A post-impact hydrothermal system lasted eight million years at Chicxulub

A crater formed by the impact of an asteroid or comet can host conditions conducive to the emergence of life. These structures, once perceived as mere destructive scars, actually harbor environments where heat and water interact, creating hydrothermal systems capable of supporting prebiotic chemical reactions. Among Earth’s craters, Chicxulub in Mexico stands out for its size and exceptional state of preservation. A recent study reveals that its hydrothermal system persisted for at least eight million years, four times longer than previously estimated.

The Chicxulub crater, with a diameter of about 200 kilometers, formed 66 million years ago, marking the end of the Cretaceous period and the mass extinction of species, including dinosaurs. Researchers analyzed samples of rocks melted by the impact, collected from the crater’s central ring. These rocks contained potassium-rich minerals, such as feldspars, whose formation is linked to hydrothermal activity. Using a dating method based on the radioactive decay of argon, scientists determined that these minerals formed over a period extending up to 58 million years before the present. This discovery proves that the hydrothermal system operated for nearly eight million years after the impact.

Numerical simulations have confirmed these findings. By incorporating precise physical data, such as rock permeability and the geothermal gradient, the models showed that the temperatures and water flows necessary for hydrothermal activity could be sustained much longer than previously thought. In the most realistic scenario, temperatures at a depth of one kilometer remained high for several million years, allowing fluids to circulate and minerals to form. The latest simulations indicate that the water flow gradually decreased, becoming negligible after about eight million years.

This prolonged hydrothermal system provides an extended time window for essential chemical reactions for life to occur. Heat- and mineral-rich environments, such as those generated by impacts, are considered potential cradles for the first microbial life forms. Thermophilic microorganisms, capable of surviving in extreme conditions, could have thrived in these environments. Although direct evidence of microbial colonization in impact craters remains rare, this study strengthens the hypothesis that post-impact hydrothermal systems played a key role in the emergence of life on Earth.

The results obtained at Chicxulub could also shed light on research into other planets. Impact craters, ubiquitous in the solar system, may have hosted similar environments. On Mars, for example, where evidence of past liquid water is abundant, such systems could have provided favorable conditions for life over extended periods. The collected data suggest that large craters, such as those in Sudbury, Canada, or Lappajärvi, Finland, also experienced long-lasting hydrothermal activity, although not as long as Chicxulub’s.

Researchers emphasize that the exceptional longevity of Chicxulub’s system is explained by the crater’s very structure. The central ring, formed by the uplift of deep and fractured rocks, facilitated fluid circulation and the maintenance of high temperatures. This unique configuration allowed hydrothermal activity to last much longer than in other craters of comparable size. Future research will need to explore other areas of the crater to confirm whether this duration is representative of the entire structure or specific to the central ring.

This discovery challenges previous models, often deemed too conservative. It shows that hydrothermal systems generated by impacts can persist much longer than estimated, thus providing extended opportunities for the emergence and development of life.

Bibliographie

Source de l’étude

DOI : https://doi.org/10.1038/s43247-026-03618-5

Titre : A long-lived impact-generated hydrothermal system at the Chicxulub impact structure

Revue : Communications Earth & Environment

Éditeur : Springer Science and Business Media LLC

Auteurs : Annemarie E. Pickersgill; Evangelos Christou; Marissa M. Tremblay; Dan N. Barfod; Cornelia Rasmussen; Martin R. Lee; Martin Schmieder; Gareth S. Collins; Ross Dymock; Sean P. S. Gulick; David A. Kring; Joanna V. Morgan; Gordon R. Osinski; Timothy Swindle; Sonia M. Tikoo; Axel Wittmann; ; Timothy Bralower; Elise Chenot; Gail Christeson; Philippe Claeys; Charles Cockell; Marco Coolen; Ludovic Ferrière; Catalina Gebhardt; Kazuhisa Goto; Heather Jones; Xiao Long; Chris Lowery; Rubén Ocampo-Torres; Ligia Perez-Cruz; Michael Poelchau; Auriol S. P. Rae; Mario Rebolledo-Vieyra; Ulrich Riller; Honami Sato; Jan Smit; Naotaka Tomioka; Jaime Urrutia Fucugauchi; Michael Whalen; Kosei Yamagachi; William Zylberman; Darren F. Mark