|
|||||
|
|
The morphologies and genesis of mega-pockmarks near the Xisha Uplift, South China Sea |
|
| Authors: | Qiliang Sun Shiguo WuMartin Hovland Peng LuoYintao Lu Tailai Qu |
| Institution: | a Key Laboratory of Marine Geology and Environment, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China b Graduate University of Chinese Academy of Sciences, Beijing 100049, China c Centre for Geobiology, University of Bergen, 5014 Bergen, Norway d Statoil ASA, Stavanger, Norway e CNOOC Energy Technology & Services Ltd., Supervision & Technology Co, Tianjin 300452, China f PetroChina Hangzhou Institute of Geology, Hangzhou 310023, China g Research Institute of Petroleum Exploration and Development, Beijing 100083, China |
| Abstract: | Pockmarks are normally regarded to be manifestations of fluids escape through the seabed. Kilometer-wide depressions, here called mega-pockmarks occur as widespread features near the Xisha Uplift, northern South China Sea. Most of the pockmarks observed in this area are multi-kilometers and much larger than normal-pockmarks reported worldwide. The maximum diameter observed is 3210 m and the maximum depth observed is 165.2 m based on multibeam data and 2D seismic data. The pockmarks are circular, elliptical and crescentic in plan view. Seismic profiles show that the genesis of pockmarks is related to fluid (gas and/or pore water) escape. According to the fluids pathways, the pockmarks fall into four types: (1) gas chimney-related; (2) depositional boundary-related; (3) gas chimney and inclined structure (fault)-related; (4) inclined structure-related. Bottom currents are strong and complex in the study area. The multibeam data and seismic profiles indicate that they may play an important role on extension, maintenance and shaping of pockmarks. The research of the study area is in its initial stage, and the identification of these features as indicators of fluid flow is probably useful for hydrocarbon exploration. |
| Keywords: | Mega-pockmarks Bottom currents Fluid flow Crescentic pockmarks South China sea |
| 本文献已被 ScienceDirect 等数据库收录！ | |