Distinct BSRs and their implications for natural gas hydrate formation and distribution at the submarine Makran accretionary zone  

作　　者：Bin LIU Waseem Haider SYED Jiangxin CHEN Xiguang DENG Li YANG Leonardo AZEVEDO Minliang DUAN Tingting WU Jinfeng MA Keliang LI 

机构地区：[1]Key Laboratory of Marine Mineral Resources,Ministry of Natural Resources,Guangzhou Marine Geological Survey,Guangzhou 510760,China [2]National Institute of Oceanography,Karachi 75600,Pakistan [3]Key Laboratory of Gas Hydrate,Ministry of Natural Resources,Qingdao Institute of Marine Geology,Qingdao 266071,China [4]Laboratory for Marine Mineral Resources,Pilot National Laboratory for Marine Science and Technology(Qingdao),Qingdao 266237,China [5]CERENA/Instituto Superior Técnico,Lisbon University,Lisbon 1049-001,Portugal [6]Key Lab of Submarine Geosciences and Prospecting Techniques,MOE andCollege of Marine Geosciences,Ocean University of China,Qingdao 266100,China

出　　处：《Journal of Oceanology and Limnology》2021年第5期1871-1886,共16页海洋湖沼学报（英文）

基　　金：the Laboratory for Marine Mineral Resources,Qingdao National Laboratory for Marine Science and Technology(No.MMRKF201810);the China Geological Survey(Nos.DD20190582,DD20191009,DD20160214);funded by the Shandong Province"Taishan Scholar"Construction Project。

摘　　要：To investigate the nature of gas hydrates in the Makran area,new high-resolution geophysical data were acquired between 2018-2019.The data collected comprise multibeam and two-dimensional multi-channel seismic reflection data.The multibeam bathymetry data show East-North-East(ENE)ridges,piggy-back basins,canyon and channel systems,and the morphology of the abyssal plain.Continuous and discontinuous bottom simulating reflectors(BSRs)occur in the piggy-back basins on most of the seismic profiles available.The BSRs cut the dipping layers with strong amplitude and reversed polarity.Discontinuous BSRs indicate a transition along a dipping high-permeable sand layers from gas-rich segment to the gas hydrate-bearing segment and sugge st alternating sediments of fine and relatively coarse grain size.Double BSRs are highly dynamic and attributed to slumps occurring in the study area.The BSRs induced by slumps are located both at deep and shallow depths,responding to the temperature or pressure variation.For the first time,BSRs are observed in the abyssal plain of the Makran area,being associated with anticline structures,which do not show large spatial continuity and are strongly conditioned by structural conditions such as anticlines and fluid migration pathways,including deep fault,gas chimney,and high-permeable sedimentary layer.Our results may help to assess the gas hydrate potential within the piggy-back basins and to determine the most promising target areas.Moreover,results about the abyssal plain BSR may help to locate hydrocarbon reservoirs in the deep ocean.

关 键 词：gas hydrate-bearing sand-prone sediments double bottom simulating reflector(BSR) multiple BSR canyon channel system abyssal plain 

分 类 号：P618.13[天文地球—矿床学]