| Popis: |
The Ozvatan carbonatite complex is located on the Eastern Part of the Central Anatolia, Turkey and host considerable Light Rare Earth Elements (LREE) mineralizations. The carbonatites in Ozvatan complex are mostly coarse grained calcio-carbonatites (sövites) with fluorites and minor opaque minerals. The carbonatites were intruded into silica undersaturated nepheline syenites and caused an intense fenitization process. The calcio-carbonatites of the study are were predominantly enriched in terms of La (up to 995 ppm), Ce (up to 1386 ppm) and Nd (up to 211 ppm). Also some of the LILE’s are enriched including Sr (up to 2%) and Ba (up to 0.75) as expected. The stable δ13CV-PDB and δ18OV-SMOW values of the Ozvatan carbonatites represent fractional crystallization and hydrothermal alteration trends. The δ13C values (-6.0 – 4.1 ‰) are generally in tune with worldwide carbonatite range. However, it cannot be concluded as a primary ignous carbonatitic melt due to relatively high δ13CV-PDB values. The δ18O values (13.3 – 49.3 ‰) are also high mostly cauesed by the high intensity hydrothermal activities (fenitization) or the contamination of meta-carbonate basement rocks. Overall, it can be stated that the, carbonatites of the Ozvatan are products of fractionation of a carbonated silicate melt, low temprature metasomatism and crustal contamination. Keywords: Alkaline Magmatism, Carbonatite, Stable isotopes |
