Remote sensing of Listvenite rock for Kaymaz Gold Deposit, Eskişehir-TÜRKİYE

The Kaymaz Gold Deposit (KGD) is an economically important gold deposit in Eskişehir, Central Anatolia, Türkiye. The deposit occurred in very rare non carbonate-containing and highly silicified listvenite rock, an alteration product of serpentine in the Tavşanlı Zone, located south of the İzmir–Ankara–Erzincan Suture Zone. We studied the alteration in the KGD through petrographic examination and XRD analyses. We used Fourier-transform infrared (FTIR) spectroscopy to study the spectral absorption properties of field samples. The absorbance and reflectance patterns of the samples were used to derive mineral maps using the Advanced Spaceborne Thermal Emission and Reflectance Radiometer (ASTER) and Sentinel-2 images. The argillized zone was mapped using ASTER band ratio images 4/6, 4/9, 7/6, and RGB (red-green-blue) composite images. In addition, the 11/2 and 10/11 band ratios of Sentinel-2 were used to map Fe-oxyhydroxide containing listvenite and serpentinite, respectively. The images of band ratios and derived RGBs discriminated the altered rocks as well as the metamorphic and ultramafic rocks occurring around the open-pit mine and can be used to explore new deposits in similar geological settings. The results were verified and confirmed in the field, which showed that the ore zone is highly silicified with significant Fe-oxyhydroxide content.