New insight into chert from silica phase transformation and (Si and O) isotope and trace element criterion constraints on origin: Implications for δ30Siseawater and paleo-temperature reconstructions

Major and minor element, TOC contents (wt.%; Supplementary Data S1), trace element and REEs concentrations (mg/kg; Supplementary Data S2). Various chert types from representative sedimentary profiles of Paleozoic, Proterozoic and Archean, invoking volcanic, S-, C- (seawater, hydrothermal), dike chert types and their Si and O isotopie and trace elements datasets (Supplementary Data S3), and Si and O in-situ isotopic datasets for representative microquartz and quartz vein of the 1.88 Ga Gunflint (Canada), 2.72 Ga Tumbiana Formation (Australia), 3.29 Ga Mendon Formation (South Africa), and 3.48 Ga Dresser Formation (Australia) chert (Supplementary Data S4). Si isotope fractionation in opal-CT dissolves and reprecipitates to microquartz process in pore water (Supplementary Data S5), and O isotope-calculated paleo-temperatures (Supplementary Data S6) are shown for the early Silurian C-chert (seawater chert) sample from the Yangtze block, South China, Proterozoic-Cambrian transition C-chert from the Bohemian Massif, Czech Republic, and 1.9 Ga Gunflint chert, Canada.