Subduction (Plate Tectonic's Trump Card)

..is oblivious to Earth expansion's joker.
 ( Blog for website at http://users.indigo.net.au/don/ )

No matter how the ocean floors grow, .. crossways or longways to the ridge (or both), oblique, up, down, inside-out or whatever,  Plate Tectonics' assumption that the Earth must remain a constant size, means they *must* be destroyed at subduction zones at the same rate as they are being created.  Plate Tectonicists believe that hypothesised subduction by a hypothesised model of convection, to get rid of hypothesised ancient ocean floors to allow the emplacement of the current (real) ones, is its trump (scientific) card.  However there is no a priori reason for subduction, other than that it *is* an assumption based on that necessity of size, .. and one that is built on another - that convection is the driver for global tectonics : -

"The internal engine of the Earth is driven by radioactively generated heat, and heat left over from the formation of the planet.  (John Sclater's first sentence describing his role in the construction of Plate Tectonics (in Oreskes, 2001, Plate Tectonics, an insider's account of the modern theory of the Earth,  p.128)

... which is itself shored up by many more assumptions and special pleadings. 

However,  Sclater's assertion founders on illogic, for the simple reason that if the loss of heat formed the lithospheric shell in the fist place, then the loss of more heat is not going to break it up (*de*form it).  The laws of thermodynamics  which address questions of work, heat, energy and entropy indicate, surely, that Sclater's statement is unfounded, for if gravity got the Earth together in the first place (and through the loss of heat organised it into its differentiated shells), then nothing that arises as a result of that differentiation (and that includes the heat distribution in the planet) can act to break those shells up."  Or to put it another way, .. if gravity is the first-order force holding the planet together then no smaller-scale thing that results from it (this side of the nuclear divide) is going to break it up.  Of course, .. release the energy locked up on the other side of that divide and the whole planet would be blasted to Kingdom Come.  In some as yet unknown way, something of this sort appears to be what is happening, .. albeit in slow motion.

For convection to work, a crust must never have properly formed, but must still be in the process of forming, ..  raising the question in the process of crustal formation, when can a crust be said finally to have formed?  'Effectively' might be a better word than "finally", because a dyke intruding the crust could be said to add to its formation - what about a whole ocean floor?

Sediments deposited on Archaean crystalline granitic basement, or on a basaltic substrate that typically overlies the granitic shell, tells us that the Earth has indeed had a crust since earliest geological time.  Likewise does the existence of life in the oceans shortly thereafter.  So for all intents and purposes the Earth must be said to have had a crust since earliest geological time, since when it has been manifestly *de*forming, and at no time moreso than the recent past. The geological record shows that spreading ridges have only existed in recent times, and that the external shell of the Earth is being ruptured and forced apart to extrude the mantle layer to form the present-day ocean floors, i.e., the continental crust is being deformed in a massively explosive way. If it were argued that this oceanic (mantle) crust is indeed crust in the making (and has always been thus through geological time), then we are faced with a stratigraphic and structural problem :-  if ocean floors always existed (making crust), how did stratigraphic sequence come to lie on continental crust?  The Plate Tectonic  'bulldozer' scraping sediments off the ocean floors at subduction zones hardly accounts for the global accummulation (and preservation) of stratigraphic sequence that has built up within continents since the beginning of geological time.  In view of what we know about crustal rupture and mantle extrusion it is facile too, to argue (as some might) that continental-floored inland seas and mantle floored oceanic ones were ever spatially or temporally separate.  Whilst volcanic edifices and their underlying network of intrusive dykes may also be argued to be 'crust in the making', simply their existence tells us of a pre-existing crust that they broke through, and that their build-up is related to its deformation.

There is no doubt that heat is an important element associated with the deformation of the Earth, but the question is one of origin.  Where is this 'extra heat'  extra energy sourced that is causing a massive blow-out of the planet and extruding 'new mantle' that not only makes up two thirds of the surface area of the Earth, but a commensurate volume as well?  Global geology tells us we cannot simply assume that it is the residue of heat that was always there to begin with, when its (residual) expression is dilating the crust and extruding the mantle on such a massive scale that has no precedent in geological history.  As a *residual* expression such behaviour is inadmissable!  Neither can we simply assume, with Plate Tectonics, that its expression has always been oceanward of the continent - ocean divide, so that earlier expressions of it are never seen. If recent massive extrusion of the mantle is a *residual* expression, what was its main one?

There is no answer to that one.    A "clean sweep" to remove ancient ocean floors so that we never see them could conceivably be argued for the Pacific (see Menard citation below), .. but not for the Atlantic, Indian, or Southern Oceans.  Evidence of mantle preservation of commensurate scale would remain somewhere in the geological record.  There is none.  At this global scale Plate Tectonics is beset by no answers, when the continental crust is included in the picture.

It should further be noted that this assumption about heat, convection and subduction as drivers for crustal deformation followed the rejection of global expansion that was already considered advocacy by a number of prominent geologists of the day, as the only logical reconciliation of massive mantle extrusion with known continental geology.  Far from any serendipitous proposal with little foundation, expansion was solidly based in geological fact, by those who knew it best  -  where its rejection was by those who knew it least!  Conversely there was nothing factual that could be levelled against it, only a failure of comprehension to explain it, which led those at the time to substitute convection and subduction as deformation-drivers for it.  After half a century of doing its level best to deny what their data was telling them in the first place - that sea-floor spreading meant global expansion, Plate Tectonics is finally heading down its inevitable road to Earth expansion, bearing the banners 'Overriding' and 'Flat subduction' as front-line, caber-tossing heraldry.  Properly appraised, both are inadmissable in historical Plate Tectonics, but are definitive of Earth expansion.

Menard appears to document a concerted effort to discredit and reject this conclusion of expansion whilst making some weak concessions in its direction. Part of the reason for this rejection appears to have been personal differences that arose between Maurice Ewing who directed much of the operations of oceanic research, and Bruce Heezen who supported expansion and whom Ewing banned from access to the emergent data (Menard, 1986, The Ocean of Truth).  Much of this schism is probably couched in this somewhat telling sentence spoken by Ewing early in his appointment to head up the marine research work : -

(Morris Ewing)  "This is by far the most important project with which I have been connected.  It is so arranged that I see no possibility of anyone stealing the credit from me."   Menard, p.34, continues - Thus he staked his claim with a number [1] that implied that more would follow and that other investigators should steer clear.  He followed the same procedure time and again.  In 1959, for example, there appeared "The floors of the oceans. 1. The North Atlantic."  It was never followed by Part II because of the falling out between Ewing and Heezen.

We are left to wonder how the very public difference that developed between these two senior figures within the closely knit research fraternity coloured the views of other workers, in respect of which side of the research bread had most butter on it, and how that perception might have coloured attitudes to Heezen's "maverick" expansionist views.

Whilst falsification (of expansion) is a laudable objective of scientific enquiry, reasons given for rejecting it were weak.  As well, strengths were either ignored, glossed over, or misrepresented.  Menard writes:-

"The expansion of the earth had many virtues as a hypothesis. Among others "it permits continental drift of the Americas away from the Mid-Atlantic Ridge without motion toward the East Pacific Rise," but the idea had many flaws.  It did not account for the down-bowing of trenches and, as proposed by Carey and Heezen, it involved doubling the diameter of the earth in the last fraction of geological time.  The density of the earth before expansion was thus 44gm / cc, "which is impossible in the present state of the universe for a body with the mass of the earth."  [His footnote reference for the quotations reads, "I tried to persuade Harold Urey to write something in this vein, assuming that the master of the origin of the planets could end the discussion.  He thought, however, that a concept involving such densities was too absurd for discussion." (Menard, 1986, p.210.)

It is not clear what he  means about "no motion towards the East Pacific Rise",  because maps even then showed the structural discordance of North America with the East Pacific Rise, a discordance that would appear self-evidently to reflect 'overriding' on a semi-global scale.  And in any case, only a few lines lower on the same page he explicitly states : -

"Where the flanks of ridges pushed against continents, compression produced trenches, and there were no trenches in the Atlantic because convection cells carried the continental crust aside,"

.. meaning, surely, that the Americas are indeed carried eastwards towards the East Pacific Rise.  Perhaps he means to have a foot in both camps - you can have American movement if you want it, but it isn't ncessary because the ridge itself could be moving towards the Americas, carried on a convecting cell underlying that driving the top plate.  McKenzie after all had proposed this to general satisfaction that if America was taken to be fixed then earthquake first motions around the Aleutian Arc indicated the whole Pacific plate was moving (in the American reference frame) northwards, and simultaneously (in the Asian reference frame) moving westwards as indicated by transform faults (Fig.6 here). (However this is another assumption which has turned out to be unwarranted according to satellite data, but is left dangling as another in the potpourri of 'multiple working stories'.)   So perhaps it was an appeal to the way of doing science according to the Prinicple of Multiple Working Hypotheses (as many as necessary to make assumptions plausible).

Menard's second point about expansion not accounting for the downbowing of the trenches is an assertion that Earth expansion would refute point-blank;  "downbowing" is exactly as Earth expansion would have it, and in describing Benioff's own interpretation of these trenches  (his Fig.15b, reproduced as Figure 'B' between Figs 3 and 4 here).  Menard himself explains how this occurs as continental lithosphere relaxes over the mantle, causing flow and counterflow in the directions illustrated.  Such 'flow and counterflow' is exactly the mechanisms of isostatic compensation to explain gravitational equilibration so it is not clear what he means here either, other than that he may be trying to avoid acknowledging any support for expansion whatsoever : if isostatic compensation applied according to Benioff (and Earth expansion) then the operative dynamic was from the continental side (Fig.1, previous link), and convection and subduction could not be used to explain movement of the ocean floors, as Menard believed could be the case:-

"Certainly in my own mind a possible clean sweep of the ocean bottoms every few hundred million years is an alternative to the development I have proposed."  (Menard, p.207)

Apparently this, and an objection to an Earth density of 44gm / cc, (the "no mechanism" card) were the principle reasons of the day for rejecting expansion, that Menard was describing.  However it seems odd that anyone with a leaing towards physics (Harold Urey) should cite density mass and volume as parameters for rejecting what surely should lie on the quantum mechanics / plasma physics side of the material divide.  Relevant considerations of the cause for the addition of mass should surely be sought in the behaviour of particles of mass and the electronic soup that binds them, .. in dark energy and dark matter, .. rather than in principles governing Archimedes' wet leg.

I don't buy this 'density' argument.  I think it's specious and that those who propose it are being disingenuous (or dense themselves).  I think it's another conveniently invented displacement to avoid facing up to inconvenient facts that highlight the slippery slope on which Plate Tectonics is built, .. namely assumptions and the approval of others coerced by the authority of institutional kudos that has permitted this morphing of assumption into assertion and, further, harder dogma.   Scientists often talk about the scientific method and the need for assumptions, ..and theories to test them.  But whatever happened to close observation of the facts, .. and taking as much care as possible to keep out of the way with 'theories'?  This business of being a ringmaster who orchestrates the natural world and calls it 'science', smacks to me of a circus, .. and as far as convection is concerned reminds me of Menard's comment : -  in an earlier post : -

 "The discussion was brief, but it offered Vine the occasion to refer to convection cells as "presumed" and "mythical." Certainly , the many problems related to convection that had been troubling the conference members would have been solved by eliminating convection entirely. " (Menard, The Ocean of Truth, p.276.)

The "briefness" referred to concerned exactly the elongation of spreading ridges, which elicited Vine's comment (above) and which is an aspect of spreading ridges that to this day remains without explanation in Plate Tectonics.  No doubt the reason for the briefness of the discussion (and Vine's comment) lay in the realisation that the topography defining these structures indicated normal faulting, and as such were not therefore as Wilson claimed "a new class of faults", but were in fact entirely the defining reason for the along-ridge spreading (/extension) that was being discussed. And therefore certainly described expansion.   It seems very much a case of  "Let's not go there", which applies even to this day.  To do so means addressing (and negating) Tuzo Wilson's "ingenious" explanation of the Great Cross Fractures as a "new class of (transform) faults", which delivered for Plate Tectonics the way out of Hess's "philosophical un-satisfaction", and secured the myth of convection as the driver for creation and destruction of the ocean floors.  Or as an earlier goal-post shift from the bag of multiple working stories has it, not convection as the driver, but subduction, .. i.e., not driving by the cycling overturn of the mantle *interior*, but by the cycling overturn of the exterior mantle shell.

Goal-post shifts :-"We are all capable of believing things which we know to be untrue, and then, when we are finally proved wrong, impudently twisting the facts so as to show that we were right. Intellectually, it is possible to carry on this process for an indefinite time."~  George Orwell

 'Subduction' or 'overriding', .. the difference can be argued according to whether the approach is from the oceanic or continental side, .. but if from the oceanward side, then first the ocean floors have to get there.  And *that* involves revisiting Wilson's "new class of (transform) faults" - which show that real  movement on cross faults at the ridges is essentially vertical as the ocean floors move up - not 'sideways' to the subduction zones.  'Sideways' is an illusion, an artifact of expansion.  Ocean floors can probably hardly make it down the flanks of the ridges, much less to the subduction zone.


(.. If subduction is Plate Tectonics' trump card,
Then 'transform faults' is the Joker in the pack. )



 [See also blog for Earth expansion at :-
http://earthexpansion.blogspot.com/ ]