Metin Bağcı

Geochemical Constraints on the Genesis of the Günyüzü Pluton, Northwest Anatolia, Turkey

The Tavsanli Zone in northwest Turkey is intruded by many Late Cretaceous to Eocene (91-45 Ma) calc-alkaline granitoids, of which the Günyüzü pluton in the Eskisehir region is the least studied. The Günyüzü rocks are high-K, calc-alkaline (I-type) intrusions, and are comprised of diorite, granodiorite, granite, and granite porphyry. Typical minerals are plagioclase, K-feldspar, quartz, biotite, hornblende and Fe-Ti oxides. Chondrite-normalized REE patterns for the Günyüzü rocks are moderately fractionated and have small negative Eu anomalies. They are enriched in LILE and LREE relative to HFSE, showing characteristics of arc-related granitoids. Low values of molar K2O/Na2O, Al2O3/(FeO+MgO+TiO2), and (Na2O+K2O)/(FeO+MgO+TiO2) ratios demonstrate that the Günyüzü magma(s) were produced from mafic lower crustal rocks.

Comparison of radon concentrations in soil gas and indoor environment of Afyonkarahisar Province

It is well known that radon is the main source of natural radiation exposure to the population. Indoor radon concentrations in an area are affected by ascending radon migration following the convection of groundwater and soil gas along fractures and faults in the bedrock sediments. There are various studies showing that positive radon anomalies in the soil gas are found to coincide with the locations of houses showing the highest concentrations. Moreover, soil gas radon levels and soil permeability are important factors in determining the radon potential of an area, because high permeability enables the increased migration of radon from the soil into houses. Since radon in homes originates mainly from soil gas radon, it is of public interest to study the correlation between soil gas radon and indoor radon in different geographic locations. In the present work, a correlation study was carried in conjunction with radon concentrations in soil gas and indoor environment of Afyonkarahisar Province. The provincial center was assumed to be divided into four regions according to the rock types and tectonic structure to show also the geological structure effect on radon concentrations. The indoor radon concentrations were measured in 74 dwellings using CR-39 passive nuclear track detectors, and the radon concentrations in soil gas were determined in 243 drilled holes using AlphaGUARD detector. The correlation coefficient of 0.97 was obtained between radon concentrations in soil gas and indoor environment of Afyonkarahisar Province.