Structural elements of the region between Kaş-Kalkan and the characteristics of carbonate veins developed in this system (Antalya, Southwest Turkey)

Fluid-involved fault systems can indicate active faults in a region. Different geological evidences are needed in order to obtain healthy data in areas where active fault systems are not available or where seismic activity is rarely observed. Tectonically orginated carbonate veins and calcite deposits are the best examples for this case. Mainly secondary joints and faults, which have developed on seismically less active Upper Cretaceous Beydağları autochthonous in Antalya region and its surroundings, were investigated. The main purpose of the study is to investigate the joints and dating the carbonate veins, which have developed in the joints, also to reveal their relations with the current deformations and to examine their interactions with the fluids. In this context, the features of developed joints on the road-cuts between Kaş and Kalkan (Antalya) are studied and mapped. The observations are investigated by the relation of fault systems. The connection with the tectonic regime in the region is interpreted. It has been observed that the carbonate veins that developed paralel to the joints' walls cause the considerably important extensions. As a result of the data from the principal stress axes analysis, it is seen that extensional tectonic regime with E-W direction developed in the region under the influence of NNW-SSE compression. This tectonic regime was compared with the literature and found to be harmonious. In mineralogical studies, are examined the calcitization of the limestones and carbonate veins of Beydağları formation. The fossils in the samples from the unit proves that the unit is in the Upper Cretaceous. U-Th dating studies on carbonate veins reveal that the veins are older than 500 ka. The results of dating indicate that carbonate veins occured approximately at the Middle Pleistocene and/or later times, and that the region is tectonically active in this time span and indicate the presence of fluids in the joint and faults. Carbon-13 (δ13C) and Oxygen-18 (δ18O) stable isotope values are obtained in the range of -7.84 to -11.37 and -4.52 to -7,16 (‰ VPDB) respectively. The negative values indicate that the origin of carbonate veins in the region may have been due to surface sourced fluids.