中国东南部晚中生代构造作用  

Late Mesozoic Tectonism of Southeast China

作　　者：舒良树[1] 周新民[1] 

机构地区：[1]南京大学地球科学系,210093

出　　处：《地质论评》2002年第3期249-260,共12页Geological Review

基　　金：国家自然科学基金项目(编号40172067);重点基金项目(编号40132010);中国地质调查局综合研究项目(编号200113000053)

摘　　要：濒太平洋西缘,位居东亚陆缘南段的中国东南部,是在EW向古亚洲构造域基底之上发育起来的。研究表明,该区在早、中侏罗世经历了一次从EW向古亚洲构造域向NE向西太平洋构造域的体制转换,其转换位置之一是在南岭一带,其地质标志是侏罗纪盆地内近东西走向的灰色沉积岩层、同位素年龄值为180 Ma左右的双峰式火山岩和中侏罗世A型花岗岩等。到早白垩世,本区已基本完成古亚洲域向西太平洋构造域的体制转换。中国东南部晚中生代火成岩的成因机制基本上可用古太平洋岩石圈消减作用、玄武岩浆底侵作用和地壳深熔作用相结合的模式来解释。日本中央构造线—台湾纵谷带—菲律宾民都洛-巴拉望带是晚中生代古太平洋板块向东亚陆缘的消减带。晚中生代古太平洋板块(伊泽奈琦和库拉板块)低角度(<30°)、快速率(>10cm/a)的俯冲,是西太平洋陆缘区能形成宽阔火山岩带的重要动力学原因。宽阔的火山—侵入杂岩区和6条区域断裂构成了中国东南部晚中生代的基本构造框架。台湾纵谷带为古太平洋板块的俯冲-缝合带,而发育在大陆内部的5条区域断裂则具不同构造属性:长乐—南澳带是晚中生代大陆内部的左旋走滑带,上虞—政和—大埔断裂是古基底隆升区与晚中生代火山—沉积盆地区的分界带,绍兴—江山—东乡—萍乡断裂是晚白垩世—古近纪红?Southeast China is located on the western margin of the Pacific and in the southern segment of the Eastern Asian Continental Margin. It developed on the basement of the Paleo-Asian tectonic system with E-W striking. During the Early Cretaceous, the transition from the Paleo-Asian to the Paleo-Pacific tectonic system was finished. The Nanling zone is probably one of the tectonic exchange domains. Late Mesozoic large-scale volcano-intrusion complex in the area was generated mainly by the subduction of the Paleo - Pacific plate. However, there are alkaline series basalt, bimodal volcanic rock, mixed crust-mantle rock in the area, implying the deep level tectono-magmatism or basalt underplating. The Late Mesozoic subduction zone is located in the zone from the Median Tectonic Line of Japan to the Longitudinal Valley of Taiwan and then to the Mindoro-Palawan of the Philippines. The subduction with lower angle (<30°) and fast velocity (>10 cm/a) is an important geodynamic mechanism that formed a huge volcanic belt along the Eastern Asian Continental Margin. A huge linear volcanic-intrusion complex belt and six large regional faults comprise a principal tectonic framework of the Late Mesozoic Southeast China Region. These six faults have the following geological property: the Taiwan Longitudinal Valley was a Late Mesozoic subduction zone of the Paleo-Pacific plate; the Changle-Nanao fault was a tectono-magmatic and sinistral strike-slip zone that was developed within the South China Continental Block; the Lishui-Zhenghe-Dapu fault was a boundary separating the Mesozoic volcanic-intrusion complex to southeast from pre-Mesozoic Paleo-Asian system to northwest; the Shaoxing-Jiangshan-Pingxiang zone was a boundary fault controlling Late Cretaceous-Eogene extensional basins; the Dexing-Dongxiang fault was the northern boundary of the Late Mesozoic volcanic domain and the Ganiiang fault was the western boundary of the Late Mesozoic volcanic domain. A transition from compression to extension took place about 100-90 Ma. Finall

关 键 词：俯冲带 构造体制转换 构造格架 区域断裂 晚中生代 中国东南部 

分 类 号：P542[天文地球—构造地质学]