Lineaments and hydrothermal alteration mapping in the Arkawit area, NE Sudan: insights from remote sensing

Abstract

Utilizing remote sensing data is a common protocol in mineral exploration, particularly during the initial stages of identifying alteration zones and understanding the interrelationships between tectonic structures and mineral deposits. The primary objective of this research is to identify and optimize lineaments for the purpose of locating areas of hydrothermal alterations with regard to orogenic gold deposits in the Arkawit area of NE Sudan’s Haya terrain. Landsat-8 OLI, ASTER, and SRTM DEM data were employed. A suite of digital image processing techniques, including false color composites, band ratio, decorrelation stretching, and principal component analysis, was employed to extract useful information and derive insights from the datasets. Landsat-8 OLI effectively delineates the hydrothermal alteration zones, which are predominantly located in the central part of the study area. In addition, the ASTER data has revealed distinctive argillic, phyllic, and propylitic alteration characteristics. The integration of lineaments extracted from Landsat-8 OLI and SRTM DEM analyses culminated in the identification of three primary directions, namely, NE-SW, N-S, and E-W. Subsequently, the resulting alteration zones were classified into four categories based on their intensity: high, moderate, low, and very low. This study demonstrates that the density of lineaments within the study area is positively correlated with the intensity of the alteration zones.