Fig. 1: Summarized S data for drill cores located within and close to the Chicxulub peak ring area.

A Simplified geological surface map of the Yucatán Peninsula in Mexico (modified from Rebolledo-Vieyra and Urrutia Fucugauchi 2004¹²⁰, Kring 2005¹²¹, and Kaskes et al. 2021⁴⁵; used with permission of The Geological Society of America) with the subsurface features of the Chicxulub impact structure marked. On the map, drill core locations are highlighted using stars of different colors: Y6 (Yucatán 6) from PEMEX (Petróleos Mexicanos); U5 (UNAM-5), U6 (UNAM-6), and U7 (UNAM-7) from UNAM (Universidad Nacional Autónoma de México); Yax-1 (Yaxcopoil-1) from ICDP (International Continental Scientific Drilling Program); and M0077A from IODP-ICDP (International Ocean Discovery Program- International Continental Scientific Drilling Program) Expedition 364. Next to each star, the corresponding measured bulk δ³⁴S range is presented. B Simplified lithological column for the IODP-ICDP Expedition 364 M0077A drill core with corresponding measured bulk δ³⁴S values and S concentrations (on a logarithmic scale). The equivalent of the K-Pg (Cretaceous-Paleogene) boundary claystone, characterized by an Ir anomaly based on Goderis et al. 2021¹¹⁷, is shown here by a red dashed line. A higher resolution visualization of the interval surrounding the K-Pg boundary claystone is displayed in Supplementary Fig. S1. For comparison, previously published pyrite-related S concentrations and δ³⁴S values from two studies of the M0077A drill core are included, Schaefer et al. 2020⁵³ (circular markers) and Kring et al. 2021⁵⁴ (triangular markers). The range of measured bulk δ³⁴S values and S concentrations for the five other drill core samples (Y6, Yax-1, U 5–7, and Yax-1, U 5–7, respectively) obtained in the present study are highlighted by a gray area in the graphs.