Abstract: Ophiolitic meta-gabbros are exposed on the Kazdağ Massif located in the southern part of the BigaPeninsula. Trace element composition of rutile and quartz was determined for metagabbros from theKazdağ Massif by LA-ICP-MS. The Zr content of both matrix rutiles and rutile inclusions in garnet rangefrom 176 to 428 ppm (average 335 ppm). Rutile grains usually have a homogeneous Zr distribution. Therutile grains from studied samples in the Kazdağ Massif are dominated by subchondritic Nb/Ta (11-23)and Zr/Hf ratios (20-33). Nb/Ta and Zr/Hf show positive correlation, which is probably produced bysilicate fractionation. The Nb/Ta and Zr/Hf ratios increase with a decrease in Ta and Hf contents. Thecore of rutile grains are generally characterized by low Nb/Ta ratios of 17-18 whereas the rims exhibitrelatively high Nb/Ta ratios of 19-23. Trace element analyses in rutile suggest that these rutile grains weregrown from metamorphic fluids.Ti-in-quartz can be used as a thermobarometer when used in combination with Zr-in-rutile thermometer.P-T conditions of ophiolitic meta-gabbros were calculated by Ti content of quartz and Zr content ofrutile, which are in equilibrium with each other. Ti contents of quartz are ranging between 28 and 42ppm (average 36 ppm). A P–T estimate can be obtained from the intersection of the Ti-in-quartz isoplethswith the Zr-in-rutile isopleths, which yield ~ 660 oC and 10 kbar. The P-T conditions of meta-ophioliticrocks suggest that they occur as a different separate higher-pressure tectonic slice in the Kazdağ Massif.Amphibolite-facies metamorphism resulted from northward subduction of the İzmir-Ankara branch of theNeo-Tethyan Ocean under the Sakarya Zone. Metamorphism was followed by internal imbrication of theKazdağ Massif resulting from southerly directed compression during the collision.