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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.

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BACKGROUND The geographical origin of tea (Camellia sinensis) can be traced using mineral elements in its leaves as fingerprints. However, the role that could be played by soil mineral elements in the geographical authentication of tea leaves has been unclear. In this study, 22 mineral elements in 73 pairs of tea leaves and soils from three regions (Pu'an, Duyun, and Liping) in Guizhou, China, were determined using inductively coupled plasma mass spectrometry (ICP‐MS) and inductively coupled plasma atomic emission spectrometry (ICP‐AES). The mineral element concentrations were processed by multivariate statistical analysis, including one‐way analysis of variance (ANOVA), correlation analysis, principal component analysis (PCA), and stepwise linear discriminant analysis (S‐LDA). RESULTS Based on a one‐way ANOVA, tea leaves and soils with different origins possessed unique mineral element fingerprints. Sixteen mineral element concentrations in tea leaves were significantly correlated with those in soils (P < 0.05). The geographical origins of tea leaves were effectively differentiated using the 16 correlated mineral elements combined with PCA. The S‐LDA model offered a 100% differentiation rate, and six indicative elements (phosphorus, Sr, U, Pb, Cd, and Cr) were selected as important fingerprinting markers for the geographic traceability of tea leaves. The accurate discrimination rate of geographical origin was unaffected by the cultivars of tea in the S‐LDA model. CONCLUSIONS Mineral elements in soils played an important role in the geographical authentication of tea leaves. Mineral elemental concentrations with significant correlations between tea leaves and soils could be robust, and could be used to trace the geographical origins of tea leaves. © 2020 Society of Chemical Industry

Black shales are easily exposed duo to human activities such as mining, road construction, and shale gas development, which results in several environmental issues including heavy metals (HMs) pollution, soil erosion and the destruction of vegetation. Moss are widely used to monitor metal pollution in the atmosphere, but few studies on the distribution and dispersion of HMs in the rock -soil -moss system are available. Here, mosses (P. exuosa Harv), growing soils, and corresponding parent rocks were collected from black shale areas. After appropriate pretreatment, samples were analyzed for multiple elements concentration by ICP-AES and ICP-MS. The results show that black shales parent rocks have elevated HMs concentration, and act as a source of multiple metals. Soil signi cantly inherit and accumulate heavy metals released from black shale. Signi cant positive correlations between HMs in P.exuosa Harv and the growing soils indicate that HMs are mainly originating from geological source rather than atmospheric deposition. Compared with other elements, only the transfer factor (TF) of Cd is greater than 1, the normal functioning of mineral elements (K and Zn) absorption and transportation may contribute to its high tolerance to Cd. Finally, both the BCF and TF for most HMs in P. exuosa Harv are less than 1, indicated that it has a tolerance and exclusion mechanism for these metals. Therefore, the luxuriant and spontaneous growth of P. exuosa Harv could be used as a phytostabilization pioneer plant in the black shale outcrop where vascular plants are rare.