Re: Plate techtonics and asteroid hits

In article <WinLMSG.468198cf.2698.7f26@xxxxxxxxxxx>,
no@xxxxxxxx (Eric Rowley) wrote:

From: don findlay <don@xxxxxxxxxxxx>:

df> Ye Old One wrote:
df> > On Tue, 26 Jun 2007 08:46:27 -0700, don findlay
df> ><don@xxxxxxxxxxxx> enriched this group when s/he wrote:
<snip>

df> > > Ok,..Question:-If the ocean floors are consumed (subducted)
df> > > at the same rate as they are formed at the spreading ridge
df> > > (accreted) (*wherever* these are) how would the ocean floors
df> > > ever open in the > >first place?

df> > The crust is pulled apart. Look at the way Africa's Great
df> >Rift Valley is starting to split the African Plate in two.
df> >One day there will be a sea between the two parts.

df> But it would never have gotten to be a rift valley (opening),
df> had it been closing (subducting) elsewhere, would it?

It most certainly would, unless you're suggesting that the earth was
shrinking?

DF is suggesting the Earth is expanding.

The total area of crust is constant (barring a shrinking or expanding earth)
If it is being pulled under in one place there must be new crust appearing
somewhere else to replace the disappearing bit.

Don Findlay thinks that ~200 million years ago the Earth was 1/2 its
present diameter. This would have made the continents, which are now
only 1/4 of the surface, cover all the surface. This is supposed to
explain why all the continents supposedly fit so neatly together.

He neglects a few obvious and important details, such as how Earth
gained 7/8 of its mass in that time, or how it had eight times its
present density before the expansion started. Having no answers for
these questions, he says they're unimportant and conveniently leaves
them up to the physicists to solve.

df> Likewise
df> its progression to a sea (ocean, actually; sea on continetal
df> crust is ok, but not an ocean (mantle crust))

Why not?

df> (Later; ...- Dayjob) >

Eric

--
Timberwoof <me at timberwoof dot com> http://www.timberwoof.com
When you post sewage, don't blame others for
emptying chamber pots in your direction. ?Chris L.

.

Relevant Pages

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