Re: [asa] DeYoung at Auckland

>
> (ii) The granite examined appears to have contained biotite material
> meaning that replacement processes have been active.

Biotite can occur in unaltered granites, but other minerals associated with
the halo-bearing granites (which are only certain granites) are
characteristic of alteration. I think Talk Origins has a detailed
exposition on the geologic details.

-- 
> Dr. David Campbell
> 425 Scientific Collections
> University of Alabama
> "I think of my happy condition, surrounded by acres of clams"
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