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时间:2020-03-26
《秦岭南缘大巴山褶皱-冲断推覆构造的特征.pdf》由会员上传分享,免费在线阅读,更多相关内容在行业资料-天天文库。
1、地质通报Vo1.27.NO.9第27卷第9期Sep.,20082008年9月GEoL0GICALBULLETINOFCHINA秦岭南缘大巴山褶皱一冲断推覆构造的特征董云鹏,查显峰,付明庆,张茜,杨钊,张燕DONGYun—peng,ZHAXian—feng,FUMing—qing,ZHANGQian,YANGZhao,ZHANGYan西北大学大陆动力学国家重点实验室.西北大学地质学系,陕西西安710069StateKeyLaboratoryofContinentdDynamics,Departmen
2、tofGeology,NorthwestUniversity,Xian710069,Shaanxi,China摘要:秦岭造山带南缘的大巴山巨型逆中推覆构造主要是在秦岭造山带板块俯冲碰撞造山与中、新生代以来陆内造山过程中长期复合作用形成的。详细的室内外构造研究表明,巴山逆冲推覆构造可以巴山弧形断裂带为界划分为北大巴山逆冲推覆构造和南大巴山逆冲推覆构造。北大巴山自北而南依次由安康一武当推覆体、紫阳一平利推覆体、高桥一镇坪推覆体和高滩推覆体逆;中叠置而成。南大巴山则以镇巴一阳日断裂为界,分为北部的前陆冲
3、断褶皱带和南部的前陆褶皱带。北大巴山主要是印支期碰撞造山作用和燕山期陆内逆冲推覆作用叠加改造的结果,南大巴山则主要是燕山期递进变形过程中的产物。构造变形北强南弱.北以冲断褶皱变形为特征,南以皱褶作用为主;北部褶皱紧闭复杂,向南渐变为宽缓的薄皮构造。逆冲作用在时序上具有由北向南扩展传递的特点。关键词:逆冲推覆构造;冲断褶皱构造;巴山弧形断裂带:南秦岭中图分类号:P542+.2;P542~.3文献标志码:A文章编号:1671—2552(2008)09—1493-16DongYP,ZhaXF,FuMQ,
4、ZhangQ,YangZ,ZhangY.CharacteristicsoftheDabashanfold—thrustnappestructureatthesouthernmarginoftheQinling,China.GeologicalBulletinofChina,2008,27(9):1493—15O8Abstract:ThehugeDabashanthrustnappestructureonthesouthernmarginoftheQiMingorogenicbeltmainlyfo
5、rmedbylong—continuedcombinedactionofLateTriassicplatesubductionandcolisionalorogenyoftheQinlingorogenicbeltandintraconfinentalorogenysincetheMeso—Cenozoic.DetailedfieldandlaboratorystudiesindicatethattheDabashanfold—thrustnappestructuremaybedividedint
6、othenorthernDabashanthrustnappestructureandthesouthernDabashanthrustnappestructurewiththeBashanarc—shapedthrustfaultastheboundaryTheformerconsistsfromnorthtosouthoftheAnkang—Wudangnappe,Ziyang—Pinglinappe,Gaoqiao—ZhenpingnappeandGaotannappe.Thesouther
7、nDabashanthrustnappestructureissubdividedintotheforelandthrustfoldbeltinthenorthandforelandfoldbeltinthesouthwiththeZhenba—Yangriwanfaultastheboundary.ThenorthemDabashanthrustnappestructuremainlyresultedfromoverlappingandmodificationoftheIndosiniancoU
8、isionalorogenyandYanshanianintracontinentalthrusting,whilethesouthernDabashanthrustnappestructureistheproductofYanshanianprogressivedeformation.Thenorthemzoneischaracterizedbyintensefoldingandthrusting,whilethesouthernzonebyfolding.Thefoldsare
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