地质通报2024，Vol.43Issue(12)：2219-2236,18.DOI:10.12097/gbc.2024.05.031
大兴安岭北段窝里河早古生代蛇绿岩识别及构造背景
Identification and tectonic setting of Early Paleozoic ophiolite in Wolihe,northern part of Greater Khingan Mountains
摘要
Abstract
A set of mafic-ultramafic rocks emerged from the Early Paleozoic volcano-sedimentary strata in the Wolihe of Duobaoshan area,northern part of the Greater Khingan Mountains,whose formation age and structural properties are still unclear.In this paper,petrology,petrogeochemistry and zircon U-Pb(LA-MC-1CP-MS)chronology are used to systematically study the set of mafic-ultramafic rocks.The results show that the mafic-ultramafic rocks include serpentinite,serpentinized pyroxene peridotite,altered gabbro,hornblende gabbro,basaltic andesite and pillow basalt,which have the characteristics of ophiolite combination;The first two are mantle rocks,gabbro has the characteristics of cumulates,basalt andesite is equivalent to basic dike,pillow basalt is submarine extruded rock;They are distributed in the matrix of Early Paleozoic stratified pyroclastic rock and clastic sedimentary rock,and together constitute a set of ophiolitic mellitic rocks.Among them,mafic rocks belong to the calc-alkaline series,ultramafic rocks and mafic rocks are rich in large ion lithophile elements Ba,K,Sr,and depleted in high field strength elements Nb,P,Ti and Th,which have the characteristics of active continental margin arc volcanic rocks.The formation age of basalt andesite in the upper unit of ophiolite is 447 Ma.In summary,it is considered that the ophiolite belongs to suprasubduction zone type ophiolite(SSZ),which formed in the tectonic setting of the arc back basin.The youngest geological body of the ophiolite tectonic emplacement is the Early to Middle Ordovician,and it is speculated that the ophiolite tectonic emplacement is located at the end of the late Ordovician,it is inferred that the ophiolite tectonic emplacement was at the end of the Late Ordovician.关键词
多宝山窝里河/SSZ型蛇绿岩/弧背盆地/晚奥陶世Key words
the Wolihe area of Duobaoshan/suprasubduction zone type ophiolite/island arc rift basin/Late Ordovician分类
天文与地球科学引用本文复制引用
付俊彧,杨晓平,崔丹丹,杨浩,那福超,庞雪娇,孙巍..大兴安岭北段窝里河早古生代蛇绿岩识别及构造背景[J].地质通报,2024,43(12):2219-2236,18.基金项目
中国地质调查局项目《东北地区数据更新及地质编图》(编号:DD20230224)、《中国大地构造演化和国际亚洲大地构造图编制》(编号:DD20190360) （编号:DD20230224）
