Chromite ore in guleman ophiolite (Se, Türkiye) petrogenesis of peridotites containing

The most important economic chrome ore formations in Turkey; The Guleman Ophiolite is located within the Southeastern Anatolia–Zagros Suture Belt and is one of the largest Neotethys ophiolites. Chromites observed in ophiolite are generally found together with dunite casings in harzburgites. This research was sustained to better understand the mantle processes and tectonic regimes associated with the original formation of chromites and to examine the mantle source region, melt-rock interaction and tectonic environment of peridotites. It provides chemical data and petrographic evaluations. Cr-spinels in chromites contain high Cr# [(Cr/ (Cr + Al)) = 0.619-0.802] and Mg# [(Mg/ (Mg + Fe+2)) = 0.66-0.72], low TiO2 (0.09-0.24) and relatively variable Al2O3. (10.23-20.40) is characterized by its contents. According to the mineral chemistry analysis presented here, the compositions of all Cr-spinels are compatible with magnesiochromites, indicating the existence of two chemically distinct groups. The first group is high-Cr chromites and is represented by relatively higher Cr# (0.74-0.80) rates, while the second group is medium-Cr chromites and is characterized by relatively lower Cr# (0.612-0.624) contents. The chemical composition of the first group indicates that the main melts of chromites are similar to typical boninitic melts in a front-arc tectonic environment. On the other hand, the relatively lower Cr# contents of the second group may indicate the inclusion of main melts such as mid-ocean ridge basalts (OOSB) or island arc tholeiites (AYT) in a heterogeneous source for the origin of chromites. Again in this study, detailed mineral chemistry studies were carried out on the host rocks containing the mentioned diabase, gabbro and chromites, which are an important component of the ophiolite. Host rock samples were made from the same locations as chromites. In this study, the tectonic environment in which the mentioned harzburgites were formed and their potential to produce chromite were examined on a regional basis. As a result of the studies and conclusions, detailed geological, geochemical and geochronological data published for the geodynamic evolution of the Southern Neotethys ocean, an intra-oceanic subduction including front-arc environment, arc or early stage of back-arc expansion environments for the origin of chromite and host rocks in the Guleman ophiolite. This indicates that it may have formed in the zone. In the petrography studies carried out on ultramafic rocks and chromite samples in the Guleman Ophiolite, detailed petrographic studies were also carried out on the host rocks (harzburgite), which is an important component of the ophiolite, in addition to the chromite samples. In this context, host rock and harzburgite samples were taken from 4 different regions and the chemical compositions of olivine, pyroxene and spinel minerals in these samples were determined by the EPMA (electron microprobe) method.