摘要
抽拉—逆冲岩片构造是杨志华等在研究秦岭造山带过程中提出的一种关于大陆造山带形成与演化的全新构造观。通过西秦岭造山带腹地的西成矿田西汉水群的解体和再划分，结合必要的测试分析，首次在该区发现元古宇地层单元。该地层单元无论在变质程度，还是在变形层次、序列、样式上均与古生界存在巨大差别。经详细的构造解析及区域地质的调研，我们认为该区元古宇是在晚三叠世由西向东抽拉—逆冲至地表的，西成矿田中矿床分布严格受抽拉—逆冲岩片控制，而且西成矿田中最大的矿床——厂坝铅锌矿是产于元古宇而不是泥盆系中。因此，过去在该区建立的热水沉积成矿模式的基础已不复存在。我们结合抽拉—逆冲岩片构造思想，提出了抽拉—逆冲岩片构造控矿模式，建立了不同岩片系统与相应的不同类型矿床相互对应的关系。这为大陆造山带成矿理论的研究提供了新的思维。
The draw thrust sheet tectonics is a new viewpoint put forward by Yang Zhihua during his study on development and evolution of the Qinling orogenic belt.On the basis of disintegration and redistribution of the Xihanshui group in the Xichen orefield in the hinterland of the western Qinling orogenic belt,and combined with essential testing results,authors firstly found the Proterozoic stratium unit in the area,which is quite different from the Palaeozoic Erathem not only in the metamorphic degree,but also in the sequence,order and form of deformation.The detailed studies indicate that the Proterozoic Erathem was drawn and thrusted to the surface from west to east at the late Trassic Epoch,that the distribution of ore deposits in the Xicheng ore field was controlled by the draw thrust sheet,and that the largest ore deposit,the Changba Pb Zn deposit in the Xicheng ore field occurs in the Proterozoic Erathem, but not in Devonian system.Therefore the basement for the mineralization model with thermal water sedimentation built in the past is not existed in this area. Authors proposed an ore controlling model by draw thrust sheet tectonics,and determined the mutual corresponding relations between the different sheet system and the corresponding ore deposits of different types.Which has provided a new thinking for study of metallogenic theory in the continental orogenic belt.
出处
《矿产与地质》
1997年第6期381-387,共7页
Mineral Resources and Geology
关键词
抽拉
逆冲
岩片构造
成矿模式
铅锌矿床
Draw thrust sheet tectonics,Xicheng ore field,Mineralization model,Lead zinc deposit
