Evolution of the ductile shear zone of the Paishanlou gold deposits,western Liaoning,China  

作　　者：NI JinLong LIU JunLai TANG XiaoLing ZHAO ChunQiang ZENG QingDong 

机构地区：[1]Shandong Provincial Key Laboratory of Depositional Mineralization & Sedimentary Minerals,College of Geological Sciences &Engineering,Shandong University of Science and Technology [2]State Laboratory of Geological Processes and Mineral Resources,China University of Geosciences Beijing [3]College of Chemistry & Environmental Engineering,Shandong University of Science and Technology [4]Institutes of Geology and Geophysics,Chinese Academy of Sciences

出　　处：《Science China Earth Sciences》2014年第4期600-613,共14页中国科学（地球科学英文版）

基　　金：supported by National Crisis Mine Program(Grant No.20089931);National Natural Science Foundation of China(Grant Nos.90814006,91214301,41172089);Foundation of Shandong Provincial Key Laboratory of Depositional Mineralization&Sedimentary Minerals(Grant No.DMSM201005)

摘　　要：The combination of field surveys with analysis of microstructure of tectonite and Electron Backscatter Diffraction(EBSD) on quartz fabric indicated that three periods of ductile shear events developed in the Paishanlou gold deposits and the E-W and NE-striking ductile shear zones were formed during each event.The E-W-striking ductile shear zone,accompanied by compressional and dextral shear slip,was shear-cut by the NE-striking shear zones,accompanied by compressional-sinistral shear slip and sinistral-normal shear slip,successively.An E-W-striking ductile shear zone developed at a deeper tectonic level and at middle- to high-temperatures,accompanied by abundant microstructures,including microlayering between a polycrystal quartz belt and mica,and quartz deformation was depended on cylinder(10-10) or <c> glide.The development of an E-W-striking shear zone can be seen as a tectonic pattern in the region of the Paishanlou gold deposits of the collision between the Mongolian tectonic belt and the North Archean Craton from Suolun to the Linxi suture zone during the Indosinian.The NE-striking ductile shear zone developed approximately 160 Ma during the early Yianshanian at middle to shallow tectonic levels and at middle- to low-temperatures,accompanied by typical microstructures,including polycrystal quartz aggregation and quartz subgrain rotation recrystallization,etc.,and quartz deformation was depended on prismatic(1011) glide.The last ductile shear event around the NE-striking shear zone developed at low temperatures and shallow tectonic levels,yielding to a pre-existing NE-striking shear zone,accompanied by abundant microstructures,including low-temperature quartz grain boundary migration and bulging recrystallization.The last ductile shear movement may be related to lithosphere thinning and the destruction of the North China Craton from approximately 130-120 Ma,and this shear event resulted directly in the mineralization in the Paishanlou region.The combination of field surveys with analysis of microstructure of tectonite and Electron Backscatter Diffraction （EBSD） on quartz fabric indicated that three periods of ductile shear events developed in the Paishanlou gold deposits and the E-W and NE-striking ductile shear zones were formed during each event. The E-W-striking ductile shear zone, accompanied by com- pressional and dextral shear slip, was shear-cut by the NE-striking shear zones, accompanied by compressional-sinistral shear slip and sinistral-normal shear slip, successively. An E-W-striking ductile shear zone developed at a deeper tectonic level and at middle- to high-temperatures, accompanied by abundant microstructures, including microlayering between a polycrystal quartz belt and mica, and quartz deformation was depended on cylinder （10-10） 〈a〉 or 〈c〉 glide. The development of an E-W-striking shear zone can be seen as a tectonic pattern in the region of the Paishanlou gold deposits of the collision between the Mongolian tectonic belt and the North Archean Craton from Suolun to the Linxi suture zone during the Indosinian. The NE-striking ductile shear zone developed approximately 160 Ma during the early Yianshanian at middle to shallow tectonic levels and at middle- to low-temperatures, accompanied by typical microstructures, including polycrystal quartz aggregation and quartz subgrain rotation recrystallization, etc., and quartz deformation was depended on prismatic （1011） 〈a〉 glide. The last ductile shear event around the NE-striking shear zone developed at low temperatures and shallow tectonic levels, yielding to a pre-existing NE-striking shear zone, accompanied by abundant microstructures, including low-temperature quartz grain boundary migration and bulging recrystallization. The last ductile shear movement may be related to lithosphere thinning and the destruction of the North China Craton from approximately 130-- 120 Ma, and this shear event resulted directly in the min- eralization in the Paishanlou region.

关 键 词：Paishanlou gold deposits ductile shear zone MICROSTRUCTURE EBSD tectonic evolution 

分 类 号：P618.51[天文地球—矿床学] TD953[天文地球—地质学]