#Subduction & Ocean Basin
21 messages in this thread
Hi, Kamron–
>> Plumes I can go for but how could rollers be a consequence of the plate
motion if the rollers are causing plate motion?
How can chickens be a consequence of eggs if chickens are causing the eggs? Let
either plate motion (maybe subduction jump-started them) or rollers (perhaps
just plumes as in my earlier ice sheet scenario) start moving a bit and the
other respond a bit, encouraging the first to move more, encouraging the other
to go faster.. they may each egg the other on until both are moving at full
speed.
>> Not bad… but… if the section in question is pulled more in one direction
and fills in to effectively move the center of the rise why do the shift faults
extends in the opposite direction into the side that isn't pulled?
If the entire plate on one side is pulled harder, the entire ridge would move
that way as I outlined – no transform faults on either side. The faults come
from differentials. In section 1 the pull is relatively harder on side A, in
section 2 the pull is relatively harder on side B. In 1, the A side moves more
than in 2 as the ridge in 1 moves A-ward; in 2, the B side moves more than in 1
as the ridge in 2 moves B-ward. The 1/2 boundary has a differential on both
sides of the ridge.
>> My theory would predict the same conditions due to the collision of the
opposing magma fronts comming to rest in disarray. The fractures and the
presence of magma also.
I would not predict the continuation of this after 65 megayears from your
theory. Your theory predicts lower pressures at depth? It seems more like
postdictions to me.
>> On the contrary erratics are far more difficult to explain with
conventional Plate Tectonics.
In plate tectonics, the Jurassic rock under the west Pacific was not an
erratic, it was a missing link predicted by the theory, which was troublesome
in its absence. It is only an erratic in your theory, which explains erratics
in the Pacific only by a mechanism that would make Jurassic rock the least
probable. The Cretaceous rocks atop the Jurassic are neutral as far as plate
tectonics go, neither proving (apart from the strings of hotspot islands) nor
disproving, but in your theory must be erratics again defying the odds, the
more so because there is so much basalt involved with nary a granite.
>> Look at this very apparent plate motion scenario. After the Atlantic Ridge
fracture opened up and North and South America separated from Europe and Africa
they pivoted slightly with the pivot point somewhere in alaska. Notice how
Greenland will fill the Basin at the North Pole as well as snuggle back into
North America. Look at the perfect widening gap starting from the North and
moving to the south. See how the mid ocean ridge is almost perfectly in the
middle and balanced on both sides. It is a vivid and irrefutable sequence,(to
me)
We seem to be in general agreement on how the supercontinent Pangaea looked and
that it broke up (I hope you are putting Greenland against Norway on the other
side). This much (including the centered ridge) is predicted by your theory
and plate tectonics, favoring neither.
–Doug
Greetings Doug
>> Let either plate motion (maybe subduction jump-started them) or rollers
(perhaps just plumes as in my earlier ice sheet scenario) start moving a bit
and the other respond a bit, encouraging the first to move more, encouraging
the other to go faster.. they may each egg the other on until both are moving
at full speed.<<
Here again mega years are the method for explanation. For the enormous plates
to move in a direction at all would take a coordinated tremendous amount of
work. It is easiest to grasp the problem when probing the beginning of the
process. Imagine the earth cooling and crust formation occurred. The earth
would have a consistent crust. The cooling would have caused mild folding. How
would you propose this initial motion could occur considering there is nowhere
for the crust to move. Then add to it the additional effort required to force
the crust to subduct. The crust material is the scum and lighter than the
material below and would need to be forced down into the denser levels below.
This combination of no room to move and no force to move it makes your bit by
bit progression into motion impossible. Add the resistance of pushing the
floating crust downward The plate motion could start without the catastrophe
beginning the process.
>>If the entire plate on one side is pulled harder, the entire ridge would
move that way as I outlined – no transform faults on either side.
The faults come from differentials. In section 1 the pull is relatively
harder on side A, in section 2 the pull is relatively harder on side B. In 1,
the A side moves more than in 2 as the ridge in 1 moves A-ward; in 2, the B
side moves more than in 1 as the ridge in 2 moves B-ward. The 1/2 boundary has
a differential on both sides of the ridge.<<
This would work if the shifts occurred back and forth but they are sequential
99% of the time. The next section is moved even farther in the same direction
as the previous so again why would the shift fault run into the side B flank
when it isn't pulling away…only filling in as you described?
>>so much basalt involved with nary a granite.<<
Good point. The Granites do have an average density less than basalt but a
lower melting temperature, it is possible the granite that fell back into the
molten basalt and due to its lower melting point, melted with the basalt
becoming a component, trace aluminum should be found in the upper levels.
>>We seem to be in general agreement on how the supercontinent Pangaea looked
and that it broke up (I hope you are putting Greenland against Norway on the
other side). This much (including the centered ridge) is predicted by your
theory and plate tectonics, favoring neither.<<
Unless my simulations are out of date the Present Plate Tectonic Theory has a
much different motion showing North America separating and moving away 135 Meg
ago…. then 35 meg later South America splits from Africa….. Then 45 Meg
ago South america moves up to meet N America. This set of motions would end up
with an entirely different ocean basin markings.
The PPTT disregards the features of the Atlantic Ridge formation and shift
fault patterns. The trenches in the carribean show that the area separated
rather than squashed together. The shift faults are roughly parallel to the
motion that occurred.
Compare again my single one time sweeping motion where the N & S Americas
pivoting at Alaska with a slight separation of South America downward
……to the current PPTT and tell me which would produce the features we see
in the Ocean Basins?
Kamron
You seem to be denying that a slow tecotonic process occurs. How would your
theory handle a direct measurement of continental drift, say, by satellite
interferometry? I heard a lecture on it once, at my university. I could look
some more if it is relevant.
David
That would be great. I am curious about the measurements and would have
responded when you commented to Doug but no time….I did make note and will
get to that unless Doug nails me to the point where I give up. Right now I
think I have raised some relevant issues in regard to what is written in the
Ocean Basins themselves.
My first impression of measuring from space to detect inches of motion
leaves a wide margin of error….but bring it on.
Kamron
Hi, Kamron–
>>For the enormous plates to move in a direction at all would take a
coordinated tremendous amount of work.
Blow on a mega-ton iceberg for a few megayears where there are no other winds
or currents, and you may be surprised at how much work you did when you measure
its progress afterwards (assuming you did not melt it). As for "coordinated",
if three people blow in one direction while four people blow in the other, the
result will be the same as one person blowing alone.
>> The earth would have a consistent crust.
Can you prove there would be no magmatic differentiation, no convection in the
magma, etc.? Let us _assume_ this and see where it goes…
>> How would you propose this initial [plate] motion could occur considering
there is nowhere for the crust to move. Then add to it the additional effort
required to force the crust to subduct. The crust material is the scum and
lighter than the material below and would need to be forced down…
We are talking about before the continents formed. At this point (before
continent formation), having already assumed no magmatic differentiation, there
were no substantial lighter fractions – mantle and crust would be of the same
elemental composition. The crust would cool faster, and thus become denser
than the topmost mantle. There is plenty of force to be harnessed.
The situation is somewhat the same today; the oceanic crust is basalt, similar
to the mantle in composition, and the bulk of the plates, the lithosphere, _is_
mantle rock. All that has been added are the continents of lighter rock
floating on top. The plates are just itching for a place to sink, at least
until they get to the 400-km depth where olivine converts to a spinel
structure.
>> it is possible the granite that fell back into the molten basalt and due to
its lower melting point, melted
If something "saved" the Pacific Jurassic sediments from melting in your
theory, why did it not save us even more granite and pre-Jurassics in the
Pacific? This tooth fairy seems a lot like a Maxwell demon in its
choosiness…
>> Unless my simulations are out of date the Present Plate Tectonic Theory has
a much different motion showing North America separating and moving away 135
Meg ago…. then 35 meg later South America splits from Africa….. Then 45
Meg ago South america moves up to meet N America. This set of motions would end
up with an entirely different ocean basin markings.
I do not have enough info to respond. When I get a _globe_ with ocean floor
detail and a more precise reading on theorized movements, I might be able to
detect a difference between the expected results.
–Doug
Hello Doug
My point on the plate motion being driven by convection rollers is that
normally convection would cause plumes. Plumes rise in a column. If they meet a
flat surface they would spread and flow outward in all directions evenly
assuming no other currents exist. The form would be a donut type of flow.
The plumes rising to meet the slanted crustal areas would naturally flow
upwards towards the mid ocean ridge driving the plate in the wrong direction.
As stated the rollers would only develop after the plate started moving so the
moving plate would supply the energy for creating the rollers.
The following section is important to me so pardon me for bringing it up
again.
We worked up to here and you responded…
>>If the entire plate on one side is pulled harder, the entire ridge would
move that way as I outlined – no transform faults on either side.
The faults come from differentials. In section 1 the pull is relatively
harder on side A, in section 2 the pull is relatively harder on side B. In 1,
the A side moves more than in 2 as the ridge in 1 moves A-ward; in 2, the B
side moves more than in 1 as the ridge in 2 moves B-ward. The 1/2 boundary has
a differential on both sides of the ridge.<<
This would work if the shifts occurred back and forth but they are sequential
99% of the time. The next section is moved even farther in the same direction
as the previous so again why would the shift fault run into the side B flank
when it isn't pulling away…only filling in as you described?
Also I have one reference showing the magnetic profile of the Mid Ocean Ridge
has the same cross-section from one shifted section to the other balanced from
the midpoint out on both sides. This eliminates the filling in proposal also.
>> The crust would cool faster, and thus become denser than the topmost
mantle. There is plenty of force to be harnessed. <<
It is this function that would groom a consistent _worldwide_ crust. The upper
layers would cool and sink over and over until the crust material was
separated as a lighter material that would eventually float over the heavy
material. The Sial crustal material having a lower melting point would not
hardened until the magma below it had cooled enough to allow the
solidification. This temperature variance insured an even worldwide layer of
floating crust.
This is the reason I believe the earth had a lighter consistent granite crust
floating on the heavier basalt. This planet wide crust in turn built up a
planet-wide geological table from the slow accumulation of dust from the sun
creating the layers of time. This slow accumulation ended with the catastrophe.
The deposits that occurred after the KT boundary were all done in a very short
time frame.
In both theories the division of the plates is the same.
In both theories the original connections of the continental pieces is similar
enough to not worry about.
The main difference is how the motion occurred & What started it. I say the
basins have all the clues to tell the story of the motions. Traces of the
motions are left in the remnant island arcs and in the shift faults.
These shift faults are parallel to the motions that I say occurred in the
plates. The shifted mid ocean ridges prove that the event was a simultaineous
single rapid event unless we can come up with a plausible reason for the
homogeneous continuous mid ocean ridge and the shifted rise sections.
A catastrophe at the KT boundary is commonly assumed. It is the extent of the
catastrophe that is not well known.
Kamron
Hi, Kamron–
>> normally convection would cause plumes
It sounds reasonable (as reasonable as the flat earth must have sounded once)
but it remains proof by assertion until I hear from an expert on convective
flows. Convection in a solid, with spherical geometry, is too foreign to our
experience to be so dogmatic about.
>> The plumes rising to meet the slanted crustal areas would naturally flow
upwards towards the mid ocean ridge driving the plate in the wrong direction.
There is no reason to assume plumes would arrive in subduction areas.
>> As stated the rollers would only develop after the plate started moving so
the moving plate would supply the energy for creating the rollers
As with your plumes, this seems the best guess, but if your case depends on it,
you are in big trouble. Again, the unfamiliarity of the situation is great;
the experiment I referred to indicates it could have happened this way, not
that it did.
Assume only plumes at first – then a plume might break the single world-plate
in the beginning (a common pattern in such sheet breakups is to crack in three
pieces, with the three cracks meeting at the dome over the plume), causing the
three or so new plates to start subducting at some far edge (they were unstable
and "itching" to do this anyway, being cold dense material atop warmer lighter
material). Now they are moving, and the rollers may become organized by the
motion.
>> This would work if the shifts occurred back and forth but they are
sequential 99% of the time. The next section is moved even farther in the same
direction as the previous so again why would the shift fault run into the side
B flank when it isn't pulling away…only filling in as you described?
It is a relative thing. I cast 1 and 2 as going in opposite directions, but
that is from the viewpoint of an observer traveling at an average of their
velocities. Let 1 and 2 go in the same direction with 1 pulled harder and
faster, and the moving observer will see what I described.
>> Also I have one reference showing the magnetic profile of the Mid Ocean
Ridge has the same cross-section from one shifted section to the other balanced
from the midpoint out on both sides. This eliminates the filling in proposal
also.
The filling in is at equal rates on both sides of the rift, which was essential
to the whole picture I gave of a moving ridge, thus the spreading features are
symmetric.
>> It is this function that would groom a consistent _worldwide_ crust. The
upper layers would cool and sink over and over until the crust material was
separated as a lighter material that would eventually float over the heavy
material. The Sial crustal material having a lower melting point would not
hardened until the magma below it had cooled enough to allow the
solidification. This temperature variance insured an even worldwide layer of
floating crust.
That is the magmatic differentiation I spoke of – this and moderate convections
are the main things that could _prevent_ a uniform crust. This differentiation
requires very slow cooling in the absence of convection –
which I am not convinced is happening at the _surface_ of a lava-hot and
_radiating_ Earth. How can convection be less than furious in a magma ocean
with savage temperature differentials?
>> These shift faults are parallel to the motions that I say occurred in the
plates. The shifted mid ocean ridges prove that the event was a simultaineous
single rapid event unless we can come up with a plausible reason for the
homogeneous continuous mid ocean ridge and the shifted rise sections.
The shift faults are parallel to the _relative_ motions of the two plates
involved – this is predicted by plate tectonics. I see no proof of rapidity
here, especially not in the light of paleomagnetic markings. Above I describe
how the regular behavior of the ridges are predictable from plate tectonics – I
find it hard to imagine them so regular with so much as you would have going
on.
>> A catastrophe at the KT boundary is commonly assumed. It is the extent of
the catastrophe that is not well known.
It is not well known because there is little evidence of any such catastrophe
at the K-T boundary. Traces of iridium are _far_ less than one would expect
with whole continents literally flying about. Can you not show us even a small
jumble of weird rocks between K and T layers? How can that boundary be so thin
nearly everywhere?
–Doug
Doug,
> How can convection be less than furious in a magma ocean with savage
temperature differentials?
<tentatively…> Viscosity?
Ben
Hi, Ben–
Um, by "furious" I meant more than enough to forbid the placid fractionation
Kamron proposed. Watching this "furious" convection might prove almost as
exciting as watching grass grow…
–Doug
Ah… never mind. 🙂
Ben
Doug
>> Convection in a solid, with spherical geometry, is too foreign to our
experience to be so dogmatic about.<<
A solid does not have convection.
>>There is no reason to assume plumes would arrive in subduction areas.<< I'm
not sure what you mean by this. Let me explain again my position here.
Convection flows like smoke rises…. if it meets a slanted surface it will
seek to move up the slant until it is as cool as the surrounding material. It
would not flow downward while it is still warmer than its surroundings. The
force it would exert on the plate would be in the opposite direction than is
required to move the plate because the plates generally slant upward towards
the rise.
>>Assume only plumes at first – then a plume might break the single
world-plate in the beginning (a common pattern in such sheet breakups is to
crack in three pieces, with the three cracks meeting at the dome over the
plume), causing the three or so new plates to start subducting at some far edge
(they were unstable and "itching" to do this anyway, being cold dense material
atop warmer lighter material). Now they are moving, and the rollers may become
organized by the motion.<<
I buy the first part with a great stretch but the the last
>> being cold dense material atop warmer lighter material<<
this would not occur. First of all the material is atop because it was lighter
as a liquid and/or solid than the liquids below it otherwise it would have sunk
upon solidification. The crust material is not as heavy as the material it is
floating on. It rose to the top in the liquid state and then solidified when
the temperature of the material below cooled enough to allow it. IT did not
sink after solidification because it is lighter.
>> How can convection be less than furious in a magma ocean with savage
temperature differentials? <<
There would be turbulent convection in the beginning but this would slow
eventually. The materials in the deep ocean of magma would stratify out with
the cooling into the condition we have now …floating continents and after the
catastrophe floating ocean plates.
>>It is a relative thing. I cast 1 and 2 as going in opposite directions, but
that is from the viewpoint of an observer traveling at an average of their
velocities. Let 1 and 2 go in the same direction with 1 pulled harder and
faster, and the moving observer will see what I described.<<
I have more problems here, if you look at the shifted sections and consider
the section that has shifted more is traveling faster…. you have a situation
where each section is moving a little faster than its partner ending with a big
difference in the speeds of motion all in the same plate. Taking the Mid
Atlantic Ridge as an example and looking at the section between the latitudes
of Florida and the eastern most tip of S. America the distance covered would
show that the plate has shifted nearly two thousand miles more than its
counterpart or it has nearly double the speed. That is clearly impossible since
the plate is a single mass how can it travel at different speeds?
You still have not solved the problem of the shift faults extending into the
opposite side of the Rise matching the pulled side.
>> The shift faults are parallel to the _relative_ motions of the two plates
involved – this is predicted by plate tectonics.<<
Ok so this is agreed…. this is one of my points for revising the motions
into a single event.
>> I see no proof of rapidity here, especially not in the light of
paleomagnetic markings. Above I describe how the regular behavior of the ridges
are predictable from plate tectonics – I find it hard to imagine them so
regular with so much as you would have going on. <<
It is much easier to reconcile the regularity of the markings into a single
event than to get these markings from various merging and diverging of plates.
For example where is the evidence that South America has moved upward to meet
North America in the last 40 million years? Not only is there a lack of
evidence there are actually deep trenches in between the crustal fragments of
the Antilles. Why would trenches open up in an area being crushed together?
>>Traces of iridium are _far_ less than one would expect with whole continents
literally flying about. Can you not show us even a small jumble of weird rocks
between K and T layers? How can that boundary be so thin nearly everywhere? <<
Iridium is very dense and rare. It would be one of the first gases to condense
into liquid then solids out of all the elements. It came from deep within the
earth where it collected in the original formation of the planet. Actually it
isn't thin everywhere I have read it is as wide as 30 centimeters in some
areas.
The entire planet has much regularity below the KT boundary area and is much
more variable above the area. There are also other weird things like the Deccan
Traps which were tremendous lava flows over a short period of time. There is
also very little gravel below this boundary aside from faults that were back
filled. Hows that for weird?
Kamron
Hi, Kamron–
>> A solid does not have convection.
Hmph, you answer a complaint about dogmatism with another proof by dogmatic
assertion. We know solids can flow (consider how copper wires are made), and
have lab experiments showing solid rock can do it under pressure. We have good
reason to think Earth's core is hot. Convection in the mantle is a reasonable
assumption given these facts, and it cannot be wished away without evidence.
Have you visited the mantle lately? That is about the only way to prove it
does _not_ convect.
>> The force it [convection] would exert on the plate would be in the opposite
direction than is required to move the plate because the plates generally slant
upward towards the rise.
Ah, the angling plate had me thinking subduction zone. Newton's ghost will get
you for this; if the rising material is driven sideways toward the rise,
conservation of momentum says the plate is thereby driven away from the rise.
>> Taking the Mid Atlantic Ridge as an example and looking at the section
between the latitudes of Florida and the eastern most tip of S. America the
distance covered would show that the plate has shifted nearly two thousand
miles more than its counterpart or it has nearly double the speed. That is
clearly impossible since the plate is a single mass how can it travel at
different speeds?
I have always assumed that while the plates are constant in shape to a first
approximation, they do some intra-plate adjusting when looked at more closely.
My mental picture is of a glacier – it is best regarded as a solid mass whose
shape is not easily changed, yet it manages to flow around bends and such
tricks. I have a vague notion that fracture zones are examples of such
adjustments.
The spreading between S. America and Africa began, I believe, at the southern
end. While the crack was spreading north, the southern areas were already
moving apart, with new seafloor being created between them. Transform faults
allowed the spreading to continue until the crack extended northward and
spreading rates become matched – the plate shape changed as it was first added
to in the south only. The southern Atlantic did not open faster so much as it
opened earlier.
>> You still have not solved the problem of the shift faults extending into
the opposite side of the Rise matching the pulled side
I thought I just did. Maybe I will try again when time permits.
>> There is also very little gravel below this [K-T] boundary aside from
faults that were back filled. Hows that for weird?
So what were those conglomerate _layers_ I hiked through in the Grand Canyon
too long ago to admit? Looked like an awful lot of gravel to me.
There are occasional irregularities near the K-T boundary, but in your theory I
would very much expect to find huge piles of gravel and pre-Cretaceous erratics
_between_ Cretaceous and Tertiary layers at almost every point, not just India
(besides, the Deccan Traps were more or less finished before the K-T and are
less remarkable than the older Siberian Traps and the Ontong-Java plateau). As
wide as 30 centimeters? You have whole continents (and all the gravel in the
world) flying through the air and never more than 30 centimeters of deposits
that show no evidence of pre-Cretaceous origin?!?
–Doug
Doug
>> We know solids can flow (consider how copper wires are made), and have lab
experiments showing solid rock can do it under pressure. We have good reason
to think Earth's core is hot.>> I agree
The temperature and pressure that a material needs to become malleable has a
threshold that must be passed for this to occur. If it does not pass this
point it is not malleable.
>>Convection in the mantle is a reasonable assumption given these facts, and
it cannot be wished away without evidence. Have you visited the mantle lately?
That is about the only way to prove it does _not_ convect.<< Well give me a
shot at it.
>>Ah, the angling plate had me thinking subduction zone. Newton's ghost will
get you for this; if the rising material is driven sideways toward the rise,
conservation of momentum says the plate is thereby driven away from the rise.<<
Are you agreeing that the plume would flow up the rising incline?
and the conservation of momentum will attempt to drag the plate upward with
the flow. What are you thinking here with the hint of a reverse flow?
>>I have always assumed that while the plates are constant in shape to a first
approximation, they do some intra-plate adjusting when looked at more closely.
My mental picture is of a glacier – it is best regarded as a solid mass whose
shape is not easily changed, yet it manages to flow around bends and such
tricks.<<
I agree, if you heated up the crust in its entirety it could flow around
objects ,it could stretch and squish together. You could also melt a holes
threw it and cause volcanoes in the ocean basins and even through the crust.
This has happened. Each of these needs a certain set of conditions to be
accomplished and each leaves a unique effect. The crust must be heated past the
temperature/pressure threshold in its entirety or the crust would shatter up
like it is in the Mid Ocean Rises.
Every where where the ocean covers the new basins the water keeps the first
few miles of crust solid and very brittle. The ocean basins are very cold
except by vents and fractures. Way too cold to be malleable. Ice by contrast is
much more malleable and look at its cracks when it goes around an Object! The
surface patterns of cracks display exactly what has happened. So too does the
crust.
Where are your signs of this brittle crust flexing around things and under its
plate neighbors? Moving in many directions at once all over the place?
>> The spreading between S. America and Africa began, I believe, at the
southern end. While the crack was spreading north, the southern areas were
already moving apart, with new seafloor being created between them. Transform
faults allowed the spreading to continue until the crack extended northward and
spreading rates become matched – the plate shape changed as it was first added
to in the south only. The southern Atlantic did not open faster so much as it
opened earlier.<<
I totally agree with this. The nice arcs in the ocean basin connecting the
two at their southern points are our proof. The pivot point of the total motion
was up around Alaska. Notice how the arcs progressively get flatter more or
less as we go north. You are getting closer and closer.
If this process was over time and the crust was pulling on the rise forming
the shift faults as you suggest the curve of the Atlantic Mid Ocean Rise at the
south end would be curved in the opposite direction than my theory predicts.
You have just proved that the shift faults are not formed by pulling.
So that leaves us only with my theory of shift fault formation.
Which would predict
1. The magma material would flow out from under the continents
2.The opposing flows meet approximately at the halfway point between the
continents.
3. The impact and motions are done during a time when there were waves in the
magma and the back and forth action made the sequence of ridges at the Mid
Ocean Rise.
4. The material exposed to the air and some water was starting to get somewhat
brittle at the time of impact.
Here is the clincher…. The opposing flows when impacting, would adjust the
stress in the frontal impact area in sections varying in width and shift
according to the amount of shear forces in the connection points.
5. The more angle in the impact area the shorter the face would be and the
more shift there will be.
6. The places here the flows meet head on the width of the shift area would be
wider and the amount of the shift would be smaller.
7. The longer the material was exposed to cooling or the greater the distance
to impact the longer the shift faults will be.
8. The shift faults taper out or fade away as you move away from the rise
because the material was less brittle/more malleable.
>>So what were those conglomerate _layers_ I hiked through in the Grand Canyon
too long ago to admit? Looked like an awful lot of gravel to me.<< Oh boy call
the airlines I'll have to meet you there to really take it apart again. I was
12 the last time I saw the inside of the Grand Canyon. My first guess of course
is erratics. I'll go back and look its been way too long anyway.
Kamron
Hi, Kamron–
>> Are you agreeing that the plume would flow up the rising incline? and the
conservation of momentum will attempt to drag the plate upward with the flow.
What are you thinking here with the hint of a reverse flow?
I agree it is _possible_ the upwelling might be directed by plate inclination,
but do not presume to know enough about convecting rock to be sure of it. While
the seafloor gets generally deeper as one moves away from the ridge, I think
the asthenosphere (underside of lithospheric plates) is at a rather constant
depth relative to sea level, very near the ridges being an exception. Thus
inclination may have no bearing on small-scale convections (the "rollers").
Any effect due to inclination may be overwhelmed by effects of plate motion
(which would seem to contradict any notion that "rollers" propel the plates).
But if a flow is forced one way, the forcer will be pushed the other way – a
jet of water hitting an angled board will push the board back and to the
opposite side from the deflected jet. Now it is flowing in a deflected
direction, it may try to drag an additional part of the board with the flow,
but which pull wins? Whatever the _net_ velocity change due to drag (as
opposed to thermal differences) is will determine the momentum change of the
plate/board.
>> I agree, if you heated up the crust in its entirety it could flow around
objects ,it could stretch and squish together
I do not think it needs heating for a limited amount of shape-changing even in
the cold crust. A glacier flows without being ductile, I think. Faults are
the most obvious mechanism for non-plastic solids to change shape; I do not
know what other mechanisms may come into play. The plates are rigid by
comparison with the deeper mantle, but I do not think that makes them
absolutely rigid.
>> Notice how the arcs progressively get flatter more or less as we go north.
You are getting closer and closer.
If the Americas moved centered on Alaska, the arcs of motion would have smaller
radii of curvature as one approached Alaska, not get "flatter". What arcs are
you looking at?
>> If this process was over time and the crust was pulling on the rise forming
the shift faults as you suggest the curve of the Atlantic Mid Ocean Rise at the
south end would be curved in the opposite direction than my theory predicts.
You have just proved that the shift faults are not formed by pulling
Plate tectonics predicts the mid-oceanic spreading rise must be near the center
of any internal (non-Pacific) ocean – the ridge is therefore expected to swing
between Africa and Antarctica, just as it does. Why is there no extra ridge
between S. America and Antarctica in your theory?
>> My first guess of course is erratics.
Sometimes older rocks get eroded and redeposited atop younger rocks, but here
we are talking about thick layers (not trivial like the K-T boundary) of what
you would claim are younger rocks with _many_ layers of Paleozoic rock atop
them. Your theory predicts gigatons of "surprises" for conventional theorists
_at_ the K-T boundary and small amounts of gravel below it – the opposite is
what we find.
–Doug
Doug
I see what you are talking about now as far as the plume rising meeting the
slanted plate and like the motion of a sail pushing it in the direction you
need it to go.
This effect would need a greater slant to create a force that could overcome
the previously discussed(that you indicated)friction of the thick magma
dragging on the plate itself. Then there is the much greater slant of the
mountain roots which extend deep below the level of the ocean basins. The edge
say at the subduction zone would be flowing up the slanted continental mass
forcing the mass in the opposite direction plus leaving the ocean basin going
against the tide as it somehow softens up to curve downward and then is forced
down into the lower levels. It would be like pushing a stick of spaghetti into
very hot water.
You can't have both conditions at once hard enough to force down yet soft
enough to bend at a 45 degree angle.
>>I do not think it needs heating for a limited amount of shape-changing even
in the cold crust. A glacier flows without being ductile, I think.
Faults are the most obvious mechanism for non-plastic solids to change shape;
I do not know what other mechanisms may come into play. The plates are rigid
by comparison with the deeper mantle, but I do not think that makes them
absolutely rigid.<<
Ocean crust is harder than Granite. I have worked granite and it is very hard
and brittle. The material would need to pass the threshold in
temperature/pressure where it would loose its rigidity. This is not possible in
the cold ocean basin. We know the characteristics of the materials in the
basins. Near the surface of the basin they are extremely brittle and would
leave a much more fractured trail as it worked around obstacles. We see this
demonstrated in Glaciers. They show the obvious fractures and cracks that
developed in order for it to bend around objects.
>>If the Americas moved centered on Alaska, the arcs of motion would have
smaller radii of curvature as one approached Alaska, not get "flatter". What
arcs are you looking at?<<
The motion is a combination pivot around Alaska with a motion away from the
Europe/Africa. Near the pivot point the motion is mostly straight away while at
the south end of the complex it is more curved. Look at the smooth arc that
connects the Southern end of South America to the Southern end of Africa. The
motions of South America slipped downward creating the caribbean basin and
trenches and Africa at the same time moved away from Europe creating the
Mediterranean Basin.
>> Plate tectonics predicts the mid-oceanic spreading rise must be near the
center of any internal (non-Pacific) ocean – the ridge is therefore expected to
swing between Africa and Antarctica, just as it does. Why is there no extra
ridge between S. America and Antarctica in your theory?<<
The Antarctica moved from behind Africa into its present position. You can see
the result in the ocean basin area between S. America and Antarctica, there is
a very interesting tongue of a basin. The two plates moving to the west while
the material of the basin resisted moving with them.
Look at the trailing crustal fragments that trail off the edges of both
plates, looking almost like they were dragging on the tongue of basin that
projects eastward through this gap. This is another profound clue of the
motions and the speed of motion that occurred.
Kamron
Hi, Kamron–
I was a bit goofy when I spoke of convection currents pushing against mountain
roots earlier. I had forgotten they are at the interface between crust and
lithosphere (the Mohorovicic discontinuity); the true bottom of the plates is
where the lithosphere meets the inner mantle (at the asthenosphere) – and the
mountain roots do not affect that boundary. It is more or less flat, no matter
what is on top of the lithosphere.
There is one place where the bottom of the plates fails to be at the same depth
relative to sea level – plate boundaries. But this region where the plate
boundaries rise near the ridges is not wide, as I understand it. It would be
irrelevant to most of the mantle convection rollers.
Those rollers may well be rotating in alternating directions; that is certainly
what I would expect based on normal convections. This leaves me again with no
clear notion of how plates could be pushed, and I see no point in discussing
the push theory further until I find out what the theory says (if it is not
dead). This does not mean I disbelieve in it – as I said, the mantle is too
strange to us surface critters to presume anything about it without evidence.
>> I have worked granite and it is very hard and brittle. The material would
need to pass the threshold in temperature/pressure where it would loose its
rigidity. This is not possible in the cold ocean basin.
Granite may be hard only from the viewpoint of our "short" attention spans. Has
anyone put it under pressure for more than a few millenia? But forget the
granite, it is _basalt_ you need to test if you are interested in ocean basins.
Glaciers show lots of cracks on their surface as they make right angle turns
within meters and the like. Seafloor shows fracture zones in places, too,
though it does not make turns within anything like that degree of sharpness
that I know of. Seafloor will be covered with sediments also, so often we will
not be able to detect any evidence of reshaping.
A Mercator projection flat map has a way of making shortest lines (great
circles) look like curves. Those "curving" airline routes are really the
shortest lines that exist (assuming one is nearly following the surface of the
Earth). Any curvature I see in my maps is less than this effect.
As for the ocean between S. America and Antarctica, why would that section
resist forces capable of uprooting continents? Why would your lava waves that
met to form ridges _only_ happen between continents separating and not between
S. America and Antarctica even if they were moving in similar directions?
Waves moving before and behind but not beside S. America's motion? For that
matter, your lava waves should travel perpendicular to the continental margins
that generated them, yet this does not fit the ridges. The Mid-Atlantic ridge
passes too close to the coast of N. Brazil for your theory. It fits the
halfway point of coasts if you connect points that were once joined, but not
the meeting points of waves generated by those coasts in their _final_
positions. The jog in the ridge at the Romanche fracture zone (corresponding
to where the horn of Brazil and the nook in Africa near Nigeria met) does not
look like anything chosen by a meeting of waves unless they are somehow
constrained to retrace the continental motions.
How does the tongue between S. America and Antarctica into the Atlantic show
_sudden_ motion?
Lava waves? Your theory predicts vaporization of the oceans and thus the total
extinction by scalding of life on Earth.
–Doug
My uploaded answer was not posted, so I guess I still have to edit on-line.
Some of your assumptions imply that there is no slow tectonic process, or at
least no way to prove such a slow process directly. There are two direct
methods for measuring continental drift. Terrestial geodosy measures distance
between two closely placed markers near a fault line. Radi interferometry
measures distances between radi receivers that can be far apart (thousands of
miles) and detect changes of only inches. One such device for radio
interferometry is the Global Positioning System (yes, I have those references,
finally). Both methods clearly show the existence of continental drift. Field
geologists are at least postulating with an entity that can be validated at the
present time by independent means. Your grand catastrophe is an unexplained
entity that can be used to explain anything. By Occams Razor, I prefer expal
explanations sticking to entities that can be validated independent of my
theory. Anyway, the flow of continental drift occurs through solids that are
really plastic, i.e., they flow under sufficient pressure. Impure solids with
defects usually have plastic properties. Your image of turbulent liquids is
really a straw man, not a true picture of continental drift. Small changes
accumalate. Zeno was wrong, sorry.
David
>>There are two direct methods for measuring continental drift. Terrestrial
geodesy measures distance between two closely placed markers near a fault line.
Radi interferometry measures distances between radi receivers that can be far
apart (thousands of miles) and detect changes of only inches. One such device
for radio interferometry is the Global Positioning System (yes, I have those
references, finally). Both methods clearly show the existence of continental
drift.<<
I was following your requests for the data.
The GPS can't resolve to inches can it?. Anyway how many years have they
tracked the motion and how fast is it? A significant factor in these
measurements would the crustal tides. I can see this alone accounting for
changes in feet across the atlantic twice a day. Of course time tables could
be developed that could adjust the measurements according to the sun/moon
phases.
What have you gathered to bolster the drift theory?
Kamron
Hi, Kamron–
Give the poor workers a little credit. I rather expect they are well aware of
tidal influences and are compensating for them – this is too obvious to be
missed and any peer review would surely bury them deeper than the lithosphere
without it (hmm, what an opportunity for study… :). There might be room for
doubt about the exact method of compensation – but that is not going to make a
huge (even relative to what we are looking for) difference. I wonder what other
sources of systematic error there might be…
I don't know about inches, but GPS can be used with far more accuracy than
ordinary civilian devices permit if one has access to military equipment or a
reference station for differential measurements. I am sure the researchers
have at least the latter if they are using GPS – they would be laughed off the
plate without it.
–Doug
Doug
Oh I think its marvelous we can locate to 50 meters. GPS is not going
to be accurate enough to prove the motion of plates over a 20 year period,
period.
Kamron