Accumulation Conditions of Organic Matter during the Deposition of Black Shales of the Buxin Formation (Early Paleogene) in the Sanshui Basin, South China
Accumulation Conditions of Organic Matter during the Deposition of Black Shales of the Buxin Formation (Early Paleogene) in the Sanshui Basin, South China
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DOI：
10.1111/j.1755-6724.2004.tb00194.x
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发表时间：
2004-06
期刊：
影响因子：
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通讯作者：
Liu Chunlian;W. Oschmann;B. Yan;Dong Yixin;Xie Yecai
中科院分区：
文献类型：
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作者：
Liu Chunlian;W. Oschmann;B. Yan;Dong Yixin;Xie Yecai
摘要 为了了解三水盆地布心组（早古近纪）黑色页岩中有机质的来源和保存情况，对有机碳、氮、硫和铁进行了分析。 C/N 比表明有机质的特征是陆地和浮游植物的混合贡献。不同来源的相对重要性取决于气候条件，大多数有机物都来自陆地。 C、S和Fe之间的关系表明，在这些富含有机物的沉积物沉积过程中，由于热层化和盐度层化的混合环境，在底层水域中形成了缺氧和低O2交替的咸水环境，后者是间歇性海水入侵的结果。细菌硫酸盐还原是影响有机质保存最有效的早期成岩作用。硫酸盐还原的强度与供给沉积物的可代谢有机物的相对比例有关。
Abstract Analyses of organic carbon, nitrogen, sulfur and iron have been performed in order to understand sources and preservation of organic matter in black shale of the Buxin Formation (Early Paleogene) from the Sanshui Basin. The C/N ratios show that the organic matter is characterized by a mixture of terrestrial and phytoplanktonic contributions. The relative importance of different sources depend on climate conditions and most of organic matter is of terrestrial origin. The relationships between C, S and Fe indicate that the brackish environment with alternation of anoxia and low‐O2 developed in the bottom waters during the deposition of these organic‐rich sediments as a result of a mixed setting of thermal stratification and salinity stratification, the latter being the consequence of intermittent sea water incursion. Bacterial sulfate reduction is the most effective early diagenesis affecting the preservation of organic matter. The intensity of sulfate reduction is related to the relative proportion of metabolizable organic matter supplied to sediments.