Many scientists have long held the theory that a massive asteroid hitting Earth caused the extinction of the dinosaurs. Another theory is that volcanic eruptions were the culprit — but a research team is now saying the two events could be linked.
Researchers studying lava flows in ancient India suggest that deadly volcanic eruptions hit at a similar time as the asteroid. These eruptions would have filled the air and covered the planet with toxic fumes, driving dinosaurs to extinction.
The findings were published in the journal Science, bringing together the two popular theories about what may have caused the death of the dinosaurs, as well as a number of other species at the time.
The Deccan Traps in India have many layers of volcanic rock — the remains of one of the world's largest volcanic eruptions ever. According to researchers, the amount of lava was around half a million cubic kilometers — which is enough to cover all of Earth in a meter (or about three feet) of lava. Some scientists suggest that it was in fact this massive event that caused the extinction of the dinosaurs, rather than the asteroid — but the new research suggests that both had a role in the end.
The study's lead author Paul Renne and his colleagues wondered whether the asteroid impact and massive volcanic flows could have actually been related — it seemed unlikely that these catastrophic events just happened to occur at the same time.
The research team therefore travelled to India to take samples of the volcanic rock and examine if any changes in the rock could be related to the asteroid impact. They were looking for evidence that the two events were linked, rather than coincidental.
What they found was that while volcanoes had been erupting before the asteroid hit, afterward, there was a big change in the flow of the lava. More precisely, the lava showed much less crustal interaction — suggesting the lava that flowed after the asteroid was probably held in one large reservoir rather than many small ones. This kind of change could have been brought on by the shock of the asteroid impact.
Currently, the window between the asteroid and the volcanic reactions is around 50,000 years, however, the scientists are working to bring this down to 5,000 years, which will bolster the causal theory.
Via: L.A. Times
