The strange case of the Shrinking Africa
             (...Not just Africa shrinks - All the continents are shrinking !

Fig.1. The African plate.  The outline of the orange represents the encircling spreading ridges, which once represented the coastline of Africa.  Either the continental crust of Africa shrinks, or the lithospheric plate of the ocean floors grow.  Either possibility causes problems for Plate Tectonics.

 

Ok now, ..concentrate hard, boys (and girls), .....  you can think about this at the breakfast table before going off to school.  But first we have to be clear what, exactly, in Plate Tectonics a 'plate' is.  A 'plate'  is the outer brittle shell of the Earth - the bit we get earthquakes in.  And that includes the crust and the upper mantle together, ..floating about on the asthenophere, ..a soft layer.  So, when we say that the African  plate is moving, we don't just mean the continent (the stripey bit in the figure), we mean the upper mantle as well, which is the orange bit, ... the bit that is now ocean floor.  That is (again) a plate is a two-layered thing  - crust and mantle together (upper mantle that is).

So Plate Tectonics mixes two things - a geophysical expression and a geological  expression.  And unfortunately the physical component fails miserably when it comes to logic.  And that's because geophysicists forget that the 'geo' comes before the 'physics'.  On every count that Plate Tectonics fails it is because of the geo-logic - or rather the lack of it - as we can easily see in...

The strange case of the shrinking Africa

By the same logic that Plate Tectonics applies to Africa on the Atlantic side to show that Africa is shrinking, ... .obviously Africa is not just shrinking there, it's shrinking all around!

Well it has to, ..doesn't it.  There's the plate (orange) and there's Africa sitting on top (stripes). And Africa has moved away from the spreading ridge where it used to join on to America.  And the ridge is the size it is in the figure; the ridge cannot spread along its length otherwise Plate Tectonics would be up the proverbial creek without the proverbial paddle (Big John Hernlund at ucla says so).  So as the plate moves (like a conveyor belt) towards the subduction zone carrying the continent of Africa with it, Africa is being shrivelled up as if being sucked dry by some giant subduction zone, leaving it little more than an empty shell.   So, ..what's going on?  What's happening to Africa to make it shrink? ("Clearly a case for Sherlock Holmes, my dear Watson....")

Now, in platespeak it's arguable whether it's the height of the spreading ridges which is pushing Africa down the Mediterranean gurgler, or whether it's Europe pushing the leading edge of the African plate (minus the continental crust which can't go down because it's too light) down that's doing it, i.e., the downgoing part is pulling everything else behind it down with it.  Either way, push or pull, Africa has to be getting smaller all around.  That's the logic that follows when Plate Tectonics is forced to make a geological distinction between the outer shell of the Earth as well as a geophysical distinction.

Which?  suck or shove? - or in platespeak, ridge-push or slab-pull?  It doesn't matter because either way it's nonsense... obvious nonsense - but it's the best that Plate Tectonics can offer to explain the facts.  Clearly what has happened is not that Africa has shrunk, but that the ocean floors have grown!  ...i.e., it is the spreading ridges that have moved away from Africa, not Africa that has moved away from the spreading ridges.  And by the same token for South America, ..the ridge has moved away from South America.  That is, the ridge moves symmetrically away from both of them at the same time.

So if the continents were once joined at the ridge, how can the spreading ridges move away from both continental margins at the same time?  There's an obvious space problem, Unless, ..unlesss, ..well, it's obvious: the fracture (which is the spreading ridge) moves *UP*.

What?  Do we mean to say that the logical explanation of events is that the ocean floors are a big uplift?  (!!)  How big?  Big enough for the mantle to break through and create the ocean floors of the world?  Well, that's what we've got, isn't it?  So what's the big deal?

Mind-boggling when we first think it, but that is indeed the only logical explanation.  Not only do the ocean floors represent a gigantic uplift ( the biggest mountain belt on the planet) it is a *ridge* as well after all, and a ridge with a huge extensional RIFT right down the middle of it

Now, .. Just imagine, .. Plate Tectonics insists that the Earth cannot get bigger, and that subduction zones swallow the same amount of ocean floor as is created at the ridges, but in the time it takes for the ocean floors to get from ridge to subduction zone the ocean floors have grown immensely along their length as well as across them.  Having already swallowed Panthalassa, subduction zones are now going to have to increase their swallowing rate to deal with that along-ridge increase as well!  ..... in order to keep everything "the same size".

Or, ..as Plate Tectonics would say, .."Obviously the subduction zone increases its subduction rate to cope with this increase in production of mantle floor at the spreading ridges - without offering any explanation how there is communication between the spreading ridge and the subduction zone other than that there is obviously a case for "More research needed").  But you can see the problem if the subduction zone is sucking down the Earth's smaller circumference of 200 or 300my ago, at the same rate as a much larger circumference is being produced at the ridge.  The Earth would be the Most Peculiar Shape.  No wonder our Sherlock looks miffed.

Irrational convolutions such as these attest to the brilliance of plate tectonics, the Jewel in the Crown of the Earth Sciences of the twentieth century?  ... And touted by its believers for this one as well.
 

Fig.1.  Cornflakes (after Carey, 1976).
(Shuffle 'em, shuffle 'em, shuffle 'em round...)

   (...Save the children of the world from Mad Platie Disease...)
Geomatosis