Sedimentary types and features of gravity flow depositional systems from Late Oligocene to Early Miocene in Liwan sag,Pearl River Mouth Basin |
| |
| Authors: | Xing Zuo-Chang Zhang Zhong-Tao Lin Chang-Song Zhang Bo Hong Fang-Hao Gong Yue |
| |
| Institution: | 1. State Key Laboratory of Marine Geology, Tongji University, Shanghai200092, China;2. China National Offshore Oil CorporationHainan Energy Co. Ltd., Guangdong Zhanjiang524057, China |
| |
| Abstract: | The sedimentary characteristics of gravity flow depositional systems(GFDS)in Liwan sag,Pearl River Mouth Basin,has not been clear. Based on a large number of high-revolution seismic data and a small amount of borehole data,the sedimentary types,spatial-temporal evolution,and controlling factors of the gravity flow depositional systems in Zhuhai Formation and the basal Zhujiang Formation in the Liwan sag are summarized. Four sedimentary types of the GFDS,can be identified according to the different seismic facies associations. Pordelta turbidite fan,the first type,is relatively small-scale compared with other type,but formed at the same time with the shelf edge delta,which is likely to be sand rich. Mass transport complex deposition,the second type,is featured by fault scarps,multiple small detachment faults,internal deformation structures such as sliding and compression,and overall southeast movement. The channelized slope fan,the third type,with lots of small channels on the head,contains microfacies such as turbidite channel,channel-levee complex and crevasse splay. The basin floor fan,the fourth type,is a bidirectionally down-lapped,mound-shaped and strong amplitude continuous intermediate-frequency reflection seismic facie association,and its microfacies such as incised valley,channel filling,front crevasse fan and sheet like lobe can be recognized. It is believed that the coupling of tectonics,climate,sea level change and sediment supply results in the GFDS in the study area and different types of GFDS are formed at different period during the base level cycle change. This research can provide a reference for the summary of gravity flow depositional law and hydrocarbon exploration in the ultra-deep water area. |
| |
| Keywords: | gravity flow depositional systems sedimentary types depositional evolution Zhujiang Formation Zhuhai Formation Liwan sag Pearl River Mouth Basin |
|
| 点击此处可从《古地理学报》浏览原始摘要信息 |
| 点击此处可从《古地理学报》下载免费的PDF全文 |
|
