Modelling of high-resolution aeromagnetic data to decipher structural deformation in parts of Kaladgi basin, Peninsular India
S. Muthyala, H. Yalla, A.K. Maurya and A.K. Chaturvedi
Journal name: Near Surface Geophysics
Issue: Vol 16, No 2, April 2018 pp. 1 - 12
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We show the effectiveness of forward and inversion modelling of high-resolution magnetic data in deciphering the geological framework in a polydeformed Proterozoic Kaladgi basin. The Meso to Neo Proterozoic Kaladgi basin exposes platformal sediments in the northern margin of Dharwar Craton, Peninsular India. The study of high-resolution magnetic data over Deshnur locality suggests two prominent trends NW–SE and NE–SW, followed by two minor trends of E–W and N–S. Analysis of the magnetic anomalies aided in understanding the succession of deformation events and their impact over sedimentation. The NW–SE trending Nalur shear zone marks the western contact between the Chitradurga Schist belt and Peninsular gneisses that are traced beneath the Badami sediments. The forward model suggests that the NE–SW trending block faulting resulted in generating a series of Horst and Graben structures. Three-dimensional compact inversion of circular features bearing remanent magnetisation indicates elliptical-shaped pipe-like bodies. The threedimensional inversion of magnetic data implied thicker sediments within these Graben structures. The basement configuration depicted as elevation of magnetic basement corroborates these threedimensional inversion results. The derived results are validated by drill holes, and the intercepts substantiate the inferred structural setup over the study area. Available drill hole and magnetic data interpretation are combined with field information to reconstruct the tectonostratigraphy and the architecture of the Kaladgi basin around Deshnur locality.