Development of kimberlite exploration Geographic Information System Moreover, the search for kimberlite involves several other factors. The kimberlite occurrences are revealed by observation such as, higher magnetic-gravity values, juxtaposition of cool cratonic mass - mobile belt -intracratonic basin, anomalous enrichment of Nb-Ni-Cr-Ce-Mg-Ba in weathered and/or soil horizon, exceptionally rich vegetation in an otherwise vegetation poor country etc. The identified exploration guides for kimberlite of MDA in the background of global exploration guide is presented in Table-1. The best correlation of topographic tectonic, geochemical and geophysical data is achieved by development of KEGIS. Development of KEGIS "The kimberlite occurs in clusters"- it is the guideline for development of Kimberlite Exploration Geographic Information System (KEGIS) in MDA. Accordingly, an area including the four known kimberlite occurrences and bounded by latitude N 20.00 to 20.30 and longitude E 82.00 to 82.30 is selected for rigorous. The selected window covers an area of approx. 2100 sq. km and falls in SOI toposheet nos. 64 L /3,4,7 & 8. The objective behind KEGIS is developing a geological information system for kimberlite exploration in MDA. KEGIS permits available data to be manipulated and displayed quickly. The results may be displayed in several formats and can be stored for repetitive application. The study takes into account the topographic, drainage, lithologic, tectonic, geochemical and other important data used for kimberlite exploration. These data are incorporated into the digital database for further manipulation and development of KEGIS. The digital data used for study are IRS-1C/1D products. The aerial photographs are used for collection of additional information for data input. The methodology adopted for development of KEGIS is presented in Fig 2.  Fig. 2: Strategy for KEGIS development Database for KEGIS The Satellite view of the Mainpur-Deobhog area is shown in Fig. 3. The image clearly indicates ideal location for the occurrence of kimberlites. The basement granitic rocks are hosting platformal Khariar sediments with boundary between two as Sondur lineament. The circular and/or oval geomorphic depressions are also distinct on the image. The Eastern Ghat Mobile Belt (EGMB) is welded to the central massif through a major thrust cum shear zone. The geologic map is presented in Fig. 4. The lineament density map and associated rose diagram are shown in Fig. 5. The database building for any GIS project involves demarcation of spatial extent of selected area in an appropriate co-ordinate system. The same co-ordinate system is used for all data inputs. The lines, polygons, control points etc. in the input are digitized to obtained the same co-ordinate system such that the spatial components overlap correctly in the map overlays. The UTM co-ordinate system is used for data input in the present study. The area co-ordinates (in metric system) are the lower left corner (x = 220234.91, y = 595928.39) and upper right corner (x = 2276651.08, y = 664999.36) |