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

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。

Abstract: 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 feature