THE QUATERNARY TRAVERTINES IN THE ÖRTÜLÜ AREA, SW TURKEY: FACIES AND DEPOSITIONAL ENVIRONMENT

Several travertine and tufa occurrences are well-exposed in the Denizli and surrounding areas which are the famous natural heritage known as “Pamukkale-Cotton Castle” in SW Turkey. The studied area is 70km eastern of the... [ view full abstract ]

Several travertine and tufa occurrences are well-exposed in the Denizli and surrounding areas which are the famous natural heritage known as “Pamukkale-Cotton Castle” in SW Turkey. The studied area is 70km eastern of the Denizli and is built from Quaternary non-marine carbonates (travertine and tufa) of the northern part of the Acıgöl Graben which is NE-SW trending. The investigated travertine deposits have occurred at the top of the Oligocene molasse type clastics composed of conglomerates and sandstones. Moreover, travertines have shown an alteration to tufa occurrences towards to the Acıgöl Graben. The travertine precipitation crops out approximately 2 km2 extend and about 40 m thick. This study has established on Örtülü travertines and their lithofacies descriptions and environmental analysis. For this aim, geochemical analysis and radiocarbon dating have been performed on these non-marine carbonates beside of detail sedimentological observations. According to facies analysis, five major lithofacies were distinguished in studied travertine field. These are mainly composed of banded travertines, reeds, intraclasts, conglomerate-marl facies, and palaesol levels in pond or shallow lacustrine environment. The Örtülü travertine precipitation has ceased 308ka according to U/Th dating. Furthermore, the determination of stable isotope compositions was performed and the δ13C values vary between 0.78‰ to 1.50‰ V-PDB while δ18O values in the range from −10.1‰ to −9.8‰ V-PDB. The stable carbon isotope signature indicates that groundwater was fed by geothermally generated CO2. The Örtülü travertines within the Acıgöl graben system are considered to be formed by extentional tectonic regime in the Aegean region. This study consists of the preliminary results of the ongoing project. The further investigations will be carried on systematically dating, palynological data and more isotopic results. These would give more information about palaeoclimatic and palaeoenvironmental conditions of the Acıgöl graben basin and surrounding areas in SW Turkey.
Acknowledgements

This study was financially supported by the Scientific and Technological Research Council of Turkey (TUBITAK 3001, 115Y493).

Keywords: Örtülü travertine, lithofacies, U/Th dating, stable isotopes, extentional tectonic, SW Turkey