Re: Ain't No Mountain Low Enough [elephants don't like steep terrain]

[Tommy Tyrberg <tommy.tyrberg@norrkoping.mail.telia.com>]

At 00:17 2006-07-28, David Marjanovic wrote:
> > I'm not sure that there
> > are any bonafide high-altitude fossil sites older than the Pliocene, though
> > there might be some in the Rockies (Florissant?).
>
> Was it you who once mentioned the Gamburtsev Mountains in Antarctica 
> onlist? Whoever did, however, ended by saying "Unfortunately, they're 
> covered by about a mile of ice."

Indeed it was, and that is also a way that an old mountain chain might be 
preserved beyond the normal span. Normally we consider ice to be a powerful 
erosive agent, and usually it is. However in the central parts of an 
ice-cap the ice is often "cold-based", i e frozen to the substrate, in 
which case all motion takes place within the ice and erosion is virtually 
zero. This can be seen e. g. in parts of northern Sweden where the ice was 
cold-based during the last glaciation and the Eemian/Early Weichselian (MIS 
5a-e) landscape is preserved intact under a very thin veneer of moraine.
The Gamburtsev mountains probably *are* quite old. At least there was a 
highland in that general area back before Australia and Antarctica 
separated. There are still traces of river valleys in Western Australia 
whose headwaters are truncated by the south coast.

Tommy Tyrberg