Tez özetleri Astronomi ve Uzay Bilimleri Anabilim Dalı

Comparatıve Investıgatıon Of Western Anatolıa Chromıte Deposıt In Aspect Of Geotectonıc Envıronment
The Western Anatolia Chromite deposits are geographically located in the north-west and south-west of Anatolia. Chromite deposits in the north-western side of Anatolia are situated in the ophiolitic slices of İzmir-Ankara Zone. Chromite deposits in the south-western of Anatolia are situated in the ophiolitic slices of Lycian Nappes. In terms of chemical content of rocks from both regions show the properties of the subduction zone ophiolites.
In this study, the chromite deposits in the west and east of Orhaneli village (Bursa) and Kavak region (Mihalıççık-Eskişehir) are considered and represent the Northwestern Chromite Deposits. This chromite deposits are located in the cumulatic-dunite. The Gökarık chromite deposits (in Tefenni-Burdur) in the southwestern Anatolia are located in the cumulate-dunite overlying the tectonite-harzburgite, whereas the Beyağac (Denizli) chromite deposits in the dunite tectonite. Chromitites in cumulate-dunite are mainly disseminated, banded and massive. Nodular structure is observed less. Chromitites in tectonite-dunite is disseminated, nodular, massive, and rarely banded.
The micro-chemical analysis of spinel contained in the chromite deposits in the İzmir - Ankara Zone are as follows; Cr₂O₃: 54.21-63.39%, Al₂O₃: 8.11 to 14.41%, FeO: 13.26-23.74%, MgO: 10.30-14.79% and TiO₂: 0.1-0.33%; the values of micro-chemical analysis of spinel contained in the chromite deposits in the NW Anatolia range as follows: Cr # = 72-84, Mg # = 50-71, Fe ²⁺ # = 29-50, and Fe³⁺ # = 1.81 - 6.90. The oxide values in terms of the microchemical analysis of spinel found in the Lycian Nappes are: Cr₂O₃: 51.63-64.50%, Al₂O₃: 4.01-18.89%, FeO: 13.82-25.62%, MgO:% 7:18 - 14.53 and TiO₂: 0:02 to 0:19%. Cr # = 65 - 91, Mg # = 37-67, 33-63, Fe^{2 +} # =33-63 and Fe³⁺ = 1.68-5.41.
The Northwest and Southwest Anatolia Chromite Deposits have low PGE contents. The PGE has typical feature of ophiolitic chromitites with high content of IPGE and, low contents of PPGE. The content of IPGE is 46 -339 ppb in the chromitites from Northwest Anatolia, whereas the content of PPGE range between 12 – 46 ppb. The chromitites from Southwest Anatolia display 62-346 ppb IPGE and 9-21 ppb PPGE contents.
Western Anatolia Chromite Deposits having boninitic character orginated as the products of a single ocean (Neotethys) based on their similar wall rock chemistry, chromitite chemistry and whole rock PGE contents, chrome-spinel mineral chemistry and took its present position to the south of Menderes Massif as a result of the movement of the Lycian nappes from northwest to southeast.