Re: Geochemistry

Kent Crispin (kent@songbird.com)
Fri, 3 Oct 1997 15:47:55 -0700


On Fri, Oct 03, 1997 at 03:54:23PM +0000, Benjamin Harding wrote:
> On 3 Oct 97 at 14:28, David Yeamans, CST-7, 5-8832, wrote:
>
> > What is the natural abundance of various quartzes in beach sands...
>
> We only need one tracer. Proper selection of a
> strategically-placed, distinctive outcrop that we know produces
> sand in today's river and has been exposed for many ky should do
> the trick.
>
> Ben

Maybe because it's Friday and I'm thicker than usual -- refresh for me
what this tracer is going to tell us, though? If you find a vestigal
sandbar 100 meters up a cliff it must have either come from a
catastrophic flood or ponding -- I'm not sure what more the tracer
tells you without some dating mechanism that goes along?

Another question that has tickled my imagination for some time now --
750000 cfs (to pick a number) sounds impressive, but can we relate it
to something more concrete -- for example, would the water reach the
footbridge at Phantom? My intuition tells me that the velocity of the
water, past some point, is purely determined by the overall slope of
the bed, which means that at any point you should be able to
calculate (to a rough approximation) the water level. Is this true,
or are there too many variables to make this feasible?

-- 
Kent Crispin				"No reason to get excited",
kent@songbird.com			the thief he kindly spoke...
PGP fingerprint:   B1 8B 72 ED 55 21 5E 44  61 F4 58 0F 72 10 65 55
http://songbird.com/kent/pgp_key.html
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