Isogon Patterns for Minor Folds and Some Effects of Deformation in the Banded Ferruginous Quartzites from the South Eastern Bababudan Hills, Mysore

Convergent isogon patterns for the minor folds in the Banded Ferruginous Quartzites of southeastern Bababudan Hills reveal that at least some of the bands are flexurally folded, but the thickness of individual bands does not remain constant throughout a fold. Hence these are not ideal parallel folds; and apart from flexure, processes like compression also played a role. Divergent isogons indicate differential compression. In multilayered sequences isogon patterns are more controlled by thickness than composition. Even though the folds are flexural, they are propagated for long distances due to alternate divergence and convergence of isogons. Bands of different compositions respond differently to the deformation. Magnetite is more competent than quartzite. Thickness also controls folding in that thinner the magnetite band the lower is the order of folding shown by it.