https://www.youtube.com/watch?v=8uIUqmXu5SE
https://en.wikipedia.org/wiki/Deccan_Traps
The Deccan Traps in India are stacked lava flows up to a couple of kilometres thick, erupted near the end of the Cretaceous.
That much basalt released huge amounts of carbon dioxide, a stress on climate that overlapped the Chicxulub impact.