Author: Hüseyin KURT, Kerim KOÇAK, Kürşat ASAN, Yusuf Kağan KADIOĞLU, Mustafa KARAKAŞ
Publishing Date: 2005
Volume 20 Issue 4
This study aimed to find out the mineralogical, geochemical and petrological characteristics of orthoamphibolites of the basement, and intruding metagabbros exposed in northeast to Niğde. Orthoamphibolites are made up of actinolites, magnesiohornblendes and tschermakite while intruding metagabbros are composed mostly of basic plagioclase (An73-91), diopside (Wo45 En42 Fs12) and enstatite (Wo1 En70 Fs29) minerals. Geochemical diagrams show that tholeiitic amphibolites typically represent back-arc basalts while the metagabbros do tholeiitic island-arc basalts. Geological and geochemical data indicate that olivine and/or pyroxene fractional crystallisation played an important role in petrological evolution of the samples, in contrast plagioclase remained in the melt.
Key Words: Amphibolite; metagabbro; island-arc basalt; back-arc basalt; Niğde massive.