The Mineralization and Distribution of Platinum Group Elements (PGE) in Chromitites around Karaburhan (Sivrihisar-Türkiye)

Kadir Sariiz ¹, Hüseyin Sendir ¹ and Hatice Kozlu²

¹ Eskişehir Osmangazi University, Department of Geological Engineering

² General Directorate of Mineral Research and Exploration

 

Abstract The study area is located northeast of Eskişehir. A total of 24 samples collected from chromites in the ultramafic rocks are analysed for whole rock, trace and Platinum Group Elements (PGE) contents. Ultramafic rocks of the Karabayır metaophiolites are composed of peridotite and pyroxenites which are completely serpentinized. Ultramafic rocks generally contain clinopyroxene, ortopyroxene and olivine. Chrizotile and antigorite are the main serpentine minerals. Mineral paragenesis at the chromites includes, magnetite, pentlandite, millerite and heaslewoodite. The microprobe studies were conducted and as a result laurite (Ru(OsIr)S₂) was determined in only one sample. Compositions of Platinum Group Metal (PGM) in laurite crystal are Ru 45.017%, Os 14.175%, Ir 3.376% and S 35.011%. In chondrite normalized diagram, most of the all samples show negative correlation. This correlation is typical for podiform chromites. All the of data show source of PGM might be derived from depleted mantle that is undersaturated with respect to sulphur. In (C8) sample, ratios of Pt/Ir and Pd/Ir are high showing formation from a fractionated magma. For this reason, in chondrite normalized diagram this sample shows a positive correlation. It is thought that Ir, Os, Ru are associated with chromite while Pt, Pd Rh are crystalized in the relict magma.

Keywords: Karaburhan Region, chromite, Platinum group elements, Eskişehir