Issues

Photomicrograph of pelitic schist from Whitehills Bay, Banffshire coast, NE Scotland. In the lower part of the image pale brown, high-relief staurolite porphyroblasts, with fine grained quartz inclusions aligned in curving patterns, are surrounded by cordierite, the latter now altered to medium brown, low-relief scaly material known as “pinite”. Also included in the pinitised cordierite are clear quartz grains and darker brown biotite crystals that show parallel cleavage planes. The irregular, corroded-looking margins of the staurolite porphyroblasts suggest that the staurolite has been partially digested by the surrounding (pinitised) cordierite. Width of base of elongate field of view: 0.7 mm. Image from 'Metamorphism of the Buchan type-area, NE Scotland and its relation to the adjacent Barrovian domain' by DRM Pattison and SA Goldsmith (10.1144/jgs2021-040).

Photo by David R.M. Pattison