There are two posts on ScienceBlogs which highlight two perspectives on the Dinosaur mass extinction, What Wiped Out The Dinosaurs? and K-T extinction debates: cranky "skeptics" or reasonable science?. I'd assumed that the Asteroids-from-the-sky was the clear consensus, but please see this old BloggingHeads.TV clip where Peter Ward seems to imply that the waters are muddier than you'd think:
Wouldn't it have cause a mild deformation of the Earth's crust in that location also? Precipitating years of volcanic by earthquakes agitating plates?
Interesting. Charcoal at the K-T line could be explained by the forests dying, then burning after the wood dried. It need not be from fires ignited by Chicxulub.
What about the iridium in the K-T layer though? I thought that was the main "smoking gun".
A deadly conjunction between asteroid impact and massive volcanic activity (perhaps even causally related, as suggested by megan) seems to fit the facts pretty well.
I have a bunch of posts on the major mass extinctions up and including the KT. You can find them on the side bar below the blogroll. However, I want to high light one of them, "Stop Dreaming! The KT is NOT the PT!" ought to be highlighted for these discussions. I do some comparisons of the Permian Extinction, one generally accepted now as having been caused by the Siberian Traps triggering the world nearly committing suicide, and the KT Extinction. They were REALLY different. It really makes it difficult to say the same mechanism was in play in both cases.
The Post is here: