Provenance composition and evolution of marine black shales in the Yangtze platform from Ediacaran to Silurian

Provenance is important in understanding the evolution of geological structure and the coupling of the basin-mountain system. Although many geochemical data document the three sets of marine black shales (Ediacaran to Silurian) in the Yangtze Platform, the evolution characteristics of their sediment sources remain unclear. We gather a huge database from 307 published papers totaling 12,342 analyzed samples to establish provenance. Pearson correlation coefficient and multivariate statistical analyses were performed to establish the element and mineral links in the black shale. Nine immobile elemental ratios (Ti/Th, Th/Sc, Cr/Th, Ti/Zr, Sc/Ta, Ti/Nb, Sc/La, Zr/Sc, and La/Ti) were employed to indicate provenance. The results show that the black shales of the Longmaxi and Niutitang formations are relatively enriched in redox sensitive and productivity related elements such as V, Cr, Mo, U, Co, Ni, Cu, Zn, and Ba. The use of provenance analysis proxies, including V, Cr, Mo, Ce, Fe, P, Ba, Cu, Ni, and Si, should be approached with caution due to the potential interference of marine authigenic components. The three black shales have provenance compositions that gradually extend from intermediate to felsic from the Doushantuo to the Niutitang to the Longmaxi shale. This difference in provenance is a response to the Pan-African and Kwangsian orogenic structures which are likely to impact the paleomarine environment by variable biotrophic element inputs.