The Characteristics of Doğanşehir (Malatya-Turkey) Bauxite Mineralization in the Eastern Taurus Orogenic Belt Using Scanning Electron Microscopy (SEM)

Abstract

The Taurus Orogenic Belt in Turkey is a prominent tectonic zone where significant occurrences of bauxite mineralization are observed. The bauxite deposits in Doğanşehir, located in Malatya, Turkey, are found as extensive bodies and lenses within the carbonate rocks of the Permian-Triassic Malatya Metamorphics, situated in the Eastern Taurus Orogenic Belt. The geological foundation of this region consists primarily of lithologies attributed to the Malatya Metamorphics. This unit mainly comprises schists, calc-schists, and marble, overlain by the Berit Metaophiolite of the Late Cretaceous-Eocene, the Maden Complex of the Eocene, the Doğanşehir Granitoid of the Early-Middle Eocene, and the Plio-Quaternary cover sedimentary units. Bauxite mineralization of oolitic and pisolitic nature is present within the Permian-Triassic carbonate rocks of the Malatya Metamorphics. These mineralizations occur in carbonate rocks containing fossils and are observed in the form of lens-shaped bodies. The bauxite lenses are covered by relatively thin, intermediate layers of Permian-Triassic carbonate rocks of the Malatya Metamorphics. With the advancement of technology, Scanning Electron Microscopy (SEM) has been utilized to analyze bauxite ores and determine the presence of elements within their crystal lattice structure. The point analysis and mapping technique were employed to identify the elements that might be present within the crystal lattice structure of the bauxite ores. SEM analysis of the samples using the mapping method revealed the distribution of elements such as Fe, Ti, Si, Al, and O, both before and after activation. The images indicate that bauxite exhibits a wide grain distribution, both below and above 50 µm. The elemental spectrum diagram demonstrates the presence of O, Al, and Si in the sample, and the detection of Fe, Ti, C, K, and Mg as well. By employing SEM analysis and the mapping method on the same samples, the distribution of Fe, Ti, Si, Al, and O elements within the structure was examined before and after activation. The images reveal that the elements Al, O, and Si display high density in specific regions before activation but show a more uniform distribution and similar structures after activation. Fe, Mg, and K exhibit a similar distribution pattern, while Ti and C exhibit different characteristics.