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| 论河北丰宁牛圈银（金）矿床的成矿时限问题 | |
| 引用本文： | 陈忠,颜文,黄奇瑜,杨华平,陆钧,陈木宏.论河北丰宁牛圈银（金）矿床的成矿时限问题[J].地学前缘,2007,14(6):0-0. |
| 作者姓名： | 陈忠 颜文 黄奇瑜 杨华平 陆钧 陈木宏 |
| 作者单位： | 1. 中国科学院,南海海洋研究所,边缘海地质重点实验室,广东,广州,510301;成功大学,地球科学系,台湾,台南,701 2. 中国科学院,南海海洋研究所,边缘海地质重点实验室,广东,广州,510301 3. 成功大学,地球科学系,台湾,台南,701 |
| 基金项目： | 国家自然科学基金 , 中国科学院知识创新工程项目 , 国家科学技术部支撑项目 |
| 摘 要： | 南沙海槽的构造和沉积受控于南海的构造运动和加里曼丹西北大陆边缘的演化,具有适于天然气水合物形成的物源基础、温压条件、输导系统和储藏场所。似海底反射层(BSR)出现在水深650~2 800 m、海底下65~350 m深的晚中新世沉积物中,与褶皱、逆冲推覆构造及穹窿构造有关;沉积物中的甲烷含量和孔隙水的SO24-含量表现出异常变化特征,硫酸盐-甲烷界面(SMI)深度仅为8~11 m;表层沉积的自生石膏和黄铁矿的成岩环境与甲烷流体排溢引起的厌氧甲烷氧化(AOM)有关,这些地球物理和地球化学指标均指示南沙海槽发育天然气水合物。研究表明,南沙海槽沉积物的甲烷以二氧化碳还原型微生物成因为主,少量为混合气,海槽东南部可能是最有潜力的天然气水合物远景区。 |
| 关 键 词： | 天然气水合物 似海底反射层 硫酸盐-甲烷界面 自生矿物 南沙海槽 |
| 文章编号： | 1005-2321（2007）06-0299-10 |
| 收稿时间： | 2007-05-20 |
| 修稿时间： | 2007-06-26 |
Geological settings and indicators of potential gas hydrates in the Nansha Trough area, South China Sea |
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| Chen Zhong,Yan Wen,Huang Chiyue,Yang Huaping,Lu Jun,Chen Muhong.Geological settings and indicators of potential gas hydrates in the Nansha Trough area, South China Sea[J].Earth Science Frontiers,2007,14(6):0-0. | |
| Authors: | Chen Zhong Yan Wen Huang Chiyue Yang Huaping Lu Jun Chen Muhong |
| Abstract: | The Nansha Trough(formerly known as Northwest Borneo Trough) lies in the southeast of South China Sea(SCS).Its structural settings and sedimentary history are controlled by the collision and evolution of the SCS and North West Borneo Margin,hence the Nansha Trough has abundant organic materials,suitable temperature-pressure,conduit systems and geological setting for gas hydrate formation.BSRs(bottom simulating reflectors) occur in the post-Miocene sediments between 65 and 350 m,beneath the seafloor at water depths of 650-2 800 m,are associated with folded,thrust,and ridge structures.The SO2-4 concentrations of pore water strongly decreased within several meters in sedimentary columns,while the methane content increased.The depth of SMI(sulfate methane interface) varies in a range of 8 to 11 m,resulting from methane venting from deep sedimentary columns.The diagenesis environment of gypsum and pyrite in surface sediments was associated with AOM(anaerobic oxidation of methane) of methane fluids.All of the above evidence shows that gas hydrates likely occur beneath the seafloor in the Nansha Trough.The results here suggest that CH4 in sediments was probably of microbial origin,produced by CO2 reduction,and partially from mixed gases,and the southeastern Nansha Trough could be a most promising area for gas hydrates. |
| Keywords: | gas hydrates bottom simulating reflector sulfate-methane interface authigenic mineral Nansha Trough area |
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