Abstract

Lithological Discrimination by Selective Image Processing Techniques

Raghu Babu K, Keshava Kiran Kumar PL and Ramakrishna P

Exploration geology involves mapping of rocks that includes delineation of different rock types known as lithological maps. Such maps provide primary information about the mineralogical and hydrological occurrences beneath the surface of the earth. Remote Sensing by satellites and their study through GIS are sophisticated techniques available today for lithological discrimination and mineralogical and hydrological exploration. Spatial technology through satellite data has become an excellent technology not only for lithological mapping, but lineament extraction, structural mapping etc. In the present study image processing techniques have been applied to IRS P6 LISS III image of 57j/7 scene covering Vempelli, Vemula and Velpula villages of 720 sq.km area. It is composed of all three varieties of rock types viz., igneous, metamorphic and sedimentary rocks. Peninsular Gneissic Complex (PGC) is the basement rock consisting of granites, granodiorites, schists and gneisses forms the basement of the area, over which Cuddapah Supergroup rocks are present. Gulcheru quartzites, Vempalli dolomites, of Papaghni group, Pulivendla quartzites, Tadipatri shales of Chitravati group are the Cuddapah Supergroup rocks occurring in the study area. Igneous activity is seen between Vempalli dolomites, Pulivendla quartzites and within Tadipatri shales in the form of sills.