%0 Journal Article
%T Authigenic sulfide minerals and their sulfur isotopes in sediments of the northern continental slope of the South China Sea and their implications for methane flux and gas hydrate formation
%A XiaoQiang Pu
%A ShaoJun Zhong
%A WenQuan Yu
%A XiaoWan Tao
%J Chinese Science Bulletin
%@ 1861-9541
%D 2007
%I 
%R 10.1007/s11434-007-0043-1
%X This is a report of the study of the authigenic sulfide minerals and their sulfur isotopes in a sediment core (NH-1) collected on the northern continental slope of the South China Sea, where other geophysical and geochemical evidence seems to suggest gas hydrate formation in the sediments. The study has led to the findings: (1) the pyrite content in sediments was relatively high and its grain size relatively large compared with that in normal pelagic or hemipelagic sediments; (2) the shallowest depth of the acid volatile sulfide (AVS) content maximum was at 437.5 cm (>2 ¦Ìmol/g), which was deeper than that of the authigenic pyrite content maximum (at 141.5¨C380.5 cm); (3) ¦Ä 34S of authigenic pyrite was positive (maximum: +15¡ë) at depth interval of 250¨C380 cm; (4) the positive ¦Ä 34S coincided with pyrite enrichment. Compared with the results obtained from the Black Sea sediments by Jorgensen and coworkers, these observations indicated that at the NH-1 site, the depth of the sulfate-methane interface (SMI) would be or once was at about 437.5¨C547.5 cm and the relatively shallow sMI depth suggested high upward methane fluxes. This was in good agreement with the results obtained from pore water sulfate gradients and core head-space methane concentrations in sediment cores collected in the area. All available evidence suggested that methane gas hydrate formation may exist or may have existed in the underlying sediments.
%K acid volatile sulfide
%K authigenic pyrite
%K sulfur isotope
%K methane
%K gas hydrate
%K South China Sea
%U http://link.springer.com/article/10.1007/s11434-007-0043-1