Strain History of Aravalli Rocks Exposed Around Village Maruwas, Udaipur District, Rajasthan

Abstract

Detailed structural analysis of the area suggests that the Precambrian rocks under investigation revealed a complex deformational history. The area has suffered one major and two minor phases of deformations. Out of which the second deformation (AF2) is most dominant structural event, which has controlled the topography. Fold produced during first deformation (AF1) are tight to isoclinals in nature and suggesting a reclined geometry. While folds of second generation (AF2) exhibit open, upright fold geometry, the third deformation is less penetrative. Analysis of shape and orientation of the AF1 and AF2 folds is suggestive of their initiation by buckling and subsequent modification by flattening resulting in to flattened parallel folds (Class 1C) geometry. Geometrically, some of the folds do not fall distinctly into one class but show a combination of two to three classes. This may be due to original layer irregularities or may be due to differential flattening. The strain ratio varies from 0.1 to 1, which indicates that different folds underwent varying amount of flattening. Stratigraphically, the area under investigation comprises rocks of Middle and Upper Aravalli Group of shelf as well as deep-sea faces.