Denizli Basin Research Articles

Investigation of the Usability of Travertine Quarry Wastes As Concrete Aggregate

Denizli basin is one of the most important travertine deposition area around the world. Kaklik, Kocabas, Honaz, Asagidagdere, Akkoy, Civril are major production areas. Tectonic activity in the region has been negatively affected the block production efficiency in the quarries. Quarry wastes by wire cutting are collected in waste disposal areas and these materials do not use for any other purposes. In this study, investigation of usability of different sized travertine quarry wastes in concrete as aggregate is aimed. For this purpose, physico mechanical properties of aggregates were investigated and concrete mixtures were prepared. Strength of 7, 28 and 56 days concrete samples which are targeted of C30 concrete class were also determined. Strength of prepared travertine aggregated concrete compared to still being produced concrete. For comparison, all procedures were performed for limestone aggregated concrete. Thin sections were prepared for investigations of distribution and coupling of grains in cement material under polarizan microscope. 32.80-42.70 MPa and 39.34-46.04 MPa strengths were determined for travertine aggregated and limestone aggregated concretes respectively. By using travertine aggregate, limit values for C30 concrete class have been reached. This study demonstrates that the travertine quarry wastes can be used as aggregates in concrete. In Denizli region there is no concrete firm use travertine wastes as aggregate. It is thought that, as an alternative building material travertine can be used in production of brick, curbs, keystone and various materials. For this aim more detailed experimental studies on travertines are needed.

La calotte crânienne de l’Homo erectus de Kocabaş (Bassin de Denizli, Turquie)

In 2002, a fragmentary skullcap was discovered in Denizli basin, in the locality of Kocabaş, in the southwest of Turkey (Kappelman et al., 2008). The skullcap was ascribed to Homo erectus on the basis of morphological and metric similarities with the Chinese fossils from Zhoukoudian L-C (Vialet et al., 2012). An in-depth morphological and metric analysis (2D and 3D) was carried out on a new 3D reconstruction of the fossil, made up of the frontal bone and parietal fragments. The results confirm that the morphology of the frontal bone, the conformation and the dimensions of the Kocabaş specimen, clearly differentiate it from Homo habilis-Homo georgicus, on one hand, and Homo heidelbergensis-Neanderthal, on the other. It displays similar metric characteristics to African (KNM-ER3733, OH9, Daka-Bouri) and Asian (skulls from Zhoukoudian L-C, Nankin 1, Sangiran 17) Homo erectus, a marked post-orbital constriction, a supraorbital torus bordered posteriorly by a supratoral sulcus and showing, on its inferior border, a supraorbital notch and tuber, temporal lines in a medium high position delimiting an infratemporal frontal zone with a clear bulge. However, the proportions of the short and large Kocabaş frontal bone (without the supraorbital torus) differentiate it from Asian Homo erectus, which present a longer squama frontalis. This feature is also present on African Homo erectus. Consequently, the Turkish fossil appears to be intermediary between the Homo erectus from Africa and Asia, both from an anatomic and geographic point of view. In the light of the new dates advanced for this fossil, at least 1.1Ma (Lebatard et al., 2014a, b; Khatib et al., 2014; Boulbes et al., 2014), it contributes, along with OH9, to bridging a palaeoanthropological gap between KNM-ER3733 (1.78Ma) and the Chinese fossils from Zhoukoudian L-C, Sangiran 17 (earlier than 0.78Ma) and Nankin 1 (approximately 0.63Ma). This study, which mainly concerns the frontal bone, implies that Homo erectus is a species with a vast geochronological distribution and marked morphometric variability.

Historique de la découverte et des recherches sur la calotte crânienne d’Homo erectus archaïque de Kocabaş, Bassin de Denizli, Anatolie, Turquie

In November 2002, during the study of the Plio-Pleistocene formations of Denizli Basin, containing significant active and fossil travertine deposits, during a visit to the Dalmersan factory, near the Kocabaş quarries, I identified a Hominid skullcap among bones retrieved during the cutting of travertine slabs. I immediately attributed this skullcap to a Homo erectus. I then handed over the study of this fossil, first to Professor John Kappelman from Texas University, then to a multidisciplinary study led by the Human Paleontology Institute in Paris.

General material properties of Denizli (SW Turkey) travertines as a building stone

The quality and material properties of Denizli travertine as a natural building stone have been investigated. The Denizli region is one of the world’s major travertine deposits and production basins. Travertine blocks are extracted from over fifty quarries in the region. In this study, investigations and evaluations of experimental test results of travertine samples from six areas (Kaklik–Kocabas, Honaz–Emirazizli, Asagidagdere, Akkoy, Karacay and Civril), which represent the entire Denizli basin, are presented. Kaklik–Kocabas is the biggest production area in the region, and therefore most of the quarries are located in this area. Physical, mechanical, micro-structural and macro-structural properties of the travertine samples are evaluated within the scope of stone quality assessment. Variations of test results by area are presented, and correlations between them are proposed. Test results are also compared with the results of various studies from Turkey and other parts of the world.

Comparison of the Quaternary travertine sites in the Denizli extensional basin based on their depositional and geochemical data

In the Denizli Basin (Turkey), located in the western Anatolian extensional province, travertine and tufa deposition has been an ongoing process for at least 600,000years. Travertine bodies, which are 30 to 75m thick and each covers areas of 1 to 34km2, are up to 1km3 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 Pınarbaşı areas and the Ca–Mg–SO4–HCO3 type at Çukurbağ. 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.

Study of the structural evolution of the Babadağ-Honaz and Pamukkale fault zones and the related earthquake risk potential of the Buldan region in SW Anatolia, east of the Mediterranean

Denizli graben (DG) is bounded in the NE by the Pamukkale fault zone and in the SW by the Babadag-Honaz fault zone. The Babadag and Honaz fault zones are generally made up as nearly E-W directed two segments. The Pamukkale fault also contains many overlapping segments in the Denizli area along the NE margin of the graben. The DG contains an NW-SE trending horst (Karakova) controlled by normal faults with oppositely dipping high angles and that truncate the Plio-Quaternary rock units. The faults that bound the DG are likely to have been initiated during the Early to Late Miocene and appear to be active today. The faults of the DG are active and the potential energy that accumulates in them is easily conducted to the other faults that they come in contact with. This signifies that a movement in one of the faults forming the grabens in the Denizli region affects the other structures as well. Earthquakes in the Buldan region usually occur 2–3 years after seismical movements occur in the Denizli Basin. The Buldan region is a ridge between DG and Alasehir graben (ALG). Based on the fact that DG in its south and ALG in its north move seismically, there is a probability that a break would appear in the Buldan region in the near future.

Fracture networks and strike–slip deformation along reactivated normal faults in Quaternary travertine deposits, Denizli Basin, western Turkey

The Denizli Basin in the West Anatolian Extensional Province in western Turkey is known for its numerous Quaternary travertine occurrences. Travertine morphology is often dependant on the relative position of the deposition with respect to basin-bounding faults. The travertine occurrences examined in this study are situated at the intersection of the locally E–W oriented Denizli Basin and the adjacent NE–SW oriented Baklan Graben in the NE. Based on an extensive field campaign, including LIDAR scanning, several high-resolution fault/fracture maps of five large quarries (>300m in length and >60m in height) are constructed in which this world-class travertine deposit is currently excavated. A structural analysis is performed in order to determine the tectonic overprinting of the travertine body and to derive the stress states of the basin after travertine deposition. The mostly open, non-stratabound joints are several tens of metres long and often bifurcate creating a dense fracture network. Minor infill of the joints resulted in the presence of a few colour-banded calcite veins. Based on the E–W, NE–SW and NW–SE orientation of three dominant joint sets it is concluded that the joint network is caused by local N-S extension, alternated by NW–SE and NE–SW extension exemplifying the presence of stress permutations in the Quaternary. High angle E–W to WNW–ESE faults cross-cut the quarries. Faults are filled with travertine debris and clastic infill of above lying sedimentary units indicative of the open nature of the faults. The specific E–W fault orientation in the locally E–W trending Denizli Basin indicates that they initiated as normal faults. A paleostress inversion analysis performed on kinematic indicators such as striations on the clayey fault infill and the sinistral displacement of paleosols shows that some of the normal faults were reactivated causing left-lateral deformation in a transient strike–slip stress field with a NE–SW oriented σ1.

Growth of fissure ridge travertines from geothermal springs of Denizli Basin, western Turkey

Fissure ridge travertines grown from geothermal springs of Denizli Basin, southwestern Turkey, are investigated through stratigraphic, structural, geochemical, and geochronological methods, with the aim of understanding the growth of these elongate mound-shaped structures. Two main types of travertine deposits are recognized: (1) bedded travertines, which grew as flowstone on sloping surfaces and form the bulk of fissure ridges, and (2) banded travertines, which grew as veins within the bedded travertine chiefly along its central feeding conduit. Stratigraphic and structural observations shed light on the bedded-banded travertine relationships, where the banded features grew through successive accretion phases, crosscutting the bedded travertine or forming sill-like structures. The bedded and banded travertines alternated their growth, as demonstrated by complicated crosscutting relationships and by the upward suture, in places, of banded travertine by bedded travertine that was, in turn, crosscut by younger banded travertine. The bedded travertine is often tilted away from the central axis of the fissure ridge, thus leaving more room for the central banded travertine to form. U-series ages confirm the bedded-banded travertine temporal relationships and show that the growth of the studied fissure ridges lasted up to several tens of thousands of years during Quaternary time. The banded travertine was deposited mainly during cold events, possibly in coincidence with seismic events that might have triggered the outflow of deep geothermal fluids. C and O stable isotope and rare earth element data indicate a shallow feeding circuit for the studied structures with a fluid component deriving from a deeper geothermal circuit. A crack-and-seal mechanism of fissure ridge growth is proposed, modulated by the interplay of local and regional influencing factors and mechanisms such as geothermal fluid discharge, paleoclimate, tectonics, and the progressive tilting of bedded travertine limbs over a soft substratum creating the necessary space for the central veins to grow.

Determination of strength parameters and quality assessment of Denizli travertines (SW Turkey)

Travertine, carbonate-rich sedimentary rocks which are deposited by hot and cold waters. As with all natural stones, strength properties of travertines have great importance, depending on the using conditions and places. Naturally porous structure of travertines is the most important parameter affecting the overall strength. Denizli basin is one of the world's major travertine regions. In this study, strength properties and relations between obtained parameters of Denizli travertines were studied. Uniaxial compressive strength (UCS) values of travertines are widely ranging between 9.58 and 132.32MPa. Noche type travertines are identified to have 59%–100% higher strength than other type of travertines. Flexural strength under concentrated load (3 point flexural strength, FLS3) and flexural strength under constant moment (4 point flexural strength, FLS4) tests which are required for CE certification were also carried out on travertine samples. Between these tests linear relationship expressed as FLS4=0.98∗FLS3+0.094 was found. Variations of strength parameters depending on the stone cutting type have been presented for the first time in this study. It is found that the strength values under parallel loading to lamination are 1.44 times higher than the perpendicular loading.

3-D imaging of the upper crust beneath the Denizli geothermal region by local earthquake tomography, western Turkey

The Denizli basin and its surroundings are one of the regions that have high seismic activity and rich geothermal fields in western Anatolia. In the first half of year 2000, an increasing seismic activity was observed around the Denizli basin without a large mainshock occurrence. A temporary seismic network consisting of 28 stations were deployed to observe the seismic activity in the region by The Scientific and Technological Research Council of Turkey-Marmara Research Center-Earth and Marine Science Institute (TÜBİTAK-MAM-EMSI). In this study, one- and three-dimensional V P and V P/ V S structure of the Denizli basin have been determined by using the travel times of the 635 recorded earthquake data. Firstly one-dimensional inversion schema was performed to stabilize initial velocity model and to have more reliable hypocentral locations. Then an iterative and simultaneous three-dimensional inversion procedure was carried out to obtain 3-D high-resolution seismic velocity models. Furthermore to assess the solution quality of our inversion, we conducted a series of resolution tests. We concluded high-resolution 3-D V P and V P/ V S seismic velocity models for the upper 20 km of the crust beneath the Denizli basin and surroundings and interpreted the results in the context of known geologic and tectonic units. The resulting 3-D V P models define the geometry of the basin, sediment thickness, and intrusive magmatic bodies as well as regions of anomalous velocity. The V P/ V S models help to constrain the location and geometry of the faults, zones of weakness, and gas or fluid saturated formations with high pore pressure zones. All tomographic results show that there is a strong correlation between local seismicity and the high V P and V P/ V S anomalies. Consequently, this relationship indicates that the reason of the high seismicity in the Denizli basin depends on activity of hydrothermal system as well as tectonic regime.

Stable isotope geochemical study of Pamukkale travertines: New evidences of low-temperature non-equilibrium calcite-water fractionation

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 13C travertine values show significant increase (from + 6.1‰ to + 11.7‰ PDB) with increasing distance from the spring orifice, whereas the δ 18O 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 13C travertine values. The high δ 13C 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 (Şimşek, 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 Egerszalók 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 Egerszalók revealed that the δ 18O travertine is equal with the δ 18O 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.

Comparison of the isotope hydrogeological features of thermal and cold karstic waters in the Denizli Basin (Turkey) and Buda Thermal Karst (Hungary)

Abstract The isotopic compositions of the Hungarian warm and cold water samples are spread in a wide range along the Global Meteoric Water Line (GMWL), which is a result of the significant change in the climate (mainly temperature) during infiltration (Last Glaciation and Holocene) and of the mixing process along the fault zone. The thermal karst water is isotopically lighter as it was infiltrated in a 7 to 9 °C cooler climate in the Ice Age. However, in the Denizli Basin isotopic composition of all of the thermal, lukewarm and cold waters varies in a relatively narrow range, with the exception of some warm waters whose d18O values have been shifted as a result of water-rock interaction. Isotope data prove that all the waters in the Denizli Basin infiltrated in the Holocene under more or less the same climate, so these waters are young indicating much shorter transit time from the recharge to the discharge areas because of faster flow under the surface or shorter path of the subsurface flow.

A Late Miocene Paratethyan mollusc fauna from the Denizli Basin (southwestern Anatolia, Turkey) and its regional palaeobiogeographic implications

We report on a Late Miocene mollusc fauna from a single locality in the Denizli Basin in southwestern Turkey that is composed of ten presumably euryhaline species and three freshwater species. The fauna is remarkably distinct from faunas of the adjacent Late Miocene Aegean and Euxinian Basins, and has elements in common with the modern Caspian Sea fauna in the form of Didacna species. The suggested age of the fauna (Late Miocene) would extend the stratigraphic range of the lymnocardiid genus Didacna (hitherto Calabrian-Extant) considerably. The palaeobiogeographic significance of the Denizli fauna is discussed.

Sedimentary facies, depositional environments and palaeogeographic evolution of the Neogene Denizli Basin, SW Anatolia, Turkey

The Denizli Basin (southwestern Anatolia, Turkey) contains a record of environmental changes dating since the Early Miocene. Detailed facies analysis of the Neogene formations in this half-graben enables us to document successive depositional regimes and palaeogeographic settings. Sedimentation commenced in the Early Miocene with the deposition of alluvial-fan and fluvial facies (Kızılburun Formation). At this stage, alluvial fans sourced from elevated areas to the south prograded towards the basin centre. The Middle Miocene time saw the establishment of marginal lacustrine and wetland environments followed by the development of a shallow lake (Sazak Formation). The uppermost part of this unit consists of evaporitic saline lake and saline mudflat facies that grade upward into brackish lacustrine deposits of Late Miocene–Pliocene age (Kolankaya Formation). The lake became shallower at the end of the Pliocene time, as is indicated by expansion shoreface/foreshore facies. In the Early Quaternary, the Denizli Basin was transformed into a graben by the activation of ESE-trending normal faults. Alluvial fans were active at the basin margins, whereas a meandering river system occupied the basin central part. Oxygen isotope data from carbonates in the successive formations show an alternation of wetter climatic periods, when fresh water settings predominated, and very arid periods, when the basin hosted brackish to hypersaline lakes. The Neogene sedimentation was controlled by an active, ESE-trending major normal fault along the basin's southern margin and by climatically induced lake-level changes. The deposition was more or less continuous from the Early Miocene to Late Pliocene time, with local unconformities developed only in the uppermost part of the basin-fill succession. The unconformable base of the overlying Quaternary deposits reflects the basin's transformation from a half-graben into a graben system.

The ad 60 Denizli Basin earthquake and the apparition of Archangel Michael at Colossae (Aegean Turkey)

Abstract This paper illustrates the results of a multidisciplinary study on the active tectonics of Hierapolis and Colossae in Aegean Turkey. Tectonic analysis is combined with a study of historical seismicity, highlighting the use of historical sources from oral tradition (legends and myths) to derive important geological information for which the legendary account is the only witness. Strong correlation between tectonic and historical/mythological data suggests that the legendary narration is based on real geological events. This allows a better understanding of the local active tectonics and seismic history. At Hierapolis, it is possible to recognize evidence of surface faulting from the ad 60 earthquake. At Colossae, we can reconstruct the local geomorphic evolution, and show its relationship to the ad 60 earthquake.

Radon concentrations in thermal waters related to seismic events along faults in the Denizli Basin, Western Turkey

The aim of this study is to investigate the relationship between the earthquakes and radon concentrations in thermal waters along faults in the Denizli Basin, an area in Turkey known for its high seismic activity and thermal waters. This area was chosen because it exhibits active crustal movements combined with seismicity and there are numerous outflow thermal waters and gas outputs. In addition, this region has the type of tectonic activity where graben groups and faults take place. Measurements of radon levels and of some chemical and physical characteristics of thermal waters were made at seven sampling stations in the region. Radon concentrations were measured by a ZnS(Ag) scintillation counter in a collector chamber. The activity levels varied between 0.67 and 25.90 kBq m - 3 during the period of May–December 2000. In the evaluation of the results, the seismic data reported by Bogaziçi University Kandilli Observatory and Earthquake Research Institute, Seismological Laboratory were used. The increases observed in radon concentration at two stations were probably related to the earthquakes that took place in the region during the study period.

Kinematic development and paleostress analysis of the Denizli Basin (Western Turkey): implications of spatial variation of relative paleostress magnitudes and orientations

Paleostress orientations and relative paleostress magnitudes (stress ratios), determined by using the reduced stress concept, are used to improve the understanding of the kinematic characteristics of the Denizli Basin. Two different dominant extension directions were determined using fault-slip data and travertine fissure orientations. In addition to their stratigraphically coeval occurrence, the almost exact fit of the σ 2 and σ 3 orientations for the NE–SW and NW–SE extension directions in the Late Miocene to Recent units indicate that these two extension directions are a manifestation of stress permutations in the region and are contemporaneous. This relationship is also demonstrated by the presence of actively developing NE–SW and NW–SE elongated grabens developed as the result of NE–SW and NW–SE directed extension in the region. Moreover, stress ratios plots indicate the presence of a zone of major stress ratio changes that are attributed to the interference of graben systems in the region. It is concluded that the plotting of stress orientations and distribution of stress ratios is a useful tool for detecting major differences in stress magnitudes over an area, the boundaries of which may indicate important subsurface structures that cannot be observed on the surface.

Determination of horizontal extension from fissure-ridge travertines: a case study from the Denizli Basin, southwestern Turkey

Travertine deposits reflect some aspects of the regional tectonics because of the close association between travertine deposits and active fractures, that later of which provide conduits along which travertine-depositing waters may rise. Fissure-ridge travertines form above extensional fissures which are located in the hanging walls of normal faults, in step-over zones between fault segments, or in active or recently active) volcanic provinces. Numerous active and inactive fissure-ridge travertines are located in the hanging walls of normal faults in the Denizli Basin. A typical fissure-ridge comprises a central fissure along its long axis and flanking bedded travertines dipping away from the fissure. Central fissures of travertine ridges have been dilating since the initiation of the fissures. Samples from both the margins and centres of banded travertine deposits were dated by Th/U methods in order to determine dilation rates. Individual fissures have been dilating at average rates of between 0.008 and 0.1 mm yr–1 during travertine deposition, and ~ 0.001 and 0.007 mm yr–1 after cessation of travertine deposition. There is a noticable decrease in dilation rate from west to east in the Denizli Basin, and this decrease in dilation rate may be related to decrease in overall extension in southwest Turkey, which decreases eastward.

Pleistocene mammals from travertine deposits of the Denizli basin (SW Turkey)

The Denizli basin, which is famous by its modern travertine accumulations such as that of Pamukkale is located at the eastern junction of Büyük Menderes and Gediz grabens in the western Anatolian extensional province. This basin contains large travertine formations, the origin and age of which are still debated. This study briefly recalls the tectonic and stratigraphic context of travertine occurrences and describes some vertebrate remains, which have recently been recorded in travertines. The material mainly consists of jaw fragments referred to Equus aff. suessenbornensis Wüst, 1901, lower teeth and antlers of Dama sp. and some lower teeth of Bos sp. The presence of E. aff. suessenbornensis, indicates a Middle Pleistocene age in agreement with thermoluminescense dating of the travertines.

Structural Attributes of Travertine-Filled Extensional Fissures in the Pamukkale Plateau, Western Turkey

Numerous active and inactive fissure-ridge travertines are located in the hanging wall of the Pamukkale range-front fault, a large normal fault bounding the northeast side of the Denizli Basin. A typical principal fissure-ridge comprises flanking bedded travertines dipping gently away from a nearly vertical, irregular central fissure, partially filled by vertically banded travertine. More complex ridges bear parasitic fissures and associated ridges on their flanks. Fissures roughly follow the long axes of ridge crests, some of them being divided into angular segments and others anastomosing. The traces of fissures are commonly parallel but some are oblique to one another. Fissures vary in width from a few millimeters to 5 m, and range in length from a few meters to a few kilometers. The widths of central fissures are at a maximum near the midpoints of ridges, but decrease toward both ends, suggesting that they grew in length over time. Lateral fissure development involved the opening of both new and old c...