The relative importance of deformation at various scales and the necessity of measuring finite strain at different scales in the analysis of geological deformations are discussed here. Most analyses of finite strain involve the use of deformed objects at the microscopic scale, since at this scale the deformation is almost homogeneous The existence of strain measurable at larger scales (for example, the minor scale) has been previously demonstrated, and the importance of measuring such strain has been pointed out (Schwerdtner, 1973). However, few attempts at quantitative analyses have been made so far, mainly, because the theory of large-scale inhomogeneous deformations is complex and the application of mathematical principles is difficult. In the first part of this paper, the general relationship between deformations measured at different scales is discussed, and some special cases are described for which the strains at various scales can be separated out and measured. In the second part, these principles are applied to the study of some folded quartzites in the South Mountain anticlinorium of the central Appalachian Blue Ridge. The object of choosing this particular area was to study the variation of strain at different scales around the major folds and thereby attempt an analysis of the mechanics of deformation in the area.

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