Hornblende-Granulite Subfacies Mineral Assemblages from Areas in Ceylon

Abstract

Hornblende and biotite occur very commonly in the granulite facies rocks of the areas mapped, and both appear to occur as stable phases. Thus, these hornblende- and biotite-bearing rocks find accommodation only in the hornblende-granulite subfacies. It appears that most of the rocks in the areas mapped would fall into this subfacies and the mineral assemblages of these rocks are recorded in this paper under the different chemical classes. Hornblende and biotite are very commonly present in the pelitic, quartzo-felspathic, basic and magnesian rocks; phlogopite and sphene are commonly present in the calcareous rocks. A tentative ACFK tetrahedral phase diagram has been constructed for these rocks.