Emplacement of Lamproites in and around Ramadugu, Nalgonda District- ground Magnetic evidence

Abstract

The total magnetic intensity data has been collected in and around Ramadugu Village in Eastern DharwarCraton to understand the magnetic evidence over the known Lamproites zones in conjunction with geology and geomorphology. Based on the magnetic, geological and geomorphological signatures observed from the known lamproites potential zones, new probable locations are identified in the study area. Nine magnetic lows and fourteen magnetic highs are traced, lows are representing the presence of Lamproites within the granite gneiss, and highs are observed over the presence of banded iron formations. The generated analytical (Horizontal, Vertical, Tilt, Analytical signal) maps from the total magnetic anomaly show the trends of the magnetic lineaments and trending in NW-SE, NE-SW &E-W direction. The coefficient of variation (CV) of the magnetic data clearly identified four tectonic disturbed (A.B,C,D) zones, various faults and other lineaments/dykes and the intersection of lineaments, geological, morpho structural, tectonic aspects of reported occurrence of lamproites near Ramadugu and Vattikodu areas were found to be localized at surrounding of the domal peripherals. Using this criterion eight potential lamproites zones were delineated(2,3,4,5,8,9,10,11 and 13) in the study region. The long normalized radial averaged power spectrum of the study area indicated that the depth to the granite gneiss basement is around 2 Km.The dyke configurations in the region was obtained via the inversion of magnetic profiles.