Petrology, geochemistry and petrogenesis of isolated dikes from the Tekirova ophiolite ( Antalya, Turkey )

The study area located in Tekirova ophiolites in Antalya ophiolite nappe in Western Taurus. Tekirova ophiolites consist of ultramafic tectonics, ultramafic-mafic cumulates, isotropic mafic rocks, sheeted dikes and isolated dikes. The aim of this thesis is to determine the petrographic, petrological, geochemical and petrogenetic properties of the ultramafic-mafic rocks and the isolated dykes intruding into these rocks in Göynük, Çamyuva, Tekirova and Tekirova-Çıralı-Adrasan coastal area. This thesis will be the first detailed study on isolated dikes in Tekirova ophiolites. The rocks in the northern part of the study area (Kemer, Göynük and Çamyuva) are composed of mafic compounds and more alteration than southern part (Tekirova-Çıralı coastline). The rocks in the southern part of the study area is ultramafic compound. The isolated dikes intruded the ultramafic rocks more abundant. According to the field work and petrographic analyzes of the ultramafic-mafic rocks and isolated dykes, it was observed that the main rocks were dunite, clinopyroxenite and serpentinites, whereas the isolated dykes were olivine diabases and diabase. According to the results of XRD and SEM analysis, it was determined that the types of primary and secondary minerals in all these rocks. According to olivines from primary minerals generally forsterite, clinopyroxenes are augite and diopside, plagioclases are labrador, and magnetite, chromite, spinel, rutile, titanite and zircon minerals in lesser amounts. Secondary minerals were generally lizardite, clinochlor, clinozoisite, calcite and smectite. According to geochemical analysis, ultramafic-mafic host rocks peridotitic and isolated dikes gabbroic composition, also they are subalkaline characters. According to AFM diagrams, both host rocks and dikes generally show tholeiitic characteristics. In N-MORB normalized multi-element diagrams, host rocks and isolated dykes generally show enrichment in LIL elements and depletion in HFS elements. In the chondrite normalization diagram, it was observed that depleted in LRE elements compared to HRE elements in both types of rocks. According to the petrogenetic studies, it can be said that both the host rocks and the isolated dykes are formed enrichment of magma in subduction zone and that they are derived from a tholeiitic magma.