Grenville and all,
The facies designation to use is whatever P-T you get for the contact
rocks and then consulting Turner's facies diagram (Spear doesn't use
contact metamorphic facies in his book). One will typically get
(low-pressure) amphibolite or granulite facies, say 3-5 kbar, where the
aureole is easily identified. I know of no wide aureoles that can clearly
be shown to be contact metamorphic in regional metamorphic terranes at
higher pressures, although narrow zones are described. There are enough
facies names already! Why introduce one that requires an understanding of
the mechanism in order to employ it?
Eric
>When plutons intrude regions already undergoing regional metamorphism they
>produce a broad aureole of higher grade rocks around the pluton. This sort
>of deep seated contact metamorphism is clearly different from the high
>level, hornfels producing contact metamorphism, but the former is really a
>hybrid between contact and regional. It really ought ot have a name, but
>I've scoured the texts at hand for one anc come up empty handed.
>
>Can anyone out there help? Has a name been suggested? If so do you have
>the original reference? nyone care to suggest a name?
>
>
>Gren Draper
>
>
>**************************************************************************
>
> Grenville Draper
>
> Feb 1999 to June 1999 on sabbatical leave at:
> Area Geodinámica
> Departamento de Geología
> Universidad de Salamanca
> 37008 Salamanca
> SPAIN
>
> Tel (34) - 932-294482
> Fax (34) - 932-294540
>
>
>**************************************************************************
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|