Manuel,
What plag comp [~An30?]? Is Act prograde? Could Act be either retrograde or incompletely consumed by prograde reaction? Exsolved? Sounds like run-of-the-mill amphibolite with Act 'extra', but Hbl and Act seem likely out of equilibrium. Pl-Hbl assemblage alone will not do much to constrain P-T.
At 03:08 PM 5/26/00 +0200, Manu wrote:
>Hello there:
>
> This is Manuel again, with serious doubts about metamorphism of mafic
>rocks. Usually, it's accepted that between greenschists facies and
>amphibolite facies, there is a transition zone in which appear assemblages
>with Pl + Hbl + Act + Chl ± Ep (for low to medium pressure conditions) or
>with Ab + Hbl + Ep (for high pressure conditions). Does anybody know of an
>assemblage with just Pl + Hbl + Act, without Ab, Chl or Ep? If it's possible
>to get this assemblage, What P-T conditions would indicate?
>
>Thanks a lot
>
>Manuel
>
>--
>Manuel Díaz Azpiroz
>Dpto. Geología, Universidad de Huelva
>Campus de La Rábida. Crtra. Palos de la Frontera s/n
>21087 Huelva
>Phone: 959-351000/351012
>Fax: 959-530175
>E-mail: [log in to unmask]
>
Jim Eckert
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