Fig. 3: Variations in volcanic activity, Hg–C–S geochemical data (concentration and isotopes), and other related parameters in the Sakmarian–Artinskian Lucaogou Formation of the Junggar Basin.
From: Volcanically driven Hg–C–S cycling and climate change across the Early Permian Artinskian warming
a Covariation of sediment Hg concentrations and Hg/TOC ratios. The peak values in Hg/TOC corresponds to that in Hg concentrations. Five volcanic events of different intensities (VP-1, −2, −3, −4, and −5) in two stages (LIP-Ⅰ and -Ⅱ) were identified (light gray shaded area). b Covariation of TOC contents and δ13Corg values. negative δ13Corg excursions (nCIEs) occur synchronously with increasing TOC contents. c Covariation of TS/TOC ratios and δ34Sbulk (bulk sulfur isotope) values. Negative δ34Sbulk excursions (nSIEs) occur synchronously with increasing TS/TOC values. d Hg/TOC ratios in isochronous strata of the North China Platform and Δ199Hg values, which together record volcanic activity43,57. e Covariation between a nutrient element (P) and geochemical proxy of primary productivity (P/Ti). f Variations in redox state (Th/U). g Covariation of land surface temperatures (LSTs) and δ18O values, and their relationship to volcanic activity.
