Re: 340 million year old caves in Australia

[Phillip Bigelow <bigelowp@juno.com>]

If any cave fauna had become "established" by 340 mya, even if the cave
was subsequently closed off from direct surface flow for most of its
geologic history (instead, being fed only by nutrient-rich ground water),
then a mini-biosphere could still have survived.  And it could have
evolved.

Purely hypothetical, of course.

For starters, I'd like to know how deep are the sediments in the caves'
floors.  Coring or seismic would help answer that question. (no, I
haven't yet read their paper).

<pb>
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On Fri, 04 Aug 2006 21:38:54 +0200 Tommy Tyrberg
<tommy.tyrberg@norrkoping.mail.telia.com> writes:
> At 10:13 2006-08-04, Phillip Bigelow wrote:
> 
> >If these caves had openings to the surface as early as the 
> Paleozoic
> >(that's actually a big "if"), and if the openings stayed connected 
> to the
> >surface throughout the Mesozoic, then there could be a nearly 
> complete
> >Carboniferous through Recent biostratigraphic sequence of cave 
> fauna!
> >That would be amazing.  The different avenues of study for 
> evolution
> >researchers is mind boggling.
> 
> Erosion and accumulation is very slow in parts of Australia, but not 
> *that* 
> slow. Apparently these caves formed way back in the 
> Devonian/Carboniferous 
> and have fairly recently become open to the surface again. Nothing 
> but clay 
> minerals seems to have been found yet, and personally I would be 
> content 
> with just a few palaeozoic fossils.
> Caves with fossils older than the Pliocene are rather rare, but  not 
> 
> unheard of ("Phosphorites de Quercy" or the Triassic fissure fills 
> in Wales 
> for example).
> 
> Tommy Tyrberg 
> 
> 
> 



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