Exploration and Validation of Porphyry Copper Deposits using Aster Data in Datta Khel Khyber Pakhtunkhwa, Pakistan

Abstract

Minerals are the most important natural resources which plays an important role in boosting economy of any country. 'Mineral is compound of naturally available substance with specific chemical composition’. North Waziristan district of KPK consists of mountainous Belt and hosts many mineral deposits in N-W of Pakistan specially Datta Khel region. Conventionally geological information for mineral explorations require the geologists to plan field visits, collect various samples for study and analysis but this is laborious task which requires a lot of experience, practice, in-depth knowledge, equipment and technical experts. Remote sensing is latest technology used for surveying/ mapping of different geological sites. Remote Sensing sensors mounted either on aircrafts or satellites detect the electromagnetic radiation reflected from the earth surface without making any direct contact. Remote Sensing images are used for mineral exploration by recognizing mineral zones by their spectral signatures. For our study ASTER satellite level 1T images were obtained from NASA website for year 2003 and 2018. Year 2003 images were utilized for copper exploration and year 2018 images for validation (Presently copper is being extracted from an existing site which started after 2003, that’s why imagery of year 2003 was used so that validation of proposed method could be done). 9 x Bands were used (3 x VNIR and 6 x SWIR). Image processing techniques of Principal Component Analysis (PCA) and Band Ratioing (BR) were used to identify the potential mineral sites. Interpretation was carried out using Eigen vectors, Eigen values, correlation and covariance matrices. Potential sites were marked and then filtered out by using PCs and BRs. These techniques identified new potential locations of porphyry copper mineralization in our study area of Data Khel, Khyber-Pakhtunkhwa. The potential sites of Copper and Iron Oxide were the final product of this research which were validated using the identification of existing site in imagery of year 2003. Results showed that the assimilation of the image processing techniques has a great ability to obtain comprehensive information for the reconnaissance stages of copper exploration in region. This research results can assist geologists to find new copper porphyry and other mineral deposits, before costly detailed ground investigations. Subsequently, the introduced image processing techniques can create an optimum idea about possible location of new potential sites.