Kiddie's Korner

....."Plates and Plate Movement"
              ( .. The House that Jack built..)

Fig.1.  Caterpillar tracks.  Stuck in the mud with its tracks churning like billy-oh!, this baby is going nowhere fast, just round and round, ..like the subducting lithospheric plate of Plate Tectonics.  No way can it even make it to the edge of the page, to collide with and crumple any 'crust'.  So plate movement (as Plate Tectonics would like to have it) is a non-starter.  When it comes to crumpling anything, plates simply don't 'move'.   Not in the way Plate Tectonics needs them to.

 
So, .."plates move"? (/subduct grind float etc..) do they?  And throw up mountain belts?  ?Precisely how do they do that - throw up mountain belts? ...when the 'movement' is that of the descending slab continually returning to the mantle  - a conveyor belt in motion.  Like the downward movement of the tracks on the front of the earthmover in the figure when it's stuck in mud, ..  sure, ..it is 'moving', .. like Billy-oh, ..churning round and round ..but going nowhere - as far as crumpling the 'crust' in front of it is concerned.

But the language above is entirely that of translational movement of lithospheric plates from 'A' to 'B', in which the plates bodily move, ..boundaries and all, ...not the convective cycling of a lithospheric shell according to the requirements of Plate Tectonics.

This picture of translational movement is not helped by such statements as, "Earth's surface is divided into a dozen tectonic plates that either drift apart, creating new oceanic crust, or collide, generating mountain belts such as the Himalayas."
http://www.sciencemag.org/cgi/content/full/300/5624/1379
How else is one possibly supposed to understand that other than as it says - "Plates collide, ...generating mountain belts.  .." - movement, ...'A' to 'B', ..boundaries and all?

"Plates collide, ...generating mountain belts." ...  This is the standard rhetoric of Plate Tectonics, yet it is false for one simple reason: plates do not move in the sense meant by Plate Tectonics to crumple the crust and throw up mountains.  How can they when the subducting slab is returning to the mantle?  ...Remember, 'Plate' = upper mantle + crust on top.   Plate Tectonics is driven by the subducting lithospheric slab, and the subducting slab is returning to the mantle, ..and  from the spreading ridge to the subduction zone the ocean floor/ 'plate' is therefore cycling on-the-spot so to speak, returning itself forever to the mantle.  It is not 'moving' anywhere to collide or crumple anything.

'Moving', but not 'moving'.  Which 'moving'?  Plate Tectonics says, "Take your pick.  Either will do."  <image to include>  And both are wrong.

Continental crust that is sitting on top might be carried along (remember 'plate' = lithosphere = upper mantle + crust) , and crumple against some resisting buttress, but 'crust' is not 'plate'.  And Plate Tectonics makes a big deal of the misuse of terminology, saying that mostly teachers get it wrong.

Anyway, all the high peaks of the Himalayan Front which is supposed to be the type area for plate collision show stratigraphic layering which is uncrumpled, ..so ,..what's with this 'crumpling'/ plate collision nonsense?  To which Plate Tectonics replies (changing the goalposts yet again), "Ahem, ..yes, ..well, .. India isn't exactly colliding with Asia, is it?  It is being pushed under and lifting it up.  Hey Presto! - no crumpling".

But by definition of Plate Tectonics  the continental crust is floating on the mantle and cannot subduct because it is too light.  Well, evidently it can if it happens to be India, ..which in Plate Tectonics is the same type area for crustal crumpling.

Crust crumpling, ..but no crumpling.
Plates moving ..but no moving.
Transform faults offsetting spreading ridges, ...but no offsets..

Even for something as fundamental as 'plate movement', Plate Tectonics screws up.   It really is a useless framework to explain anything of global geology.
 
 

Fig.2.  Plates move.  Grinding here, pulling apart there, and colliding to create mountain belts island arcs and sedimentary basins, the plates of Plate Tectonics "move independently" about the surface of the Earth.   (A google-up gets about 947 for <plates "move independently" tectonics>)