Tectonics and Stratigraphy of the Gurgunta Schist Belt of the Dharwar Craton, South India

The early Archaean oval-Shaped, high-Grade Gurgunta schist belt in the northern part of the eastern Dharwar craton of south India constitutes a part of the intensely deformed magmatized basement of the low-Grade volcano-Sedimentary sequence of the Dharwar craton. The Gurgunta schist belt consists of two blocks of a migmatised volcano-Sedimentary sequence separated by an E-W trending shear zone. Contrary to the earlier interpretations, the regional structure of the belt is not a dome.

The earliest episode of deformation (D₁) has produced pervasive planar fabric in metavolcanics and in granitoid rocks after migmatisation of volcano-Sedimentary rocks in its early history D₂ has produced major and minor isoclinal folds along with axial planar pervasive gneissic banding while the D₃ has produced major and minor tight to isoclinal folds on foliation. The map pattern is controlled by D₃ deformation D₄ and D₅ are of mild intensity and less prominent on a regional scale in comparison to earlier deformations.

The grade of metamorphism, migmatisation, the structural history and the presence of E-W trending shear zone suggest that the belt is probably older than the low-Grade supracrustal belts in the adjoining areas.