Patterns of deformed early lineations over later folds formed by buckling and flattening

Ghosh, S. K. ; Chatterjee, A. (1985) Patterns of deformed early lineations over later folds formed by buckling and flattening Journal of Structural Geology, 7 (6). pp. 651-666. ISSN 0191-8141

Full text not available from this repository.

Official URL:

Related URL:


The patterns of deformed early lineations (L1) over later folds (F2) can be classified into several morphological types depending on the nature of variation of L1Λ F2 over the folds. The field relations indicate that the folds under consideration are neither shear folds nor parallel folds modified by flattening. The lineation patterns are therefore interpreted in terms of an empirical model of simultaneous buckling and flattening in which it is assumed that (i) the central surface of the folded layer remains a sine curve in transverse profile, (ii) the ratio of rates of buckle shortening to homogeneous strain is proportional to sin 2a, with a as the dip angle and (iii) the progressive deformation is coaxial with the Z-axis of bulk strain parallel to the planar segments of the early folds. The model gives an insight into the relative importance of different physical factors which control the development of dissimilar lineation patterns. Not all lineation patterns are explicable by this simplified model. Thus complex patterns with variable L1 Λ F2 along the fold axis may develop by a progressive rotation of the geometrically defined fold hinge through successive material lines. The theoretical results have been applied to interpret the lineation patterns in Central Rajasthan, India. It is concluded that L1was initially very close to the E-ESE trending subhorizontal Z-axis of bulk deformation during F2-folding and that the X-axis was subhorizontal or gently plunging with a N-NNE trend.

Item Type:Article
Source:Copyright of this article belongs to Elsevier Science.
ID Code:27146
Deposited On:08 Dec 2010 12:38
Last Modified:31 Dec 2011 08:49

Repository Staff Only: item control page