Sedimentology, three‐dimensional geobody reconstruction and carbon dioxide origin of Pleistocene travertine deposits in the Ballık area (south‐west Turkey)

Abstract

The Denizli Basin in the West Anatolian Extensional Province in western Turkey is well‐known for its numerous travertine occurrences. A combined sedimentological, diagenetic and geochemical investigation is executed on the Ece and Faber travertines of the Ballık area, the largest travertine site in the Denizli Basin. The first aim of this study is the reconstruction of a three‐dimensional geo‐model in combination with a detailed sedimentological description from fabric to lithotype, lithofacies and geobody scale, with a focus on integrating pore‐typing. The second aim involves the delineation of the CO2‐origin of ancient travertine precipitating waters. Peloidal, phyto and dendritic lithotypes dominate the studied travertines and honeycomb and bacteriform shapes and encrusted bacterial or fungal filaments related to their fabrics suggest a microbial influence. The environment of travertine precipitation evolved from dominantly sub‐aqueous, as represented by the sub‐horizontal and biostromal reed travertine facies, to dominantly sub‐aerial in a thin water film, resulting in the cascade, waterfall and biohermal reed travertine facies. A general progradation of the travertine mound is indicated by the occurrence of stacked waterfall travertines. This results in sigmoidal clinoforms inside a general mound boundary configuration. Strontium and oxygen‐carbon isotope signatures of the travertines point to a mixing mechanism of palaeofluids with deeply originated, heavy carbon CO2 with lighter carbon CO2 of shallow origin. These deposits can thus be considered as endogenic travertines. Carbonates of the Lycian Nappes acted as main parent carbon source rocks. The relative contribution of the lighter carbon isotopes is most likely to have originated from organic matter or soil CO2. This study provides a unique three‐dimensional insight into the Ballık travertine architecture that potentially can be used as an analogue for subsurface travertine reservoirs worldwide and illustrates the importance of the combined use of δ13C and 87Sr/86Sr signatures in the delineation of the CO2‐origin of travertine precipitating waters.

Comparative study of the Pleistocene Cakmak quarry (Denizli Basin, Turkey) and modern Mammoth Hot Springs deposits (Yellowstone National Park, USA)

“…The modern active spring water erupting from vents at Pamukkale are of CaeMgeSO 4 eHCO 3 -type, emerge at temperatures of 35e57 C with pH between 6.0 and 7.4, and evolve along the downstream outflow drainage system to a pH of 7.8 with temperatures of 20 C (Pentecost et al, 1997;Kele et al, 2011;. Travertine d 13 C values in the Denizli area suggest a mixture of CO 2 sources with important contributions of thermometamorphic (Paleozoic metamorphosed carbonates) and magmatic CO 2 , in addition to CO 2 derived from the degradation of organic matter (Kele et al, 2011;Claes et al, 2015). d 13 C compositions of recent travertine deposited at Pamukkale are enriched (Uysal et al, 2007;Kele et al, 2011;, whereas the associated oxygen isotopes are often , 2015).…”

“…9). Travertine breccia fragments (lithoclast travertine, Claes et al (2015); Guo and Riding (1998)) occur along and above this surface. It correlates with the deposition and intercalation of argillaceous deposits with occasional coquina beds ( Fig.…”

“…5B, C), one of the few previously unstudied and best-exposed active quarries in the "domal" area of Ballık and representative of the different facies underlying and building up the domal structures. Several other quarries, both on the northern and southern flank of the Denizli Basin, have been studied from a sedimentological, diagenetic, geochemical or dating perspective ( € Ozkul et al, 2010Kele et al, 2011;De Filippis et al, 2012;Claes et al, 2015;Lopez et al, in press). Two adjacent quarries in the "domal" area, Faber and Ece were investigated, sampled and mapped by Claes et al (2015) with the goal to develop a threedimensional geobody model (Fig.…”

“…the Subhorizontal, Reed, Cascade and Waterfall Facies, are a basis for travertine reservoir rock types. Currently, different approaches and terminology exist to describe the travertine depositional fabrics and facies in the Denizli Basin ( € Ozkul et al, 2010Kele et al, 2011;De Filippis et al, 2012;Claes et al, 2015;Lopez et al, in press). This study builds on this extensive and detailed description of fabrics, especially those carried out in the nearby quarries.…”

“…Different travertine depositional facies models of modern spring systems have been proposed to describe the complex textural and geometric variations of ancient spring deposits (Guo and Riding, 1998;Fouke et al, 2000;Capezzuoli et al, 2014;Claes et al, 2015;Della Porta, 2015) and to accurately reconstruct the environmental conditions under which ancient deposits originally formed and evolved (Chafetz and Folk, 1984;Veysey et al, 2008;Fouke, 2011;Gandin and Capezzuoli, 2014;Sotohian and Ranjbaran, 2015). A facies, as summarized by James and Dalrymple (2010), is a 'body of (sedimentary) rock characterized by a particular combination of lithology and physical and biological structures that bestow an aspect that is different from the bodies of rock adjacent.…”