A new study conducted by Princeton and MIT researchers challenges the mainstream theory of dinosaur extinction. It seems that the asteroid impact was not the unique cause of the global die-off, but there was also a massive volcanic eruption in India that had its contribution.
The common theory that explains why dinosaurs were extinct suggests that about 66 billion years ago a mountain-sized asteroid impacted Earth and triggered dinosaur extinction. Scientists also believe that the crater on tip of the Yucatan Peninsula in Mexico marks the spot where the initial collision occurred. Also, impact debris was found scattered in hundreds of places across the planet.
However, there is also a small group of researchers that believe the die-off was the result, at least in part, of an unprecedented volcanic eruption in western India. These researchers say that the eruption was so great that it surpassed 1.3 million times the eruption of Mount St. Helens in 1980. The lava produced during the eruption created the Deccan Traps, a 200,000 square mile area covered by solidified lava shaped as step-like hills. The initial area covered by the lava flows in this area was estimated to half the size of modern India.
Earlier studies have dated the Deccan Trapps formation by using a margin of error of plus/minus 1 million years. The new study, published this week in Science, shows that the volcanic eruption that created the Deccan area occurred 250,000 years ago before the dinosaur die-off and lasted about 500,000 years. Scientists say the findings reveal that although the volcanic eruption was not the only cause for dinosaur extinction, it may be one of its leading causes.
Mr Blair Schoene, Princeton geosciences professor and lead author of the study, said that both asteroid impact and gradual volcanic activity in India could have led to the mass extinction.
“Both are potentially really important. I don’t know if we can say the extinction would have or would not have happened without both of them,”
Mr. Schoene said.
Princeton researchers say that the volcanic activity may have changed the climacteric conditions in such a way that after the asteroid collision dinosaurs went extinct.
However, other scientists are not so willing to abandon their old theory about how things really happened by admitting that a volcanic eruption killed the dinosaurs.
Dr Kirk Johnson, an expert on the mass extinction, said that the asteroid impact was a remarkable event that lined up exactly with the extinction while additional theories to explain it seemed to him useless.
David Fastovsky, geoscientist, said that the volcanic eruption theory was possible but pointless since the scientific community had enough evidence from the asteroid theory.