DBPapers
DOI: 10.5593/sgem2012/s02.v2040

THE INVESTIGATION OF ALTERATION IN GUNYUZU (ESKISEHIR -TURKEY) GRANITE USING MINERALOGICAL-PETROGRAPHICAL AND PHYSIQUE-MECHANICAL METHODS

A. YILDIZ, M. BAGCI, I. DUMLUPUNAR, M. DEMIRBILEK, Y. KIBICI, S. GURCAN, N. ILBEYLI
Wednesday 1 August 2012 by Libadmin2012

References: 12th International Multidisciplinary Scientific GeoConference, www.sgem.org, SGEM2012 Conference Proceedings/ ISSN 1314-2704, June 17-23, 2012, Vol. 2, 303 - 312 pp

ABSTRACT

In this study, the mineralogical, physical and mechanical changes in Gunyuzu
(Eskisehir-Turkey) granites depending on alteration were investigated. Studied samples
with different alteration degree were taken from granite pits and road cuts. The granite
samples were grouped based on their visual inspection in the field and schimidt hammer
results. Polarizan light microscope, x-ray diffraction (XRD), chemical analyses and
physiqo-mechanical tests were done to determine mineralogical-petrographical,
geochemical, physical, and mechanical properties of granites.
Günyüzü granites with Upper Cretaceous-Lower Paleocene were exposed over an area
of 50 km2 and trended approximately NW-SE. Granites consist mainly of plagioclase
(oligoclase-albite), K-feldspar (orthoclase, microcline), quartz, biotite, hornblende, and
minor zircon, titanite, apatite, allanite, and opaque minerals. Chlorite, epidote, sericite,
and calcite occur as secondary minerals. Feldspar alteration index (FAI), ultrasonic
index (K) and strength ratio (Rs) were measured for designation of alteration effect on
Günyüzü granites. The alteration state of feldspars (alkali feldspar and plagioclase) was
determined by polarizing light microscope with image analyses system and then,
feldspar alteration index is counted. UI was counted based on method by proposed by
[1] and Rs, by [2]. A good correlation is obtained among FAI, UI and Rs. It was
concluded that FAI, UI and Rs indices can be used to determine of changes in Gunyuzu
granites due to alteration.

Keywords: Granite, mineralogy-petrography, physico-mechanical tests, alteration,
Günyüzü, Eskisehir.