Stable carbon and nitrogen isotopic composition of gas hydrate-bearing sediment from Hydrate Ridge, Cascadia Margin

作者：Yu Xiaoguo^*; Ll Jiabiao; Gong Jianming; Chen Jianfang; Jin Xiaobing; Lee Young Joo; Ll Hongliang; Xu Jie

来源：Science in China - Series D: Earth Sciences , 2006, 49(8): 872-880.

DOI：10.1007/s11430-006-0872-9

• gas hydrate
• carbon isotopes
• nitrogen isotopes
• C/N ratio
• nitrogen fixation

54 sediments were sampled at 5 sites, 1244, 1245, 1246, 1250 and 1251 from ODP Leg 204, Hydrate Ridge, Cascadia Margin. The stable carbon and nitrogen isotopic composition,delta C-13 of organic matter and delta N-15, have been used to characterize the depositional variation of sediments with gas hydrate bearing. Values of delta C-13 of bulk organic matter range between -22.37 parts per thousand and -24.72 parts per thousand PDB, with a mean value of -23.54 +/- 1.17 parts per thousand PDB; delta N-15 of the same sedimentary samples range from 3.30 parts per thousand to 5.68 parts per thousand, with a mean value of 4.49 +/- 1.19 parts per thousand; Values of C/N ratio range from 4.53 to 9.26, with a mean value of 6.90 +/- 2.37. The occurrence of gas hydrate changed the diagenetic evolution trend of the carbon and nitrogen in organic matter. The, delta N-15 and C/N ratio depletion suggest that the nitrogen fixation related with the bacteria/archaea. maybe occurred in the sediments near the hydrate. The stable carbon and nitrogen isotopic composition could be used to evaluate the depositional environment in the study area.

• 出版日期2006-8
• 单位国家海洋局第二海洋研究所; 青岛海洋地质研究所