Nonsense 3 - Himalayan push or pull?
(..Laying this Emperor dude bare...)
Nonsense 3 - Himalayan push or pull?
(..Laying this Emperor dude bare...)
Fig.1. Map of the world showing the direction of plate movement in the regions of India and the Western Pacific. The Indian plate collides with Asia (green arrow) squeezing Asia as in a vice, and pushing up the Himalayas; the Pacific plate (red arrow) collides with Asia and drags off the chain of islands, creating 'back-arc basins'. This contradictory behaviour of forward motion of plates - pushing (India) and pulling (Western Pacific) is regarded here as nonsensical rubbish, and is substituted for by simple dilation of the mountain belt (brown) by the intruding Pacific diapir which has ruptured this megafold, dilated it, and scissored it open to spread the American Cordilleras about the Caribbean Pivot (purple). (Blue line = so-called 'subduction' zone.) The motion is writ as plain as, and is related to, the dilation which has opened the Atlantic. (plate map of the same | here |
| The
nonsense refuted here lies in the explanation plate tectonics gives for
the relation between so-called subduction along the Himalayan front, and
subduction along the Western Pacific margin. In the case of
the Himalayan front, India, carried 'piggie-back' on the Indian plate,
is supposed to be pushing into Asia, compressing it as in a vice and producing
the folds of the Himalayas and the uplift of Tibet ("far-field tectonics").
In the Western Pacific however the Pacific plate moving westwards,
is supposedly doing exactly the opposite - it is supposed to be pulling
off the edge of the Asian continent to form the so-called 'back-arc
basins' of the Pacific.
How so? The difference according to Plate Tectonics is whether or not there is continental crust sitting on top of the moving plate. which can be used like a battering ram and crumple any other crust that gets in its way. Remember the plate is not moving like a barge, .."ploughing through the channel on a mad March day". It's really stationary. Movement is like caterpillar tracks of a bulldozer that is stuck in mud, going round and round, but going nowhere. But anything on top of the tracks, ..like a continent (say) (or a dead boat), is carried along and plastered up against any resisting buttress that may get in the way - like another piece of continental crust. And that, exactly, is how mountains, Plate Tectonic style, are made. Buttress folded and all. And if there is no continental crust on top of the moving plate? Then instead of the crushing and crumpling of the buttress into folds, the crust pulls chunks of continent right off. ! . |
The
original pull-and-push? Seems so. It goes like this:- the caterpillar
track of the oceanic lithospheric plate turns, moving the piece of continent
on top along till it meets the continental lithospheric plate, which then
forces or pushes the oceanic
lithospheric plate down. As the slab of oceanic lithosphere
goes down it creates a kind of 'suck' - like the Titanic when it's sinking,
and the water gets pulled over the disappearing stern, ..so the continental
crust gets pulled over the slab as it goes down, creating the back-arc
basins of the Western Pacific.
Now just wait a minute, ...the continental lithosphere is pushing the mantle slab down, and the downgoing mantle slab is pulling chunks of continental lithosphere off? I don't know about you, but that sounds to me like a recipe for runaway pulling-off of the crust, and runaway slab-sinking too, ..more than a perpetual motion machine ! And if that is not enough there is rollback, where the descent of the downgoing slab causes the bend in the downgoing lithosphere to migrate in the direction of the ridge, which increases the migration of pull-apart basins of the Western Pacific (there are no others) oceanwards. It is this 'sinking of the
slab that drives plate Tectonics. All incredibly dynamic stuff, and
all consequent on the continental lithosphere pushing the oceanic lithosphere
down. What? Just by sitting there, doing nothing, the continental
lithosphere drives the Earth's deformation? Are they kidding?
(Nope.)
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So, ...how about wiggling your fingers in the holes in the Emperor's old clothes - and giving them the Big Rip? - Wiggly fingers of the world, ...unite!....lay this Dude bare!