Re: Owen's Two-Phase Model of Earth Expansion

From: Stuart (bigdakine_at_aol.com)
Date: 03/02/05 

Date: 2 Mar 2005 13:29:08 -0800

don findlay wrote:
> Matt wrote:
>
> > I think I'm seeing this - will have to think about it more. Thanks
> > for taking the time to explain.
>
> Growth/ spreading/ 'movement', ..is not easy to get your mind around.
> And 'uplift' equates with sea-level change, not outwards movement of
> the Earth's surface from the centre - though they are related.
>
> >
> > > But you can see the difference between the zones in plan quite
> easily:-
> > > http://users.indigo.net.au/don/ng/123.html
> > > Fast or slow? I don't know. The point is that the ages of the
> ocean
> > > floors based on a model of thermal contraction are quite wrong.
It
> > > needs reappraised.
> >
> > What is wrong with the dating method?
>
> It's based on the **ASSUMPTION** (assumption) that an increase of
> depth away from the ridge is caused by the thermal contraction as the
> plate cools on moving away from the ridge axis, and that this
reflects
> the age.

Not an assumption, but fact. What Don talks about however, does also
happen. Google "Propagating Rifts". However ocean basin form by
spreading at ridges, not their propagation.

Second, there are no PT assumptions involved in the direct dating of
rocks. Plenty enough rocks have been dated directly to render Don's
point moot.

Stuart