Precambrian Ashe Formation. No correlation between mineral assemblages and metamorphic zones. Modal analyses and quantitative chemical analyses for Mg, Al, Ca, Fe, Ni, Mn, Cu, Co, K, and Zn lead to the recognition of two distinct types of metamorphosed ultramafic bodies based on the degree of metasomatic alteration. A retrograde hydration of the ultramafic protolith produced the tremolite-chlorite-talc anthophyllite assemblage with relict olivine. In a second stage, serpentine replaced some of the tremolite and olivine. A later partial dehydration led to the more strongly foliated tremolite-chlorite-talc schist or phyllonite.--Modified journal abstract.

You do not currently have access to this article.