Petrological properties of mafic and ultramamic rocks observed around kiratli (İpekyolu-Van)

This thesis study was performed to investigate petrographic-geochemical investigation of mafic and ultramafic rocks in the vicinity of Kıratlı Village, east of Lake Van. In the study area, Bakışık Melange consist of harzburgite, dunite, serpentinite and pyroxenite, gabbro and diabase dikes which cut them. Toprakkale formation, which consists of limestone, overlay the Bakışık Melange. These units are discordant to each other. Petrographic studies in harzburgite and dunite in the observed melange are highly affected by alteration. Generally, serpentinization and bastitization are very intense in the thin section. Porphyroblastic texture of the rocks are common. Sieve texture is observed in the serpentinized sections after the alteration. Within the mafic rocks gabbro and diabase dikes are composed of plagioclase+pyroxene±olivine minerals. Ophitic texture is dominant in this rocks. The presence of sericite and chlorite minerals in mafic rocks is an indication of the alteration of these rocks. Geochemical studies on ultramaphic rocks, according to this unit is abyssal peridotites and is determined that they are quite depleted primitive mantle. In mafic rocks, these rocks have been observed to have both alkaline and subalkali features. It has been determined that the Kalkalkali rocks are tholeiitic. Generally, the dykes, which are thought to have two different magmatic derivations, appear to have the characteristics of volcanic arc regions and plateau basalts.