The aim of this study is to extract information about mineral distribution and percentages of Oymaaga&ccedil / granitoid (Beypazari-Ankara) by using remote sensing techniques. Two methods are applied during the studies which are spectral analysis and Crosta techniques. Spectral measurements are done for fresh and weathered samples collected at 32 locations. Mineral percentages are calculated using spectral mixture analysis for each sample by considering main, accessory and secondary mineral content of granodiorite. A total of 10 endmembers for fresh samples and 15 for weathered samples are used. USGS spectral library data is utilized through the analyses. For Crosta technique (image analysis) the multispectral ASTER satellite image is used. Five alteration minerals are discriminated and their maps are generated during this analysis. Interpretation and comparison of the results of both methods and testing these results with the existing petrographical and geochemical data indicate that: 1) according to the results of both spectral analyses and Crosta technique a zonation is not observed in the granitoid, 2) comparison of the results for alteration minerals of these two analyses are partly compatible but not exactly similar, 3) Results of spectral analysis do not fit geochemical nor modal analyses because of inconsistency of the data sets.

The purpose of this study is to investigate the origin, source characteristics, evolution petrogenesis and emplacement mechanisms of Beypazari-Oymaaga&ccedil / granitoids. These granitoids are intruded into a metamorphic basement and nonconformably overlain by Neogene clastic rocks. Field work, petrographical and geochemical studies are carried out to determine the petrologic features and tectonic setting of the granitoid body. The Beypazari-Oymaaga&ccedil / pluton is a composite pluton with its host batholith, enclaves, aplite dykes and a pegmatite. The batholith is generally composed of quartz, K-feldspar, plagioclase and hornblende. Field observations and petrographic investigations indicate that the host batholith has granodiorite composition and shows distinct differences in the abundances of quartz, amphibole minerals (e.g., hornblende) and of enclaves. The samples taken from TavuktaSi Tepe contain relatively less amphibole and enclaves but more quartz. Compared with them, samples from the rest of the batholith have relatively abundant amphibole, K-feldspar megacrysts, and enclaves but less quartz. Enclaves derived from magma mixing/mingling processes are dioritic in composition. Geochemical data obtained from whole rock analyses show that the pluton is shallowly emplaced and has calc-alkaline, metaluminous to peraluminous chemistry. It is characterized by enrichments in LIL and LREE, especially in K, Rb and Th. Although, there is a distinct petrographic variation in the batholith, the geochemical characteristics are uniform throughout the pluton. The Oymaaga&ccedil / Granitoids which have I-type identity are typical representatives of magmatic arc environment. The present study suggests that the possible source of magma is the upper crust and can be compared with the coeval volcanism in Galatean Volcanic Arc.