Sedimentology and geochemistry of the Kavakköy Travertine (Konya, central Turkey)

Abstract

In the Kavakkoy region located at Southwest of Konya (central Turkey), four Quaternary travertine mounds and two recent travertine deposition sites are roughly aligned along the Seydisehir Fault Zone. Water temperature of recent travertine sites is about 39 and 19 °C. Six different facies were determined from the Kavakkoy Travertine: crystalline crust travertine, paper-thin raft travertine, coated bubble travertine, pisoid, lithoclast travertine and shrub travertine facies. Sedimentological, morphologic and geochemical characteristics of these facies point toward depositions in slope and depressional depositional systems. Rare element content and isotopic values of different facies are distributed on diagrams as two separate clusters. After comparing with two recent travertines, it is hypothesized that they are most probably related to the temperatures of travertine formation water. High δ13C contents and calculated δ13C values, using Panichi and Tongiorgi’s (in: Proceedings of the 2nd UN symposium on the development and use of geothermal resources, San Francisco, CA, 20–29 May 1975, pp. 815–825, 1976) equation, imply that parent water was charged with CO2 from a deep origin. Significant differences in the δ13C and δ18O isotopic values of recent travertines at two different sites have been interpreted as being related to water circulation path and source of CO2. The travertine precipitated by water with a temperature of 19 °C has comparatively short and shallow fluid flow paths and low (normal) heat flow and has CO2 isotopic signatures, indicating a comparatively large quantity of CO2 contribution from decarbonation of limestone. In contrast, the travertine formed by relatively hot water (39 °C) had been conductively heated during percolating through thick Paleozoic–Cenozoic sequence and has incorporated a comparatively large quantity of CO2 derived from mantle sources.