Disclinations in Folded Structures and Geological Strata

Abstract

DEFORMATION of rocks on a large scale¹ and laboratory scale² produces a variety of flow patterns which have been extensively discussed. These observations show that the wide variety of macroscopic patterns introduced by plastic deformation are very similar to those introduced in more nearly homogeneous materials such as single crystals. These configurations, especially those in single crystals, have been extensively explained in terms of dislocation theory^3,4, with a great deal of success. Some recent experiments on silver crystals have shown that disclinations can exist in special metal structures⁵. This has led me to consider if any of the folded structures in rock structures can be associated with typical patterns of disclinations. Here, I present a striking example of a structure which is consistent with a disclination and point out that the introduction of such figures might play a role in subsequent deformation patterns.