Trace Elements Characteristics of Black Shales from the Ediacaran Doushantuo Formation, Hubei Province, South China: Implications for Redox and Open vs. Restricted Basin Conditions
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In the present study, we carried out trace element analyses of black shales of the Ediacaran Doushantou Formation from two sections (Jiulongwan, Baiguoyuan) in Hubei Province, South China. Mo-U characteristics of black shales from the two sections and compiled Mo-U data of Doushantuo black shales from sections of a variety of sedimentary facies described the temporal/spatial variability in the redox conditions of paleo-seawater during deposition of the Doushantuo Formation. Changes in Mo-U patterns of the Doushantuo Member II (DST2) shales of open marine environments are consistent with a shift from a predominately oxic to a predominately anoxic ocean during their deposition. Mo-U patterns of the DST2 black shales from intra-shelf sections reflect basin restriction may have happened in the intra-shelf basin and are compatible with the redox-stratified model of the intra-shelf basin. Mo-U patterns of black shales of the Doushantuo Member IV (DST4) reveal that the shales from intra-shelf sections have more pronounced Mo enrichment and more significant enrichment of Mo over U than the slope shales, indicating the operation of a Mn particulate shuttle in the intra-shelf basin. High Mo/TOC ratios of the DST4 at the intra-shelf sections, in combination with similar Mo-TOC patterns of the DST4 from both intra-shelf and slope sections, indicate the intrashelf basin was well connected to the open ocean during deposition of the DST4.
Key wordsDoushantuo Formation Mo-U covariation Mo/TOC South China
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This work was supported by the National Natural Science Foundation of China (Nos. 41302018, 41230102, 41203021), the National 973 Project (No. 2013CB835000), the Foundation of State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing (No. PRP/open-1305) and the PhD Programs Foundation of Ministry of Education of China (No. 20130094120008). The final publication is available at Springer via https://doi.org/10.1007/s12583-017-0907-5.
- Guo, Q. J., Shields, G. A., Liu, C. Q., et al., 2007. Trace Element Chemostratigraphy of Two Ediacaran–Cambrian Successions in South China: Implications for Organosedimentary Metal Enrichment and Silicification in the Early Cambrian. Palaeogeography, Palaeoclimatology, Palaeoecology, 254(1/2): 194–216. https://doi.org/10.1016/j.paleo.2007.03.016CrossRefGoogle Scholar
- Hatch, J. R., Leventhal, J. S., 1992. Relationship between Inferred Redox Potential of the Depositional Environment and Geochemistry of the Upper Pennsylvanian (Missourian) Stark Shale Member of the Dennis Limestone, Wabaunsee County, Kansas, U.S.A.. Chemical Geology, 99(1/2/3): 65–82. https://doi.org/10.1016/0009-2541(92)90031-yCrossRefGoogle Scholar
- Kendall, B. S., 2008. Rhenium-Osmium Geochronology of Precambrian Organic-Rich Sedimentary Rocks, Systematics and Applications: [Dissertation]. University of Alberta, Edmonton, Alberta. 59Google Scholar
- Liu, P. J., Yin, C. Y., Gao, L. Z., et al., 2009. New Material of Microfossils from the Ediacaran Doushantuo Formation in the Zhangcunping Area, Yichang, Hubei Province and its Zircon SHRIMP U-Pb Age. Science Bulletin, 54(6): 1058–1064. https://doi.org/10.1007/s11434-008-0589-6CrossRefGoogle Scholar
- Liu, P. J., Chen, S. M., Zhu, M. Y., et al., 2014. High-Resolution Biostratigraphic and Chemostratigraphic Data from the Chenjiayuanzi Section of the Doushantuo Formation in the Yangtze Gorges Area, South China: Implication for Subdivision and Global Correlation of the Ediacaran System. Precambrian Research, 249: 199–214. https://doi.org/10.1016/j.precamres.2014.05.014CrossRefGoogle Scholar
- Liu, P. J., Yin, C. Y., Chen, S. M., et al., 2013. The Biostratigraphic Succession of Acanthomorphic Acritarchs of the Ediacaran Doushantuo Formation in the Yangtze Gorges Area, South China and Its Biostratigraphic Correlation with Australia. Precambrian Research, 225: 29–43. https://doi.org/10.1016/j.precamres.2011.07.009CrossRefGoogle Scholar
- Mi, T. W., Lin, L., Pang, Y. C., et al., 2010. The Sequence Stratigraphy and Genesis of Phosphorites of Doushantuo Formation at Baiguoyuan, Yichang, Hubei. Acta Sedimentologica Sinica, 28(3): 471–480 (in Chinese with English Abstract)Google Scholar
- Perkins, R. B., Piper, D. Z., Mason, C. E., 2008. Trace-Element Budgets in the Ohio/Sunbury Shales of Kentucky: Constraints on Ocean Circulation and Primary Productivity in the Devonian–Mississippian Appalachian Basin. Palaeogeography, Palaeoclimatology, Palaeoecology, 265(1/2): 14–29. https://doi.org/10.1016/j.paleo.2008.04.012CrossRefGoogle Scholar
- Xiao, S. H., Yuan, X. L., Steiner, M., et al., 2002. Macroscopic Carbonaceous Compressions in a Terminal Proterozoic Shale: A Systematic Reassessment of the Miaohe Biota, South China. Journal of Paleontology, 76(2): 347–376. https://doi.org/10.1666/0022-3360(2002)076<0347:mcciat>2.0.co;2CrossRefGoogle Scholar
- Zhai, L. N., Wu, C. D., Ye, Y., et al., 2016. Marine Redox Variations during the Ediacaran–Cambrian Transition on the Yangtze Platform, South China. Geological Journal. https://doi.org/10.1002/gj.2878Google Scholar
- Zhou, C. M., Jiang, S. Y., 2009. Palaeoceanographic Redox Environments for the Lower Cambrian Hetang Formation in South China: Evidence from Pyrite Framboids, Redox Sensitive Trace Elements, and Sponge Biota Occurrence. Palaeogeography, Palaeoclimatology, Palaeoecology, 271(3/4): 279–286. https://doi.org/10.1016/j.paleo.2008.10.024CrossRefGoogle Scholar
- Zhou, C. M., Xie, G. W., McFadden, K., et al., 2007. The Diversification and Extinction of Doushantuo-Pertatataka Acritarchs in South China: Causes and Biostratigraphic Significance. Geological Journal, 42(3/4): 229–262. https://doi.org/10.1002/gj.1062Google Scholar