Evidence of intense methane seepages from molybdenum enrichments in gas hydrate-bearing sediments of the northern South China Sea
文献类型：期刊论文
| 作者 | Chen, Fang; Hu, Yu; Feng, Dong; Zhang, Xin; Cheng, Sihai; Cao, Jun; Lu, Hongfeng; Chen, Duofu |
| 刊名 | CHEMICAL GEOLOGY
 |
| 出版日期 | 2016 |
| 卷号 | 443页码:173-181 |
| 关键词 | Cold seep Anaerobic oxidation of methane Seepage intensity Molybdenum enrichment Hydrate South China Sea |
| 通讯作者 | Hu, Y (reprint author), Shanghai Ocean Univ, Coll Marine Sci, Shanghai Engn Res Ctr Hadal Sci & Technol, Shanghai 201306, Peoples R China. ; Feng, D (reprint author), Chinese Acad Sci, South China Sea Inst Oceanol, CAS Key Lab Marginal Sea Geol, Guangzhou 510301, Guangdong, Peoples R China. |
| 中文摘要 | The application of molybdenum(Mo) enrichment to sediments can potentially provide unique constraints on the methane seepage dynamics at continental margins. We report herein elemental and isotopic measurements for authigenic carbonates and sediment samples in drill cores (similar to 95mlong; Site GMGS2-08 at similar to 800mwater depth) from gas hydrate-bearing sediments in the northern South China Sea. Five intervals that were impacted by methane seepages in the sediment profile were identified by the presence of strongly C-13-depleted carbonates (delta C-13 values as low as-56.8%). The carbonates often cement chemosynthetic bivalve shell fragments and have anomalous delta O-18 positive values. These observations suggest that methane seepage was intense during those time intervals and that carbonate precipitation occurred in the uppermost sediments, probably due to gas hydrate dissociation. Interestingly, the five intervals were all characterized by strong Mo enrichments. We thus hypothesize that the presence of strong Mo enrichments is a good indicator of past episodes of methane seepage. Such an environment results in sulfidic conditions that occur in a narrow zone in proximity to seawater close to the seafloor, leading to resultant Mo enrichments in associated sediments. In contrast, environments with low methane flux would lead to the distribution of Mo throughout a wide sulfidic zone and, consequently, an absence of Mo enrichment in the sediments. The insights into the environment for Mo enrichments at seeps have significant implications for tracing past methane seepages, their intensities, and even possible occurrences of gas hydrate dissociation. (C) 2016 Elsevier B. V. All rights reserved. |
| 学科主题 | Geochemistry & Geophysics |
| 源URL | [http://ir.scsio.ac.cn/handle/344004/15311]  |
| 专题 | 南海海洋研究所_中科院边缘海地质重点实验室 |
| 推荐引用方式 GB/T 7714 | Chen, Fang,Hu, Yu,Feng, Dong,et al. Evidence of intense methane seepages from molybdenum enrichments in gas hydrate-bearing sediments of the northern South China Sea[J]. CHEMICAL GEOLOGY,2016,443:173-181. |
| APA | Chen, Fang.,Hu, Yu.,Feng, Dong.,Zhang, Xin.,Cheng, Sihai.,...&Chen, Duofu.(2016).Evidence of intense methane seepages from molybdenum enrichments in gas hydrate-bearing sediments of the northern South China Sea.CHEMICAL GEOLOGY,443,173-181. |
| MLA | Chen, Fang,et al."Evidence of intense methane seepages from molybdenum enrichments in gas hydrate-bearing sediments of the northern South China Sea".CHEMICAL GEOLOGY 443(2016):173-181. |
入库方式： OAI收割
来源：南海海洋研究所
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