Re: Plate tectonics - Back to the FAQS

From: don findlay (don_at_tower.net.au)
Date: 01/30/05 

Date: 30 Jan 2005 15:46:51 -0800

Landy wrote:
> "George" <george@wtfiswrongwithyou.com> wrote in message
> news:_G0Ld.26525$ox3.3773@attbi_s04...
> >
> > "Landy" <none@nowhere.com> wrote in message
> > news:cth03k$22m$1@seagoon.newcastle.edu.au...
> >>
> >> "don findlay" <don@tower.net.au> wrote in message
> >> news:1107012674.823933.211810@z14g2000cwz.googlegroups.com...
> >>> Q1. Call it 'expanded' or 'growth' or whatever, ...what is the
> >>> fundamental, last word, bottom line evidence that the Earth has
got
> >>> bigger?
> >>>
> >>> A1. The creation of the ocean floors. These amount to two
thirds of
> >>> the Earth's surface at the present time, and give us an
indication of
> >>> the order of magnitude of enlargement of the Earth. The abyssal
hills,
> >>> which provide the record of ocean floor growth are the most
prolific
> >>> (and least mentioned - within plate tectonics) structures of the
ocean
> >>> floors.
> >>
> >> I just can't help myself.....
> >> So then why, Don, is there no ocean floor older than Jurassic? I
could
> >> say
> >> that you're forgetting (conveniently) that ocean floor is
destroyed at
> >> the same
> >> rate it is created. But that would be like trying to argue
evolution
> >> with a
> >> creationist.
> >>
> >> So what's the answer Don? To deny that seafloor is destroyed by
> >> subduction
> >> is to argue that there was no seafloor prior to the Jurassic and
hence
> >> the earth
> >> had no oceans. In fact if you're arguing that the current area of
oceans
> >> represent
> >> earth expansion since the Jurassic, the you're arguing by default
that
> >> prior to then
> >> the earth was entirely continental crust.
> >> cheers
> >> Bill
> >>
> >
> > Actually, Bill. There is, in point of fact, plenty of ocean floor
that is
> > older than Juassic.
>
> George
> You miss my point. I'm very well aware that there's ocean floor (now
no
> longer ocean floor) older than Jurassic. I've mapped Cambrian ocean
floor
> and overlying ribbon cherts in the New England Fold Belt of eastern
> Australia. The adjective I missed putting in my statement was
"current".
> There is no *current* ocean floor older than Jurassic. Of course
there is
> older seafloor material - but it's either been subducted or accreted
as part
> of accretionary complexes - or in rare cases obducted. The point is,
that
> Don's arguments hinge on there being no oceanic crust prior to the
> Jurassic - as he quite clearly states in his reply - and is quite
clearly
> wrong.
> cheers
> Bill

Why? That's when the breakout started, more or less. At least the main
part.

So, George has a bit of basalt in his backyard. And Stuart has a
paperweight. So what? He might as well have a bit of dew on his grass
and claim it a remnant tsunami. By his logic and sense of proportion
it figures.

And by the way, what was stratigraphically underlying your "Cambrian
ocean floor with the ribbons of chert" when you mapped it?

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