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

From: George (george_at_wtfiswrongwithyou.com)
Date: 03/04/05 

Date: Fri, 04 Mar 2005 17:10:08 GMT

"Matt" <matt.edwards@utoronto.ca> wrote in message
news:e25c654e.0503040737.30254351@posting.google.com...
> "Carsten Troelsgaard" <carsten.troelsgaard@mail.dk> wrote in message
> news:<4226f403$0$191$edfadb0f@dread11.news.tele.dk>...
>
>> I believe one of the EE's favoured points is, that the marine sediments on
>> the crust is the EE evidence that earth indeed was different then
>> (continents had the ocean on top, not next to it). A thorough oceanic earth
>> does, by and large, not erode and deposit at all; compared to the present
>> situation. It obviously did, but I hardly dare consider the relief and the
>> gradients, a rugged earth for sure.
>
> Not quite following you here. In EE we would say that in the initial
> phases the Earth's crust was entirely continental (sial) crust.

This is not possible, as "continental" crust is composed of much more than
"sial". This is the problem with making such comparisons - saying that
continental rock is "sial" while oceanic rock is "sima". If one looks at the
continents, they are composed of many rock types - silica-rich, and silica-poor.
There are limestones, shales, sandstones (all sedimentary, by the way), as well
as granites, granodiorites, etc, metamorphic rocks or various grades, as well as
mafic and ultramfic rock. All of this points to a diverse history, not one
single "initial" phase". Additionally, some of the oldest rock now part of the
continents are not sialic at all. Oversimplification only makes matters worse.

> It was more water-covered than today's crust, but gradually emerged over
> time (especially in slow EE). Erosion could have taken place once
> enough basins were present for sediments to be deposited in.

If the earth was/is expanding, why would the basins even exist?

>> What do they gain by such a construction? Continental rocks, sima, wouldn't
>> it basicly have been placed and composed 'as is' and express a factual
>> decompression of heavier rock at an earlier period and thus loose the
>> observed incentive for the earth to expand by evolving lighter rocks? It's
>> often been pointed out, that the 'lighter rock evolved' is not continental
>> as it preferentially places itself as a heavy oceanic rock.
>
> You're saying that lighter 'continental' rocks tend to form or be
> deposited on older rocks, which then become denser rocks. But ocean
> crust is formed in situ as more dense rock than the sial rock. This
> process is ongoing. Now some continental rocks are added
> volcanically, but in general the EE picture of lighter continental
> blocks being uplifted by newly formed rocks of heavier density is
> quite simple, even elementary. You might find the paper by Weijermars
> interesting.

As I've pointed out several times, the basement rock of most continents, or at
least part of the continents is composed mostly of mafic rock within ancient
rift systems. You cannot look at the geologic history of the ocean basins in
isolation from the geologic history of the continents.

>> I squinted at the online presentation of Owen's model of expansion. He
>> places plasma in the core with a reference to physicists for details. I did
>> then look for Owen's own credentials since he respects professionalism, but
>> he did not present himself. I have some preconsieved notions and no real
>> knowledge on plasma, but wouldn't it's eledged presence (however unlikely)
>> be a result of compression and heat rather than a course for the uppersit?
>> Is there any scientific rationale for plasma to aggregate in space as a
>> precurser for planets?
>>
>> Carsten
>
> Where did you find Owen's work online? In his papers he is listed as
> being at the British Museum of Natural History. Is that credentials
> enough for you? In any case, I don't find the plasma core idea that
> compelling.
>
> Matt

What do you find compelling?

Relevant Pages

  • Re: Owens Two-Phase Model of Earth Expansion
    ... > the crust is the EE evidence that earth indeed was different then ... > (continents had the ocean on top, ... that the 'lighter rock evolved' is not continental ... > places plasma in the core with a reference to physicists for details. ...
    (sci.geo.geology)
  • Re: Owens Two-Phase Model of Earth Expansion
    ... >> ocean basins, why do the basins still exist? ... So if the earth expanded even just 10%, ... (continents had the ocean on top, ... that the 'lighter rock evolved' is not continental ...
    (sci.geo.geology)
  • Re: Owens Two-Phase Model of Earth Expansion
    ... >> the crust is the EE evidence that earth indeed was different then ... >> (continents had the ocean on top, ... > phases the Earth's crust was entirely continental crust. ... I considered the expansion of heavy oceanic rock toward ...
    (sci.geo.geology)
  • Re: (non) Expanding Earth
    ... > is the water, not the rock, that is expanding). ... and is also in direct contradiction with earth observations. ... crust, the growth-cracks will appear at random too, becourse the tensile ... fracture - or use the transverse faults for growth. ...
    (sci.geo.geology)
  • Re: Owens Two-Phase Model of Earth Expansion
    ... >> enough basins were present for sediments to be deposited in. ... I considered the expansion of heavy oceanic rock toward ... > formed rock, or rather a lower less viscous part. ... both under present ocean basins and under continents. ...
    (sci.geo.geology)