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研究所用样品由“海洋四号”船于2005年8月在三亚市SEE方向约150 km处采取。XRD和扫描电镜观察表明样品普遍存在自生碳酸盐、硫酸盐和草莓状(framboidal)黄铁矿。自生矿物组合和显微结构特征与冷泉沉积物类似,属微生物成因。孔隙水中Mg~(2+)、Ca~(2+)和硫酸根的浓度均有随深度增加而降低的趋势,说明这些组分在成因过程中被消耗。成岩反应过程中的溶解二氧化碳可能来自甲烷的厌氧氧化。样品中硫酸根的消耗主要和硫酸盐矿物沉淀有关,而非硫酸根还原。这意味着造成沉积物中黄铁矿大量沉淀的还原态硫并非来自采样深度,它和甲烷及Ba~(2+)一样,均来自地层更深处。
The samples used for the study were taken by the “Ocean No. 4” ship at about 150 km from SEE in Sanya in August 2005. XRD and scanning electron microscopy observations show that the samples are prevalent with authigenic carbonates, sulfates and framboidal pyrites. Authigenic mineral assemblages and microstructures are similar to cold spring sediments and are microbial origins. The pore water Mg ~ (2 +), Ca ~ (2+) and sulfate concentrations both decreased with increasing depth, indicating that these components are consumed in the genesis process. Dissolved carbon dioxide during diagenetic reactions may result from the anaerobic oxidation of methane. The consumption of sulfate in the sample is mainly related to the precipitation of sulphate minerals, rather than sulfate reduction. This means that the reduced sulfur that causes massive precipitation of pyrite in sediments does not come from the sampling depth, it is the same as methane and Ba2 +, all from the deeper layers.