New study suggests two incidents caused the extinction, not one.
By Raif Karerat
It’s long been assumed that the dinosaurs were cataclysmically wiped out by a massive asteroid impact 66 million years ago, but scientists are now claiming the earth-shaking missile from space may have had an accomplice.
Researchers studying the ancient Deccan Traps lava flows of present-day India have implicated volcanic eruptions that they say turned deadly around the same time that the asteroid hit – which together with the impact would have filled the air and covered the earth with a toxic cloud that would have driven countless species to extinction.
“Based on our dating of the lavas, we can be pretty certain that the volcanism and the impact occurred within 50,000 years of the extinction, so it becomes somewhat artificial to distinguish between them as killing mechanisms: both phenomena were clearly at work at the same time,” said lead researcher Paul Renne, a University of California, Berkeley professor of earth and planetary science, while speaking with Discovery News.
According to the scientists, the impact of the asteroid changed the “underground plumbing” in the volcanoes, making some magma chambers larger so they spouted more lava when they erupted.
Such a change in the nature of eruptions — from frequent but small to occasional but enormous — could have been brought on by the shock of the asteroid impact, Renne told the Los Angeles Times.
“If our high-precision dates continue to pin these three events – the impact, the extinction and the major pulse of volcanism – closer and closer together, people are going to have to accept the likelihood of a connection among them,” said co-author Mark Richards, also a UC Berkeley professor of earth and planetary science.
“The scenario we are suggesting — that the impact triggered the volcanism — does in fact reconcile what had previously appeared to be an unimaginable coincidence,” he continued.