NJG56-2-08
1976
A projection for analysis of mineral assemblages in calc-pelitic metamorphic rocks
56
2
203-209

A projection from clinozoisite in the Al2O3-FeO-MgO-CaO tetrahedron allows graphical representation of the mineral assemblages of low to medium-grade calc-pelites containing quartz, K-feldspar and epidote. Mineral assemblages in rocks of the Beiarn area, north Norway, allow construction of three different topologies for this projection, representing different grades of metamorphism. The changes in topology define three (ideally) univariant reactions, which may be mappable as isograds; changes in grade should be reflected in changes of mineral composition in low-variance assemblages.

0029-196X
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