On Sat, 27 May 2000, meredith lamb wrote:
> Think you're absolutely right on with the rising plume answer.  Theres really
> no other way it could have made this mass transition otherwise.  Speculate
> it must have been a extra large plume to have made the trip up, without the
> interaction of other lava mixing it up into less recognizable components
> chemically
> and its resulting minerology composition.  Time and erosion likely
> presented it
> in its present state.

Yes, they used stream gravels which were the eroded remnants of the pipes.
They also said that: "many of the macrocrysts exhibit a distinctive surficial
polish that is interpreted to have been caused by abrasion during turbulent
magmatic emplacement."  This implies an awfully fast moving magma.

> The article also mentioned possible diamond mining possiblities.  What
> struck me was the size of the garnet crystal mentioned.

Yes, 1 cm X 0.5 cm X 0.5 cm...all the way from hundreds of kilometers beneath
our feet.

John Hernlund
E-mail: hernlund@.......
WWW: http://www.public.asu.edu/~hernlund/

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