摘要
应用马杏垣教授倡导的构造解析方法，对湘赣边区ＮＮＥ 向走滑盆岭山链的构造发展过程及样式进行了研讨，论证了该地区前中生代ＥＷ 向古特提斯构造体系与中新生代ＮＮＥ向滨太平洋构造体系之间的立交桥式横跨叠加关系和构造背景，建立了华南陆壳俯冲 会聚走滑转换造山模型，提出了新华夏式变质核杂岩构造的新概念，并对其基本特征和形成机制进行了阐述。文中强调，发育在湘赣边区的ＮＮＥ 向走滑断裂是郯庐断裂带南段的主干成分，由ＮＥ３０°同向走滑断裂（Ｐ） 和ＮＷ３２０°反向走滑断裂（Ｒ′） 交织而成的雁列菱形网结系统是该断裂在地表的基本构造样式。大多数陆壳俯冲型和会聚走滑型的花岗岩都具剪切重熔成因，雁列的半地堑盆地和新华夏式变质核杂岩体主要受走滑 伸展变形场所控制。指出自晚三叠世以来，该地区曾经历了两次不同的重大构造转换和两个性质及发展趋向相反的走滑造山过程，即印支晚期的陆壳俯冲向陆内会聚走滑转换和侏罗纪时期的会聚走滑造山；早白垩世开始的会聚走滑向离散走滑转换和白垩纪－ 老第三纪的离散走滑造山。每次构造转换和构造变形对该地区的成岩成矿都起到了重要的作用。
According to the principles and methods of structural analysis by professor Ma Xingyuan, the structural pattern and tectonic evolution of the NNE trending strike slip basin rang structure in the border region of Hu'nan and Jiangxi Provinces are discussed.The overpass superposed relationship between the pre Mesozoic EW trending paleo Tethyan tectonic system and the Mesozoic Cenozoic NNE trending marginal Pacific tectonic system as well as the tectonic background are verified.In this paper, a transform orogenic model of continental crust underthrust convergent strike slip in South China landmass is establised, and the conception of Neocathaysian metamorphic core complex is proposed.At the same time its fundamental features and forming mechanism are also discussed.This paper emphasizes that the NNE trending strike slip fault in the border region of Hu'nan and Jiangxi Provinces is a main part of the southern section of the Tan Lu fault belt.On the earth's surface,it shows as an echelon lozenge network system and was formed by the intersection of the NE30° trending synthetic strike slip fault(P) and the NW320° trending antithetic strike slip fault(R′), that so constituted the basic structural pattern.Most granites of the continental crust underthrust group(γ 1 5)and the convergent strike slip group(γ 2 5)were formed by shear remelting. The echelon style arranged semi graben basins and the Neocathaysian metamorphic core complexes are controlled by strike slip and extension deformation field.The border region had experienced two processes of tectonic transformation and two strike slip orogenies processes with different movement nature and tendency after later Triassic epoch(T 3).These were shown as the transformation from continental crust underthrust to strike slip(210 Ma)and convergent strike slip orogeny in Jurassic period(J),and also as the transformation from the convergent to the divergent strike slip(K 1)and the divergent strike slip orogeny in Cretaceous Palaeogene period(K—E).Each of them had played a significant role in diagenesis and mineralization.
出处
《地学前缘》
EI
CAS
CSCD
1999年第4期263-273,共11页
Earth Science Frontiers
基金
国家自然科学基金项目
核工业中南地质局项目
关键词
湘赣边区
走滑造山带
陆壳俯冲
构造发展样式
the border region of Hu'nan and Jiangxi Provinces, strike slip orogenic belt,continental crust underthrust,overpass superposition,Neocathaysian metamorphic core complex
