Volcanic Activity:
Another
prominent K-T extinction theory is that a massive volcanic eruption
occurred at this time.
Extensive
volcanism could account for the iridium layer. Evidence supporting
this theory is found in the extensive volcanic deposits of the Deccan
Traps of India and Pakistan, dated at the K-T boundary (West,
1997).
These
lava flows would have produced enormous amounts of ash, and gaseous
elements which would alter gobal climatic conditions, and change
ocean chemistry, possibly causing a mass extinction.
Some
speculate that such a massive volcanic event would not have been as
explosive, sudden, or global enough to have caused an extinction as
extensive as the K-T extinction.
Shocked
quartz is not found at volcanic eruptions, even violently explosive
ones, and is considered an unequivocal indicator of a meteorite
impact (Lemon, 1993).
Regardless
of the cause 65mya, the effect was catastrophic!