21 Magmatism in evolving orogens: Collision to extension. Posters Part 2

Tuesday, 5 October 2010
8:30 AM - 6:30 PM
Exhibition Hall

INVESTIGATION OF BUZLUKDAGI (KIRSEHIR-TURKEY) SYENITOIDS BY CONFOCAL RAMAN SPECTROSCOPY

Paper number: 21-16
Program: Scientific Sessions
Time: 8:30 AM – 6:30 PM

Authors

Abstract

Alkaline intrusive rocks are products of Late Mesozoic magmatism of Central Anatolia Crystalline complex. Buzlukdagi intrusive rocks are exposed as a small alkaline pluton in the Central Anatolia around Alisar and Tatarilyas villages of the region. The body is typically observed at Buzluk hill as circular in shape and covers an area of approximately 15.75 km2. Buzlukdagi syenitoid is intruded to the metamorphic rocks of Central Anatolia Crystalline Complex in the composition of foid bearing syenitoid. Migmatite and marble are observe at the outer zone as a product of contact metamorphism. The pluton can be distinguished with its high rough keen tophography in the area. The intrusive body is differentiated into three subunits as a coarse, medium and fine crystalline foid bearing syenite on the basis of textural features and grain sizes. Fine crystalline foid syenites have xenolitic enclaves with contacts and metamorphic texture in hand specimen. All the subunits of the syenite have similar mineral compositions with different mineral proportions and colors. Fine, medium and coarse crystalline foid syenites are pinkish, pinkish gray and gray in color respectively. They are mainly composed of nepheline, K-feldspar, oligoclase, pyroxene, biotite, phlogopite, amphibole with rare amount of garnet, cancrinite, titanite and opaque minerals. Confocal Raman Spectroscopical studies reveal that the garnets of these units are in the composition of uvarovite and andradite.

Whole rock geochemical data reveal that the syenites are peralkaline to metaluminous in character. The Buzlukdagi syenitoids both show enrichment in large-ion lithophile and light rare earth elements (LILE and LREE) with respect to high field strength and heavy rare earth elements (HFSE and HREE).

The geology, petrography and geochemical data suggest that the Buzlukdagi alkaline intrusive rocks are products of silica undersaturated and may derived from crustal thinning of Central Anatolia during the late period of Mesozoic and early Cenozoic.