Science Daily has an interesting article on the extinction of the dinosaurs, 65 million years ago.  The K-T extinction event has been thought to be caused by a large meteor impact off the coast of the Yucatan peninsula.  However, at the same time, there were massive volcanic eruptions occurring in the middle of the Indian sub-continent.  This volcanic deposit is called the Deccan Traps.  The deposit formed over a period of a million years, and the source is believed to be a mantle plume.  That mantle plume existed and was flowing before the impact.  Now, a group headed by Mark Richards at UC Berkeley has proposed the the plume itself was affected by the Chicxulub impact.  Specifically, they ask did the impact cause a sudden, large increase in the flow.

Original paper in Geological Society of America Bulletin, April 30, 2015.

The asteroid that slammed into the ocean off Mexico 66 million years ago and killed off the dinosaurs probably rang the Earth like a bell, triggering volcanic eruptions around the globe that may have contributed to the devastation, according to a team of University of California, Berkeley, geophysicists.

Specifically, the researchers argue that the impact likely triggered most of the immense eruptions of lava in India known as the Deccan Traps, explaining the “uncomfortably close” coincidence between the Deccan Traps eruptions and the impact, which has always cast doubt on the theory that the asteroid was the sole cause of the end-Cretaceous mass extinction.

“If you try to explain why the largest impact we know of in the last billion years happened within 100,000 years of these massive lava flows at Deccan … the chances of that occurring at random are minuscule,” said team leader Mark Richards, UC Berkeley professor of earth and planetary science. “It’s not a very credible coincidence.”