[9][10] The Deccan Traps are thought to have been produced in major part by the still active Réunion hotspot, responsible for the creation of the modern Mascarene Islands in the Indian Ocean.

It is derived from the Swedish word for stairs (trapp) and refers to the step-like hills forming the landscape of the region.

The Deccan Traps region was reduced to its current size by erosion and plate tectonics; the present area of directly observable lava flows is around 500,000 km2 (200,000 sq mi).

While it was previously interpreted that these groups represented their own key points in the sequence of events in Deccan extrusion, it is now more widely accepted that these horizons relate more closely to paleotopography and distance from the eruption site.

[17] It has been theorized that sudden cooling due to sulfurous volcanic gases released by the formation of the traps and toxic gas emissions may have contributed significantly to the K–Pg mass extinction.

[20][21] This was followed by a similar study in 2015, both of which consider the hypothesis that the impact exacerbated or induced the Deccan volcanism, since the events occurred approximately at antipodes.

In a March 2019 article in the Proceedings of the National Academy of Sciences, an international team of twelve scientists revealed the contents of the Tanis fossil site discovered near Bowman, North Dakota, that appeared to show a devastating mass destruction of an ancient lake and its inhabitants at the time of the Chicxulub impact.

In the paper, the group reports that the geology of the site is strewn with fossilized trees and remains of fish and other animals.

The lead researcher, Robert A. DePalma of the University of Kansas, was quoted in the New York Times as stating that "You would be blind to miss the carcasses sticking out...

Evidence correlating this find to the Chicxulub impact included tektites bearing "the unique chemical signature of other tektites associated with the Chicxulub event" found in the gills of fish fossils and embedded in amber, an iridium-rich top layer that is considered another signature of the event, and an atypical lack of evidence for scavenging, perhaps suggesting that there were few survivors.

The exact mechanism of the site's destruction has been debated as either an impact-caused tsunami or lake and river seiche activity triggered by post-impact earthquakes, though there has yet been no firm conclusion upon which researchers have settled.

Mantle xenoliths have been described from Kachchh (northwestern India) and elsewhere in the western Deccan and contain spinel lherzolite and pyroxenite constituents.

Regional crustal thinning supports the theory of this rifting event and likely encouraged the rise of the plume in this area.

The spreading rate then dropped off, with the decrease occurring around 63 million years ago, by which time the main phase of Deccan volcanism ended.

[34] The combination of the asteroid impact and the resulting increase in eruptive volume may have been responsible for the mass extinctions that occurred at the time that separates the Cretaceous and Paleogene periods, known as the K–Pg boundary.