龙马溪组高丰度有机质页岩中铁硫元素生物化学行为特征及其对有机碳控制作用

The organic carbon content is more than 2% is the lower limit of commercial development. The content of iron and the degree of pyritization between the content of organic carbon were positive correlation by content of the organic carbon was less than 2% in Silurianis Longmaxi Formation shale. and the relationship between them is not obvious or negative correlation by the content of organic carbon was more than 2%.The formation mechanism is not clear. For the scientific problems, biochemics behavior , the isotopic fractionation process, source of iron and sulfur elements, organic process, active iron buffered on sulfide capacity in abundance organic matter of hydrocarbon source rock were studied. Iron and sulfur elements effects on microbial induced and sulfide effects on organic matter preservation under different conditions are simulating; It will be clarified that relationship of biochemics behavior of iron and sulfur between organic carbon in abundance organic matter shale. It is more profound understanding of distribution characteristics of abundance organic shale in spatial.

有机碳含量大于2%是商业开发的下限；志留系龙马溪组页岩的有机碳含量小于2%时，铁总量、黄铁矿矿化度与有机碳含量呈正相关性，而有机碳含量大于2%时，它们之间关系不明显或负相关性，其形成的机理还不清楚。针对该科学问题，研究高丰度有机质烃源岩中铁硫化学生物行为特征、同位素分馏过程、铁硫来源、有机质作用过程、活性铁对硫化物缓冲容量；模拟不同条件下铁硫元素对微生物诱发作用和硫化物对有机质保存的贡献；阐明高丰度有机质页岩层段的铁硫元素生物化学行为特征与有机碳内在联系。对高丰度有机质页岩空间分布特征上具有更为深刻的认识。

A. 开展了研究区相关剖面等进行了测量与取样，测定了相应的铁组分，利用活性铁含量/总铁含量等指标对五峰组时期-龙马溪组时期的古海洋氧化还原进行了还原。. B. 根据硫存在状态把硫组分分为硫化物硫、硫酸盐硫和有机硫3类。探讨了硫化物硫、硫酸盐硫和有机硫含量与有机碳相互关系，认为该阶段微环境的变化导致硫酸盐菌群落上较大的差异，硫酸盐还原菌属间的遗传和生理差异决定硫同位素的分馏。.C.模拟铁硫元素对微生物诱发与保存机制的研究，完成多组实验体系，探讨了构成针铁矿-微生物-污染物相互作用体系，分析了不同浓度苯胺对针铁矿异化还原的影响。.D. 取得了有机质丰度的主要控制机理，五峰组-龙马溪组有机质赋存机理是不同的，五峰组时期，氧化-还原条件是关键因素；而龙马溪组有机质赋存受到古生产力和陆源碎屑物质输入是主要影响因素。构建了该时期古海洋水化学条件，建立了水介质的铁化与硫化阈值“临界点”双稳态方程模型，认为从铁化环境变为硫化环境是一个渐进的过程，而硫化环境变为铁化环境是瞬间的过程；. 通过针铁矿异化还原实验，探讨了针铁矿-微生物-污染物相互影响过程。认为微生物加速了针铁矿异化还原过程。以上研究进展为铁-硫元素与微生物间相互作用与影响过程、有机质赋存机理提供理论基础。 .发表论文4篇，其中SCI2篇，完成了项目申请书预计的目标。