Late Magmatic – Hydrothermal Tourmaline Occurrences within Leucogranites in NW Anatolia (Turkey): Mineral Chemistry and Genetic Implications

Abstract Numerous Oligo-Miocene plutonic and associated aplite-pegmatite rocks occur in the Western Anatolian Magmatic Complex. However, only the plutons of Namazgah, Karadag, Sogucak and Karadoru, in the Biga Peninsula, host three different types of tourmaline: disseminated, nodular, and vein-type. These all fall into the alkali subgroup and schorl-oxy-schorl-dravite-oxy-dravite solid solution series. This study shows they were formed during late magmatic to hydrothermal stages in the roof sections (at shallow crustal levels) of the granitoid intrusions. Tourmaline compositions remained fairly homogeneous during the formation and evolution of each stage.