You wrote," That the basalt and ash must occur during the flood also. To me
the young-earth creationists must account for ALL the volcanism in the
Phanerozoic during that single year. The noxious gases and volatiles coming
out of the lavas would surely choke the occupants of the ark."
Basalt is deposited under water (basalt pillows) and, if one assumes that
the flood covered the whole earth, the formation of a basalt layer might not
have produced a lot of noxious gases. I don't know very much about
volcanism, but is it possible that volcanic "ash" could also have been
deposited under water or does this not happen? If it could, would the flood
waters then not have absorbed the noxious fumes, forming, among other dilute
sulfuric acid?
My comment is not intended to support a YEC view, but more a matter of
consistency. If volcanic ash cannot be formed under water, then the flood
could not have covered the entire earth. If it can (and did), there may not
have been any noxious fumes.
Chuck Vandergraaf
Pinawa, MB