An article published this month in the journal “Science” describes a research that brings evidence to support the theory that the extinction of the dinosaurs was caused by the combination of the impact of an asteroid and a strong volcanism caused precisely by that event. About 66 million years ago, at the end of the Cretaceous period, the impact of an asteroid near today’s Yucatan peninsula might have caused exceptional phenomena of volcanism in India, in the area known as the Deccan Traps (photo ©Nicholas aka Nichalp).

The extinction of the dinosaurs is one of the events that has been causing the biggest arguments among paleontologists and geologists for decades. In the late ’70s, the physicist Luis Alvarez suggested that the impact of an asteroid could be the cause. The evidence of the impact occurred at the time of that extinction with the crater in the Yucatan, called Chicxulub, and the abnormal presence of iridium in geological strata around the world supported this theory but many scientists still had doubts.

Paul Renne and Mark Richards, two scientists from the University of Berkeley, have been investigating for a long time on the issue. Already in April 2015 they were among the authors of an article published in the journal “The Geological Society of America Bulletin” in which asserted that the impact that originated the Chicxulub crater triggered the huge eruptions of lava in the Deccan Traps.

Reindeer, Richards and other colleagues investigated what seems an incredible coincidence with two catastrophic events that took place over a time that was very short from the geological point of view. In very simple words, they collected evidence that the magmatic system of the Deccan Traps was already active and the impact in Yucatan was so violent as to cause a significant increase in its activity.

The new article in “Science” also includes among its authors Walter Alvarez, Luis Alvarez’s son and together with him creator of the thesis of the asteroid as a cause of the extinction of the dinosaurs. The theory described a few months ago by Renne Richards is resumed and developed to assert that this exceptional volcanism went on for about half a million years, the period needed to life form to recover after that extinction which eliminated not only dinosaurs but about three-quarters of the existing species.

The scenario that emerges from these findings shows an atmosphere filled with dust raised by the asteroid impact and then dust and toxic fumes released for millennia by the volcanic eruptions. The climate was influenced heavily disrupting the ecosystems of that era and slowing their recovery.

Research continues to better understand the mechanisms of influence of the asteroid impact on the Deccan Traps. Their relationship, however, is more and more difficult to deny. It’s therefore possible that the extinction of the dinosaurs and many other species of the Cretaceous period was caused by the combined effects of the asteroid impact and the exceptional volcanism.