Thursday, December 22, 2011

Mountains arise (!)

(Through a Head of Cloud)




Mountain.  The word defies definition, for the very good reason that it means different things to different people.  Professor Cloud's need to describe 'the crumpling that happens' ("when plates collide") places it well and truly in the domain of biblical belief.



Fig.1. India collides with Asia.  [Preston Cloud, 1988.  Oasis in Space, Fig.16.5, p.420 (adapted from Zhang, Liou and Coleman, 1984, Geol.Soc. Amer.Bull., v. 95, p.296, Fig.1).


This image from Preston Cloud's book illustrates the consensus view of mountain building in the type area of continental collision: "When continents collide, they pile up into mountains with deep roots, as in the complex multicollisional Himalaya." - p.207.


* (Fly-leaf) - Preston Cloud, professor emeritus of geology at the University of California at Santa Barbara, holds a doctorate from Yale University. He is the editor and co-author of Resources and Man and of Adventures in Earth History as well as the author of Cosmos., Earth and Man. Dr. Cloud is a member of the National Academy of Sciences, the American Philosophical Society, and the American Academy of Arts and Sciences. In 1976 he was awarded the Penrose Medal of the Geological Society of America. For many years associated with the United States Geological Survey. (died 1991)

 .. Or compare with these :-

"When plates and the continents riding on them collide, the accumulated layers of rock crumple and fold like a tablecloth that is pushed across a table." (link)
"The pressure of the colliding plates could only be relieved by thrusting skyward. The folding, bending, and twisting of the collision zone formed the jagged Himalayan peaks. This string of towering peaks is still being thrust up as India, embedded in the Indo-Australian Plate, continues to crunch relentlessly into Tibet, on the southern edge of the Eurasian Plate.  (link). 
[Or this one, .. I really like this one.]


The quotes cited are typical of the current consensus as regards so-called 'Fold Mountains", .. mountains that are formed by the "buckling, crumpling, and upward thrusting of continental crust as plates collide" (or otherwise variably "move"), and are so named to distinguish them from volcanoes and 'erosional mountains'. The Himalayas are generally regarded as the type area. [20171109 or at least used to be (at the time of writing this page.  The wikipedia has changed it to the Zagros mountains to accommodate the change from "mountain building" to "mountain formation" (link)

What Professor Cloud's figure does (by showing the limits of Indian crumpling restricted to simply the Himalayan sector), is give voice to the consensus view how mountains are formed at the date of publication of his book (1988), by which time Plate Tectonics had become well entrenched.  Of course he knows full well that the mountain belt continues sideways out of the figure, ..extending eastwards to encircle the Pacific and westwards to the Carpathians and the Alps (and with the Atlantic closed the Appalachians as well).   And so does everyone else.  So what we are witnessing in this 'figurative voice' is a kind of struggling for words around a silent question, "How is this uniformity of circumglobal elevation to be explained by "independent plate movement?" -  India crumpling Asia, Africa crumpling Europe (but what is crumpling the Americas?) ..  and a certain tacit agreement not to try to answer it.

"So arose at different times the Atlas Mountains of northwestern Africa, the Pyrenees, the Alps, and their eastern European extensions and, with them, the distinctive flysch deposits of Alpine deformation. The orogenies responsible for that picture-book scenery then gave way to the vigorous erosion whose distinctive post-tectonic sedimentary product is the Alpine molasse."

"And so arose"... There reads to me a certain lyrical, almost creationist tone here, and Professor Cloud is deftly displacing the reader's attention by introducing erosion.  But notice he attributes to it, not to the formation of the jagged peaks everybody calls mountains, but the rubbish down the slope we all call 'dirt'.  With which I would agree (about dirt), .. but not the bit about arising.  It is an expert sleight-of-word from a professorial purveyor of meaning that does two things, 1. it avoids addressing the question how, exactly, this "arising" happened, and 2. with it, Professor Cloud gets to state his own probable view (as a geographer) about the 'arising' of mountains without actually having to state exactly how they do that, .. because (as a pre-Plate Tectonic, old-school geographer) it is almost certainly different from the view he is having to state and is tip-toeing around.

Really, what he should be doing is not promoting Plate Tectonics at all, but from the vantage of his geographical experience, questioning it.  And since he doesn't question it, I'll do it for him : "How in the face of all this convergence, collisional crumpling and the thrusting skyward of so-called "fold-mountains", does the surface from which the mountains are carved (Fig.2) manage to stay flat as a tack?" - (or perhaps I should say, it being a scale thing and all,
"smooth") - and as well, how does that flatness, in the face of all the professed collision and crumpling, manage to stay as flat as the flatness that was deposited on the sea-floor. How do we get all this flatness from way down there (beneath the sea) to way up there on the Roof of the World, .. mmmh?   

And no doubt Mr Cloud could answer it to my satisfaction very well (being, as he is, a pre-Plate Tectonic geographer - as could all geographers before the advent of Plate Tectonics).  But somehow, with the need to be part of the plate-colliding club, the significance of plateaus has come to be unlearned.  Of necessity too, if one is to conform to consensus.  Obeisance to consensus is no small thing in the academic world and has its metaphorical equivalent of nose-rings and belly studs in the crafting of language to signify being part of the herd, .. which, in his use of "docking" and "arising" (instead of 'crushing' and 'crumpling'), professor Cloud (him being old-school and all), is decidedly not.  
 

Fig.2  Mount Kailash, the Holy Mountain of Tibet.   The remnant flatness of the Mesozoic sea floor preserved in Mount Kailash is mirrored in the flatness (/smoothness) (it's a scale thing) of the Tibetan Plateau.  Flatness extends even to Mount Everest.  The white line is the Himalayan front.  India to the south. (Right click / new window for bigger figures.)

 So to properly understand Professor Clouds subterranean dichotomy (how to present his view without actually presenting it), we should have another read of his description of fold mountains (Fig.1) in conjunction with those just below his, but this time compare the careful wording chosen by Mr Cloud with the gung-ho flamboyance of the others.. Does he mention folding?  No.  Crumpling?  No.  Why?  Because the architectural relationship of the folding that does occur, to that of the erosional surface of the plateau, contradicts outright what Plate Tectonics is saying - as it does everywhere along the circumglobal belt of elevation where folding is exposed. =>

And Professor Cloud knows this very well because he is old-school, a palaeontologist /geographer, and also knows very well the erosional signifance of the plateau surfaces from which mountains are carved.  He's just not telling anybody since the rise and rise of Plate Tectonics, and the need (then) to fit in with it if he wanted to sell his book.  ("Preston Ercelle Cloud, Jr. (September 26, 1912 – January 16, 1991) was an American paleontologist, geographer, and professor - wikipedia.). 

And first-year geologists know this too.  But Plate Tectonics is a new song to be sung (and there are exams to pass).

It couldn't have been easy, trying to find words that would convey to the reader what the reader wanted to read, and the same time satisfy what Mr Cloud wanted to write.

"Wherever the current cycle of continental motion has caused plates to converge and collide, mountains have arisen."  Preston Cloud Oasis in Space, (p.417).

 Does Mr Cloud use the word crumpling?  No.  Folding?  No.  Contorting, crushing, crashing etc etc etc.?  No, .. just (obligingly) (if a word must be used) "arisen" - like Jesus on the third day.  No need for the histrionics of 'plates'.  No need for anything other than citing the litany according to Saint Tectonics or to clarify anything for the reader who is being given the message that he should put his trust in experts.

So mountains do not crumple by collision, they just "arise" and "pile up" (?)  What he does say is that India first "docked" then (according to seismic evidence) proceeded to "tuck its leading edge" beneath the Asian Plate, thickening the crust and uplifting the Himalayas.

"When the leading (oceanic) edge of India itself first docked along the present northern margin of the Himalaya, it generated a 2,400-kilometre-long suture, or zone of joining (refs fig. above) tracked now by the sacred Indus and Brahmaputra rivers.  Seismic reflections from the crust-mantle boundary in this region indicate that India thereafter tucked its leading edge beneath that boundary and was over-ridden from the north in the main Himalayan mountain-building event terminating perhaps 10myBP"

"Docked"?  "Tucked"?  What sort of language is that to describe the spectacular consequences plate collision,  crustal crumpling, buckling, and the 'mountain-building' upheaval to form the roof of the world that so pervades the literature so?  No sort of language at all, really. By his use of the much more moderate language of "arising" we might expect some qualification along lines that emphasise the retention of essential flatness.  We don't get it, but at least we don't get the popular litany of "tossing high of mountains by crumpling and folding, twisting and collision".  Instead we merely get sedate "docking", and  "tucking under".

Publication may have been jeopardised had he cast doubt on Plate Tectonics from the vantage of his lifetime credits. Yet this is in fact what a close reading of his book suggests, cloaked as it appears to be in academic diplomacy and written more as an impartial onlooker, than as participant, ... which is interesting given that he (Cloud) lived the transition from continental drift to Plate Tectonics and knew full well the arguments for Earth Expansion, as well as its global expression in geomorphology.  He was also critical enough of the arguments for subduction, referring to Panthalassa (one of the lynchpins of Plate Tectonics) as  "The phantom global sea"  (p.166).  (Still, .. he was old-time, and knew the significance of plateaus.)  Geologists and geophysicists today apparently don't.  He impartially puts the two emerging hypotheses of the day in the same "outrageous" and "preposterous" bag (an interesting word-choice, given the nearly 20-year (supposed) acceptance of Plate Tectonics by the time of publication of his book in 1988): -

 "Two seemingly outrageous hypotheses have been proposed.  One calls on plate tectonics and subduction since the Archean to recycle the ocean floor so completely that no trace of it is left outside the residual greenstone minioceans.  The other hypothesis is even more outlandish.  It proposes that an Earth of a once much smaller volume has literally expanded like baking bread, extending its diameter to the present size.  Preposterous as these ideas may seem they meet the essential criteria of scientific hypotheses.  They explain what we know and they have verifiable consequences.  They are testable."

Testable?  They certainly are, and the test is the simple one of flatness and smoothness in Figure 2 that Professor Cloud fails to draw attention to, yet as a geographer he is equally certainly cognisant of it!

The writing seems to be of one who is personally bemused by the conundrums of  both hypotheses yet who, possibly on account of keeping a certain 'professorial distance', is at pains to represent the status quo impartially and let the voice of others speak. "Will crustal compression continue?" he asks.   "Assuming it does, will the Himalaya grow still higher, or will they at some point flow to lower levels under their own weight?"   (p.421.) 

The question is an interesting one (considering it already has; eastwards to Indonesia) (and Mr Cloud probably knew that too), .. and carries a barb that goes right to the core of Plate Tectonics and supports the argument for Earth Expansion - that the Himalyas are intrinsically gravitationally unstable and are, as professor Cloud says (but the Plate Tectonics' consensus of his time didn't), collapsing over India.  That is, .. India is not pushing from the south, Tibet is pushing from the north under its own gravitational weight due to the collapse of the now unstable, remnant curvature of the Pangaean Earth =>.  India never was anywhere else relative to the collapsing Himalayas, .. but was attached to Africa (according to a smaller Earth) =>

One thing we can admire about Professor Cloud's carefully chosen wording is an angelic hesitation to tread where others have no qualms rushing.  Plate collision by "docking" and "tucking" is excellent circumspection.  Others have been far more extravagant in their advertisement of an event that in fact never happened.  So we should thank Professor Cloud for his choice of language, if perhaps not for the disingenuousness that underpins it, .. and also give some consideration to the benefits of 'going-with-the-flow' when the price is merely one of lip-service and suspension of belief  - and maybe excuse him some dog-whistling (
"outrageous"), by way of retaining some self-respect. 



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