Ice Crystals in Glaciers Compared with Quartz Crystals in Dynamically MetaMorphosed Sandstones

• Published in: Journal of Glaciology
• Main Author: MacGregor, A. G.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1951
• Subjects: Journal of Glaciology
• Online Access: http://dx.doi.org/10.1017/s0022143000026289; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000026289

Abstract Attention is drawn to resemblances between two contrasted styles of mosaic crystallization—tessellate and equigranular as compared with irregularly interlocking (sutured) and inequigranular—that characterize ice in alpine glaciers and quartz in dynamically metamorphosed sandstones of the Moinian area of the northern Scottish Highlands. It is suggested that in both environments the contrasted types of mosaic are due to crystallization under conditions of shearing stress that were respectively minimal and maximal. Similarities are also pointed out between the orientation of the principal crystallographic axes of crystals in ice subjected to shearing stress, and the “girdle” arrangement of the principal crystallographic axes of quartz in Moinian metamorphic sandstones.