....Subduction
- the crux of Plate Tectonics
"The strength
of Plate Tectonic theory lies in its ability to explain everything about
the processes we see both in the geologic record and in the present. Our
understanding of the subtleties continues to evolve as we learn more about
our planet, but plate tectonics is truly the foundation upon which the
science of geology is built." http://www.visionlearning.com/library/module_viewer.php?mid=66
In fact there is virtually no single element of Plate Tectonics that stands alone without being contradicted by another from the same page. |
http://pubs.usgs.gov/fs/2000/fs060-00/
http://www.ucmp.berkeley.edu/education/dynamic/session1/sess1_earthcurrents.html
Fig.1. Two standard templates for subduction. We need go no further than these images, in conjunction with the emerging evidence for Flat Subduction, to know that Plate Tectonic theory is fatally flawed and bears little resemblance to reality.
Subduction is the crux of plate tectonics. It is the lynchpin on which Plate Tectonics depends for without it the mantle would simply be extruding with no compensating correction. And the planet would therefore be getting bigger.
It is important to recognise the essential role that subduction plays here. Plate Tectonics is not to do with the separation of the continents, nor anything to do with the creation of the ocean floors - spreading ridges, transform faults, nor indeed the differential overriding/ underthrusting movement on the subduction zone, ...for all of that is about the extrusion of the mantle and the Earth getting bigger - which is the nemesis of Plate Tectonics. Plate Tectonics is specifically about the actual underthrusting of oceanic lithosphere and its return to the mantle, for it is this that maintains the areal balance of the planet and the integrity of Plate Tectonics. Without subduction 'Plate Tectonics' would in fact be Earth Expansion. As the crux of Plate Tectonics, .. Subduction Rules.
Of course, because subduction *is* an assumption (and a convenient one) doesn't mean to say it is wrong. It could be right after all. It's just that there are as many elements of contradiction as there are elements of support.
So which are to be believed? The crust floats on the mantle? No, the crust (lithosphere) forces the mantle (oceanic lithosphere) down. The colliding plate pushes up mountains by crumpling the crust (as in the type area of the Himalayas)? No, the colliding plate slides underneath the other and lifts it bodily upwards with no crumpling (as in the type area - again - of the Himalayas). Continental crust cannot subduct? Yes it can (if it happens to be India, ..sliding under the Himalayas to lift them up) (or any other piece of continent - like Africa, colliding with Europe to 'crumple' the crust and throw up the Alps (even though the Mediterranean sea between Africa and the Alps is an extensional basin and the fold structures are manifestly gravitational collapse (re*afalps) structures, not crumpling 'push' structures in the sense of Plate Tectonics. The subducting slab drags the ocean floor down with it? No, the ocean floor is riddled with fractures from the ridge and transform faults and has no cohesive strength and so cannot be pulled. So the 'rubble' of the ocean floor is carried on convection currents like a conveyor belt? No, the driver is not convection, but the brittle subducting slab. The subducting plate ('slab') sinks because it is cold and therefore more dense? No, it sinks because it is being forced down when it meets the continental lithosphere (which is floating on it). The subducting slab pulls the ocean floor down with it? No, the ocean floor is being pushed from the ridge ("ridge-push"). Of course in this instance of contradiction if both were to operate, as Plate Tectonics says - as"slab-pull / ridge-push", then there would be accellerating runaway dynamics that would be tantamount to more than a perpetual motion machine. And no, it is not like the pull-and-push of a freight train, with an engine at the front and one at the back, because in the freight train example the power units are independent; in Plate Tectonics' reasoning the push of the following engine (ridge intrusion) is powered by the pull of the leading unit (subduction). Continental crust cannot be subducted because it is less dense than the mantle? Yes it can if it happens to be even less dense, i.e., unconsolidated, ..and full of water. As can water, which is less dense still. (Gee, .. and *Earth expansion* contradicts the laws of physics??)
Pull at one end generates push at the other? Rubbish. But in the name of 'convenience' this inconvenient logical glitsch is simply ignored. Likewise the notion in general of Plate Tectonics being driven by the subducting slab. It is a mighty subducting plate indeed that pulls the Earth's crust apart in two places at once - back-arc basins on the right (in the lower figure above), and the spreading ridge in the middle, ..the latter more than half a world away across a terrain that geologically speaking has little more cohesion than rubble. And clearly (if subduction is the driver for Plate Tectonics, which is the current view) then the spreading ridge would stay where it is and the ocean floor would grow only on the subducting side. How one subducting slab balances with the other on the opposite side of the ridge half a world apart to maintain ridge symmetry and equalise spreading is not even addressed in Plate Tectonics; there is nothing about convecting cells that says convection has to be a symmetrical phenomenon.
Let's continue, shall we?The subducting slab grinds down the subduction zone at an angle causing frictional partial melting which makes its way to the surface in the hinterland as volcanic extrusions (the Fiery Ring of the Pacific)? No, it falls vertically, causing rollback of the down-bend and pulling off chunks of continental crust to form back-arc basins ("blobtonics"), and thus, in free-fall - like the Titanic - driving Plate Tectonics. The falling slab pulls on the ocean floor from the ridge? No, roll-back means there is no pull on the oceanic plate back to the ridge. The pull of the slab terminates on the turn-down; the slab falls, and the line of mantle turn-down ('rolls back'). Convection is driven by the heat of the Planet's interior? No, it is driven by coldness of the falling slab. The slab is cold and falls? No, being cold is not enough. It has to get hot enough to convert to its denser equivalent, eclogite before it can sink. Older dense slabs sink faster than younger lighter ones? No "dense plates tend to be held in the upper mantle, while younger and lighter plates sink more readily into the lower mantle" <link>.)
Transform faults are expressions of slow ductile mantle flow? Mmm, theoretically they are said to be <entry 25>, but in fact no, they are brittle faults with earthquakes. The Earth's crust is segmented into a number of plates? No, beyond the short distance from the ridge where earthquakes (fault movement) occur the entire ocean floor is locked as one across all transform 'faults' (fractures). Thus there are no 'plates' "moving independently" (another point that Plate Tectonics conveniently ignores) Even in Plate Tectonics the concept of 'plates' only has relevance in the immediate vicinity of the ridge, yet we are supposed to accept plates as separate independent entities moving this- way- and- that across the entirety of the planet's surface. And for the history of the planet.
So, in view of all the above contradictions we have to ask how did it ever come to a pass that subduction ever gained such acceptance, when it is tantamount to little more than a convenient lie? What was it shoring up?
Firstly it was shoring up a false assumption - that the Earth could not get bigger (because there was no known way in the current understanding of physics theory that it possibly could), ..when empirically it clearly had - by the amount of the ocean floors; obvious in the region of the Atlantic Indian and Southern Oceans, ...not so obvious in the Pacific. It was this apparent lack of a continental fit across the Pacific that edged structural interpretation closer to interpreting Pacific continental margins as subduction zones, where the oceanic crust (/lithosphere) was being returned to the mantle.
Secondly, ..and most importantly, it was shoring up reputations. Not of the fathers of Plate Tectonics who were full of doubts about the emerging model, but of the new generation eager to embark on a career of publishing with a whole new theory. Little did they care about doubts when there was the opportunity to build on reputations. The doubts got left behind, whilst the reputations of the Fathers lived on in references, which career artists know are the important parts of peer review, and the only bits taken seriously by anybody shoring up credibility in science.
.............................
It really is bizarre when we think about it, how such a complicated, self-contradictory assortment of assertions which are so at odds with the facts can possibly survive as a model, ..all to avoid discarding the initial assumption that the Earth cannot get bigger (because we know of no way that it can) and to avoid exploring the implications. By the same measure we would be bound to ignore the fact of gravitational attraction, for which there is still no understanding of its workings.
This is not a case as is often said similar to justifying research for extraterrestrial beings (for which there is no evidence, nor ever has been), everything of planetary structure of the Earth that is known supports Earth expansion. To say there is no evidence because there is "no mechanism" is a denial of the whole enterprise of science, and a revelation of the asininity and perverse scepticism of the sayer.
It is well to say that science should be skeptical, and so it should be. So let's apply it to subduction (as above) and reject that aberration. Then to the Junk Science of Plate Tectonics as a whole. And reject that too, for when the geology is reconfigured in the context of expansion the Earth sciences become an entirely different field.
But a plea is also in order to geologists (and geophysicists) to ignore the temptation to speculate on mechanism. It will be no easy job to turn this ship around without it beaching on the same shoal, by the same crew, and for the same reasons (and motives), that Plate Tetctonics did. Geological (and geophysical) emphasis should most emphatically be directed towards the geology, not as a hypothesis or a theory; that much is virtually a given, but by its direct empirical application to the planet. Although everything must (and will) work, it must also be seen to work before the physics community will put their house in order, and clean out the rubbish there too. If, through geophysicists geology has fallen into such a bad way, then it is virtually axiomatic that physics will be in the same boat.
The more speculation there is on mechanism, the longer a proper answer to the question why the Earth is expanding will take: the physics community will not take easily to the suspicion that its house is not in order, and even less if that insinuation is coming from the Earth sciences.
| "Doublethink is a Newspeak term from Nineteen Eighty-Four (George Orwell), and is the act of holding two contradictory beliefs simultaneously, fervently believing both." (Wiki) |
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