Rains of incandescent rocks, heat waves of up to 80 degrees Celsius, spontaneous fires, and almost two years of darkness, among other disturbances, are the main effects of the collision with the 10-km Chicxulub asteroid which unleashed the hell on Earth and killed 75% of the species, including the dinosaurs. The ground zero impact zone, a crater over 180-kilometer in diameter, seemed to be the worst place for organisms to thrive but a study shows that life has made its way even in such a hostile place.
Those responsible for the study analyzed rocks extracted from the crater in the Yucatan Peninsula that conserve sediments formed in the first 200,000 years after impact.
In the sample strata, there is a suevite, a rock associated with meteoric impact craters, and pelagic limestone from the Paleocene era, deposited between 30,000 and 200,000 years after impact.
“Among them is a ‘transition unit’ in which we found no fossil remains, indicative of the moment when life was restored in the crater,” said Christopher Lowery, a paleo-oceanographer at the University of Texas, in Austin, in the USA.
Life in the Chicxulub asteroid impact area emerged only 30,000 years after the collision
Surprisingly, the limestone stratum “contains evidence of a prosperous, diverse and productive ecosystem,” Lowery added.
Scientists discovered this after analyzing small fossils such as planktonic foraminifera, that are organisms used as paleoecological indicators, and calcareous nanoplankton, as well as fossil-traces of biological activity.
What’s striking about the finding is that the impact area was thriving of life long before other regions.
Considering that the speed of recovery of marine-terrestrial ecosystems varied, taking up to 300,000 years in the Gulf of Mexico and North Atlantic, the period of 30,000 years it took for the life forms to populate the ground zero, the Chicxulub asteroid impact area, is stunning.
The scientists argue that some ecological processes, such as interactions between organisms within the Chicxulub asteroid crater, probably helped rapid repopulation. “Sea animals larger than these organisms returned at the same time as the plankton, as they are the basis of their food chain,” Lowery explains.