Floaties.

 
"..Hm, ... Just think, .. if you have a floatie, ..the size of India, say, .. and it floats along till it meets another floatie, ..the size of Eurasia say, ..  (An' that's by sliding down off the Southwest Indian Ocean ridge which is what they do say is how India got where it is ) (Gravity collapse, ..how about that? ... the essence of Earth expansion deformation, is the key to the deformation of Asia.)  ...  what power of convectional thrust (flush)  would be needed to catch it off-guard and drive it downunder, under Asia.  I mean, ..it would need that 'surprise' factor, wouldn't it? ..since continental floaties cannot sink.  It would need to be fooled into thinking it has to 'dive', ...  in order to get underneath Asia. "
"Nah, it's rivetted on.  When the mantle goes down, India goes under too."
"How do you mean?  It's sliding down off the ridge.  How is that rivetted?"
"Well, yeah, but that's just a simple way of putting it so ordinary people can *understand* it.  It's really the whole lot of lithosphere that's sliding down off the ridge, the continent AND the upper mantle underneath.  Every year, there's a dyke about ten centimetres wide being intruded at the ridge, and it's that, that's pushing everything along."
"Really?  Ten centimetres, ..every year? "
"Yeah."
"Right the whole way around, ..pushing the whole plate away from the ridge and up against Asia..?"
"Yup."
"Every Year.."
 "Well, ......   .....    .....   You know what I mean."
"Not really.  How is it supposed to work?  I mean the dyke, .. it's got to cut across all the transform faults to do that, and yet it's the transform faults that cut the dyke (All ..10cm of it..)"
"Yeah, that's right.  The dyke, .. it cuts the transforms, then the transforms cut it.."
"Every year?   You mean every transform fault does this,  ..every year?"
"Yeah...  It has to, doesn't it?
"Does it?"
"That wasn't a question.  It was a statement of fact..."
"WowW!  Awesome!  ...  *MASSIVE*  ! !  But how do transform faults know what year it is?"
<... .... ...>
"I mean, .."
"Look, ..hundreds of papers are written every year by researchers who work hard thinking about this.  It's the best verified theory ever, and there are reams and reams of scientists all over the world, .. clever people, *professionals* even,, ..who make a living from this, scribbling about it on every bit of paper they can find.   And they all check each other's stuff to make sure.   If there is one thing we can be sure of, it is that it is not wrong."
"To make sure what?"
"To make sure it's all right."
"But if it *is* all right, ..why would they need to check?  What is it they're checking?"
"The results, of course.  What's wrong with you?  Science is all about results don't you know?  Research and results. You have to make sure everybody's results are sensible."
"What about the beginning bit, the bit the research is based on, ..about the dykes and the transform faults, the intrusion and the cutting?  ...And the every year bit...?"
"That's just ideas, hypotheses, ..anybody can have an idea.  It's not important.  Ideas and hypotheses are changing all the time. It's results that count."
"Yeah, but if that's ideas, what about the facts?"
"That's results, dopey. Results are facts.  See?"
"Oh, ..right, ..  ...    Anyhow, ..where's Daisy?  Anybody seen Daisy today?"
"Why?  Aren't you interested in science?  I think she's over there, ..behind the shed.."
"Well, ..yes, ..I suppose I am, .. interested.. ...  What pushes the mantle down anyway? "
"The continental lithosphere, ..when the floating oceanic lithosphere comes along (with a bit of crust rivetted on) the floating continental lithosphere pushes it down, ..because it's denser see?   Makes it sink. ...   It's like scissors cut paper, ...  The lighter lithosphere pushes the denser lithosphere down."
"While the denser lithosphere pushes the lighter crust up.."
"Yeah, that's right, .. how did you guess?"
"Logic, I suppose, ..simple logic.  To every action there must be an equal and opposite reaction..."
"Brilliant.  Hey, ....  that's brilliant!  See?  What you can do when you try?  You're not that daft after all."

---

"Subduction is the result of two tectonic plates converging, as one plate, typically the oceanic plate, is forced down or subducted under the less dense continental plate.... <snipped> ...The gravitational pull of the denser oceanic plate drives the subduction."
http://www.utexas.edu/tmm/npl/mineralogy/Mineral_Genesis/index.htm
 

(Forced down, .. or subducts?  Which?  And what's the difference?)