triple oxygen isotope data

The research dataset centers on the triple oxygen isotope systematics of marine carbonates in the Sichuan Basin, testing the hypothesis that Δ'17O can differentiate diagenetic processes such as burial heating, meteoric water infiltration, and thermochemical sulfate reduction (TSR) that are often ambiguous in traditional isotopic proxies. We propose that distinct carbonate phases, including bulk rock, saddle dolomite, and TSR-calcite, preserve unique Δ'17O signatures reflecting their specific fluid sources and formational temperatures.The dataset contains high-precision δ13C, δ18O, and Δ'17O values, along with 87Sr/86Sr ratios, derived from 13 carbonate samples (27 data points total) collected from deep drill cores in the Sichuan Basin. Notable results show that dolomite phases exhibit Δ'17O between -55 and -110 ppm, while TSR-related calcites display significant negative deviations. Furthermore, diagenetic phases like cements and saddle dolomites show elevated Δ'17O values relative to the host bulk rock.These findings suggest that the depleted Δ'17O in TSR calcites is an inherited signature from sulfate-derived fluids, whereas the elevated values in saddle dolomites reflect the combined influence of increased burial temperatures and potential meteoric water input. Model inversions indicate Triassic dolomite formation at 33-34 ℃ within seawater having a δ18O of -3‰ to -2‰ The data were gathered using the O2-CO2 Pt-catalyzed equilibration method and normalized to the VSMOW-SLAP scale, providing a robust benchmark for oxygen isotope modeling in sedimentary basins and regional geological correlations.