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RE: Obnoxious Oceans [




-----Original Message-----
From:   Jim Kirkland [SMTP:dis@gj.net]
Sent:   Saturday, August 22, 1998 4:05 AM
To:     augwhite@neosoft.com
Cc:     Dinosaur Listserver
Subject:        Re: Obnoxious Oceans [

<<Today deep water is cold(carries more o2). Without ice caps, deep ocean
bottom water is warm saline water from the low latitudes (warm water
carries less O2). During high stands in sealevel evaporitic basins are
flooded leading to less ne bottom water. Deep ocean goes anoxic and
oxygen minimum zone rises spilling over onto shelves and interior seas.
Great source rock for oil (much studied). Two big episodes of this
happened during "middle" Cretaceous (in Albian and at end of
Cenomanian).
        Nothing like this occurred at end of Cretaceous.>>

I take it that there would be a (considerable?) degree of convective mixing 
under normal circumstances.  When higher density, low latitude warm water 
stopped being added, the depths would also cool, reducing mixing.  This 
would further reduce oxygen concentration at depths.  Am I on the right 
track here?

On the other hand, without polar caps, how do you substantially increase or 
decrease sea levels?  Volcanic outgassing?  Or is it enough to eliminate 
shallow seas, and thus evaporative basins, through chance configuration of 
continents?

  --Toby White