2017 Volume 123 Issue 2 Pages 59-72
Schistose staurolite-bearing pelites occur in the Ryoke Metamorphic Belt, Dando-san area, Aichi Prefecture, Japan. These rocks contain andalusite porphyroblasts and coarse-grained elongate mica-quartz aggregates composed of muscovite, biotite, and quartz in a matrix of muscovite, biotite, quartz, and fibrolite. Staurolite occurs as inclusions in andalusite porphyroblasts and in the minerals of the micaquartz aggregates. Detailed microscopy indicates that a staurolite-consuming and andalusite-producing reaction occurred before the deformation causing the schistosity, such that staurolite grains apart from andalusite porphyroblasts have been replaced by mica-quartz aggregates, and those adjacent to the porphyroblasts have been replaced by andalusite. It is possible that the prograde P-T paths of the staurolite-bearing pelites of the Dando-san and Hazu-Hongu-san areas lie on the high-pressure side of those of staurolite-free pelitic rocks with similar metamorphic grades in other areas of the Ryoke Belt.
