中国地质调查2025，Vol.12Issue(4)：24-35,12.DOI:10.19388/j.zgdzdc.2024.205
内蒙古东部马鞍山地区蛇绿混杂岩的地质特征及构造意义
Geological characteristics and tectonic significance of ophiolite mélange in Ma'anshan area of the eastern Inner Mongolia
摘要
Abstract
Erlianhaote Hegenshan ophiolite belt is the largest exposed area of Late Paleozoic ophiolite in the east-ern part of the Central Asian Orogenic Belt.It was once considered to be the suture zone of the last collision be-tween the North China Craton and Siberian Plate,and there is still controversy in its tectonic attributes.The newly identified ophiolitic mélange in Ma'anshan area of Inner Mongolia is located in the eastern part of Xingmeng Oro-genic Belt and is the eastern extension of the Erlianhaote-Hegenshan ophiolite belt.The discovery of the ophi-olitic mélange fills the gap of the middle section of the Erlianhaote-Hegenshan-Heihe suture zone and provides new evidence for the evolution of Paleo-Asian Ocean tectonic domain.It was found that the mélange is composed of blocks and matrix through petrographic,geochemical and chronological studies of Ma'anshan ophiolitic mélange.The blocks are serpentinized peridotite,peridotite,diabase,basalt,high-magnesium andesite,andes-ite and rhyolite,and the matrix is mainly turbidite.The serpentinized peridotite has the characteristics of supra-subduction zone(SSZ)type ophiolite,and the diabase has the characteristics of SSZ tectonic background gene-sis.The basalt has the characteristics of(enriched mid-ocean ridge basult E-MORB)and island arc basalt,indicating that it was formed in a back-arc basin environment.The zircon U-Pb age(344.4±1.4)Ma of the diabase in Ma'anshan ophiolitic mélange is similar to the age obtained by previous researchers from Hegenshan ophiolite,confirming the existence of a subduction zone(suture zone)in this area,which is of great significance for the determination of the regional tectonic framework.关键词
蛇绿混杂岩/SSZ型/玄武岩/马鞍山地区/内蒙古Key words
ophiolitic mélange/SSZ type/basalt/Ma'anshan area/Inner Mongolia分类
天文与地球科学引用本文复制引用
张彬,任龙,赵院冬,王存柱,王春晖,曲成成..内蒙古东部马鞍山地区蛇绿混杂岩的地质特征及构造意义[J].中国地质调查,2025,12(4):24-35,12.基金项目
中国地质调查局"吉林那尔轰一带金铜多金属找矿靶区优选与评价(编号:DD20230371)"及"内蒙古1∶5万哈拉黑等八幅区域地质调查(编号:DD20160201)"项目联合资助. （编号:DD20230371）
