Science > Physics > Underthrusting versus overthrusting. : Mechanical versus thermal.
| Topic: |
Science > Physics |
| User: |
"don findlay" |
| Date: |
27 Aug 2007 10:34:41 AM |
| Object: |
Underthrusting versus overthrusting. : Mechanical versus thermal. |
Why is there such a discrepancy between the mechanical versus the
thermal view of subduction?
First it was continents ploughing through the mantle.
But that didn't work.
Then it was the mantle ferrying the crust around on a 'conveyor belt'
That didn't work either.
?Dykes intruding at the Ridges (ridge push)? Nope
Now it's the lithosphere itself that is the conveyour belt.
And that doesn't work
The citation below is 20 years old. Pushing or pulling the mantle
lithosphere down into the mantle has never been an option. The
cursory entry, and the 'soft words' are a concession to manners.
<--begin quote
--------------------------------------------------------
Underthrusting versus Overthrusting
-------------------------------------------------------
"The kinematic pattern produced by overthrusting, in which the hanging
wall is the active element, is a duplicate of that produced by
underthrusting, in which the active element is the footwall.
Theoretical and empricial data on the strength of rocks however tend
to indicate that underthrusting may be a phenomenon of limited scale
and importance. The force necessary to push or pull a large mass of
rock any considerable distance down and under another mass, making
room for the thrust mass in the subsurface is almost certainly in
excess of the strength of Earth materials. Examined from this
mechanical viewpoint, gravity-assisted overthrusting is by far the
more appealing process .
V.E. Gwinn.
Encyclopedia of Structural Geology and Plate Tectonics. 1987
Encyclopedia of Earth Sciences, volume X Ed. Rhodes Fairbridge, p.804
-----------------------------------------------------------
--end quote>
(Subduction by convection is a nonsense. So where to from here for
subduction?
Codespeak:-
"There can be no doubt that slab-pull is an important force moving
some plates"
(= "Slab-pull is *****:)
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| User: "Timberwoof" |
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| Title: Re: Underthrusting versus overthrusting. : Mechanical versus thermal. |
27 Aug 2007 01:22:58 PM |
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In article <1188228881.331569.275660@m37g2000prh.googlegroups.com>,
don findlay <don@tower.net.au> wrote:
Why is there such a discrepancy between the mechanical versus the
thermal view of subduction?
Why do you think that geophysicists' disagreeing on the details of plate
tectonics is evidence for expanding earth?
Let's see now...
Among DF, JT, and F there is disagreement on a few issues about
expanding earth. For instance, it's not clear whether it's caused by
added mass or by decreased density, the rate at which the expansion was
or is occurring is not agreed upon, and whether GPS or VLBI data can be
used to measure the size of the Earth is not agreed upon. Sometimes even
the proponents of the hypothesis change their minds about things.
If we apply their own criteria for validating other hypotheses to their
own, then EE fails.
--
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.
an important web site: http://www.muslim-refusenik.com/
.
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| User: "oriel36" |
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| Title: Re: Underthrusting versus overthrusting. : Mechanical versus thermal. |
27 Aug 2007 12:42:03 PM |
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On Aug 27, 4:34 pm, don findlay <d...@tower.net.au> wrote:
Why is there such a discrepancy between the mechanical versus the
thermal view of subduction?
First it was continents ploughing through the mantle.
But that didn't work.
Then it was the mantle ferrying the crust around on a 'conveyor belt'
That didn't work either.
?Dykes intruding at the Ridges (ridge push)? Nope
Now it's the lithosphere itself that is the conveyour belt.
And that doesn't work
The citation below is 20 years old. Pushing or pulling the mantle
lithosphere down into the mantle has never been an option. The
cursory entry, and the 'soft words' are a concession to manners.
<--begin quote
--------------------------------------------------------
Underthrusting versus Overthrusting
-------------------------------------------------------
"The kinematic pattern produced by overthrusting, in which the hanging
wall is the active element, is a duplicate of that produced by
underthrusting, in which the active element is the footwall.
Theoretical and empricial data on the strength of rocks however tend
to indicate that underthrusting may be a phenomenon of limited scale
and importance. The force necessary to push or pull a large mass of
rock any considerable distance down and under another mass, making
room for the thrust mass in the subsurface is almost certainly in
excess of the strength of Earth materials. Examined from this
mechanical viewpoint, gravity-assisted overthrusting is by far the
more appealing process .
V.E. Gwinn.
Encyclopedia of Structural Geology and Plate Tectonics. 1987
Encyclopedia of Earth Sciences, volume X Ed. Rhodes Fairbridge, p.804
-----------------------------------------------------------
--end quote>
(Subduction by convection is a nonsense. So where to from here for
subduction?
Codespeak:-
"There can be no doubt that slab-pull is an important force moving
some plates"
(= "Slab-pull is *****:)
What is undermining the motoin of the fractured surface crust is the
'convection cell' mechanism and 'slab pull'is an unfortunate outrigger
of that pathetic mechanism.
Because 'convection cells as a mechanism is so limited,the best
approach is to take a wider view to encompass the actual shape of the
Earth and extract the mechanism from that perspective and rework it
into surface features such as the mid-Atlantic ridge and finally into
the motions of the fractured crust.
It is always going to be about the mechanism no matter how people trry
to avoid it.I am not surprised at all that the guys who have
Wegener'soriginal proposals would rather allow the execellent
reasoning to sink due to a pathetic mechanism than actually consider
how the rotational dynamics of the Earth,specifically differential
rotation in the molten/flexible interior somehow influences crustal
evolution and motion.
'Slab pull' looks like it was created by children and this is coming
from the person who has little interest in the eevs convection cell
debate going on here.
.
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| User: "don findlay" |
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| Title: Re: Underthrusting versus overthrusting. : Mechanical versus thermal. |
27 Aug 2007 06:40:09 PM |
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oriel36 wrote:
On Aug 27, 4:34 pm, don findlay <d...@tower.net.au> wrote:
Why is there such a discrepancy between the mechanical versus the
thermal view of subduction?
First it was continents ploughing through the mantle.
But that didn't work.
Then it was the mantle ferrying the crust around on a 'conveyor belt'
That didn't work either.
?Dykes intruding at the Ridges (ridge push)? Nope
Now it's the lithosphere itself that is the conveyour belt.
And that doesn't work
The citation below is 20 years old. Pushing or pulling the mantle
lithosphere down into the mantle has never been an option. The
cursory entry, and the 'soft words' are a concession to manners.
<--begin quote
--------------------------------------------------------
Underthrusting versus Overthrusting
-------------------------------------------------------
"The kinematic pattern produced by overthrusting, in which the hanging
wall is the active element, is a duplicate of that produced by
underthrusting, in which the active element is the footwall.
Theoretical and empricial data on the strength of rocks however tend
to indicate that underthrusting may be a phenomenon of limited scale
and importance. The force necessary to push or pull a large mass of
rock any considerable distance down and under another mass, making
room for the thrust mass in the subsurface is almost certainly in
excess of the strength of Earth materials. Examined from this
mechanical viewpoint, gravity-assisted overthrusting is by far the
more appealing process .
V.E. Gwinn.
Encyclopedia of Structural Geology and Plate Tectonics. 1987
Encyclopedia of Earth Sciences, volume X Ed. Rhodes Fairbridge, p.804
-----------------------------------------------------------
--end quote>
(Subduction by convection is a nonsense. So where to from here for
subduction?
Codespeak:-
"There can be no doubt that slab-pull is an important force moving
some plates"
(= "Slab-pull is *****:)
What is undermining the motoin of the fractured surface crust is the
'convection cell' mechanism and 'slab pull'is an unfortunate outrigger
of that pathetic mechanism.
Because 'convection cells as a mechanism is so limited,the best
approach is to take a wider view to encompass the actual shape of the
Earth and extract the mechanism from that perspective and rework it
into surface features such as the mid-Atlantic ridge and finally into
the motions of the fractured crust.
It is always going to be about the mechanism no matter how people trry
to avoid it.I am not surprised at all that the guys who have
Wegener'soriginal proposals would rather allow the execellent
reasoning to sink due to a pathetic mechanism than actually consider
how the rotational dynamics of the Earth,specifically differential
rotation in the molten/flexible interior somehow influences crustal
evolution and motion.
'Slab pull' looks like it was created by children and this is coming
from the person who has little interest in the eevs convection cell
debate going on here.
Reading the entry on convection in the encyclopedia mentioned above is
quite interesting. Seyfert took over from Rhodes Fairbridge as
editor. The book was published (finally) in 1987, and records the
Acme of thinking on Plate Tectonics, before it began to go into
ridiculous decline. In the preface Seyfert says the book was
originally intended to be on just structural geology, but when he took
over he decided to include Plate Tectonics. Seyfert himself does the
entry on convection which makes interesting reading. There are ten
pages; about 50% is illustration. The book itself is heavily weighted
towards Plate Tectonics rather than Structural Geology ( in which
latter topic it is rather superficial). It is difficult to tell
whether he is being tongue-in-cheek about Plate Tectonics. I read it a
long time ago as an honest attempt at portrayal, but now I find it
difficult to see it that way at all. After nit-picking his way
through just about everything on Plate Tectonics and discarding it all
as virtually unworkable or based on highy questionable assumptions,
his concluding sentence reads:-
----------------------------------------
"In summary there appears to be convection within at least the upper
mantle of the Earth, but the weight of geological and geophysical
evidence indicates that convection cells do not exist within the upper
mantle."
-----------------------------------------
Talk about speaking with a forked tongue! I think before I would
have put that aside as me not quite understanding all this complex
business that took ten pages including many diagrams to explain.
But now, ..taken in conjunction with his ..<quote> "The convection
model I prefer is one in which dikelike diapiric intrusions of
peridotite are emplaced under spreading (mid-ocean) ridges and force
700km thick plates apart laterally as a result of the buoyant force of
the upwelling diapir." <unquote> I htink you can almost hear him
laughing.
It's him giving the lithosphere a special mention as 700km thick that
gets me... Half a world away, .. By ten centimetres of a ***** (this
year) ppp..pp.pushing all that oceanic lithosphere down the
gurgler.. It's difficult to believe he's serious. I mean, ..have
you ever seen a ***** ten centimetres wide? Ever bothered to follow
one along strike? Has anybody?
..."Yes, ..you can trace this one from the tip of Africa to the North
Pole.." .. "..And we know this because it's down at the bottom of
the ocean floor.."
Do you wonder why all the goats and donkeys (we don't even hear from
the gorilla any more) are scrabbling about the way they are? And why
Stuart prattles on about raleigh-taylor numbers and volumetric
whatsit, and potassium in the core. It's an industry in publication,
that's all. Talk about con men ! How do they get away with it, is
probably the most valid question about the whole thing.
And Stunami Sue says, "No, ..it's getting pulled... The slab is
pulling it.. Numbers say so." No wonder they marooned him on an
island in the middle of the Pacific, looking at waves washing up on
the beach.
.
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| User: "Stuart" |
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| Title: Re: Underthrusting versus overthrusting. : Mechanical versus thermal. |
27 Aug 2007 08:08:40 PM |
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On Aug 27, 1:40 pm, don findlay <d...@tower.net.au> wrote:
oriel36 wrote:
On Aug 27, 4:34 pm, don findlay <d...@tower.net.au> wrote:
Why is there such a discrepancy between the mechanical versus the
thermal view of subduction?
First it was continents ploughing through the mantle.
But that didn't work.
Then it was the mantle ferrying the crust around on a 'conveyor belt'
That didn't work either.
?Dykes intruding at the Ridges (ridge push)? Nope
Now it's the lithosphere itself that is the conveyour belt.
And that doesn't work
The citation below is 20 years old. Pushing or pulling the mantle
lithosphere down into the mantle has never been an option. The
cursory entry, and the 'soft words' are a concession to manners.
<--begin quote
--------------------------------------------------------
Underthrusting versus Overthrusting
-------------------------------------------------------
"The kinematic pattern produced by overthrusting, in which the hanging
wall is the active element, is a duplicate of that produced by
underthrusting, in which the active element is the footwall.
Theoretical and empricial data on the strength of rocks however tend
to indicate that underthrusting may be a phenomenon of limited scale
and importance. The force necessary to push or pull a large mass of
rock any considerable distance down and under another mass, making
room for the thrust mass in the subsurface is almost certainly in
excess of the strength of Earth materials. Examined from this
mechanical viewpoint, gravity-assisted overthrusting is by far the
more appealing process .
V.E. Gwinn.
Encyclopedia of Structural Geology and Plate Tectonics. 1987
Encyclopedia of Earth Sciences, volume X Ed. Rhodes Fairbridge, p.804
-----------------------------------------------------------
--end quote>
(Subduction by convection is a nonsense. So where to from here for
subduction?
Codespeak:-
"There can be no doubt that slab-pull is an important force moving
some plates"
(= "Slab-pull is *****:)
What is undermining the motoin of the fractured surface crust is the
'convection cell' mechanism and 'slab pull'is an unfortunate outrigger
of that pathetic mechanism.
Because 'convection cells as a mechanism is so limited,the best
approach is to take a wider view to encompass the actual shape of the
Earth and extract the mechanism from that perspective and rework it
into surface features such as the mid-Atlantic ridge and finally into
the motions of the fractured crust.
It is always going to be about the mechanism no matter how people trry
to avoid it.I am not surprised at all that the guys who have
Wegener'soriginal proposals would rather allow the execellent
reasoning to sink due to a pathetic mechanism than actually consider
how the rotational dynamics of the Earth,specifically differential
rotation in the molten/flexible interior somehow influences crustal
evolution and motion.
'Slab pull' looks like it was created by children and this is coming
from the person who has little interest in the eevs convection cell
debate going on here.
Reading the entry on convection in the encyclopedia mentioned above is
quite interesting. Seyfert took over from Rhodes Fairbridge as
editor. The book was published (finally) in 1987, and records the
Acme of thinking on Plate Tectonics, before it began to go into
ridiculous decline. In the preface Seyfert says the book was
originally intended to be on just structural geology, but when he took
over he decided to include Plate Tectonics. Seyfert himself does the
entry on convection which makes interesting reading. There are ten
pages; about 50% is illustration. The book itself is heavily weighted
towards Plate Tectonics rather than Structural Geology ( in which
latter topic it is rather superficial). It is difficult to tell
whether he is being tongue-in-cheek about Plate Tectonics. I read it a
long time ago as an honest attempt at portrayal, but now I find it
difficult to see it that way at all. After nit-picking his way
through just about everything on Plate Tectonics and discarding it all
as virtually unworkable or based on highy questionable assumptions,
his concluding sentence reads:-
----------------------------------------
"In summary there appears to be convection within at least the upper
mantle of the Earth, but the weight of geological and geophysical
evidence indicates that convection cells do not exist within the upper
mantle."
-----------------------------------------
Talk about speaking with a forked tongue!
Frankly, I can't make heads or tails out of it either. I don't know
who Seyfert is, but he should do a better job of editing.
Perhaps it was an oblique refernce to Richter Rolls, I have no idea.
Don, if you're interested in leanring about mantle convection,
You can get a copy of "Mantle Convection in the Earth and Planets"
Or you can continue to suck your tootsie pop.
Stuart
.
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| User: "don findlay" |
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| Title: Re: Underthrusting versus overthrusting. : Mechanical versus thermal. |
28 Aug 2007 05:35:41 AM |
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Stuart wrote:
On Aug 27, 1:40 pm, don findlay <d...@tower.net.au> wrote:
oriel36 wrote:
On Aug 27, 4:34 pm, don findlay <d...@tower.net.au> wrote:
Why is there such a discrepancy between the mechanical versus the
thermal view of subduction?
First it was continents ploughing through the mantle.
But that didn't work.
Then it was the mantle ferrying the crust around on a 'conveyor belt'
That didn't work either.
?Dykes intruding at the Ridges (ridge push)? Nope
Now it's the lithosphere itself that is the conveyour belt.
And that doesn't work
The citation below is 20 years old. Pushing or pulling the mantle
lithosphere down into the mantle has never been an option. The
cursory entry, and the 'soft words' are a concession to manners.
<--begin quote
--------------------------------------------------------
Underthrusting versus Overthrusting
-------------------------------------------------------
"The kinematic pattern produced by overthrusting, in which the hanging
wall is the active element, is a duplicate of that produced by
underthrusting, in which the active element is the footwall.
Theoretical and empricial data on the strength of rocks however tend
to indicate that underthrusting may be a phenomenon of limited scale
and importance. The force necessary to push or pull a large mass of
rock any considerable distance down and under another mass, making
room for the thrust mass in the subsurface is almost certainly in
excess of the strength of Earth materials. Examined from this
mechanical viewpoint, gravity-assisted overthrusting is by far the
more appealing process .
V.E. Gwinn.
Encyclopedia of Structural Geology and Plate Tectonics. 1987
Encyclopedia of Earth Sciences, volume X Ed. Rhodes Fairbridge, p.804
-----------------------------------------------------------
--end quote>
(Subduction by convection is a nonsense. So where to from here for
subduction?
Codespeak:-
"There can be no doubt that slab-pull is an important force moving
some plates"
(= "Slab-pull is *****:)
What is undermining the motoin of the fractured surface crust is the
'convection cell' mechanism and 'slab pull'is an unfortunate outrigger
of that pathetic mechanism.
Because 'convection cells as a mechanism is so limited,the best
approach is to take a wider view to encompass the actual shape of the
Earth and extract the mechanism from that perspective and rework it
into surface features such as the mid-Atlantic ridge and finally into
the motions of the fractured crust.
It is always going to be about the mechanism no matter how people trry
to avoid it.I am not surprised at all that the guys who have
Wegener'soriginal proposals would rather allow the execellent
reasoning to sink due to a pathetic mechanism than actually consider
how the rotational dynamics of the Earth,specifically differential
rotation in the molten/flexible interior somehow influences crustal
evolution and motion.
'Slab pull' looks like it was created by children and this is coming
from the person who has little interest in the eevs convection cell
debate going on here.
Reading the entry on convection in the encyclopedia mentioned above is
quite interesting. Seyfert took over from Rhodes Fairbridge as
editor. The book was published (finally) in 1987, and records the
Acme of thinking on Plate Tectonics, before it began to go into
ridiculous decline. In the preface Seyfert says the book was
originally intended to be on just structural geology, but when he took
over he decided to include Plate Tectonics. Seyfert himself does the
entry on convection which makes interesting reading. There are ten
pages; about 50% is illustration. The book itself is heavily weighted
towards Plate Tectonics rather than Structural Geology ( in which
latter topic it is rather superficial). It is difficult to tell
whether he is being tongue-in-cheek about Plate Tectonics. I read it a
long time ago as an honest attempt at portrayal, but now I find it
difficult to see it that way at all. After nit-picking his way
through just about everything on Plate Tectonics and discarding it all
as virtually unworkable or based on highy questionable assumptions,
his concluding sentence reads:-
----------------------------------------
"In summary there appears to be convection within at least the upper
mantle of the Earth, but the weight of geological and geophysical
evidence indicates that convection cells do not exist within the upper
mantle."
-----------------------------------------
Talk about speaking with a forked tongue!
Frankly, I can't make heads or tails out of it either. I don't know
who Seyfert is, but he should do a better job of editing.
looking at it afresh it's clearly a misprint/ mistake, the first
"upper mantle" should read 'lower mantle'. It's his own entry; he
never had anybody proof read it.
Perhaps it was an oblique refernce to Richter Rolls, I have no idea.
(Richter Rolls,.. Who's he? )
Don, if you're interested in leanring about mantle convection,
You can get a copy of "Mantle Convection in the Earth and Planets"
Or you can continue to suck your tootsie pop.
Stuart
Not really Stuart. It's as silly in its way for Plate Tectonics as
spacedust is for Earth Expansion. A moment's thought shows it be
irrelevant. And indefensible, except for pulling the wool over
simpletons' eyes. You should be ashamed of yourself, ..firstly for
(as you seem to wish others to think) believing in it, and secondly
for not pointing out to these poor sheep here the many nonsenses of it
in the name of 'falsification' - what 'science' is supposed to be
about.. But we do understand that it has simple memic appeal for
sheep, rooted as it is deep in human psyche ffrom the earliest time of
observances of volcanoes. The fire and brimstone emanating from the
Earth's interior is not an easy one to ignore, even though seismically
it rings, as you owould say, .. like a bell and is as solid as a rock
- "mild steel" I think you called it. ( "The gift that keeps on
giving". )
The parallels of simple-mindedness are obvious. I very much doubt,
even if you could lay your 'prejudice' aside, if you could believe in
spacedust as a possible mechanism for Earth expansion, yet that one-
dimensional simplemindedness is precisely what you are revealing when
you are recommending convection to others. There might be conceptual
physical support (arithmetically speaking - of the sleight-of-hand-
type) (although phase changes are not part of a convecting system)
but there is certainly no geo- or logical support. As well you know.
....And thirdly for not extending its one-dimensionality and addressing
the problems raised by the insurmountable mechanical fallacies.
The tootsie pop is yours I'm afraid, if you are serious (which I verty
much doubt) ..but the loss is others, when people in your position
are perceived to seriously uphold it. In my book you are extremely
disingenous, as you were when you huffed and puffed about "massive
academic fraud".
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| User: "Desertphile" |
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| Title: Re: Underthrusting versus overthrusting. : Mechanical versus thermal. |
28 Aug 2007 12:12:10 PM |
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On Mon, 27 Aug 2007 08:34:41 -0700, don findlay <don@tower.net.au>
wrote:
Why is there such a discrepancy between the mechanical versus the
thermal view of subduction?
It's the same thing.
--
http://desertphile.org
Desertphile's Desert Soliloquy. WARNING: view with plenty of water
"Why aren't resurrections from the dead noteworthy?" -- Jim Rutz
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| User: "oriel36" |
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| Title: Re: Underthrusting versus overthrusting. : Mechanical versus thermal. |
28 Aug 2007 01:59:07 PM |
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On Aug 28, 6:12 pm, Desertphile <desertph...@nospam.org> wrote:
On Mon, 27 Aug 2007 08:34:41 -0700, don findlay <d...@tower.net.au>
wrote:
Why is there such a discrepancy between the mechanical versus the
thermal view of subduction?
It's the same thing.
Just say - ' I am a stationary Earther and I love my stationary Earth
convectiion cells'
Its all about the mechanism now (unfortunately) and as you jokers
created 'dark matter' you let the ee guys off the hook and I think
that is fair enough.
It is incredible to see the birth of this particular conceptual
monster even if it is not surprising,the fact that 'convection cells
require no association to the dynamics of axial rotation or any
orientation whatsoever makes you stationary Earthers exist at the
level below creationists..
--http://desertphile.org
Desertphile's Desert Soliloquy. WARNING: view with plenty of water
"Why aren't resurrections from the dead noteworthy?" -- Jim Rutz
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