METASTABLE PARAGENETIC SEQUENCE OF ANDALUSITE, KYANITE, AND SILLIMANITE, KWOIEK AREA, BRITISH COLUMBIA

Abstract

Model involving initial metastable crystallization of andalusite in contact metamorphic terrane adjacent to Coast Range batholith, is proposed to interpret constant lithostatic pressure, increasing temperature observed sequence of polymorphic transitions, andalusite to kyanite to sillimanite; texturally, fibrolite occurs as phase distinct from sillimanite and at lower temperature than first appearance of sillimanite; prevailing pressure of metamorphism, and hence prevailing pressure of emplacement of part of Coast Range batholith, was between 5. 5 and 7. 1 kbar.