Structural evaluation and mineral prospects: Insights from gravity studies in segments of Mahakoshal and Vindhyan Regions, central India

Abstract

In this paper, gravity dataset acquired from a recent ground survey spanning 3500 km² in parts of Mahakoshal–Vindhyan Basin, central India, has been analysed with an aim to evaluate gravity anomalies and assess structural attributes that could identify potential areas for mineral exploration. The Bouguer gravity anomaly exhibits a total variation of 41 mGal with a prominent high in ENE–WSW axis demarcating the Mahakoshal Fold belt, whereas, a low gravity anomaly (–48 to –59 mgal) is predominantly observed over Vindhyan basin. Various geophysical processing techniques identify absence of deformations in the Vindhyan basin. The data analysis shows the presence of ultramafic intrusives, a few anomalous zones corresponding to shear and fault zones in Mahakoshal, trending in multiple directions (E–W, ENE–WSW, NE–SW, and N–S). These tectonic features significantly impacted the development of the Mahakoshals and Vindhyans. Derivative-based anomaly maps reveal three distinguished high-gradient fault zones in the north, east and south of the Mahakoshal belt. In the southeast of the Mahakoshal belt, a prominent low gravity anomaly of shear zone, probably caused by rifting, is delineated. The depths of anomaly sources are estimated using spectral analysis, Euler solutions, Werner solutions, and analytical maxima solutions. Furthermore, 2D forward modelling of gravity data along a specific profile aid in constructing a schematic evolutionary model for the Mahakoshal and Vindhyan regions in the study area. Notably, the present work reveals distinct curvilinear sheared basement zones in the southeastern Mahakoshal belt, suggesting potential zones for future mineral exploration through integrated studies.

Highlights

• The paper presents the geophysical anomalies of a ground gravity dataset acquired at a station density of 2.5 km² over 3500 km² in segments of Vindhyans and Mahakoshals.

• Gravity data evaluation discerns the presence of high-density ultramafic rock as well as a distinctive anomalous shear zone controlled by supracrustal faults within the Proterozoic Mahakoshal Fold belt.

• Based on the geophysical characteristics and structural assessments, three potential target zones have been identified for future mineral exploration.