Carbon-Oxygen-Strontium Isotopes, Major and Trace Elements, and Rare Earth Elements Data of the Sepiolite-containing successions in the First Member of Maokou Formation, Sichuan Basin

The samples were ground into 200 μ m powder and then measured for major, trace, and rare earth element content using inductively coupled plasma mass spectrometry (ICP-MS). The standardized europium anomaly values of Australian shale were calculated; Use a stable isotope ratio mass spectrometer (MAT 253) to test the carbon oxygen isotope composition (δ ¹³ C, δ ¹⁸ O, using VPDB as the standard) of carbonate rocks; Obtain strontium isotope ratios (⁸⁷ Sr/⁸⁶ Sr) through a thermal ionization mass spectrometer; Quantitative analysis of sepiolite content was conducted using X-ray diffraction (XRD), and paleotemperature was calculated based on oxygen isotope data.

The correlation between δ Eu and paleoenvironmental indicators such as paleoredox, paleotemperature, and paleoclimate was systematically demonstrated. In data processing, due to incomplete full index testing of some samples (such as incomplete strontium isotope analysis of some samples), there were differences in the number of data points between subgraphs, and missing data has been excluded during fitting and plotting.