Stable isotopic geochemistry of organic carbon and pyrite sulfur from the Early Cambrian black shales in Northwestern Hunan, China
Stable isotopic geochemistry of organic carbon and pyrite sulfur from the Early Cambrian black shales in Northwestern Hunan, China
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DOI：
10.1080/10020070412331343331
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发表时间：
2004-02
期刊：
影响因子：
--
通讯作者：
S. Cao;D. Ma;Jiayong Pan
中科院分区：
文献类型：
--
作者：
S. Cao;D. Ma;Jiayong Pan
对湘西北早寒武世黑色岩系进行了有机碳和黄铁矿硫稳定同位素地球化学研究。有机质δ 13 C值较低。-29.7 ‰。-34.2 ‰，解释为早寒武世大气/海洋中高CO2浓度和缺氧沉积环境所致。变量，但显著正值δ 34 S值。+10.2‰。- +28.2‰，沉积黄铁矿揭示细菌硫酸盐还原作为黄铁矿形成过程，但在硫酸盐限制条件下。中国南方早寒武世可能存在一个受保护的缺氧盆地，该盆地与大洋的接触非常有限，其沉积物中富含可代谢有机质，缺乏生物扰动作用，可能是硫酸盐限制环境。
Abstract The early Cambrian black shale sequence in Northwestern HunanProvince has been investigated for its stable isotopic geochemistry of organic carbon and pyrite sulfur. The relatively low δ13C values of organic matter. −29.7‰. −34.2‰., are interpreted as caused by the high CO2 concentration in atmosphere/ocean and an anoxic depositional environment in early Cambrian. Variable, but significantly positive δ34S values. +10.2‰. – +28.2‰., for sedimentary pyrite reveals bacterial sulfate reduction as the pyrite-forming process but undersulfate-limited conditions. A protected anoxic basin, which had very limited access to open ocean, and its sediments, where metabolizable organic matter was rich and bioturbation was absent, are supposed to be the sulfate-limited environments and might have existed in South China in the early Cambrian.