Replication Data for: Massive dolomitization of interior and slope to basin-margin facies of the Triassic Yangtze Platform through superposed earth-surface and burial mechanisms; Nanpanjiang Basin, south China

This database presents fluid inclusion microthermometry, stable isotope geochemistry, rare earth element data, and U-Pb age dates of dolomite samples collected from the Yangtze Platform in southern Guizhou Province from 2015 to 2024. Laboratory work was completed at Trinity University and the University of Green Bay. U-Pb geochronology, Sr isotope analysis, REE data were collected at Stony Brook University and the University of Arizona. Triassic strata of the Yangtze Platform at Guanling contain a dolomitized interior, undolomitized margin, and partially dolomitized slope to basin margin. Dolomitized microbial laminate caps of peritidal cycles and massive dolomite with associated evaporite nodules and solution collapse breccias are consistent with penecontemporaneous tidal flat and evaporative dolomitization in the platform interior. Preferential dolomitization of the slope and basin margin (up to 7 km basinward of the margin), dolomitization along fractures, and selective dolomitization of matrix in slope breccia that diminishes toward the margin is interpreted to have resulted from incursion of basin-derived fluids during burial. Integrated analysis of fluid-inclusion microthermometry, oxygen, carbon and strontium isotopes, trace element geochemistry, U-Pb age dates of carbonate phases and burial history support recrystallization of interior dolomite and slope to basin-margin dolomitization by brines at high temperatures during burial. The Yangtze Platform at Guanling provides an excellent example of widespread stratiform dolomitization resulting from the superposition of multiple mechanisms including penecontemporaneous dolomitization by evaporative seawater brines, high-temperature dolomitization of the slope and basin margin by basinal brines and high temperature recrystallization of dolomite by brines during burial. Similar mechanisms likely contributed to the widespread dolomitization of platforms across the Nanpanjiang and Sichuan basins. This study suggests that many widespread stratiform dolomites in the rock record may result from superposed Earth surface and high-temperature burial dolomitization processes. The study also provides a useful analogue for other platforms in which the margin remains undolomitized while the interior and basin margin are dolomitized.