Extinction [Deccan triggered by Yucatan?]
Discussions by Yann Oliver
Suggestion was made that an asteroid fall should cause tectonic activity, and perhaps volcanism, at the point on the earth opposite to the impact, due to seismic waves.
The Deccan is today at the opposite of the Yucatán, but this was not the case in the late Cretaceous. Moreover, the iridium layer appearing between lava flows indicates that the trapps were active before the impact> The volcanic activity could have stremgthened by the impact, but the iridium is not melted in the lava flows, indicating that there were no eruptions during the time the iridium was deposited on the Earth.
There is no known asteroid to explain the Permo-Triassic volcanism.
Furthermore, the other volcanic activities supposedly correlated with extinctions are generally a bit older than the extinctions.
Up: Extinction [Other hypotheses]