Stuart wrote:
> On Sep 8, 12:35 am, don findlay <d
...@tower.net.au> wrote:
> > df wrote:-
> > http://tinyurl.com/yu5xtdhttp://tinyurl.com/32zg52
> > ---------------------------------------
> > Come on Stuart, My world is falling apart, I thought I knew what
> > Plate Tectonics was saying but I didn't know it was like this. Tell
> > me Mr Bercovici is wrong and that the subducting slab is not pulling
> > the world apart (because it's cold ) (because it's dense). The slab,
> > that is. Tell me the subducting slab doesn't really drive Plate
> > Tectonics after all. I always thought the earth being hot inside
> > and making convection currents had something to do with it, but now I
> > learn, No, ..there is no need for potassium or any other 'um' in the
> > core, ..
> Sheesh. Such a silly diatribe. Or is it really a plea for help?
> Of course heat sources are needed. If the Mantle was not hot, there
> wouldn't
> be any subduction. Slabs have buoyancy because the mantle is hot.
> I explained the basic physics of this mode of convection in posts
> to Timberwoof. I suggest you review it.
> Once again you've gone off half cocked and made a fool of yourself.
> Again.
Is that all you took out of it? And all you have to say in reply:-
"The mantle is hot and the 'slab' has 'buoyancy'" Not much value is
there? - a concoction of fluid mechanics with no reference to
geological parameters. Not very illuminating.
Geologically speaking it's not worth a zack, really. (Transform
faults as zones of minimum dissipation of stress - Is that so?) And
a model that begins by *assuming* the 'source-sink' cycle. Value out
equates with value in. ('If's and Coulds')
Apparently you're not even getting the point of your own
construction, which is that in Plate Tectonic 'reality' the 'source'
is subsidiary to the 'sink',. therefore there *is* no 'cycle'. The
slab sinks because of gravity, pulls the plate creating pressure
reduction and the partial melting at the ridges. The 'heat' at the
ridges is therefore a 'gap-filler'. What follows is a one-way
street. The mantle sinks once and that's it. Moreover your
'volumetric heat' considerations ignore that most of the heat is very
quickly on the outside of the system; the radioactive elements are not
something that are divorced from the rock and can remain at depth to
heat the next batch of cold slab. The heatsource must rise with the
rock it is heating. It's a once-only turn. That's what the original
differentiation of core mantle and crust was all about. If things
were as you say that distinction would not be there.)
You ridicule what consensus says about the slab being "forced down",
but avoid giving any reason yourself for the location of subduction on
continental margins. You offer no criticism of the popular consensus
views of crustal crumpling by plate collision.
And you offer nothing on how the Plate Tectonic cycle (the 'source-
sink' cycle) begins.
You virtually avoid all questions that include geology.
You don't offer much, Stuart, ..beyond saying the mantle is hot and
slabs are buoyant (negatively). The less you say the less you run the
risk of saying something stupid? (The mark of the bad scientist is
lack of adventure, ..being afraid to make mistakes. Consensus suits
many people. No matter how silly it is, it is safe.
(Moribund cadavers with their leaden feet in leaden ruts. "We are
the footsoldiers of consensus. Convince us - if you can!)
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