云南楚雄盆地东南缘安龙堡下侏罗统含恐龙化石地层的时代厘定  

REVISION OF THE LOWER JURASSIC DINOSAUR-BEARING HORIZONS IN ANLONGBAO OF SOUTHEASTERN CHUXIONG BASIN, YUNNAN PROVINCE, CHINA

作　　者：王国付 潘世刚 李俊 任鑫鑫 尤海鲁嘶 WANG Guo-fu;PAN Shi-gang;LI Jun;REN Xin-xin;YOU Hai-lu(Fossil Research Center of Chuxiong Prefecture^,Chuxiong 675000;Chuxiong Prefectural Museum,Chuxiong 675000;Key Laboratory of Vertebrate Evolution and Human Origins,Institute of Vertebrate Paleontology and Paleoanthropology,Chinese Academy of Sciences,Beijing 100044;CAS Center for Excellence in Life and Paleoenvironment,Beijing 100044;College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049)

机构地区：[1]云南省楚雄州古生物化石研究中心,云南楚雄675000 [2]楚雄彝族自治州博物馆,云南楚雄675000 [3]中国科学院脊椎动物演化与人类起源重点实验室,中国科学院古脊椎动物与古人类研究所,北京100044 [4]中国科学院生物演化与环境卓越创新中心,北京100044 [5]中国科学院大学地球与行星科学学院,北京100049

出　　处：《地层学杂志》2019年第4期432-441,共10页Journal of Stratigraphy

基　　金：中国科学院战略性先导科技专项(B类)(XDB26000000);国家自然科学基金项目(41688103,41872021);楚雄州古生物化石研究中心研究经费共同资助

摘　　要：云南楚雄盆地东南部侏罗纪地层中富含以基干蜥脚型类为代表的恐龙化石。基干蜥脚型类在全球范围内尚未在中侏罗世地层中被发现,而1:20万地质图中该区域含上述化石的层位被划入中侏罗统。笔者在安龙堡一带恐龙化石调查中,发现之前对该区域下侏罗统冯家河组划分有误。我们对冯家河组进行了重新厘定,并确定了该区域恐龙化石所在层位。厘定后该区域冯家河组为上三叠统舍资组和中侏罗统张河组之间的一套紫红色粉砂质泥岩,以及泥岩与紫红色-灰黄色粉砂岩、泥质粉砂岩韵律互层,中部和顶部富含恐龙化石,时代为早侏罗世。通过岩石地层学与生物地层学研究,该区域下侏罗统冯家河组与上下地层间未发现明显的沉积间断,笔者推测其为连续沉积。连续沉积的下侏罗统在滇中十分罕见,尤其是该区域下侏罗统中部和顶部富含大量恐龙化石,为研究恐龙早期演化提供了重要的地质时代依据。Dinosaur fossils represented by basal sauropodomorphs are rich in the southeastern Chuxiong Basin,Yunnan Province,China,and these fossil-bearing horizons were assigned to the Middle Jurassic in the local 1:200000 geological map,contradicting with the fact that basal sauropodomorphs have never been found in the Middle Jurassic strata worldwide.During the investigation into dinosaurs in the Anlongbao area of the southeastern Chuxiong Basin,the authors found that the previous division and assignment of the Lower Jurassic Fengjiahe Formation were incorrect in this area.Here,we redefine the formation and determine the dinosaur-bearing horizons in this area.And subsequently the Fengjiahe Formation is considered herein to consist of cyclothem interbeds of purplish red silty mudstone,mudstone and purplish red,grayish yellow siltstone and muddy siltstone,overlying the Upper Triassic Shezi Formation and underlying the Middle Jurassic Zhanghe Formation.Its middle and upper parts yield rich dinosaur fossils,and its age is considered to be Early Jurassic.Lithostratigraphic and biostratigraphic studies show no obvious sedimentary discontinuity between the Fengjiahe Formation and the overlying strata as well as between this formation and the underlying strata in this area,indicating that the Lower Jurassic was very probably deposited continuously,a rare phenomenon in central Yunnan Province.Moreover,the middle and upper parts of the Lower Jurassic in this region are rich in dinosaur fossils,providing an important chronostratigraphic basis for studying the early evolution of dinosaurs.

关 键 词：恐龙 岩石地层 生物地层 冯家河组 下侏罗统 楚雄盆地 云南 

分 类 号：P534.52[天文地球—古生物学与地层学]