It is widely believed that a gigantic asteroid is what led to the mass extinction of the dinosaurs 66 million years ago, and new research suggests volcanic activity also played a role.
A team of scientists believe the ancient asteroid impact triggered a dramatic increase in volcanic activity that likely led to the mass extinction, the American Association for the Advancement of Science reported. The new measurements of volcanic activity are believed to be the most precise to date, and suggest a significant increase in the rate of eruption of the Deccan volcanoes for 50,000 years following the impact.
"Massive eruptions formed the Deccan Traps flood basalts in India at around the same time as the mass extinction event 65 million years ago. Renne et al. precisely dated the massive volcanic field, which suggests a simultaneous increase in volcanism associated with the famous Chicxulub impact. Strong ecologic recovery may have been impossible until the volcanism slowed down 500,000 years later," the editor summary for the paper published in the journal Science stated.
To make their findings, the researchers used high-resolution argon dating of local igneous minerals. The data showed some subsections of volcanic rock in India were already active before the asteroid collision. After the asteroid hit the mean eruption frequency of a particular subsection decreased, but the lava volume increased; this phenomenon caused the mean magma eruption rate to almost double.
The researchers believe the transition from "high-frequency, low-volume eruptions to low-frequency, high-volume eruptions" suggests there was a change in the magma plumbing system that occurred around the same time as the asteroid strike.
"Therefore the authors suggest that the Cretaceous extinction may have resulted from the combined effects of both the asteroid collision and increased volcanic activity," the researchers said.
The findings were published in a recent edition of the journal Science.
