[net.origins] Overthrusting

heller@shell.UUCP (Don Heller) (10/18/84)

Larry Bickford's recent posting included the following statement:

> The big problem with "overthrust geology" is the complete lack of
> evidence that it ever occurred. The challenge to the evolutionist: APART
> FROM THE ASSUMPTION OF EVOLUTION, what evidence is there that
> overthrusting has occurred? There is very good evidence that it hasn't -
> * we're not talking about a few small boulders moved by a flood (:-);
>   these rocks are HUGE and the distances on the order of 35 miles!
> * a noticeable absence of brecciation at the contact plane (i.e., moving
>   the top rock into place should have devastated the surfaces of both
>   rocks. The contact plane is particularly noted because later surface
>   erosion could not occur there).
> * the rock on top rests very comfortably on the rock below - not a very
>   natural occurrence, yet distinctly present in all "overthrusts."
> 
> To the contrary of Bill Jefferys claim, it is not Flood Geology which is
> preposterous, it is evolutionary geology which has more holes than a tax law.

This is nonsense.  The Alps are the most studied example of overthrusting;
any text on structural geology will have the details.  The Himalayas are the
result of a collision between the Indian subcontinent and Eurasia, where the
compression forces lead to slices of the Indian surface being stacked upon
each other.  There is overthrusting in the Appalachians and Rockies in
North America.  The Blue Ridge and Piedmont mountain ranges are crystalline
and metamorphic rocks thrust as sheets over the continental shelf sediments
of ancient North America in a collision with ancient Africa.  A piece of
Africa was left behind.  The Mauritanide mountain belt of Western Africa is
the complementary part of this collision.  In the western US and Canada there
are major regions of overthrusting.  These are of great interest to the oil
industry since the folding has trapped petroleum.  While we don't understand
all the details of the mechanism, and we are quite busily looking for an
explanation, the fact that old rocks occur over young rocks is not disputed.

Now for some comments about "the courage of one's convictions."  The above
statements are presented as facts for which there is evidence in the earth
itself.  A more cautious statement would be that they are the best available
explanations for the known facts, and we shall have to change those explana-
tions when more facts are discovered.  At some point, though, a decision is
made about whether or not to spend $500,000,000 to drill for oil.  This
decision is based on measurements of the earth, explanations, interpretations,
analogies, guesswork and finger-crossing.  There is a company in Salt Lake City
that is planning to use the Bible to explore for oil in Israel.  How will you
invest your money?

-----
Don Heller, Physics and Computer Science Dept., Shell Development Company
Houston, Texas
{ihnp4, pur-ee, ut-sally}!shell!heller