Geobody architecture of continental carbonates: “Gazda” travertine quarry (Süttő, Gerecse Hills, Hungary)

The Gazda quarry is one of the largest outcrops of the present-day Süttő travertine complex that is situated close to the town of Süttő (Hungary), in the Pannonian Basin. Sedimentological and petrographical analyses show that the Gazda travertine body is built out of phytohermal, wavy laminated, massive and flat laminated travertine lithofacies representing reed mound, slope, lacustrine and palustrine depositional environments, respectively. Based on petrographic analyses, the following three main textural features were recognized that allow to describe the most common microscopic features: (1) micrite textures; (2) micritic coatings and crusts; and (3) different types of clasts. Each major lithofacies is characterized by a particular association of these textural types. The geometry of the travertine beds follows the antecedent land-surface, a NE-SW striking pre-Pleistocene valley. It is proposed that in this valley travertine precipitation took place along a gently sloping terrain. The Gazda travertine system was fed by at least two groundwater-springs. One of them was located NE of the quarry from which waters were flowing along the axis of the valley. The other source was located to the East of the Gazda quarry and waters joined the main water-course along the valley. Closest to the confluence, a phytohermal mound developed with lateral slope and eventual pond depositional systems. Onlapping and interfingering with the flat laminated lithofacies indicate alternating activity of the two springs. Fractures observed in the quarry are mainly related to postdepositional gravitational sliding, however, neotectonic forces resulting in SE–NW tension also played a role in the formation of the fractures. Stable oxygen and carbon isotope analyses show that water temperature was approximately 25°C. Petrographic studies indicate that only syn-diagenetic processes affected the precipitates. Therefore the original stable oxygen isotope signatures, characteristic of the depositional environment, were preserved. Detailed sedimentological and geochemical study of the Gazda travertine complex allowed small-scale facies characterization providing information about the ancient depositional environment and the heterogeneous nature of these carbonates