[null and void]

There is some indication that it triggered a major volcanic event - the centuries long basaltic flow that created the Deccan traps - enough lava flowed to pretty much cover India to a depth of a mile.

Lots of ash, dust, CO₂ and sulfur dumped into the atmosphere. Major global warming and acid rain...

[Doctor Stochastic]

Any evidence of another iridium layer? Perhaps the impact wasn't as effusive.