Quaternary fluvial tufas of Sarıkavak area, southwestern Turkey: Facies and depositional systems

In the Quaternary Sarıkavak fluvial tufa deposits, situated in south-western Turkey, different facies have been identified and their mutual relationships have been unravelled. This tufa formation is located at the northern part of Acıgöl Graben. The development of the Sarıkavak tufas represents typical fluvial and fluvio-palustrine environments. In total eight tufa lithofacies have been differentiated, namely: moss tufa facies, oncolitic tufa facies, stromatolitic tufa facies, phytoclastic tufa facies, intraclastic tufa facies, extra-formational clastic tufa facies, sapropelitic tufa facies, and palaeosol. Preliminary U/Th datings indicate that these deposits formed prior to 219 ka and continued until 80 ka (MIS 7 till 5). δ13C signatures (0.78‰ to −1.63‰ V-PDB) best can be explained by limestone dissolution processes or respiration from C4 plant vegetation into the soil or both. For that reason, the Sarıkavak tufa deposits can be classified as 'travitufa' which precipitated in a distal facies system of travertine occurrences. δ18O values (−7.49‰ to −10.83‰ V-PDB) of the whole data set reflect some significant changes, which is interpreted in terms of temperature variations reflecting warm and cold periods among MIS 7 (interglacial), MIS 6 (glacial) and MIS 5 (interglacial). The development of the Sarıkavak tufa deposits are related to the Maymundağı fault that borders the Acıgöl Graben in the north. This fault and its synthetic fault segments play a pivotal role with regard to the palaeo-flow direction of water and control the basin topography. These structural structures are likely responsible for all active and ancient springs in the study area, as well as their respective carbonate precipitates.