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安徽南部晚震旦世蓝田组、皮园村组和早寒武世荷塘组主要由黑色页岩和硅质岩组成。分析结果表明 ,蓝田组和荷塘组的总有机碳 (可达 10 %— 18% )和总有机氮 (可达 2 .0‰— 2 .6‰ )的高含量 ,应归于富有机质埋藏所致 ,反映新元古代末次冰期后和早寒武世海洋浮游生物处于大发展时期。由于海洋植物的光合作用产生大量 O2 ,并消耗大量 CO2 ,导致大气中 O2 / CO2 比率明显增加 ,为震旦纪晚期多细胞真核生物的辐射、后生动物的出现和‘寒武纪生物大爆发’提供了条件。蓝田组黑色页岩中部的有机碳与有机氮含量大体呈现正比例增加 ,并且分别达到17.74 %和 2 .6 6‰的最高值 ,与该剖面发现的蓝田植物群相对应 ;荷塘组黑色页岩的有机碳和有机氮垂直分布曲线之间呈现相互背离 ,即有机氮含量与时增加 ,而有机碳含量与时减少 ,与扬子地台相应的地层层位产生的澄江动物群相对应 ,表明 TON和 TOC分布特征有可能与早期生物演化历程相关
Late Sinian Lantian Formation, Piyuan Village Formation and Early Cambrian Hetang Formation in southern Anhui are mainly composed of black shale and chert. The results showed that the high contents of total organic carbon (up to 10% -18%) and total organic nitrogen (up to 2.0 ‰ -2.6%) in the Lantian group and the Hetang group should be attributed to the burial of organic matter Reflecting the great development of marine plankton after the Neoproterozoic last glacial epoch and the Early Cambrian. Due to the photosynthesis of marine plants produces a large amount of O2, and consumes a large amount of CO2, resulting in a significant increase in the O2 / CO2 ratio in the atmosphere, the radiation of multicentric eukaryotes, the emergence of metazoans and the “Cambrian explosion” ’Provided the conditions. Organic carbon and organic nitrogen in the central part of the black shale in the Lantian Formation generally increased in direct proportion to the maximum value of 17.74% and 2.6%, respectively, corresponding to the Lantian flora found in the profile. The black shale The vertical distribution curves of organic carbon and organic nitrogen show a deviation from each other, that is, organic nitrogen content increases with time, while the organic carbon content decreases with time, which corresponds to the Chengjiang fauna from the corresponding stratigraphic layers in the Yangtze platform. TOC distribution may be related to the evolution of early biological processes