摘要
北山造山带是天山—兴蒙造山带的关键枢纽地带,该地区蛇绿岩系统的地质—地球化学研究,对于探讨中亚造山带的演化有着非常重要的意义。系统报道了月牙山蛇绿岩的主量元素、微量元素、Sr-Nd-Pb-Hf同位素组成及SHRIMP年代学研究成果。蛇绿岩套中斜长花岗岩的精细SHRIMP锆石U-Pb年龄为(536±7)Ma,表明该蛇绿岩形成于早寒武世晚期。月牙山蛇绿岩中蚀变橄榄岩、变基性岩系统的地球化学特征推测其应形成于与岛弧无关的构造环境。结合区域地质特征分析表明它应形成于板内深大断裂—初始裂谷演化至陆间有限小洋盆构造环境。
Beishan Orogen is a key area of Tianshan-Xing＇an Mongolian Orogen.The geological-geochemical study on the ophiolite units from the region will be of great significance for the evolution research of the Central Asian orogenic belt.This research focuses on major elements,trace elements,Sr-Nd-Pb-Hf isotopic compositions and SHRIMP geochronology of the Yueyashan ophiolite suites in Beishan.The fine zircon SHRIMP U-Pb age of plagiogranite is（536±7） Ma,showing that the ophiolites formed in the late Early Cambrian.The geochemical characteristics of the alteratic peridotite and metabasic rocks of the Yueyashan ophiolites indicate that the ophiolites formed in the mid-ocean ridge environment independent of island arcs.With respect to the regional geological features,this paper suggests that the Yueyashan ophoplites formed in a tectonic setting of intraplate discordogenic fault-the original rift evolving to a limited small oceanic basin.
出处
《现代地质》
CAS
CSCD
北大核心
2012年第5期1008-1018,共11页
Geoscience
基金
国家自然科学基金项目(40603011)
关键词
北山
中亚造山带
蛇绿岩
地球化学
SHRIMP定年
Beishan
Central Asia orogenic belt
ophiolite
geochemistry
zircon SHRIMP U-Pb age
作者简介
侯青叶，女，副教授，1978年出生，地球化学专业，主要从事区域地球化学和环境地球化学的教学和科研工作。Email：qingyehou@cugb．edu．cn。
