Pozantı-Karsantı ofiyoliti (Aladağ, Adana) Hızar bölgesi kromit mineralizasyonu ve tekil daykların kökeni

The Pozantı-Karsantı (Aladağ) ophiolite (PKO) in the Eastern Tauride was emplaced onto the Tauride platform during the Late Cretaceous and is represented by ophiolite-related mélange, metamorphic sole, and a complete oceanic lithosphere remnant, in ascending order. Mantle peridotites, ultramafic to mafic cumulates, isotropic gabbro, sheeted dikes, plagiogranite, and volcanics make up the oceanic lithosphere. The PKO contains two types of chromitite occurrences. These are (a) banded chromitites found in cumulate dunites near the Moho and (b) podiform chromitites found in harzburgites beneath the Moho. Hızar area, located northwest of Aladağ, is distinguished by banded chromitites, dunites, and numerous isolated dikes cutting the aforementioned rocks. The alternation of chromitites and dunites is a prominent feature in the Hızar area. This suggests that they formed near the Moho transition zone as a result of peridotite-melt interaction around the mantle-crust boundary. Diabase characterizes the isolated dikes, which range in thickness from 50 cm to 8 m. The mafic dikes are basaltic in composition and have chondrite-normalized REE patterns that are depleted in LREE. The N-MORB normalized multi element diagram and tectonic discrimination diagrams based on immobile elements both indicate that isolated dikes formed in a subduction-related setting. A plagiogranite dike cuts the gabbro unit of the PKO (Aladağ), is tonalite in composition, and its genesis is similar to that of oceanic gabbro. Geochemistry of the plagiogranite indicates that it formed in a subduction-related tectonic setting. LA-ICP-MS Zircon U-Pb dating of the plagiogranite yielded a crystallization age of 89.34±0.32 Ma (Late Cretaceous). All evidence suggests that the PKO formed in forearc setting of suprasubduction zone during the Late Cretaceous.