The relationship between environment and geochemical characteristics of black rock series of Lower Cambrian in northern Guizhou

被引：0
|
作者：
Fu Y. [1 ]
Zhou W. [1 ,2 ]
Wang H. [2 ]
Qiao W. [4 ]
Ye Y. [2 ,3 ]
Jiang R. [1 ]
Wang X. [2 ]
Su J. [2 ]
Li D. [1 ,2 ]
Xia P. [1 ]
机构：
[1] College of Resources and Environmental Engineering, Guizhou University, Guiyang
[2] Key Laboratory of Petroleum Geochemistry, Research Institute of Petroleum Exploration and Development, Beijing
[3] Key Laboratory of Orogenic Belts and Crustal Evolution, Ministry of Education, School of Earth and Space Sciences, Peking University, Beijing
[4] 102 Geological Brigade of Guizhou Bureau of Geology and Mineral, Zunyi
来源：
Dizhi Xuebao/Acta Geologica Sinica | 2021年 / 95卷 / 02期
关键词：
Black rock series; Geochemical characteristics; Lower Cambrian; Niutitang Formation; Northern Guizhou; Sedimentary environment;
D O I：
10.19762/j.cnki.dizhixuebao.2021102
中图分类号：
学科分类号：
摘要：
The lower Cambrian black rock series are widely distributed in North China, South China, and Tarim basin, but the controlling factors and distribution characteristics of organic-rich mudstone and shale are still being debated. In this study, we collected samples of the Niutitang Formation (or its time-equivalent) from eight typical profiles of different sedimentary environments and carried out integrated geochemical analyses. The results suggest that different sedimentary environments are characterized by different redox conditions during the early Cambrian. Sediment lithologies of the inner platform are mainly black shales with some thinly bedded phosphatic rocks and cherts or phosphate/chert nodules. The black shales are thick and have high abundance of organic matter. Trace elements (V, Ni, Mo and U) of black shale from the inner platform facies are significantly enriched, which indicate sulfidic environment. Mo/TOC reflects a restricted water column. The upper slope settings may have developed under sulfidic-suboxic dynamic water masses. The thickness of black shales is small, but organic matter abundance is the most high. Trace elements (V, Ni, Mo and U) enrichments are low and Mo/TOC data suggest a moderately restricted water column. Basin facies strata are composed of interbedded black chert and black siliceous shale, which are thin and have low organic matter abundance. The enrichment factors of V and U are higher than those in the inner platform, but for Ni and Mo, their EF values are relatively lower. The majority of the basinal strata were deposited in anoxic conditions; however, the fluctuation of Mo/TOC may reflect ephemeral upwelling activities. In conclusion, the thickness, organic matter abundance and enrichment of trace elements of the lower Cambrian black rock series in northern Guizhou are mainly controlled by the belts of different sedimentary environment and different redox states. © 2021, Science Press. All right reserved.
引用
收藏
页码：536 / 548
页数：12
相关论文
共 53 条
  • [31] Rimmer S M, Thompson J A, Goodnight S A, Robl T L., Multiple controls on the preservation of organic matter in Devonian-Mississippian marine black shales: geochemical and petrographic evidence, Palaeogeography Palaeoclimatology Palaeoecology, 215, 1-2, pp. 125-154, (2004)
  • [32] Sageman B B, Murphy A E, Werne J P, Straeten C A V, Hollander D J, Lyons T W., A tale of shales: the relative roles of production, decomposition, and dilution in the accumulation of organic-rich strata, middle-upper Devonian, Appalachian Basin, Chemical Geology, 195, 1-4, pp. 229-273, (2003)
  • [33] Scott C, Lyons T W, Bekker A, Shen Y, Poulton S W, Chu X, Anbar A D., Tracing the stepwise oxygenation of the Proterozoic ocean, Nature, 452, 7186, pp. 456-459, (2008)
  • [34] Shi C, Cao J, Hu K, Bian L, Yao S, Zhou J, Han S C., New understandings of Ni-Mo mineralization in early Cambrian black shales of South China: Constraints from variations in organic matter in metallic and non-metallic intervals, Ore Geology Reviews, 59, 4, pp. 73-82, (2014)
  • [35] Shu L S, Faure M, Yu J H, Jahn B M., Geochronological and geochemical features of the Cathaysia block (South China): New evidence for the Neoproterozoic breakup of Rodinia, Precambrian Research, 187, 3~4, pp. 263-276, (2011)
  • [36] Shizhen Tao, Deliang Liu, Changwei Li, Gaoshe Cao, Zhensheng Li, Suyun Hu, Shengfei Qin, Xiaohui Gao, Quanyou Liu, Guorong Deng, Xianghua Wu, Guangzhi Li, HuBin, Exploration frontiers of unexplored shale layer in new district, north China block:Source rock and its gas system of Madian Formation of Lower Cambran in the southern part of North China Block (SNCB), Natural Gas Geoscience, 25, 11, pp. 1767-1780, (2014)
  • [37] Tribovillard N, Algeo T J, Baudin F, Riboulleau A., Analysis of marine environmental conditions based on molybdenum-uranium covariation, applications to Mesozoicpaleoce anography, Chemical Geology, 324, 325, pp. 46-58, (2012)
  • [38] Tribovillard N, Algeo T J, Lyons T, Riboulleau A., Trace metals as paleoredox and paleoproductivity proxies: An update, Chemical Geology, 232, 1-2, pp. 12-32, (2006)
  • [39] Wang D, Struck U, Ling H F, Guo Q J, Shields-Zhou G A, Zhu M Y, Yao S P., Marine redox variations and nitrogen cycle of the early Cambrian southern margin of the Yangtze platform, South China: Evidence from nitrogen and organic carbon isotopes, Precambrian Research, 267, pp. 209-226, (2015)
  • [40] Wei H, Chen D, Wang J, Yu H, Tucker M E., Organic accumulation in the lower ChihsiaFormation (middle Permian) of South China: Constraints from pyrite morphology and multiple geochemical proxies, Palaeogeography Palaeoclimatology Palaeoecology, 353-355, pp. 73-86, (2012)
123456