GRAVITY AND MAGNETIC STUDIES OVER PARTS OF KHAIRAGARH BASIN, CENTRAL INDIA

Interpretation of gravity and magnetic data in a strip of 250 sq.km. o ver Lanji-Darekasa tract of Khairagarh basin has been attempted in ord er to delineate regional structures and controls of uranium mineralisa tion in the province. Magnetic map indicates three parallel east-west trending lineaments representing basic dykes cutting across the geolog ic formations. The orthogonally intersecting gravity and magnetic tren ds around Saheki (80-degrees-31': 21-degrees-27' 30'') reveal a tecton ised zone favourable for uranium mineralisation. Gravity low of the or der of five milligals near Nimbanaka (21-degrees-19' : 80-degrees-31') suggests a sharp increase in the thickness of Bijli rhyolites. Based on observed gravity, magnetic data and the available surface geologica l information, the paper proposes a model for configuration of Khairag arh basin along Lat. 21-degrees-25' between Parsori and Khairagarh. Ma ximum thickness for volcano-sedimentary pile filling the basin along t his section is estimated to be around 2300 m. The model also indicates possibility for the presence of a concealed high density formation (P itepani Volcanics?) below Bortalao sandstones.