>Does anybody know WHO first defined what a "piezothermal array" is - and
>(The line connecting the thermal metamorphic peaks of rocks through
>depth and time)
>Institut fuer Geologie und Palaeontologie
>Universitaet Graz, Heinrichstr 26.
>email: [log in to unmask]
A quick look at some older books indicates that Frank Turner
discussed the issue extensively in Chapter 8 of his 1968 book
(Metamorphic Petrology - Mineralogical and Field Aspects), referring
to them as "P-T gradients" or occasionally as "metamorphic
gradients". He makes some reference to Miyashiro's 1962 J. Petrology
article. There are numerous lines shown on a P-T diagram in
Turner's Fig. 8-4 that are clearly what we now refer to as MFG's or
piezothermal arrays. My guess is that this way of thinking about P-T
evolution during metamorphism began to appear on the general radar
screen of the metamorphic community in the late 50's and early 60's.
I wouldn't be at all surprised if the concept had occurred to either
Goldschmidt or Eskola (or others) forty or fifty years earlier, but
finding documentation in print might be difficult. In the "modern"
era, I'd guess that Miyashiro is the likeliest candidate to have
first "defined" the concept.
Dr. Robert J. Tracy
Professor of Geological Sciences
Blacksburg VA 24061-0420
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"We can't solve problems by using
the same kind of thinking we used
when we created them."
-- Albert Einstein