现代地质2017，Vol.31Issue(3)：498-507,10.
内蒙古索伦山地区蛇绿岩岩石单元地质特征、就位机制及时限
Geological Characteristics, Emplacement Mechanisms and Timing of the Ophiolites in Solonker Zone, Inner Mongolia
摘要
Abstract
The ophiolites in Solonker zone,Inner Mongolia is of significance on evolution of the Paleo-Asian Ocean.The ophiolites from the study area have been investigated and studied systematically on petrology.On that basis,emplacement mechanisms and timing of the Solonker zone ophiolites were discussed.Combined with analyses of the geological and tectonic characteristics of the ophiolites from Solonker,we concluded that the ophiolites consist of compositions of both mantle and oceanic crust.There are a relatively complete sequence of the ophiolite in Solonker zone.In Solonker zone,mantle rocks are composed of serpentinized dunite,serpentinized lherzolite,serpentinized harzburgite,olivine pyroxenite and silicified,carbonated metamorphic ultrabasic rock (weathering crust)and so on.Oceanic crust rocks are composed of gabbro,diabase,basalt and chert.The ophiolites occur in the form of tectonic slices and blocks.The contact relationship between the ophiolites and adjacent geological body rocks is fault contact.Based on different proeesses and characteristics,four mechanisms of ophiolite emplacement are mainly discussed:collision-obduction type,accretion-underplating type,subduction-flake type,and corner flow type.Among the four mechanisms,the characteristics of subduction-flake type ophiolite emplacement mechanisms are as the following:sequence in rock associations of ophiolite is complete;the ophiolites emerge in the form of tectonic slices and blocks;the contact relationship between tectonic slices,blocks and matrix is fault contact;arc magmatic rocks occur in the subducting belts next to continent and so on.Geological characteristics of the ophiolites from Solonker conform basically with the characteristics of subductionflake type ophiolite emplacement mechanisms.Emplacement mechanism of ophiolites in the Solonker zone is mainly subduction-flake of mid-ocean ridge type.Since ophiolites emplacement occur in 10 Ma after forming oceanic lithosphere and the SHRIMP U-Pb age dating of zircons from the gabbro of ophiolite is (280.7 ± 5.3) Ma,emplacement timing of the ophiolites in Solonker zone is 270 Ma or so.关键词
蛇绿岩/就位机制/就位时限/内蒙古索伦山Key words
ophiolite/emplacement mechanism/emplacement timing/Solonker, Inner Mongolia分类
天文与地球科学引用本文复制引用
薛建平,苏尚国,李成元,侯万荣,董明明,刘永新,梁月升..内蒙古索伦山地区蛇绿岩岩石单元地质特征、就位机制及时限[J].现代地质,2017,31(3):498-507,10.基金项目
中国地质调查局区域地质矿产调查项目(12120113071800). （12120113071800）
