海洋地质前沿2017，Vol.33Issue(7)：32-44,13.DOI:10.16028/j.1009-2722.2017.07004
南海北部神狐东南海域沉积物孔隙水地球化学特征及其对天然气水合物的指示
PORE WATER GEOCHEMISTRY IN SHALLOW SEDIMENTS FROM SOUTHEASTERN SHENHU AREA OF NORTHERN SOUTH CHINA SEA AND THEIR IMPLICATIONS FOR GAS HYDRATE OCCURRENCE
摘要
Abstract
Proper conditions occur in the southeastern Shenhu area of northern South China Sea for gas hydrate accumulation.The geophysical signature of gas hydrate,i.e.the bottom simulating reflector (BSR),has been discovered.Site SH-CL13,SH-CL16 and SH-CL17 are within the area of BSR.Cl concentrations and δD values of pore water samples from gravity-piston cores of SH CL16 and SHCL17 significantly decrease and increase with depth,respectively,which suggests gas hydrate accumulation underneath.The contents of methane in headspace gas samples from the three sites vary between 10.0 and 37.7 μL/kg,indicating very low methane fluxes in shallow sediments.The depths of sulfatemethane interface (SMI) are between 28.5 and 39.5 m,and sulfate (or methane) fluxes change between 3.6 and 5.9 mmol · m-2 · a-1.As we know,the depth of SMI and sulfate fluxes are constrained by methane fluxes.The trend of SO42--variations and δ13 CDIC values of pore water indicates that consumption of sulfate is dominated by organoclastic sulfate reduction (OSR) in shallow sediments and anaerobic oxidation of methane (AOM) occurs in relatively deep layers.In summary,the three sites are within the potential areas of gas hydrate occurrence.关键词
孔隙水/地球化学/天然气水合物/神狐东南海域/南海北部Key words
pore water/geochemistry/gas hydrate/southeastern Shenhu area/northern South China Sea分类
天文与地球科学引用本文复制引用
冯俊熙,杨胜雄,粱金强,方允鑫..南海北部神狐东南海域沉积物孔隙水地球化学特征及其对天然气水合物的指示[J].海洋地质前沿,2017,33(7):32-44,13.基金项目
国家天然气水合物专项(GZH201100301,GZH201100305,GZH200200203) （GZH201100301,GZH201100305,GZH200200203）
