|
|
Biological evidence and its significance of Ouli Formation in Miduonan hamlets of Geji County, Tibet |
CHEN Meitao, YANG Liu, XU Changhui, JIA Di, ZHANG Hengge |
No.109 Geological Team of Sichuan Bureau of Geologicy & mineral Resources, Sichuan, Chengdu 610100, China |
|
|
Abstract The study area is located at the interseltion of Qiangtang plots and Bangong-Nujiang junction. Since there is well-preserved Late Jurassic-Early Cretaceous marine sedimentary record, this area is believed to be an ideal site for the research of Late Jurassic-Early Cretaceous environmental evolution and basin sediment types. In order to discuss the stratigraphic age of Ouli Formation and types of sedimentary basins in this area, careful study was taken on lithology combination, sedimentary environment, paleontological characteristics and so on. A lot of Late Jurassic fossils, such as Actinastraea minor Wu, Allocoenia trochiformis Etallon, Stylina andoensis Liao et Li, Stylosmilia michelini Milne-Edwards et Haime, were found in the Ouli Formation. The presentence of these fossils provides strong evidence to verify that the stratigraphic age of Ouli Formation is the Late Jurassic. The Ouli Formation is mainly made up of the restricted platform-tidal flat siliciclastic deposits intercalated with the carbonate deposits and sandwiched tidal channel gravel limestone. The results show that the sedimentary basin is a back-arc foreland basin in the study area in the Late Jurassic-Early Cretaceous.
|
Received: 19 July 2016
|
|
|
|
|
[1] 王立全,潘桂堂,丁俊,等.青藏高原及邻区大地构造图(1:150万)及说明书[M].北京:地质出版社,2010:12-13. [2] 李华亮.班公湖—怒江缝合带西段洋陆转换的标志及时间[D].武汉:中国地质大学,2014:39-40. [3] 肖志坚,邹爱建,谢国刚,等.1:25万日土县幅区域地质调查报告[R].2004:64-66. [4] 谢国刚,莫宣学,赵志丹,等.西藏班公湖地区侏罗纪—白垩纪沉积及古海洋盆地的演化[J].地质前缘,2009,16(4):31-39. [5] 郭铁鹰,梁定益,张宜智.西藏阿里地质[M].武汉:中国地质大学出版社,1991:214-215. [6] 汪啸风,陈孝红,萧宗正,等.中国各地质时代地层划分与对比[M].北京:地质出版社,2005:437-452. [7] 张明利,金之钧,汤良杰,刘国林.前陆盆地研究的回顾与展望[J].地质评论,2002,48(2):214-210. [8] 吴疆.前陆盆地研究现状及主要进展[J].内蒙古石油化工,2011,37(3):126-129. [9] 张波,张进江,杨武玲,等.我国中西部前陆盆地归属及其含油气性评述[J].高校地质学报,2005,11(1):126-136. [10] 戴宗明,孙传敏.松潘—甘孜造山带义敦岛弧中段三叠纪火山-沉积盆地的演化[J].地质通报,2008,27(6):799-813. [11] 马德胜,熊兴国,吴滔,等.西藏1:5万改则县北亭贡南部地区地质矿产调查主要成果[J].中国地质调查,2015,2(4):56-61. [12] 吕育林,梁吉坡.章丘煤田含煤区石炭—二叠煤系层序地层学研究[J].山东国土资源,2014,30(1):13-18. [13] 张克信,何卫红,徐亚东,等.沉积大地构造相划分与鉴别[J].地球科学:中国地质大学学报,2014,39(8):915-928. [14] 夏代祥,刘世坤.西藏区域地质志[M].武汉:中国地质大学出版社,1993:214-215. |
|
|
|