Gravity and Magnetic Studies Over Parts of Khairagarh Basin, Central India

Interpretation of gravity and magnetic data in a strip of 250 sq.km. over Lanji-Darekasa tract of Khairagarh basin has been attempted in order to delineate regional structures and controls of uranium mineralisation in the province. Magnetic map indicates three parallel east-west trending lineaments representing basic dykes cutting across the geologic fonnations. The orthogonally intersecting gravity and magnetic trends around Saheki (80° 31' : 21° 27' 30") reveal a tectonised zone favourable for uranium minelisation. Gravity low of the order of five milligals near Nimbanaka (21° 19' : 80° 31' ) suggests a sharp increase in the thickness of Bijli rhyolites.

Based on observed gravity, magnetic data and the available surface geological information, the paper proposes a model for configuration of Khairagarh basin along Lat. 21° 25' between Parsori and Khairagarh. Maximum thickness for volcano-sedimentary pile filling the basin along this section is estimated to be around 2300m. The model also indicates possibility for the presence of a concealed high density formation (Pitepani Volcanics?) below Bortalao sandstones.