西秦岭天水地区关子镇蛇绿岩的厘定及其地质意义  

Definition of the Guanzizhen ophiolite in Tianshui area,western Qinling, and its geological significance

作　　者：裴先治[1] 丁仨平 胡波[1] 李勇[1] 张国伟[2] 郭军锋[1] 

机构地区：[1]长安大学地球科学与国土资源学院,陕西西安710054 [2]西北大学地质学系,陕西西安710069

出　　处：《地质通报》2004年第12期1202-1208,共7页Geological Bulletin of China

基　　金：国家自然科学基金重点项目(编号:40234041);教育部科学技术研究重点项目(编号:104175);国土资源部"十五"科技项目(批准号:20010201);中国地质调查局地质调查项目(编号:200013000154)资助。

摘　　要：西秦岭天水地区关子镇蛇绿岩由变质基性火山岩(斜长角闪片岩)和蛇纹岩、变辉石岩、变辉长岩等构造岩块组成。其中的变质基性火山岩具有N-MORB的地球化学特征,显示关子镇蛇绿岩是洋脊型蛇绿岩残片,是新元古代—早古生代期间西秦岭李子园-关子镇-武山洋盆扩张过程中岩浆活动的产物,代表了东秦岭商丹早古生代古缝合带在西秦岭造山带向西延伸的组成部分。The Guanzizhen ophiolite in the Tianshui area, western Qinling, is composed of metabasic volcanic rocks (amphibolite) and tectonic blocks of serpentinite, metapyroxenite and metagabbro. Of these rocks, metabasic volcanic rocks have the geochemical features of N-MORB, which indicates that the Guanzizhen ophiolite is a remnant fragment of oceanic ridge ophiolite, formed by magmatic activity in the process of extension of the Liziyuan-Guanzizhen-Wushan ocean basin in the western Qinling from the Neoproterozoic to early Paleozoic and represents a westward extension of the Early Paleozoic Shangdan paleosuture zone of the East Qinling in the West Qinling orogenic belt.

关 键 词：蛇绿岩 古缝合带 N-MORB 天水 西秦岭 

分 类 号：P588.125[天文地球—岩石学] P588.145[天文地球—地质学]