辽西凌源地区中侏罗统邓杖子组沉积环境探讨.pdfVIP

辽西凌源地区中侏罗统邓杖子组沉积环境探讨 马文坡 张海龙 辽宁省地质勘查院，辽宁 大连 116100 摘要：通过对辽西凌源地区牛营子盆地邓杖子组地层剖面测制，结合岩石组合、沉积构造及相序叠置关系等因素分析研究，认为邓 杖子组沉积环境为冲积扇相.邓杖子组下部岩性为灰色厚层—巨厚层中—粗粒石灰岩质砾岩，沉积环境为扇根亚相，由筛积物沉积、 泥石流沉积组成；中部主要为灰绿色薄层中细粒长石砂岩、细粒钙质砂岩，夹灰色石灰岩质砾岩、含砂质灰岩等，由扇中亚相和扇端亚 相组成；上部岩性为灰色中厚层—厚层夹厚层—巨厚层石灰岩质砾岩，沉积环境可识别出扇中亚相和扇根亚相，二亚相均由河道沉积 和漫流沉积组成. 关键词：邓杖子组；沉积环境；扇根亚相；扇中亚相；扇端亚相；辽宁省 SEDIMENTARYENVIRONMENTOFJURASSICDENGZHANGZIFORMATIONIN LINGYUANAREAOFWESTERNLIAONINGPROVINCE MAWen-poZHANGHai-long LiaoningInstituteofGeologicalExploration,Dalian116100,LiaoningProvince,China Abstract:BasedonthemappingofstratigraphicsectionforDengzhangziFormationinNiuyingziBasininLingyuanarea, WesternLiaoningProvince,withcomprehensiveanalysisofrockassociation,sedimentarystructureandsuperimposed relationsoffaciessequence,itisrecognizedthatthesedimentaryenvironmentofthisformationisalluvialfanfacies.The lithologyofthelowerpartisthick-hugethickmedium-coarsegrainedgraylimestoneconglomerate,withsedimentary environmentofrootfansubfaciescomposedofsievesedimentsanddebrisflowdeposits.Themiddlepartconsistsofmainly thingreyishgreenmedium-finegrainedarkoseandfinegrainedcalcareoussandstonewithgraylimestoneconglomerateand sandylimestone,composedofmiddleandsidefansubfacies.Theupperpartisofmediumthick-thickwiththick-hugethick graylimestoneconglomerate,depositedintheenvironmentofmiddleandrootfansubfacies,whicharebothcomposedof channeldepositsandsheetflowdeposits. Keywords:DengzhangziFormation;sedimentaryenvironment;rootfansubfacies;middlefansubfacies;sidefansubfacies; LiaoningProvince 地 质 与 资 源 性，为前早侏罗期断裂(1)(2)的复活断裂和同沉积断限于牛营子盆地，其断陷盆地构造线方向与前早侏罗 裂(见图1)． 期一致呈北北东向．该组以灰色厚层块状石灰岩质砾 岩为主，呈北北东向延断裂带分布，角度不整合覆于中