Studies on geochemical characteristics and biomineralization of Cambrian phosphorites, Zhijin, Guizhou Province, China

PLoS One. 2023 Feb 10;18(2):e0281671. doi: 10.1371/journal.pone.0281671. eCollection 2023.

Abstract

Phosphate rocks, an important ore resource in Guizhou Province, China, are mainly hosted within the Sinian Doushantuo Formation and the Cambrian Meishucun Formation. In addition, the phosphate rocks of the Cambrian Meishucun Formation are rich in biological fossils. Although numerous studies investigating the genesis of phosphate deposits have been performed, the relationship between biological activity and the formation of phosphate deposits in the lower Cambrian Meishucun Formation has not been convincingly explained. This study focuses on the biological fossil assemblage, the characteristics of phosphorus, and the relationship between biological and phosphorus enrichment of the lower Cambrian phosphorites. The primary objectives of our study are to analyze the role of organisms in the formation of phosphorites, restore the phosphorus-formation environment of the Cambrian Meishucun Formation, and construct a sedimentary model of the phosphorites in the Meishucun Formation. The results indicate that there is a significant positive correlation between biological activity and the deposition of phosphorites, that is, the higher the degree of biological enrichment and differentiation, the stronger the deposition. The geochemical analysis of several profiles in the Zhijin phosphorite block shows that the phosphorite block was deposited in an oxygen-rich environment and was affected by a high-temperature hydrothermal fluid. Upwelling ocean currents supplied abundant phosphorus and other nutrients, which provided the conditions for small shells and algae to flourish. Biochemical activity was a crucial factor in the deposition of the phosphorite.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biological Evolution
  • Biomineralization*
  • China
  • Fossils
  • Geologic Sediments* / chemistry
  • Phosphates / analysis
  • Phosphorus / analysis

Substances

  • phosphorite
  • Phosphates
  • Phosphorus

Grants and funding

This research was supported by the National Natural Science Foundation of China (41890841, U1812402), the Project of The Department of Science and Technology of Guizhou Province (Guizhou Science and Technology Cooperation Platform Talents [2018]5613), the Study on metallogenic regularity and prospecting prediction of rare earth, barium, fluorine and other special resources in Guizhou ([2022]ZD004), and the Postgraduate Innovation Fund of Guizhou Province (Guizhou Education Cooperation YJSCXJH [2019]040). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.