A team of scientists identified an exceptional geological record in Viñales, Pinar del Río, of the violent earthquakes triggered by the impact of the Chicxulub asteroid around 66 million years ago, the event associated with the mass extinction that wiped out non-avian dinosaurs and numerous other species.
The discovery was reported by Granma based on statements from Doctor in Geological Sciences Reinaldo Rojas Consuegra, a researcher at the Oil Research Center (CEINPET) and leader of the project studying the formations in Cuba associated with the Cretaceous-Paleogene boundary.
The evidence was found specifically in Arroyo Las Piedras, in the Pons Valley, in Viñales, where researchers located an extensive variety of deformations in the rocks caused by the seismic movements that followed the impact that occurred in the current Yucatán Peninsula.
The results were published in the scientific journal Journal of South American Earth Sciences, under the title "Registro de sismitas vinculadas al impacto de Chicxulub en depósitos de aguas profundas: evidencias del occidente de Cuba" (Record of seismites linked to the Chicxulub impact in deep-water deposits: Evidence from western Cuba).
For the authors, this is the first documentation in Cuba of seismic events directly attributed to the impact of Chicxulub and a unique record of those seismic events in the ancient Caribbean.
The study identifies faults, fractures, folds, and numerous deformation structures in soft sediments extending over more than 70 meters in thickness.
Scientists interpret these structures, known as sismitas, as a result of the intense seismic activity generated by Chicxulub.
The analyzed rocks originally formed in a deep marine environment of the ancient Caribbean.
The earthquakes caused liquefaction processes and the mobilization of sediments, leaving deformations that have been preserved for tens of millions of years and are currently exposed in western Cuba.
Rojas explained that they obtained "an exceptional record of the earthquakes that shook the planet following the asteroid impact," an event that marked the end of the Mesozoic era and the beginning of the Cenozoic.
The force of the movements would have been sufficient to violently stir up the sediments from the ocean floor.
According to the researcher, some of the liquefied material was expelled in a manner similar to geysers or mud volcanoes, mixing fossils and other sedimentary materials.
The article itself describes large extrusions similar to mud volcanoes and deposits containing a mix of late Cretaceous microfossils, resulting from the significant alteration of the seafloor caused by seismic activity.
The research is part of the project “Complex Clastic Unit of the Cretaceous-Paleogene Boundary in Cuba and its Relation to Geological Evolution”, developed since 2024 under the leadership of CEINPET in collaboration with the Geology Department of the University of Pinar del Río.
At work, researchers from other institutions also participated, and there was collaboration from the National University of Colombia, according to information released by Granma.
The discovery adds to decades of research on the traces left in Cuba by Chicxulub.
Since the 1990s, Cuban, Japanese, and Spanish specialists have documented significant rock formations related to the Cretaceous-Paleogene boundary in various regions of the country.
Evidence from that period has been found in sites across Pinar del Río, Artemisa, Havana, Matanzas, Villa Clara, Sancti Spíritus, and Holguín. Previous research had already identified marine deposits associated with earthquakes and tsunamis generated by the impact.
Due to the scientific value of the new location, the researchers propose that Arroyo Las Piedras be protected as a new geosite within the Viñales National Geopark.
Conservation would allow for the area to remain available for new research, educational activities, and scientific outreach.
In addition to contributing to the reconstruction of one of the most catastrophic events in the planet's history, the study can provide information on the geological evolution of western Cuba, subsurface mapping, and certain processes related to hydrocarbon exploration.
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