Mapping the Mineralogical Footprints of Petroleum Microseepage Systems in Redbeds of the Qom Region (Iran) Using EnMAP Hyperspectral Data

This study utilizes EnMAP hyperspectral satellite data to map the mineralogical footprints of hydrocarbon microseepage systems induced in the Upper-Red Formation (URF), a clastic Upper Miocene sedimentary sequence in the Qom region (Iran) affected by petroleum leakage from the underlying Alborz reservoir. The Level 2A surface reflectance product of EnMAP was processed using spectral matching and polynomial fitting techniques to characterize diagnostic absorption features associated with microseepage-induced alteration minerals. The identified mineralogical changes include partial to complete bleaching of hematite from redbeds, the formation of secondary goethite, and the development of montmorillonite, calcite, and Fe2+-bearing chlorite across the affected zones. Compared to previous studies conducted using ASTER and Sentinel-2 multispectral data, EnMAP demonstrated superior performance in identifying mineralogy and delineating petroleum-affected zones, with results aligning closely with field observations and laboratory spectroscopy. This study highlights the advantages of EnMAP hyperspectral data for mapping diagenetic mineralogical alterations induced in sedimentary strata, facilitating remote sensing-based detection of microseepage, and advancing petroleum exploration in exposed terrains.