An SEM study of microfossils in the black shale of the Lower Cambrian Niutitang Formation, Southwest China: Implications for the polymetallic sulfide mineralization
An SEM study of microfossils in the black shale of the Lower Cambrian Niutitang Formation, Southwest China: Implications for the polymetallic sulfide mineralization
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DOI：
10.1016/j.oregeorev.2014.07.004
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发表时间：
2015-03
影响因子：
3.3
通讯作者：
Junyuan Xu;Yiliang Li
中科院分区：
文献类型：
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作者：
Junyuan Xu;Yiliang Li
扬子地台东南缘下寒武统牛蹄塘组黑色页岩中赋存一层镍含量极高（高达3.8wt%）的多金属硫化物矿石和Mo（至多7.5重量%）。扫描电镜观察发现，在镍钼硫化物富集层中有丰富的微米级微体化石。微体化石包括具有清晰的有机壁结构和矿化内部内容物的囊泡。这些结构类似于单细胞绿色藻类。生物质吸附的过渡金属和生物结构蛋白金属可以从开花的藻类积累和矿化，然后缺氧微生物还原和固定化。在典型的局限洋盆环境中，生物影响可能是块状镍、钼硫化物沉积的重要机制。
The black shale in the Lower Cambrian Niutitang Formation on the southeastern margin of the Yangtze Platform hosts a layer of polymetallic sulfide ores containing extremely high concentrations of Ni (up to 3.8 wt.%) and Mo (up to 7.5 wt.%). Abundant micrometer-sized microfossils were observed in the Ni–Mo sulfide enriched layer under scanning electron microscopy. The microfossils include vesicles with clear organic wall structures and permineralized internal contents. These structures resemble unicellular green algae. Both biomass-adsorbed transition metals and biological structural protein metals could be accumulated and mineralized from the blooming algae, followed by anoxic microbial reduction and immobilization. The biotic impact may be a substantial mechanism for the massive Ni- and Mo-sulfide deposition in a typical restricted ocean basin environment.