论甘肃玉门红柳峡下沟组的时代  

ON THE AGE OF THE XIAGOU FORMATION IN THE HONGLIUXIA AREA, YUMEN, GANSU PROVINECE

作　　者：杨利超 王训练[1] 周洪瑞[1] 高正升 张海军[1] YANG Li-chao;WANG Xun-lian;ZHOU Hong-rui;GAO Zheng-sheng;and ZHANG Hai-jun(School of the Earth Sciences and Resources,China University of Geosciences,Beijing 100083;Yumen Tourist Administration,Gansu Province,Yumen 735211)

机构地区：[1]中国地质大学(北京)地球科学与资源学院,北京100083 [2]甘肃省玉门市旅游局,甘肃玉门735211

出　　处：《地层学杂志》2018年第4期444-454,共11页Journal of Stratigraphy

基　　金：甘肃省"甘肃玉门国家公园地质景观基础地质研究"项目资助

摘　　要：甘肃玉门红柳峡地区下沟组双壳类化石丰富,计有7属18种,包括Musculiopsisfuxinensis,M.yixianensis, M. subrotundus, Sphaerium anderssoni, S. coreanicum, S. selenginensis, S. chientaoense, S. ellipticoides,Gansuellaxinminpuensis,G.angulate,Nakamuranaiachingshanensis,N.subrotunda,N.aff.chingshanensis,Arguniellalingyuanensis,A.yanshanensis,A.liaoxiensis,Inversidenswuerheensis和Unioyanbianensis。据此建立Nakamuranaia subrotunda-Musculiopsis fuxinensis组合。该组合可与外贝加尔东部、浙江西部、辽宁西部、黑龙江东部、韩国东南部、日本西南部的早白垩世双壳类动物群对比,时代为Aptian期—Albian期。下沟组上段发育的火山颈相辉绿岩锆石U-Pb同位素测年结果为109±1.6Ma,形成时代也为早白垩世。双壳类化石和火山颈锆石年龄都表明下沟组时代为早白垩世Aptian中期—Albian早期,并且早于109 Ma。The Xiagou Formation in the Hongliuxia area, Yumen, Gansu Province is rich bivalve fossils. The bivalve fauna of the Xiagou Formation includes 18 species belonging to 7 genera. They are Musculiopsis fuxinensis, M. yixianensis, M. subrotundus, Sphaeriurn anderssoni, S. coreanicum, S. selenginensis, S. chienta-oense, S. ellipticoides, Gansuella xinminpuensis, G. subrotunda, Nakamuranaia chingshanensis, N. subrotunda, N. aff. chingshanensis, Arguniella lingyuanensis, A. yanshanensis, A. liaoxiensis, lnversidens wuerheensis and Unio yanbianensis. Based on the fossils, the Nakamuranaia subrotunda-Musculiopsis fuxinensis assemblage is established. Bivalves in this fossil assemblage can be correlated with Aptian to Albian bivalve faunas in Western Zhejiang, Western Liaoning, Eastern Heilongjiang, Southeastern Korea, Eastern Transbaikalia, and South- western Japan. A zircon U-Pb age （109±1.6 Ma） from volcanic neck facies diabase that penetrates the upper Xiagou Formation, also indicates that the Xiagou Formation is early Cretaceous in age. Both bivalve fossils and the zircon U-Pb age suggest that the age of the Xiagou Formation ranges from middle Aptian to early Albian, and is earlier than 109 Ma.

关 键 词：生物地层 年代地层 双壳类化石 锆石U-PB年龄 下沟组 下白垩同 玉门 甘肃 

分 类 号：P534.53[天文地球—古生物学与地层学]