古地理学报 ›› 2020, Vol. 22 ›› Issue (6): 1143-1156. doi: 10.7605/gdlxb.2020.06.077

• 岩相古地理学及沉积学 • 上一篇    下一篇

珠江口盆地荔湾凹陷晚渐新世—早中新世重力流沉积类型及其特征

邢作昌1, 2, 张忠涛3, 林畅松4, 张博3, 洪方浩2, 宫越2   

  1. 1 核工业北京地质研究院,北京 100029;
    2 中国地质大学(北京)能源学院,北京 100083;
    3 中海石油(中国)有限公司深圳分公司研究院,广东深圳 518000;
    4 中国地质大学(北京)海洋学院,北京 100083
  • 收稿日期:2020-01-05 修回日期:2020-03-15 出版日期:2020-12-01 发布日期:2020-12-03
  • 通讯作者: 林畅松,男,1958年生,教授,博士生导师,主要从事盆地分析和沉积学的科研和教学工作。E-mail: lincs@cugb.edu.cn。
  • 作者简介:邢作昌,男,1988年生,博士,工程师,主要从事沉积地质学研究。E-mail: xzcxing@163.com。
  • 基金资助:
    松辽盆地核能开发项目(编号:[2017]1403)及国家自然科学基金项目(编号: 91328201,91528301)共同资助;

Sedimentary types and features of gravity flow depositional systems from Late Oligocene to Early Miocene in Liwan sag, Pearl River Mouth Basin

Xing Zuo-Chang1, 2, Zhang Zhong-Tao3, Lin Chang-Song4, Zhang Bo3, Hong Fang-Hao2, Gong Yue2   

  1. 1. Beijing Research Institute of Uranium Geology, Beijing100029, China;
    2. School of Energy Resources, China University of Geosciences, Beijing100083, China;
    3. Research Institute of Shenzhen Branch, CNOOC, Shenzhen518000, China;
    4. School of Ocean Sciences, China University of Geosciences, Beijing100083, China
  • Received:2020-01-05 Revised:2020-03-15 Online:2020-12-01 Published:2020-12-03
  • Contact: Lin Chang-Song,born in 1958,is a professor and Ph.D. supervisor. He is mainly engaged in researches on basin analysis and sedimentology. E-mail: lincs@cugb.edu.cn.
  • About author:Xing Zuo-Chang,born in 1988,is a doctor and an engineer. He is mainly engaged in research on sedimentology. E-mail: xzcxing@163.com.
  • Supported by:
    Co ̄funded by Nuclear Energy Development Project on Songliao Basin (No. [2017]1403) and the National Natural Science Foundation of China(Nos.91328201,91528301)

摘要: 针对珠江口盆地荔湾凹陷内重力流沉积特征不清楚的问题,在大量高精度地震及少量钻孔资料的基础上,通过地震相组合分析,对荔湾凹陷珠海组—珠江组底部重力流体系的沉积类型、时空演化及控制因素进行归纳。根据地震相组合的差异,认为研究区存在前三角洲浊积扇、块体搬运沉积、水道化斜坡扇、盆底扇4种重力流沉积类型: 前三角洲浊积扇为与陆架边缘三角洲同期形成的较小规模浊积扇体(裙),富砂可能性大;块体搬运沉积以头部具有断坡崖和多条小型滑脱断裂、内部显示滑移和挤压等变形构造、整体向东南移动为特征;水道化斜坡扇头部发育多条小型水道,沉积相由浊积水道、堤岸复合体等微相构成;盆底扇以双向下超丘形强振幅连续中频地震相为识别标志,可识别出下切谷、水道充填、前缘决口扇、席状朵叶体等微相。推测构造、气候、海平面变化及沉积物供给的耦合作用造就了研究区内的重力流沉积,在基准面旋回变化的不同阶段发育不同类型的重力流沉积。该研究成果可为盆地超深水区重力流沉积规律的总结和油气勘探提供参考。

关键词: 重力流体系, 沉积类型, 沉积演化, 珠江组, 珠海组, 荔湾凹陷, 珠江口盆地

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.

Key words: gravity flow depositional systems, sedimentary types, depositional evolution, Zhujiang Formation, Zhuhai Formation, Liwan sag, Pearl River Mouth Basin