Re: Hell Creek (long)

["James R. Cunningham" <jrccea@bellsouth.net>]

David Marjanovic wrote:

> Gigantic amounts of sulphur (dioxide) must indeed have been injected into at
> least the stratosphere and have led to cooling sulphuric acid droplets and
> then acid rain, but because of the anhydrite (waterless gypsum -- calcium
> sulphate) at the impact site, not because of the dolomite (mixed
> calcium/magnesium carbonate). :-) The latter yields carbon dioxide when
> vaporized, though -- greenhouse effect and acid rain, too.

I'm not entirely sure that the in-situ molecular compounds at the immediate
impact site would be as important as the overall element ratios.  The reason
being that the energy in the vicinity of the impact site would likely have been
sufficient not only to break all molecular bonds (thereby destroying most of the
in-situ compounds), but also to strip the outer electrons from the atoms,
leaving an elemental plasma which after cooling would reaquire the free
electrons and form new and different compounds from the individual particles
that had contributed to the plasma.  There's a lot of talk about the water vapor
kicked off, but one should keep in mind that in the immediate vicinity of the
impact there was not much water vapor left.  There were a lot of protons, free
electrons, and some oxygen nuclei.  Little proximate salt either.  A lot of
sodium, chlorine, calcium, and sulpher available to form whatever after the
initial temperatures declined sufficiently.  Further away from the impact,
outside the area of plasma formation, one could expect in-situ compounds to be
more directly related to the final product.

> > Also the Chixculub bolide hit in (admittedly shallow) salt water. This
> > means that large amounts of water vapour and _salt_ must have gone into
> the  stratosphere.

See above.  Though I wholeheartedly agree that a lot of salt, plus other
compounds that contain sodium and chlorine did wind up in the atmosphere, as did
a lot of water vapor (probably thousands of cubic miles of water vapor).

> > Furthermore very large amounts of methane would have been liberated
> > from methane hydrates and gone into the atmosphere and reinforced the
> > hothouse effect from carbon dioxide.

Again, in the immediate vicinity, it would have been mostly elemental carbon,
protons, and electrons rather than methane.  But since the entire Atlantic
continental shelf from Florida north to the Grand Banks of Newfoundland appears
to have failed and slumped eastward to the mid-Atlantic ridge, it is likely that
a lot of methane would have been released during the slide.