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Post-Collisional A-Type Magmatism in the Central Anatolian Crystalline Complex: Petrology of the İğdiş Dağı Intrusives (Avanos, Turkey)

1997; Volume: 6; Issue: 2 Linguagem: Inglês

10.55730/1300-0985.1717

1303-619X

M. Cemal Göncüoğlu, Serhat Köksal, P.A. Floyd,

Astro and Planetary Science

The İğdiş Dağı Igneous Complex (IIC) is one of the late-stage plutonic bodies within the Central Anatolian Crystalline Complex (CACC) which intrudes the Paleozoic-Mesozoic metamorphic basement and late Crateceous granitoids. Uppermost Crateceous (?)-Lower Paleocene olistostromal volcaniclastik rocks represent the oldest cover on the IIC. Petrographic and gechemical data indicate that the IIc mainly comprises quartz synite with well-defined alkaline and peralkaline over saturated trends. The analysed samples show humped patterns on chondrite- and ORG-normalized spidergrams with peaks at Rb, Th and Ce, and also negative Nb anomalies. These features are similar to patterns considered typical of post collisional A_2-type granitoids produced by crustal anatexis. A post-collision setting is also suggested by the distribution of data over different fields in chemically-basedtectonic discrimination diagrams employing Nb, Y and Rb. These characteristics are consistent with gechemical data from other CACC granitoids and the regional geology. The late-orogenic plutonic rocks of the CACC (granites and syenites) represent the melt products of continental crust during post-collisional uplift. This event followed crustalthickening that was related to the southward emplacement of ophiolitic nappes during the closure of the İzmir-Ankara-Erzincan Ocean.