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Sandor Kele - One of the best experts on this subject based on the ideXlab platform.
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a multi methodological approach to reconstruct the configuration of a Travertine fissure ridge system the case of the cukor quarry suttő gerecse hills hungary
Geomorphology, 2019Co-Authors: Hannes Claes, Andrea Brogi, Agnes Torok, Domenico Liotta, Adam Toth, Andrea Mindszenty, Istvan Kudo, Sandor KeleAbstract:Abstract Travertines are continental carbonates that precipitate from spring waters, mainly due to CO2 degassing. They are widely quarried as building stone, which has led to numerous (often abandoned) Travertine quarry outcrops. These and other outcrops, however, merely represent the surface expressions of the complex architecture of Travertine bodies and their deep–rooted feeding systems. Integration of field observations and geochemical analyses with crucial subsurface geophysical data is required in order to fully understand Travertine systems and their relationship to the local geological framework. Such a multi-methodological approach is illustrated here for the case of the abandoned Cukor quarry. Radio-magnetotelluric (RMT) and Electrical Resistivity Tomography (ERT) surveys provide unique insights into local tectonics, geobody architecture and the topography preceding Travertine deposition. Altogether, the lens–shaped, isolated domal geobody with spring-proximal lithofacies and subvertical bedding, in addition to the contrasting geochemistry and age with surrounding Travertine, enabled the unequivocal reconstruction of the dismantled Cukor fissure ridge. This study illustrates the high potential of this multi–methodological approach on poorly exposed, strongly weathered, quarried and tectonically deformed Travertine bodies, and provides information on the complex feeding system beneath Travertine deposits. Their reconstruction can be interpreted in light of the neo–tectonic expression of regional uplift, helps to complete the regional tectonic history and provides insights into older landscapes that lack preservation or would no longer be immediately recognized at the surface.
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growth of a pleistocene giant carbonate vein and nearby thermogene Travertine deposits at semproniano southern tuscany italy estimate of co2 leakage
Tectonophysics, 2016Co-Authors: Gabriele Berardi, Michele Soligo, Andrea Billi, Sandor Kele, Mehmet Oruc Baykara, Gianluca Vignaroli, Federico Rossetti, Stefano M Bernasconi, Francesca CastorinaAbstract:Abstract A giant carbonate vein (≥ 50 m thick; fissure ridge Travertines) and nearby Travertine plateaus in the Semproniano area (Mt. Amiata geothermal field, southern Tuscany, Italy) are investigated through a multidisciplinary approach, including field and laboratory geochemical analyses (U/Th geochronology, C, Nd, O and Sr isotope systematics, REE abundances, and fluid inclusion microthermometry). The main aim of this work is to understand: (1) modes and rates for the growth of the giant vein and nearby Travertine deposits within a Quaternary volcano-tectonic domain; (2) implications in terms of the CO 2 leakage; and (3) possible relationships with Quaternary paleoclimate and hydrological oscillations. Results show that the giant vein was the inner portion of a large fissure ridge Travertine and grew asymmetrically and ataxially through repeated shallow fluid injections between > 650 and 85 ka, with growth rates in the 10 − 2 –10 − 3 mm/a order. The giant vein developed mainly during warm humid (interglacial) periods, partially overlapping with the growth of nearby Travertine plateaus. Estimated values of CO 2 leakage connected with the vein precipitation are between about 5 × 10 6 and 3 × 10 7 mol a − 1 km − 2 , approximately representing one millionth of the present global CO 2 leakage from volcanic areas. Temperature estimates obtained from O-isotopes and fluid inclusion microthermometry indicate epithermal conditions (90–50 °C) for the circulating fluid during the giant vein growth, with only slight evidence of cooling with time. Geochemical and isotope data document that the Travertine deposits formed mainly during Pleistocene warm humid periods, within a tectonically-controlled convective fluid circuit fed by meteoric infiltration and maintained by the regional geothermal anomaly hosted by the carbonate reservoir of the Mt. Amiata field.
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sedimentological and geochemical characteristics of a fluvial Travertine a case from the eastern mediterranean region
Sedimentology, 2014Co-Authors: Mehmet Ozkul, Sandor Kele, Ali Gokgoz, Mehmet Oruc Baykara, Chuanchou Shen, Yuwei Chang, Ali Kaya, Mete Hancer, Cihan Aratman, Taylan AkinAbstract:A sedimentological and geochemical study was performed on the Travertines in the southern part of the Usak geothermal field, western Turkey, to assess the applicability of a fluvial tufa facies model in interpreting late Quaternary Travertine deposits developed along the stream valleys that follow fault and fracture systems. Modern thermal (31 to 38°C) springs are found on the floor of the valley between 480 m and 520 m above sea-level. The distribution and nature of Travertine facies were determined from natural outcrops. Samples of the Travertines and spring water were characterized using a range of geochemical and petrographic methods. Waterfall, slope and pool facies associations consist of various combinations of Travertine facies and subordinate detrital facies. Waterfall and slope facies associations of the older deposits occur where the springs emerged onto a hillslope or topographic break. In contrast, the pool facies association developed in depressions or flat areas that were fed by thermal springs. The youngest generation (1� 85 ka) precipitated at lower elevations than the older ones (147 to 153 ka). Stable carbon and oxygen isotope values of the Aksaz Travertines range between +4� 3& and +6� 3& (Vienna Pee Dee Belemnite) and � 12� 6& and � 7� 2& (Vienna Pee Dee Belemnite), respectively. The high d 13 C values suggest that the thermal waters were charged with isotopically heavy CO2 of deep origin. Based on palaeotemperature calculations, the temperatures of the palaeosprings are slightly higher (up to 44°C) than the present equivalents, but sometimes the temperature is lower, probably due to mixing with the stream water. Although the thermal waters occasionally are impeded by fluvial activity, Travertine precipitation occurs in the protected parts of the Aksaz Stream valley. This contribution highlights the applicability of the fluvial facies model for tufa for the interpretation of Travertine deposits worldwide.
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comparison of the quaternary Travertine sites in the denizli extensional basin based on their depositional and geochemical data
Sedimentary Geology, 2013Co-Authors: Mehmet Ozkul, Sandor Kele, Tibor Nemeth, Ali Gokgoz, Mehmet Oruc Baykara, Chuanchou Shen, Yuwei Chang, Brian Jones, Istvan Fόrizs, Mehmet Cihat AlçiçekAbstract:Abstract In the Denizli Basin (Turkey), located in the western Anatolian extensional province, Travertine and tufa deposition has been an ongoing process for at least 600,000 years. Travertine bodies, which are 30 to 75 m thick and each covers areas of 1 to 34 km2, are up to 1 km3 in volume. Today, spring waters in this area have temperatures of 19 to 57 °C, are of the Ca–Mg–HCO3–SO4 type in the Pamukkale, Kelkaya and Pinarbasi areas and the Ca–Mg–SO4–HCO3 type at Cukurbag. Thermal waters along the northern margin of the basin are generally hotter than those in the east–southeast and south. The δ18O and δD values of the spring waters indicate a meteoric origin. The average temperatures of the hydrothermal systems in the Denizli Basin appear to have decreased from Pleistocene to Holocene. Travertine, which formed from the hotter water, is more widespread than the tufa that formed in the cooler spring waters. Deposition of the Travertine, which formed largely on slopes, in depressions, and along fissure ridges (mostly on northern basin margins), was controlled by the interplay between various intrinsic and extrinsic parameters. The Travertines are formed largely of calcite with only minor amounts of aragonite in some of the vertically banded, crystalline crust, raft and pisoid Travertines found in some of the northern sites. The aragonitic samples, rich in Sr, are typically found around the spring orifices and along the central axis of the fissure ridges. The stable isotope values of the Travertine found in the northwest and southeast parts of the basin are different. The δ13C values of the northern Travertine deposits are more positive (3.7 to 11.7‰ VPBD) than those found in the south–southeast areas (− 4 to 5.8‰ VPDB). In contrast, the Travertine and tufa in the southeastern areas have higher δ18O values (− 15.2 to − 7.8‰ VPDB) than those of the northern areas (− 16.6 to − 4.8‰ VPDB). Available evidence indicates that spring activity and associated Travertine precipitation in the Denizli Basin were controlled largely by tectonic activity rather than by climatic conditions.
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stable isotope geochemical study of pamukkale Travertines new evidences of low temperature non equilibrium calcite water fractionation
Sedimentary Geology, 2011Co-Authors: Sandor Kele, Mehmet Ozkul, Ali Gokgoz, Mehmet Oruc Baykara, Mehmet Cihat Alçiçek, Istvan Forizs, Tibor NemethAbstract:Abstract In this paper we present the first detailed geochemical study of the world-famous actively forming Pamukkale and Karahayit Travertines (Denizli Basin, SW-Turkey) and associated thermal waters. Sampling was performed along downstream sections through different depositional environments (vent, artificial channel and lake, terrace-pools and cascades of proximal slope, marshy environment of distal slope). δ 13 C Travertine values show significant increase (from + 6.1‰ to + 11.7‰ PDB) with increasing distance from the spring orifice, whereas the δ 18 O Travertine values show only slight increase downstream (from − 10.7‰ to − 9.1‰ PDB). Mainly the CO 2 outgassing caused the positive downstream shift (~ 6‰) in the δ 13 C Travertine values. The high δ 13 C values of Pamukkale Travertines located closest to the spring orifice (not affected by secondary processes) suggest the contribution of CO 2 liberated by thermometamorphic decarbonation besides magmatic sources. Based on the gradual downstream increase of the concentration of the conservative Na + , K + , Cl − , evaporation was estimated to be 2–5%, which coincides with the moderate effect of evaporation on the water isotope composition. Stable isotopic compositions of the Pamukkale thermal water springs show of meteoric origin, and indicate a Local Meteoric Water Line of Denizli Basin to be between the Global Meteoric Water Line (Craig, 1961) and Western Anatolian Meteoric Water Line (Şimsek, 2003). Detailed evaluation of several major and trace element contents measured in the water and in the precipitated Travertine along the Pamukkale MM section revealed which elements are precipitated in the carbonate or concentrated in the detrital minerals. Former studies on the Hungarian Egerszalok Travertine (Kele et al., 2008a, b, 2009) had shown that the isotopic equilibrium is rarely maintained under natural conditions during calcite precipitation in the temperature range between 41 and 67 °C. In this paper, besides the detailed geochemical analyses along downstream sections, we present new evidences of non-equilibrium calcite-water fractionation in lower temperature range (13.3 to 51.3 °C). Our measurements and calculations on natural hot water Travertine precipitations at Pamukkale and Egerszalok revealed that the δ 18 O Travertine is equal with the δ 18 O HCO3 at the orifice of the thermal springs, which means that practically there is no oxygen isotope fractionation between these two phases. High rate of CO 2 degassing with rapid precipitation of carbonate could be responsible for this as it was theoretically supposed by O'Neil et al. (1969). Thus, for the determination of the deposition temperature of a fossil Travertine deposit we propose to use the water-bicarbonate oxygen isotope equilibrium fractionation instead of the water-Travertine fractionation, which can result 8–9 °C difference in the calculated values. Our study is the first detailed empirical proof of O'Neil's hypothesis on a natural carbonate depositing system. The presented observations can be used to identify more precisely the deposition temperature of fossil Travertines during paleoclimate studies.
Enrico Capezzuoli - One of the best experts on this subject based on the ideXlab platform.
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hierarchical approach to define Travertine depositional systems 3d conceptual morphological model and possible applications
Marine and Petroleum Geology, 2019Co-Authors: Marcelle Marques Erthal, Enrico Capezzuoli, A Mancini, Rony SwennenAbstract:Abstract 3D modelling represents a powerful tool to characterize the geobody architecture of depositional systems. Several examples have been proposed in literature both for marine carbonates and siliciclastics rocks. For modelling, quantitative data related to orientation, shape and dimension are fundamental. Continental carbonates, however, are not considered yet, likely because they cover a large range of deposits such as speleothems, tufas, lacustrine carbonates and Travertines. The interpretation of the depositional environments of the latter is still in fact debated by the scientific community. However, the interest in continental carbonates and especially Travertines increased over the last decades due to the discovery of supergiant unconventional reservoirs in the Southern Atlantic (i.e. the so-called “Pre-salt play”). Aim of this paper is to present an innovative workflow to investigate and describe continental carbonates as geobodies based on a hierarchical approach applied to three large scale Travertine settings, i.e. Terme di San Giovanni (Italy), Pamukkale (Turkey) and the Lapis Tiburtinus Travertines (Italy). Travertine depo-systems are divided in three different depo-zones, namely proximal, intermediate and distal, that are characterized by different depo-elements, depo-shapes and depo-facies. Finally, a 3D morphological model is created based on numerical and vector approaches and interpolation of both. The model can be applied to seismic data of Brazilian and Angolan Pre-salt, highlighting the similarities between these systems and for the first time the scale independence of these depositional system, representing an important advantage in their interpretation. The 3D model and the approach proposed facilitates seismic interpretation, allowing to define and characterize geometries of inaccessible geological contexts.
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facies character and depositional architecture of hydrothermal Travertine slope aprons pleistocene acquasanta terme central italy
Marine and Petroleum Geology, 2017Co-Authors: Giovanna Della Porta, Enrico Capezzuoli, Alessandro De BernardoAbstract:Abstract Hydrothermal Travertines develop various depositional geometries, from tabular to high-relief mounds or aprons with steep slopes, under the control of local topography, location and geometry of the vents, fault activity, hydrology, water physico-chemical properties, rates of thermal water flow and carbonate precipitation rates. This study focuses on two Pleistocene, tens of metres thick, Travertine slope aprons accumulated on fluvial terraces in the Tronto River Valley (Acquasanta Terme, Central Italy) to investigate their facies character, geochemical signature, porosity and evolution of the depositional geometry through time. The two Travertine aprons consist of four aggradational-progradational units, vertically and laterally stacked with onlap and downlap stratal terminations, separated by erosional unconformities produced by events of non-deposition and erosion, due to temporary interruptions of vent activity, shifts of the vent location and/or deviation of the flow directions. The Travertine units include various depositional environments: 1) smooth slope, 2) terraced slope with metre-scale sub-horizontal pools separated by rounded rims and vertical walls, and 3) sub-horizontal, tens of metres wide ponds. Smooth slope clinoforms are made of centimetre to decimetre thick layers of crystalline dendrite cementstone, laminated boundstone and radial coated grain grainstone, precipitated by fast-flowing water on inclined substrates. Rims and walls of terraced slopes are built by crystalline dendrites and laminated boundstone. Sub-horizontal layers of terrace pools and ponds consist of facies precipitated by slow-flowing to standing water (clotted peloidal micrite dendrite, coated bubble boundstone, raft rudstone) associated with radial coated grains and laminated boundstone. Carbonate coated reeds occur in distal ponds adjacent to toe of slopes or overlie packstone/rudstone with Travertine intraclasts and substrate extraclasts, marking events of subaerial exposure and erosion. Travertine facies porosity and permeability range from 4 to 21% and 0.03 to 669 mD, respectively, showing no direct correlation. Stable isotope values (δ 13 C: 5.7–9.3‰; δ 18 O −9.6‰ to −12.2‰) are similar to other Travertines precipitated by thermal water in Central Italy. This study identifies the centimetre-scale Travertine facies variability linking it to the environment of deposition and to the depositional geometry of Travertine units affected by the substrate topography and lateral shifts of the active springs. Despite the different scale and facies composition, the geometry of aggradational-progradational units of Travertine aprons might resemble marine flat-topped high-relief carbonate platforms. Travertine units in the subsurface, if present with sizes that can be seismically resolved, might be wrongly interpreted as carbonate platforms with steep slopes without a detailed facies analysis.
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depositional architecture of a mixed Travertine terrigenous system in a fault controlled continental extensional basin messinian southern tuscany central italy
Sedimentary Geology, 2016Co-Authors: Andrea Croci, Giovanna Della Porta, Enrico CapezzuoliAbstract:Abstract The extensional Neogene Albegna Basin (Southern Tuscany, Italy) includes several thermogene Travertine units dating from the Miocene to Holocene time. During the late Miocene (Messinian), a continental fault-controlled basin (of nearly 500-km2 width) was filled by precipitated Travertine and detrital terrigenous strata, characterized by a wedge-shaped geometry that thinned northward, with a maximum thickness of nearly 70 m. This mixed Travertine–terrigenous succession was investigated in terms of lithofacies types, depositional environment and architecture and the variety of precipitated Travertine fabrics. Deposited as beds with thickness ranging from centimetres to a few decimetres, carbonates include nine Travertine facies types: F1) clotted peloidal micrite and microsparite boundstone, F2) raft rudstone/floatstone, F3) sub-rounded radial coated grain grainstone, F4) coated gas bubble boundstone, F5) crystalline dendrite cementstone, F6) laminated boundstone, F7) coated reed boundstone and rudstone, F8) peloidal skeletal grainstone and F9) calci-mudstone and microsparstone. Beds of terrigenous deposits with thickness varying from a decimetre to > 10 m include five lithofacies: F10) breccia, F11) conglomerate, F12) massive sandstone, F13) laminated sandstone and F14) claystone. The succession recorded the following three phases of evolution of the depositional setting: 1) At the base, a northward-thinning thermogene Travertine terraced slope (Phase I, Travertine slope lithofacies association, F1–F6) developed close to the extensional fault system, placed southward with respect to the Travertine deposition. 2) In Phase II, the accumulation of Travertines was interrupted by the deposition of colluvial fan deposits with a thickness of several metres (colluvial fan lithofacies association, F10 and F12), which consisted of massive breccias, adjacent to the alluvial plain lithofacies association (F11–F14) including massive claystone and sandstone and channelized conglomerates. Travertine lenses, of 2–3-m thickness, appeared intermittently alternating with the colluvial fan breccias. 3) In the third phase, the filled fault-controlled basin evolved into an alluvial plain with ponds rich in coated reed Travertines, which record the influence of freshwater (Travertine flat lithofacies association, F7–F9). This study shows the stratigraphic architecture and sedimentary evolution of a continental succession, wherein the hydrothermal activity and consequent Travertine precipitation were driven by the extensional tectonic regime, with faults acting as fluid paths for the thermal water. Fault activity created the accommodation space for Travertine and colluvial fan accumulation. Erosion of the uplifted footwall blocks provided the source of sediments for the colluvial fan breccias, which alternated with the thermogene Travertine precipitation. Climatic oscillations might have led to the recharge of the aquifer that fed the hydrothermal vents. The studied continental succession in an extensional basin provides valuable information about the interplay between thermogene Travertine and alluvial/colluvial deposition, which in turn might improve the understanding of similar fault-controlled continental depositional systems in outcrops and the subsurface.
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Studying Travertines for neotectonics investigations: Middle-Late Pleistocene syn-tectonic Travertine deposition at Serre di Rapolano (Northern Apennines, Italy)
International Journal of Earth Sciences, 2009Co-Authors: Andrea Brogi, Enrico Capezzuoli, Riccardo Aqué, Marilì Branca, Mario VoltaggioAbstract:Middle–Late Pleistocene tectonic activity has been inferred through studies on Travertine deposits exposed in a tract of the hinterland Northern Apennines. A detailed study on the relationships between tectonics and Travertine deposition coupled with 230Th/234U age determination of Travertines at Cava Oliviera quarry, located close to Serre di Rapolano village (southern Tuscany, Northern Apennines), allowed us to recognise Pleistocene faults, whose activity has been referred to 157–24 ka, at least. Travertine deposition was tectonically controlled by WSW-ENE striking, oblique and normal faults, associated to a main fault (named as the Violante Fault). This structure dissected a regional normal fault (known as the Rapolano Fault) Early–Middle Pliocene in age, which bounded the eastern side of the Pliocene Siena Basin, and gave rise to space accommodation for clayey and sandy marine sediments. Hydrothermal circulation (and related Travertine deposition) was favoured by the damaging enhancement due to the fault–fault intersection. Tectonic activity has been also documented by deformation recorded by Travertines, which suggest a main tectonic event between 64 ± 5 and 40 ± 5 ka. The tectonic activity described for the study area agrees with the Quaternary tectonic evolution documented in the surrounding areas (e.g. Mt. Amiata and Mt. Vulsini), as well as the Tyrrhenian margin of the Central Apennines, indicating that a widespread tectonic activity affected the inner part of the Apennines until the latest Quaternary.
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Travertine deposition and faulting: the fault-related Travertine fissure-ridge at Terme S. Giovanni, Rapolano Terme (Italy)
International Journal of Earth Sciences, 2008Co-Authors: Andrea Brogi, Enrico CapezzuoliAbstract:In this paper we describe an example of Travertine fissure-ridge development along the trace of a normal fault with metre displacement, located in the eastern margin of the Neogene–Quaternary Siena Basin, in the Terme S. Giovanni area (Rapolano Terme, Italy). This morphotectonic feature, 250 m long, 30 m wide and 10 m high, formed from supersaturated hot waters (39.9°C) flowing from thermal springs aligned along the trace of the normal fault dissecting Travertines not older than Late Pleistocene (24 ± 3 ka). A straight, continuous fissure with a maximum width of 20 cm occurs at the top of the ridge, along its crest. Hot fluids flow from cones mainly located at the extremities of the ridge, where Travertine is depositing. The Travertine fissure-ridge shows an asymmetrical profile since it buries the fault scarp. The difference in height of slopes corresponds to the vertical displacement of the normal fault. Fissuring of the recent Travertine deposits along the strike of the crestal fissure, as well as recent hydrothermal circulation, lead us to believe that the Terme S. Giovanni normal fault may be currently active. On the whole, the Terme S. Giovanni fissure ridge can be defined as a Travertine fault trace fissure-ridge, adding a helpful example for studying the relationship between faulting and Travertine deposition.
Mehmet Ozkul - One of the best experts on this subject based on the ideXlab platform.
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shrub and pore type classification petrography of Travertine shrubs from the ballik belevi area denizli sw turkey
Quaternary International, 2017Co-Authors: Hannes Claes, Jeroen Soete, Marcelle Marques Erthal, Mehmet Ozkul, Rudy SwennenAbstract:Petrographical and petrophysical properties of the Turkish Ballik-Belevi Travertine shrubs demonstrate the necessity of reservoir oriented classifications for shrub-related lithotypes and associated pore types. The presented shrub-related lithotype classification incorporates morphology, size and fabric, which are linked to specific pore-types and sizes. The Travertines show highly complex pore networks, as observed from Computed Tomography reconstructions, making them of interest for the development and optimization of pore characterization methodologies and techniques, following an upscaling approach. Porosity (3–15%) and permeability (0–505 mD) strongly vary for the Ballik-Belevi Travertines. The highest porosities and permeabilities are measured for horizontal samples dominated by slightly dissolution enlarged intershrub and interdigit growth framework porosity, mostly found for dendritic shrubs. The presented shrub and pore-type classification can be applied to shrubs worldwide. Studying outcrop analogues of continental carbonates helps to better understand heterogeneities, lateral variability and properties of Pre-Salt Cretaceous continental carbonate reservoirs, offshore Brazil and Angola.
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sedimentology three dimensional geobody reconstruction and carbon dioxide origin of pleistocene Travertine deposits in the ballik area south west turkey
Sedimentology, 2015Co-Authors: Hannes Claes, Jeroen Soete, Koen Van Noten, Hamdy Ahmed El Desouky, Marcelle Marques Erthal, Frank Vanhaecke, Mehmet Ozkul, Rudy SwennenAbstract: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 Ballk 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 Ballk Travertine architecture that potentially can be used as an analogue for subsurface Travertine reservoirs worldwide and illustrates the importance of the combined use of C-13 and Sr-87/Sr-86 signatures in the delineation of the CO2-origin of Travertine precipitating waters.
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sedimentological and geochemical characteristics of a fluvial Travertine a case from the eastern mediterranean region
Sedimentology, 2014Co-Authors: Mehmet Ozkul, Sandor Kele, Ali Gokgoz, Mehmet Oruc Baykara, Chuanchou Shen, Yuwei Chang, Ali Kaya, Mete Hancer, Cihan Aratman, Taylan AkinAbstract:A sedimentological and geochemical study was performed on the Travertines in the southern part of the Usak geothermal field, western Turkey, to assess the applicability of a fluvial tufa facies model in interpreting late Quaternary Travertine deposits developed along the stream valleys that follow fault and fracture systems. Modern thermal (31 to 38°C) springs are found on the floor of the valley between 480 m and 520 m above sea-level. The distribution and nature of Travertine facies were determined from natural outcrops. Samples of the Travertines and spring water were characterized using a range of geochemical and petrographic methods. Waterfall, slope and pool facies associations consist of various combinations of Travertine facies and subordinate detrital facies. Waterfall and slope facies associations of the older deposits occur where the springs emerged onto a hillslope or topographic break. In contrast, the pool facies association developed in depressions or flat areas that were fed by thermal springs. The youngest generation (1� 85 ka) precipitated at lower elevations than the older ones (147 to 153 ka). Stable carbon and oxygen isotope values of the Aksaz Travertines range between +4� 3& and +6� 3& (Vienna Pee Dee Belemnite) and � 12� 6& and � 7� 2& (Vienna Pee Dee Belemnite), respectively. The high d 13 C values suggest that the thermal waters were charged with isotopically heavy CO2 of deep origin. Based on palaeotemperature calculations, the temperatures of the palaeosprings are slightly higher (up to 44°C) than the present equivalents, but sometimes the temperature is lower, probably due to mixing with the stream water. Although the thermal waters occasionally are impeded by fluvial activity, Travertine precipitation occurs in the protected parts of the Aksaz Stream valley. This contribution highlights the applicability of the fluvial facies model for tufa for the interpretation of Travertine deposits worldwide.
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comparison of the quaternary Travertine sites in the denizli extensional basin based on their depositional and geochemical data
Sedimentary Geology, 2013Co-Authors: Mehmet Ozkul, Sandor Kele, Tibor Nemeth, Ali Gokgoz, Mehmet Oruc Baykara, Chuanchou Shen, Yuwei Chang, Brian Jones, Istvan Fόrizs, Mehmet Cihat AlçiçekAbstract:Abstract In the Denizli Basin (Turkey), located in the western Anatolian extensional province, Travertine and tufa deposition has been an ongoing process for at least 600,000 years. Travertine bodies, which are 30 to 75 m thick and each covers areas of 1 to 34 km2, are up to 1 km3 in volume. Today, spring waters in this area have temperatures of 19 to 57 °C, are of the Ca–Mg–HCO3–SO4 type in the Pamukkale, Kelkaya and Pinarbasi areas and the Ca–Mg–SO4–HCO3 type at Cukurbag. Thermal waters along the northern margin of the basin are generally hotter than those in the east–southeast and south. The δ18O and δD values of the spring waters indicate a meteoric origin. The average temperatures of the hydrothermal systems in the Denizli Basin appear to have decreased from Pleistocene to Holocene. Travertine, which formed from the hotter water, is more widespread than the tufa that formed in the cooler spring waters. Deposition of the Travertine, which formed largely on slopes, in depressions, and along fissure ridges (mostly on northern basin margins), was controlled by the interplay between various intrinsic and extrinsic parameters. The Travertines are formed largely of calcite with only minor amounts of aragonite in some of the vertically banded, crystalline crust, raft and pisoid Travertines found in some of the northern sites. The aragonitic samples, rich in Sr, are typically found around the spring orifices and along the central axis of the fissure ridges. The stable isotope values of the Travertine found in the northwest and southeast parts of the basin are different. The δ13C values of the northern Travertine deposits are more positive (3.7 to 11.7‰ VPBD) than those found in the south–southeast areas (− 4 to 5.8‰ VPDB). In contrast, the Travertine and tufa in the southeastern areas have higher δ18O values (− 15.2 to − 7.8‰ VPDB) than those of the northern areas (− 16.6 to − 4.8‰ VPDB). Available evidence indicates that spring activity and associated Travertine precipitation in the Denizli Basin were controlled largely by tectonic activity rather than by climatic conditions.
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stable isotope geochemical study of pamukkale Travertines new evidences of low temperature non equilibrium calcite water fractionation
Sedimentary Geology, 2011Co-Authors: Sandor Kele, Mehmet Ozkul, Ali Gokgoz, Mehmet Oruc Baykara, Mehmet Cihat Alçiçek, Istvan Forizs, Tibor NemethAbstract:Abstract In this paper we present the first detailed geochemical study of the world-famous actively forming Pamukkale and Karahayit Travertines (Denizli Basin, SW-Turkey) and associated thermal waters. Sampling was performed along downstream sections through different depositional environments (vent, artificial channel and lake, terrace-pools and cascades of proximal slope, marshy environment of distal slope). δ 13 C Travertine values show significant increase (from + 6.1‰ to + 11.7‰ PDB) with increasing distance from the spring orifice, whereas the δ 18 O Travertine values show only slight increase downstream (from − 10.7‰ to − 9.1‰ PDB). Mainly the CO 2 outgassing caused the positive downstream shift (~ 6‰) in the δ 13 C Travertine values. The high δ 13 C values of Pamukkale Travertines located closest to the spring orifice (not affected by secondary processes) suggest the contribution of CO 2 liberated by thermometamorphic decarbonation besides magmatic sources. Based on the gradual downstream increase of the concentration of the conservative Na + , K + , Cl − , evaporation was estimated to be 2–5%, which coincides with the moderate effect of evaporation on the water isotope composition. Stable isotopic compositions of the Pamukkale thermal water springs show of meteoric origin, and indicate a Local Meteoric Water Line of Denizli Basin to be between the Global Meteoric Water Line (Craig, 1961) and Western Anatolian Meteoric Water Line (Şimsek, 2003). Detailed evaluation of several major and trace element contents measured in the water and in the precipitated Travertine along the Pamukkale MM section revealed which elements are precipitated in the carbonate or concentrated in the detrital minerals. Former studies on the Hungarian Egerszalok Travertine (Kele et al., 2008a, b, 2009) had shown that the isotopic equilibrium is rarely maintained under natural conditions during calcite precipitation in the temperature range between 41 and 67 °C. In this paper, besides the detailed geochemical analyses along downstream sections, we present new evidences of non-equilibrium calcite-water fractionation in lower temperature range (13.3 to 51.3 °C). Our measurements and calculations on natural hot water Travertine precipitations at Pamukkale and Egerszalok revealed that the δ 18 O Travertine is equal with the δ 18 O HCO3 at the orifice of the thermal springs, which means that practically there is no oxygen isotope fractionation between these two phases. High rate of CO 2 degassing with rapid precipitation of carbonate could be responsible for this as it was theoretically supposed by O'Neil et al. (1969). Thus, for the determination of the deposition temperature of a fossil Travertine deposit we propose to use the water-bicarbonate oxygen isotope equilibrium fractionation instead of the water-Travertine fractionation, which can result 8–9 °C difference in the calculated values. Our study is the first detailed empirical proof of O'Neil's hypothesis on a natural carbonate depositing system. The presented observations can be used to identify more precisely the deposition temperature of fossil Travertines during paleoclimate studies.
Tonguc I Uysal - One of the best experts on this subject based on the ideXlab platform.
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temporal changes in geochemical isotopic systematics of the late pleistocene akkaya Travertines turkey implications for fluid flow circulation and seismicity
Chemie der Erde, 2020Co-Authors: Gokhan Yildirim, Tonguc I Uysal, Volkan Karabacak, Halim Mutlu, Kadir Dirik, Abidin Temel, Galip Yuce, Jianxin ZhaoAbstract:Abstract We investigate the temporal variations in stable carbon and oxygen and radiogenic Sr isotope as well as rare earth element contents of Akkaya Travertine deposits in the Eskipazar region, northwest Turkey. U-Th age data indicate that studied Travertines in the periphery of the 1944-earthquake rupture of the North Anatolian Fault Zone formed in a time span of 93 to 1.8 ka BP. The younger group is represented by fissure-filling carbonates whereas the older sequence is composed of veins with varying crystallization ages that are injected to bedded Travertines. The age data on vein injections and fissure-ridge Travertines in the Akkaya site indicate the seismic reactivation along the west-central part of the North Anatolian Fault Zone to be intensified at least 4 periods (1.8, 20, 47 and 88 ka BP) during the last 90 ka. δ18O and δ13C systematics of Akkaya Travertines, which are precipitated by CO2–rich fluids depressurized during episodic seismic unrest, are in the range from −15.86 to −7.67‰ (VPDB) and 4.66–8.68‰ (VPDB), respectively. δ18O of the fluid equilibrating with the studied Travertines is estimated in the range of −11.2 to −10.2‰ which is quite consistent with the average value (−12.3‰) reported for the Akkaya thermal spring. Stable isotope values of Travertines indicate modification by rapid CO2 degassing associated with seismic events. Helium isotope compositions of gas phase and dissolved gas of thermal fluids in the area refer to mantle contribution up to 12 %. Sr isotope values of Akkaya Travertines are probably originated from Upper Cretaceous marine limestones or mafic basement rocks. REY contents are about 3 orders of magnitude lower than those of basement lithologies.
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hydrothermal co2 degassing in seismically active zones during the late quaternary
Chemical Geology, 2009Co-Authors: Tonguc I Uysal, Yuexing Feng, Veysel Isik, Perach Nuriel, Jianxi Zhao, S D GoldingAbstract:Natural CO2 discharges are abundant in Turkey as evident from ongoing deposition of recent terrace-mound Travertines and emplacement of significant Travertine vein and breccia deposits in fractured damage zones of active fault systems. We report high-precision U-series age data for the vein carbonates combined with important field observations and geochemical data to evaluate the Travertine veining and CO2 degassing history in seismically active areas. Field evidence suggests that Travertine-filled veins and associated breccias represent hydrothermal eruption products, which probably formed by hydraulic fracturing in response to overpressure Of CO2-rich fluids. Stable isotope and REE data support the field observations and indicate that Travertine veins formed as thermogene deposits from rapidly ascending CO2-rich fluids. Travertine veins from the Kirsehir geothermal field give U-series ages in a range from 10.6 +/- 0.3 ka to 86.16 +/- 1.24 ka, with a majority of ages failing between 10.6 +/- 0.3 and 11.3 +/- 0.2 ka. Vein samples from the Pamukkale geothermal field yield U-series ages between 21.1 +/- 0.1 ka and 73.6 +/- 0.6 ka. Two major age groups are evident in Pamukkale that cluster coherently around 21 ka and 25 ka. A large number of Travertine veins we dated by high-precision U-series technique coincide with times of cold/dry climate events. This is different from surface sinter deposits in geothermal fields, which more frequently form during warm and wet periods. We propose that a significant reduction in surface discharge Of CO2 by spring or geothermal waters during dry climate periods may promote oversaturation of CO2 in deep reservoirs. Host rock fracturing in response to seismic shaking and fluid overpressure results in rapid exsolution and expansion of the dissolved gas and may lead to hydrothermal eruptions. Crown Copyright (C) 2009 Published by Elsevier B.V. All rights reserved.
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hydrothermal co2 degassing in seismically active zones during the late quaternary
Chemical Geology, 2009Co-Authors: Tonguc I Uysal, Yuexing Feng, Jianxin Zhao, Veysel Isik, Perach Nuriel, S D GoldingAbstract:Natural CO2 discharges are abundant in Turkey as evident from ongoing deposition of recent terrace-mound Travertines and emplacement of significant Travertine vein and breccia deposits in fractured damage zones of active fault systems. We report high-precision U-series age data for the vein carbonates combined with important field observations and geochemical data to evaluate the Travertine veining and CO2 degassing history in seismically active areas. Field evidence suggests that Travertine-filled veins and associated breccias represent hydrothermal eruption products, which probably formed by hydraulic fracturing in response to overpressure Of CO2-rich fluids. Stable isotope and REE data support the field observations and indicate that Travertine veins formed as thermogene deposits from rapidly ascending CO2-rich fluids. Travertine veins from the Kirsehir geothermal field give U-series ages in a range from 10.6 +/- 0.3 ka to 86.16 +/- 1.24 ka, with a majority of ages failing between 10.6 +/- 0.3 and 11.3 +/- 0.2 ka. Vein samples from the Pamukkale geothermal field yield U-series ages between 21.1 +/- 0.1 ka and 73.6 +/- 0.6 ka. Two major age groups are evident in Pamukkale that cluster coherently around 21 ka and 25 ka. A large number of Travertine veins we dated by high-precision U-series technique coincide with times of cold/dry climate events. This is different from surface sinter deposits in geothermal fields, which more frequently form during warm and wet periods. We propose that a significant reduction in surface discharge Of CO2 by spring or geothermal waters during dry climate periods may promote oversaturation of CO2 in deep reservoirs. Host rock fracturing in response to seismic shaking and fluid overpressure results in rapid exsolution and expansion of the dissolved gas and may lead to hydrothermal eruptions. Crown Copyright (C) 2009 Published by Elsevier B.V. All rights reserved.
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u series dating and geochemical tracing of late quaternary Travertine in co seismic fissures
Earth and Planetary Science Letters, 2007Co-Authors: Tonguc I Uysal, Erhan Altunel, Yuexing Feng, Jianxin Zhao, D K Weatherley, Volkan Karabacak, Oya Cengiz, S D Golding, Michael G Lawrence, Kenneth D CollersonAbstract:We present a method to constrain the timing of fissure generation related to late Quaternary seismic events using the uranium-series technique. Dated samples were from Travertine deposits precipitated in co-seismic extensional fissures along major active faults in Western Turkey. Stable isotope and REE data indicate that the precipitation of the fissure Travertines was not controlled by the hydrologic regime that is responsible for the speolethem deposition in the same region. Moreover, the REE composition and concentration of the water from which the fissure Travertine precipitated were significantly different from those of the current geothermal waters in the study area. The carbonate generation in the co-seismic fissures is interpreted to be the product of rapid precipitation from deeply infiltrated and CO2-enriched surface water during seismic strain cycles. Results show that U-series dating of fracture-filling Travertine deposits from seismically active areas provide important temporal information relevant to establishing recurrence intervals of late Quaternary and prehistoric major earthquake events. Precise dating of prehistoric earthquakes may be of great value for seismic hazard studies and earthquake forecasting research, for which accurate estimates of recurrence intervals are critical. (c) 2007 Elsevier B.V. All rights reserved.
Jianxin Zhao - One of the best experts on this subject based on the ideXlab platform.
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temporal changes in geochemical isotopic systematics of the late pleistocene akkaya Travertines turkey implications for fluid flow circulation and seismicity
Chemie der Erde, 2020Co-Authors: Gokhan Yildirim, Tonguc I Uysal, Volkan Karabacak, Halim Mutlu, Kadir Dirik, Abidin Temel, Galip Yuce, Jianxin ZhaoAbstract:Abstract We investigate the temporal variations in stable carbon and oxygen and radiogenic Sr isotope as well as rare earth element contents of Akkaya Travertine deposits in the Eskipazar region, northwest Turkey. U-Th age data indicate that studied Travertines in the periphery of the 1944-earthquake rupture of the North Anatolian Fault Zone formed in a time span of 93 to 1.8 ka BP. The younger group is represented by fissure-filling carbonates whereas the older sequence is composed of veins with varying crystallization ages that are injected to bedded Travertines. The age data on vein injections and fissure-ridge Travertines in the Akkaya site indicate the seismic reactivation along the west-central part of the North Anatolian Fault Zone to be intensified at least 4 periods (1.8, 20, 47 and 88 ka BP) during the last 90 ka. δ18O and δ13C systematics of Akkaya Travertines, which are precipitated by CO2–rich fluids depressurized during episodic seismic unrest, are in the range from −15.86 to −7.67‰ (VPDB) and 4.66–8.68‰ (VPDB), respectively. δ18O of the fluid equilibrating with the studied Travertines is estimated in the range of −11.2 to −10.2‰ which is quite consistent with the average value (−12.3‰) reported for the Akkaya thermal spring. Stable isotope values of Travertines indicate modification by rapid CO2 degassing associated with seismic events. Helium isotope compositions of gas phase and dissolved gas of thermal fluids in the area refer to mantle contribution up to 12 %. Sr isotope values of Akkaya Travertines are probably originated from Upper Cretaceous marine limestones or mafic basement rocks. REY contents are about 3 orders of magnitude lower than those of basement lithologies.
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hydrothermal co2 degassing in seismically active zones during the late quaternary
Chemical Geology, 2009Co-Authors: Tonguc I Uysal, Yuexing Feng, Jianxin Zhao, Veysel Isik, Perach Nuriel, S D GoldingAbstract:Natural CO2 discharges are abundant in Turkey as evident from ongoing deposition of recent terrace-mound Travertines and emplacement of significant Travertine vein and breccia deposits in fractured damage zones of active fault systems. We report high-precision U-series age data for the vein carbonates combined with important field observations and geochemical data to evaluate the Travertine veining and CO2 degassing history in seismically active areas. Field evidence suggests that Travertine-filled veins and associated breccias represent hydrothermal eruption products, which probably formed by hydraulic fracturing in response to overpressure Of CO2-rich fluids. Stable isotope and REE data support the field observations and indicate that Travertine veins formed as thermogene deposits from rapidly ascending CO2-rich fluids. Travertine veins from the Kirsehir geothermal field give U-series ages in a range from 10.6 +/- 0.3 ka to 86.16 +/- 1.24 ka, with a majority of ages failing between 10.6 +/- 0.3 and 11.3 +/- 0.2 ka. Vein samples from the Pamukkale geothermal field yield U-series ages between 21.1 +/- 0.1 ka and 73.6 +/- 0.6 ka. Two major age groups are evident in Pamukkale that cluster coherently around 21 ka and 25 ka. A large number of Travertine veins we dated by high-precision U-series technique coincide with times of cold/dry climate events. This is different from surface sinter deposits in geothermal fields, which more frequently form during warm and wet periods. We propose that a significant reduction in surface discharge Of CO2 by spring or geothermal waters during dry climate periods may promote oversaturation of CO2 in deep reservoirs. Host rock fracturing in response to seismic shaking and fluid overpressure results in rapid exsolution and expansion of the dissolved gas and may lead to hydrothermal eruptions. Crown Copyright (C) 2009 Published by Elsevier B.V. All rights reserved.
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u series dating and geochemical tracing of late quaternary Travertine in co seismic fissures
Earth and Planetary Science Letters, 2007Co-Authors: Tonguc I Uysal, Erhan Altunel, Yuexing Feng, Jianxin Zhao, D K Weatherley, Volkan Karabacak, Oya Cengiz, S D Golding, Michael G Lawrence, Kenneth D CollersonAbstract:We present a method to constrain the timing of fissure generation related to late Quaternary seismic events using the uranium-series technique. Dated samples were from Travertine deposits precipitated in co-seismic extensional fissures along major active faults in Western Turkey. Stable isotope and REE data indicate that the precipitation of the fissure Travertines was not controlled by the hydrologic regime that is responsible for the speolethem deposition in the same region. Moreover, the REE composition and concentration of the water from which the fissure Travertine precipitated were significantly different from those of the current geothermal waters in the study area. The carbonate generation in the co-seismic fissures is interpreted to be the product of rapid precipitation from deeply infiltrated and CO2-enriched surface water during seismic strain cycles. Results show that U-series dating of fracture-filling Travertine deposits from seismically active areas provide important temporal information relevant to establishing recurrence intervals of late Quaternary and prehistoric major earthquake events. Precise dating of prehistoric earthquakes may be of great value for seismic hazard studies and earthquake forecasting research, for which accurate estimates of recurrence intervals are critical. (c) 2007 Elsevier B.V. All rights reserved.
