Many now think the meteor strike off the Yucatan was just a finishing touch, if that. The main work was already done by massive volcanic action on the Indian subcontinent.

65 million years ago, the events creating the Deccan Traps produced a basalt flow 6,500 feet thick covering over a million square miles, all in a remarkably short time. Near Mumbai (Bombay) this flow is still 1-1/2 miles thick. These events would have had a severe effect on both atmosphere and climate.