中国西北地区南华纪—古生代构造重建及关键问题讨论  

Tectonic reconstruction of northwest China in the Nanhua-Paleozoic and discussions on key issues

作　　者：计文化[1,2] 李荣社[1,2] 陈奋宁[1,2] 杨博[1] JI Wenhua;LI Rongshe;CHEN Fenning;YANG Bo(Xi′an Center of Geological Survey,China Geological Survey,Xi′an 710054,Shannxi,China;Center for Orogenic Belt Geology,China Geological Survey,Xi′an 710054,Shannxi,China)

机构地区：[1]中国地质调查局西安地质调查中心,陕西西安710054 [2]中国地质调查局造山带地质研究中心,陕西西安710054

出　　处：《地质力学学报》2020年第5期634-655,共22页Journal of Geomechanics

基　　金：中国地质调查局基础性公益性地质矿产调查项目(DD20160009);中国地质调查局基础性公益性项目(DD20190364)。

摘　　要：中国西北是古亚洲构造域和特提斯构造域共同作用的地区,南华纪—古生代时期经历了复杂的洋-陆演化过程,诸陆(地)块于三叠纪基本拼贴就位,奠定了中生代以来陆内盆山演化的基础。但对于西北地区南华纪—古生代时期古亚洲洋盆最终关闭的时限、位置,以及秦祁昆古生代造山带属于特提斯构造域还是古亚洲构造域等重大区域地质问题目前仍存在较大争议。文章在最新地质填图的基础上,通过对沉积建造、岩浆建造、变质变形等的综合分析,将西北地区南华纪—古生代的构造单元厘定为3个洋板块、4个弧盆系和2个陆(地)块群等9个二级、46个三级和112个四级构造单元,力图刻画消失的大洋盆地的残留组成和诸陆(地)块的边缘增生结构。结合古地磁、生物古地理研究成果,恢复了古生代不同时期西北洋-陆系统在全球的位置,讨论了洋盆消减、诸陆(地)块拼贴的过程。The Paleo-Asian and Paleo-Tethyan tectonic collages in northwest China experienced a complex oceancontinent evolution from the Nanhua period to Paleozoic era,and the continent-continent collisions in Triassic formed the basement to the formation of the intracontinental basin and mountain since the Mesozoic.There are still controversies on the closure and location of the Paleo-Asian oceanic basin and tectonic attribution of the Paleozoic Qin-Qi-Kun orogenic belt.Based on the new geological mapping,and analyses of sedimentary formations,magmatism formations,metamorphism and structural deformations,the Nanhua to Paleozoic tectonic units of northwest China are composed of three oceanic plates,four arc-basin systems and two continental blocks,which can be subdivided into 9 second-order,46 third-order and 112 forth-order tectonic units.These units could be used to depict the residual compositions of disappeared oceanic basins and marginal accretionary structures of the blocks(lands).Integrated with paleomagnetic and bio-paleogeographical data,we propose the Paleozoic paleogeography reconstructions of northwest China,and discuss the tectonic evolutionary process of oceanic subduction and continental assemblages.

关 键 词：古亚洲构造 特提斯构造域 南华纪—古生代 构造重建 

分 类 号：P544[天文地球—构造地质学]