Sr evolution in the Upper Permian and Lower Triassic carbonates, northeast Sichuan basin, China: Constraints from chemistry, isotope and fluid inclusions

► Combined effects of various mechanisms resulted in abnormally high Sr concentrations. ► Aragonite neomorphism and closed-system dolomitization led to early Sr enrichment. ► Dissolution of early celestite and calcium sulfate via TSR constantly released Sr2+. ► TSR-water controlled dissolution-precipitation process of Sr-bearing minerals. ► Origin of double-spheroid elemental sulfur-bearing immiscible inclusion was studied.