Ground Magnetic and Very Low Frequency Electromagnetic Surveys to Locate Probable Kimberlites in Panna Diamond Belt, Madhya Pradesh, India

The Panna Diamond Belt of Madhya Pradesh is known for the occurrence of kimberlites that are host rocks to diamonds. Presently, one kimberlite pipe at Majhgawan-Panna is the only diamond mine in India. This is a very old mine producing diamonds for more than 60 years. In order to locate probable kimberlites in the Panna region for diamond mining for an economical growth of the diamond industry in India, ground Magnetic and Very Low Frequency Electromagnetic (VLF-EM) surveys were conducted on probable kimberlite zones. The ground magnetic and VLF-EM surveys were conducted over the Hatinitor Pahar and Kadwara areas which are probable kimberlite zones. Magnetic survey was conducted in grid pattern with profile and observation interval of 50 m in north-south direction. A total of 3,272 magnetic observations were measured along 5 grids and 4 profiles were conducted for the VLF-EM method in the study area. From the magnetic observations in Hatinator Pahar reduce-to-pole map showed east-west near circular anomaly and over a known kimberlite pipe B125. The reduce-to-pole map of the Kadwara showed a near circular magnetic anomaly and was identified as a kimberlite zone. This anomaly was similar to the known kimberlite B125. From 2-D modeling of the magnetic anomaly a depth of about 100 m was obtained over the Kadwara kimberlite pipe. The VLF-EM data also correlated with the magnetic observations and a low current density was observed over the Kadwara kimberlite. Thus, the magnetic and VLF-EM observations have clearly demarcated the kimberlite in the PDB.