTH CHINA PLATFORM AND ITS RELATION TO HYDROTHERMAL M ETALLOGENESIS

Hu Shouxi1, Ye Ying2, Zhao Yiying1, Liu Hongying1   

  1. 1. Dept. of Earth Sci. , Nanjing University; 2. Dept. of Earth Sci., Zhejiang University
  • Received:1995-03-20 Revised:1995-03-20 Online:1995-09-20 Published:1995-09-20

摘要: 本文阐述的是在海西末期自初始欧亚板埠形成后,具有早前寒武结晶基底的华北地台,自中生代开始,便处于古太平洋板块强烈挤压俯冲以及与北面西伯利亚板块,南面华南板是一步挤压俯冲所造成的两大构造应力场和构造环境中。前者所造成的构造线方向主要为NE和NNE走向,并由于古太平洋板块作用于我国东部大陆的Farallon、Kula和Ianagisl板块都具有左行运动的特征,这就造成华北地台、整个中国东部大陆NE和NNE的构造带及有关花岗岩带和成矿带的分布,并使矿床、矿田、矿带等普遍地具有左行走滑的特征;后者板块问南北向挤压造成EW向花岗岩带和有关的热液矿床、矿带的分布。 古太平洋板块作用于初始欧亚板块所产生的“面距离效应”是随着离开俯冲带或海岸线而减弱。本文以华北地台东缘胶北地体和南缘华熊地体内部中生代金、铝等热液矿床、矿田、矿带和成矿带为例,讨论了热液成矿的构造环境。

Abstract: The initial Eurasian plate was formed during the Late Hercynian cycle. Its intense interaction with Paleo-Pacific plate (includmg Farallon,Kula and Izanagi plates) took place during the Indosinian event and was the kinetic source not only for the extensive metamorphism and ductile shearing, but also for A -type subduction and relevant granitoid formation in the North China Platform, espacially along its margin. After the formation of initial Eurasian Plate in the final phase of the Hercynlan cycle, North China Platform with its Early Precarnbrlan crystalline basement was situated in an intensely campressive tectonic setting caused by two dominant stress fields related respectively to Paleo-Pacfic subduction and further compression and to compression and A-type subduction between that platform and the Siberian plate to the north and the South China Plate to the south. Tectonic line created by the former stress field strikes in NE and NNE directions, along which there are important granitic and metallogenic belts in East China. Mineral deposits, ore fields and belts controlled by this tectonic line shows inistral strike-slip character following the pattern along which the components of the Paleo-Pacific, such as Farallon,Kuia and Izanagi, acted on East China continent. The latter stress fie1d is related to intraplate compression in S-N direction and has brought about granitic belts and relevant hydrothermal ore deposits arranged in E-W strike. “The remote tectonic effect” caused by the Paleo-Pacific acting on initial Eurasian Plate dies away from the subduction zone or coast line, so that the predominant NE-and NNE-trending tectonic pattern in the coastal area gives its way to the NWW-and EW-trending pattern westwards. This is demonstrated by the examples from Mesozoic Au, Mo and other hydrothermal mineral deposits and orefields in Jiaobei and Huaxiong Terranes at the cast and south margin of North China Platform.