热带海洋学报 ›› 2012, Vol. 31 ›› Issue (5): 18-25.doi: 10.11978/j.issn.1009-5470.2012.05.004

• 海洋地质学 • 上一篇    下一篇

南海西北陆坡天然气水合物调查区滑坡带特征及成因探讨

陈泓君1,2,3, 黄磊2, 彭学超2, 吴峧岐2, 李文成2, 王英民4   

  1. 1.中国科学院边缘海地质重点实验室, 中国科学院南海海洋研究所, 广东 广州510301; 2. 国土资源部广州海洋地质调查局, 广东 广州, 510075; 3.中国科学院大学, 北京100049; 4. 中国石油大学, 北京 102249
  • 收稿日期:2010-05-26 修回日期:2010-08-17 出版日期:2012-11-01 发布日期:2013-02-06
  • 作者简介:陈泓君(1973—), 男, 海南省海口市人, 高级工程师, 主要从事海洋区域地质调查与研究。
  • 基金资助:
    中国地质调查局项目(项目编号: 1212010611302); 国家自然科学基金项目(40972077)

Discussion of characteristics and formation of landslide zones in the gas hydrate survey area of northwest continental slope, the South China Sea

CHEN Hong-jun1,2,3, HUANG Lei2, PENG Xue-chao2, WU Jiao-qi2, LI Wen-cheng2, WANG Ying-min4   

  1. 1.CAS Key Laboratory of Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; 2.Guangzhou Marine Geological Survey, Ministry of Land and Resources, Guangzhou 510075, China; 3. University of Chinese Academy of Sciences, Beijing 100049, China; 4.University of Petroleum, Beijing 102249, China
  • Received:2010-05-26 Revised:2010-08-17 Online:2012-11-01 Published:2013-02-06

摘要: 近十几年来, 我国在南海琼东南陆坡区、西沙海槽区和神狐海域陆续开展了多个航次的天然气水合物资源调查工作。调查资料揭示南海西北陆坡海底滑坡较为发育。其成因复杂, 因地形地貌、底质、沉积作用、构造活动的影响而发育规模不等、形态各异的滑坡带。利用近年来调查获得的高分辨率单道地震及多波束测深资料, 在以往天然气水合物调查区内识别出3个滑坡带: 神狐滑坡带、西沙海槽北坡滑坡带和琼东南陆坡滑坡带。神狐滑坡带位于神狐暗沙东南侧陆架坡折带, 水深400—600m, 长约100km, 宽约25km, 呈NE—SW向展布, 其形成与天然气水合物分解密切相关, 稳定性较好。西沙海槽北坡滑坡带位于西沙海槽北侧陆坡, 水深约2000—3100m, 长约90km, 宽约15—20km, 呈近EW走向, 为巨厚沉积物在重力作用下发生整体性滑移, 稳定性较好, 但局部仍存在不稳定区域, 极易发生滑坡扇。琼东南陆坡滑坡带位于琼东南陆坡陡坡处, 水深约250—850m, 呈NE—SW向展布, 长约150km, 宽约5—10km, 其主要受活动断层及底流侵蚀影响, 稳定性较差。本研究成果可为天然气水合物资源调查与勘探提供科学依据。

关键词: 南海, 陆坡, 天然气水合物, 滑坡带, 特征

Abstract: Several cruises of gas hydrate resource survey have been carried out at Qiongdongnan continental slope, Xisha trough as well as Shenhu area since 1999. The geological data revealed that sub-marine slides were developed in the northwestern continental slope of the South China Sea. Three landslide zones were identified based on high-resolution single-channel seismic profiles and multi-beam echo sounding data. This paper discusses in detail the characters and formation mechanism of these landslide zones. Shenhu landslide zone is about 100 km long, 25km wide, and is oriented along the NE-SW direction at a water depth of 400?600m. It has close relationship with gas hydrate dissociation and stable geological engineering condition. Xisha trough northern slope landslide zone is about 90 km long, 15?20km wide, and has an EW trending at a water depth of 2000?3100m. It was formed by huge thickness sediment movement under process of gravity. Xisha trough slide has a better geological engineering condition, but its slide fan still can be seen in some unstable segments. Qiongdongnan continental slope landslide zone is about 150 km long, 5?10km wide, and is oriented in a NE-SW direction at a water depth of 250?850m. It was affected by active faults and bottom current erosion, and has an unstable geological condition. The results of this study can be a scientific base for gas hydrate survey and exploration.

Key words: South China Sea, continental slope, gas hydrate, landslide zones, characteristics

中图分类号: 

  • X43: P618.13