Asteroid that caused mass extinction of dinosaurs had help from volcanoes, says study

A new study has revealed that the mass extinction of the dinosaurs was caused not only by asteroids, but also from massive volcanic eruptions that started around the same time, Los Angeles Times reports.

The findings were published in the journal Science.

The study brings together two earlier theories about the mass extinction of the dinosaurs, along with other species.

Scientists studying ancient lava flows in India have said that massive volcanic eruptions started at the same time, as did the asteroid eruptions. Together, the impact of the eruptions must have filled the air and covered the earth with toxic fumes and dust, causing extinction of numerous species, say scientists.

Lead author Paul Renne, a geochronologist at the Berkeley Geochronology Center said that the amount of lava extruded "would correspond to something like half a million cubic kilometers,"

"It's enough to cover the entire Earth to a depth of something like a meter or so. It's really big."

For the study, Renne and other members of the team traveled to India to the Deccan traps and sampled different levels of volcanic rock to see if any changes with the rock coincided with the asteroid impact.

"What we wanted to do was sample from the bottom of the pile, the middle of the pile and the top of the pile -- and try and determine where, within that whole sequence, the age of the impact and the extinction occurs," Renne said.

The researchers concluded that a change in the nature of volcanic eruptions could have been brought on by the asteroid impact. They were able to show that the changes in the eruptions occurred roughly 50,000 years of the asteroid's arrival.

The findings don't directly prove that the two events were linked but the findings offered compelling circumstantial evidence, Renne said.

"It should hopefully inspire people not to try and bolster one or the other of the two hypotheses and quit saying, 'Well it was all impact and the volcanism had nothing to do with it,'" Renne said.

"We really have to look at the two of these processes more organically than before."