Targeting iron prospective within the Kabul Block (SE Afghanistan) via hydrothermal alteration mapping using remote sensing techniques

The application of remote sensing has significant time- and cost-saving benefits as a technological tool for the delineation of iron prospects. Afghanistan is a prime target for these methods owing to the presence of several metallic and nonmetallic mineral deposits, most of which remain undiscovered. This study aims to target iron prospective areas within the Kabul Block (SE Afghanistan) by detecting hydrothermal alteration zones and iron-bearing minerals, using Landsat 8 OLI/TIRS. With this objective, we applied four different techniques, including false-color composite (FCC), band ratioing (BR), principle component analysis (PCA) via the Crosta technique, and the spectral angle mapper (SAM). The results of each algorithm are in high correlation with the conventional data. FCC was successful in highlighting the hydrothermal alteration zones, while the BR and PCA techniques were able to detect iron oxide and ferrous and ferric minerals. The SAM algorithm, as expected, detected iron-bearing minerals. The obtained results were validated by previously limited iron occurrences, and favorable/permissible areas are marked by USSR and USGS, presenting high accuracy. Under the findings of this study, 18 iron prospective areas in total were detected throughout the northern, eastern, southern, and central regions of the Kabul Block, including 6 previously verified areas and 12 newly proposed favorable regions.