Re: extinction

["Dewey M. McLean" <dmclean@vt.edu>]

Response to David Marjanovic's post of Fri, 16 Jan 2004 21:35:34.

David wrote:

>  > Volcanic debris can float for long
>  > distances via marine currents.

"But certainly not uphill to the purely terrestrial Nanxiong Basin. You'd
need a second impact to create the gihugrongous tsunami necessary to wash
seawater into that basin, and I _am_ taking paleogeography into account."

Re the K-T transition iridium spikes, are you advocating that the 
splendid works of Zhao, and other Chinese scientists be disregarded 
because they do not fit your notions of K-T science?

Incidentally, as regards a K-T climate change, here is what Zhao and 
Yan had to say about me in their paper, "Stable isotopic studies of 
dinosaur eggshells from the Nanxiong Basin, South China" (Studies in 
China, 2000, v. 43, pp. 84-92):

"Therefore, it seems logical to reason that the trend toward more 
negative C-13 values of the eggshells in the two studied sections 
could be an indirect consequence of a lasting increase in CO2 
concentration in air during the K/T transition. This seems to agree 
with the model developed by McLean [22-24] who proposed that 
CO2-induced greenhouse warming was caused by the Deccan Traps 
volcanism during the K-T transition."

Cordially,
Dewey McLean