2026
Record of seismites linked to the Chicxulub impact in deep-water deposits: Evidence from western Cuba
Reinaldo Rojas Consuegra, Esther María Cruz Gamez, Wilmer Perez Gil, Sylvia Teresita Blanco Bustamante, Isabel Beatriz Griñan Ferrer, Mercedes Torres La Rosa, Rogelio Agüero Lopez, Sujai Banzo Morales, Damanso Caceres Govea,kenya Elvira Núñnez Cambra, Hermann D. Bermúdez
PaleoexplorerCárdenas, M.
The Chicxulub asteroid impact (~66 Ma) marks the end of the Cretaceous period and represents the only asteroid impact on Earth with a global record. The planetary collision was accompanied by catastrophic events related to the release of vast amounts of energy. Although one of the predictable consequences of the Chicxulub event was the release of enormous amounts of seismic energy, its signature in the geological record remains poorly reported and documented. Here, we document exceptional soft-sediment deformation structures, interpreted as seismites, within the Upper Cretaceous (Campanian – Maastrichtian) Peñas Formation exposed at Arroyo Las Piedras, western Cuba. The rhythmically interbedded mudstone-chert sequence exhibits pervasive brittle and ductile deformations produced by liquefaction and fluidization processes. We identify faults, fractures, folds, and numerous soft sediment deformation structures (SSDS) across a thickness exceeding 70 m. These deformations are interpreted as seismic-induced structures (seismites), resulting from the Chicxulub impact event located < 500 km west. Those seismites are interpreted to occur alongside massive mud-volcano-like extrusions that expelled liquefied material onto the seafloor, forming a resedimented deposit with a mixed microfossil assemblage of Late Cretaceous taxa. This K-Pg deposit is concordantly overlain by Paleocene calcilutite of the Ancon Formation. Our findings indicate that seismic shocks affected deep-ocean sediments and partially lithified rocks, triggering large-scale sediment remobilization. This site represents a unique record of K-Pg Chicxulub-derived seismic events in the Proto-Caribbean.
