Travertine Quarry Research Articles

Virtual reconstruction and geometric morphometric analysis of the Kocabaş hominin fossil from Turkey: Implications for taxonomy and evolutionary significance

The Kocabaş specimen comes from a travertine quarry near the homonymous village in the Denizli basin (Turkey). The specimen comprises three main fragments: portions of the right and left parietal and left and right parts of the frontal bone. The fossil was assumed to belong to the Homo erectus s.l. hypodigm by some authors, whereas others see similarities with Middle Pleistocene fossils (Broken Hill 1/Kabwe, Bodo, or Ceprano). Here, we present the first attempt to make a complete reconstruction of the missing medial portion of the frontal bone and a comprehensive geometric morphometric analysis of this bone. We restored the calotte by aligning and mirroring the three preserved fragments. Afterward, we restored the missing portion by applying the thin-plate spline interpolation algorithm of target fossils onto the reconstructed Kocabaş specimen. For the geometric morphometric analyses, we collected 80 landmarks on the frontal bone (11 osteometric points, 14 bilateral curve semilandmarks, and 41 surface semilandmarks). The comparative sample includes 21 fossils from different chronological periods and geographical areas and 30 adult modern humans from different populations. Shape analyses highlighted the presence in Kocabaş of features usually related to Middle Pleistocene Homo, such as a developed supraorbital torus associated with a relatively short frontal squama and reduced post-toral sulcus. Cluster analysis and linear discriminant analysis classification procedure suggest Kocabaş being part of the same taxonomic unit of Eurasian and African Middle Pleistocene Homo. In light of our results, we consider that attributing the Kocabaş hominin to H. erectus s.l. may be unwarranted. Results of our analyses are compatible with different evolutionary scenarios, but a more precise chronological framework is needed for a thorough discussion of the evolutionary significance of this specimen. Future work should clarify its geological age, given uncertainties regarding its stratigraphic provenance.

Investigating the impact of travertine powder on strength and permeability of swelling clay

Stabilization of swelling soils with high volume change potential is an important topic in geotechnical engineering because irreversible and catastrophic damages will occur if they are not appropriately managed. This study aimed to determine the effect of travertine powder on the swelling, strength, and permeability properties of weak and swellable soils. Within the scope of the study, soil improvement performance of travertine powder, which can be used as a soil improvement tool, was analyzed in detail, and the effect of travertine powder on the hydraulic and strength properties of the soil was discussed comparatively. Waste powder from travertine quarries taken from Eskipazar (Turkey) and Bentonite clay with high swelling potential taken from Tokat (Turkey) was used in the study. Samples were prepared by adding 10%, 20%, 30%, and 40% by weight of travertine powder to the Bentonite, and these mixtures were cured for 0-7-14-21-28-35 and 42-day periods. Unconfined compressive strength test, direct shear test, swelling pressure, and permeability tests were then conducted on each of the cured-stabilized samples. While the permeability coefficient, unconfined compressive strength, cohesion, and internal friction angle of bentonite samples with the additive increased over the curing time, the swelling pressure value decreased. The addition of travertine led to a substantial enhancement in the unconfined compressive strength (by 35%), internal friction angle (by 350), and cohesion (by 26%), while simultaneously reducing the swelling pressure by 58%. These findings emphasize that travertine powder enhances weak and swellable soils, offering an eco-friendly and cost-effective solution for improving engineering properties.

Rockmass Fracture Analysis at Cărpiniş Travertine Quarry Using Ground Penetrating Radar and Geophysical Methods

Abstract Travertines are susceptible to fracturing/ cracking, making it difficult to extract large uncracked blocks of significant commercial value. In our study, we used the GPR – Ground Penetrating Radar and other geophysical methods (resistivity and seismic methods) to evaluate the degree of fracturing. Following the interpretation of the longitudinal and transversal GPR profiles, corroborated with the resistivities minima, led us to identify fractures and highly fracturing areas in the Carpinis quarry. In addition, using these combined methodologies and corroborating geophysical, geological, tectonic and geomorphological information creates the premises for an effective investigation of Carpinis quarry, which assists with optimising the mining process.

Use of bacterial binder in repair mortar for micro-crack remediation.

Micro-cracks are one of the types of stone deterioration which can propagate and lead to surface detachments and larger cracks in the long run. The present study developed a sustainable and environmentally friendly infill material-biological mortar (BM), as an alternative to conventional approaches. Using a biomineralization approach, this BM was explicitly designed for healing micro-cracks (less than 2 mm) in historic travertines. To this end, the mortar was prepared using a calcifying Bacillus sp. isolated from thermal spring water resources in Pamukkale Travertines (Denizli), stone powder gathered from travertine quarries in the vicinity, and a triggering solution specifically designed to set off calcium carbonate precipitation reaction. After setup, BM was applied to micro-cracks of artificially aged test stones for testing. Scanning electron microscopy revealed calcium carbonate-coated Bacillus sp. bodies in the BM matrix, optical microscopy showed secondary calcite minerals throughout the BM applied micro-cracks, and stereomicroscopy and nanoindentation analyses demonstrated bonding of BM with stone due to microbial calcification activities. Furthermore, BM and original material contact showed a continuous and coherent structure in all samples. Within this context, BM could be considered a promising and alternative approach for the remediation of micro-cracks of historic stones. KEY POINTS: A binder was produced by the MICP of Bacillus sp. Pamukkale. Physical, mineralogical, and nanomechanical characterization demonstrated microbial calcite precipitates in BM. A significant bond was determined between the grains and matrix of BM due to Bacillus sp. calcite production activities.

Factors conditioning soil PTE contents and the associated health risk in an area with mixed land use.

The study of soil chemical composition and geochemical characterization is of great concern. In 2020, a soil survey of the Ararat region (Armenia) was conducted to study the contents of soil elements (Cr, V, Ti, As, Zn, Cu, Co, Fe, Mn, Ba, Pb, Mo, Ca, and K), identify pollution sources and factors conditioning their spatial distribution patterns, and assess the health risk associated with potentially toxic elements (PTEs). The combined application of compositional data analysis and geospatial mapping allowed to reveal three subsamples with unique chemical signatures. Group I included soils in which Fe, Co, Ti, Mn, V, Ba, Pb, and Zn had mainly a natural origin. Soils of Group II are localized in heavily urbanized and industrialized parts of the region, and their spatial distribution is in line with relatively high contents of Cu and partially As, Cr, and K. The spatial distribution of Group III coincides with positions of soils with relatively high contents of Ca and is in line with the geological features and the locations of stone quarries. The human health risk assessment showed that As contents pose a mono-elemental noncarcinogenic health risk to children in two sites (near the Gold Factory and Tigranashen village), whereas a multi-elemental health risk to children was identified on almost the entire region's territory. Moreover, the comparatively high level of As risk was identified in Group III and linked to the travertine quarries exploitation. The results of this study indicated the need for additional in-depth studies targeting As contents and its unrevealed features linked to the travertine quarries exploitation.

Investigation of the anisotropic structure of travertine in terms of geological and physico-mechanical properties: Sarıhıdır (Avanos-Nevşehir) travertine quarry

Travertine is a sedimentary rock with generally layered structure, mainly comprising carbonate. They are used for different purposes in interior and exterior spaces by cutting parallel or perpendicular to the bedding according to use. Travertine may contain several facies linked to variations in conditions during formation. With these features, travertine is one of the rocks with anisotropy most commonly observed. In this study, the anisotropic structure due to facies and bedding in travertine was investigated considering geological and engineering properties. The Sarıhıdır travertine quarry face was divided into four different zones with different features. Chemical, mineralogic, physical, index and mechanical properties of the samples taken from these zones were determined. During determination of engineering parameters, samples were prepared parallel and perpendicular to bedding. The source of the travertine is a mixture of limestone, dolomite, evaporite and ultramafic rocks and they have epigean character, though they were affected by the hypogean environment. It appeared there were textural differences between the zones, rather than differences in chemical and mineralogic composition. When travertine was cut parallel to bedding, all zones were suitable for decoration and facing. Only T-4 zone samples cut parallel were useable for flooring and load-bearing elements. In terms of compression and abrasion resistance, T-4 zone was better than the other zones. The cut direction of the travertine samples is an important factor for physical and mechanical behavior. Samples cut parallel to bedding were observed to provide better results. According to the results, it is recommended to use products from the same travertine zone side-by-side in structures and to consider the cutting direction for long life of the building and to prevent economic losses.

Caught in travertine: computed tomography reveals the youngest record of Amphicyon giganteus from the travertine deposits of Karacalar (late middle Miocene, central Anatolia, Turkey)

A computed tomography scan of a travertine slab from the Karacalar Silver Travertine Quarry (Afyonkarahisar Province, Turkey) revealed the presence of an encased partial cranium, partial mandible and three vertebrae. 3D reconstruction of the fossil helped identifying it as Amphicyon giganteus. As the travertine caps a section correlated to MN7/8, the specimen represents the youngest record of Amphicyon giganteus, the known range previously being limited to MN4 – MN6. This young age is in line with the more advanced morphology of the lower molars.

The Lower Palaeolithic assemblages in Central Europe in stratigraphic and palaeogeographic background

The hominin presence during Lower Palaeolithic in Central Europe was sporadic and followed cold-warm climatic cycle connected with spreading of Scandinavian ice sheet. Up to now there had been discovered about 50 archaeological assemblages from 17 sites from 700 ka years, mostly from second part of it, during c. 300 ka between MIS 15 and 9. The Lower Paleolithic hominins visited Central Europe during warmer periods with deciduous or coniferous forests, even during open domination of open or partly open landscape. Incredible finds, like Bilzingsleben and Schöningen show how complex was life of early hunter-gatherers. In opposite to the previous concept, according to which Lower Palaeolithic hominins were mostly scavengers. The discovery of wooden tools, like spears in lakeshore in opencast mine Schöningen, denies this concept. Contrary to that, early hominins were smart hunters following animal herds and hunted distant way and experienced gatherers. Local lithic technology based on core-flake processing in opposite to Western and Southern Europe dominated by handaxes. Moreover, the preferred usage of “small tools”, which are difficult to use only by fingers may be explained by identification of wooden hafts on few lithic artifacts in Schöningen. However, very long duration of unchanged lithic technology is surprising. An intense accumulation of glacial, eolian and alluvial sediments covered large part of Central Europe and this way Lower Palaeolithic sites are very difficult to discover. All known sites were identified in deep travertine quarries or opencast mines. Future research must be focused on systematic prospection of such outcrops.

A multi–methodological approach to reconstruct the configuration of a travertine fissure ridge system: The case of the Cukor quarry (Süttő, Gerecse Hills, Hungary)

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.

Pleistocene-Holocene tectonic reconstruction of the Ballık travertine (Denizli Graben, SW Turkey): (De)formation of large travertine geobodies at intersecting grabens

Travertine geobodies have been identified as potential reservoir analogues to carbonate build-ups in pre-salt hydrocarbon systems. To investigate travertine geobody deformation, faults were mapped in 35 travertine quarries that excavate the Ballık travertine, i.e. a c. 12.5 km2 large travertine geobody that precipitated at the intersection of the NE margin of the Denizli Basin and neighbouring Baklan Graben (SW Turkey). This travertine precipitated from cooling carbonate-saturated thermal spring waters that resurfaced along the margin fracture/fault network and through Neogene unconsolidated underlying sediments. From the Denizli basin floor to the uplifted graben shoulders, fault orientation is dominantly WNW-ESE oriented with major basin faults showing a left-stepping trend. Along the upper Denizli margin, travertine is only deformed by extensional normal faults. Along the lower margin, travertine starts with a subhorizontal facies but evolves to a travertine facies formed by a sloping topography with a domal architecture. Paleostress inversion of fault-slip data reveals that an Early Pleistocene NNE-SSW extensional-transtensional phase initiated the WNW-ESE oriented, graben-facing normal fault network. In the Middle Pleistocene, the Ballık fault network was left-lateral strike-slip reactivated because it acted as a transfer zone between the NW-SE extending neighbouring Baklan Basin and NW-SE extension along NE-SW oriented margin faults of the DGHS. In this stress configuration, travertine precipitated along the SW margin fault of the Baklan Graben. After strike-slip reactivation, a Late Pleistocene-to-current NNE-SSW extensional stress regime reinstalled during which margin faults widened and active travertine precipitation moved to more central parts of the DGHS. As different tectonic regimes affect graben intersections, reservoir analogues can have a complex deformation history driven by fault reactivation and recurrent stress permutations. This study concludes that large travertine geobodies can form at graben intersections because of their susceptibility to enhanced fluid flow through the complex fault-fracture network.

Applicability quality assessment of dimension stones for service in the buildings (A new approach using a mathematical model and fuzzy logic)

Determining the most suitable application(s) of a stone increases its service life in the buildings. Quality of building stones is associated with numerous physicomechanical properties or Impacting Factors (IFs). However, no comprehensive framework has yet been developed in this regard. In this study, firstly, each IF for each stone type was classified into three scenarios as ‘Poor’, ‘Medium’, and ‘Good’, the limits of which were obtained by investigating the data from multiple sources and standards. Then, three magnitudes in the range of 1–3 were assigned to the scenarios with the aid of a fuzzy inference system. Finally, using Folchi mathematical model, 6 common applications were evaluated from the viewpoint of 14 IFs by a correlation matrix. Eventually, a new index called the Applicability Score (AS) was defined to facilitate the stone selecting process and also finding its most suitable application. Implementing this model in Ask Travertine Quarry, Iran, gave an AS score of 120.45, placing the quarry at a medium quality level, which is consistent with the current sale price of quarry's polished stones. Moreover, the facade was recognized as the most appropriate application for the intended quarry.

A new sustainable closed-loop supply chain model for mining industry considering fixed-charged transportation: A case study in a travertine quarry

Mining industries in general and stone mining in particular play a vital-infrastructural role in any economy due to its vast impacts on other sectors such as construction, production, and even banking. The main purpose of this research is to investigate sustainability aspects of mining industry of decorative stone quarries in Iran in general and a specific case study in particular through a mathematical optimization approach. In this paper, a novel closed-loop approach is proposed for the first time (to the best of our knowledge) to be utilized in a real-case travertine quarry. Indeed, a stone quarry is considered and a closed-loop network is provided to determine appropriate strategies for stone wastes and end of life stones of the buildings. The quarry extracts the stone blocks from the mountain and then cut them into the appropriate pieces by wire sawing machines. Besides, at the decorative stone quarry, based on the insight observations, the outputs are in 4 grades based on their quality depend on the fractures and cleavages of the cut stones.In the presented network, by focusing on decorative stones, recycling centers are the main player of collecting, processing, and selling the wastes and end of life stones. In order to regard sustainable approach, minimizing energy consumption is considered as well as profit maximization in the objective functions of the model and service level requirements. In addition, due to the real requirements, fixed-charged is considered in transportations. Then, in order to achieve the Pareto front and the non-dominated solutions, a repetitive ε-constraint approach is developed here. The principal results prove that the sustainable closed-loop approach is able to be implemented successfully in mining industry. The major conclusion of this study specially about the case study show that closed-loop supply chain of decorative stone quarries can be both profitable and feasible.

Geometric quality assessment of in situ blocks in dimension stone quarries

The profitability of stone quarries depends on the appearance (color and texture) and, more importantly, on the size of the blocks, which is determined by the three-dimensional discontinuity pattern of the rock mass. However, to date there is no comprehensive criterion by which to assess the size of blocks in quarries. The aim of the study reported here is to identify factors that facilitate decision-making on the desirability of an individual block and ultimately on all blocks for extraction as a dimension stone. To this end, we first developed a novel algorithm to calculate the largest rectangular parallelepiped that can be placed inside a block and then defined a regularity factor (α) and a quarry block shape factor (q) that enable the geometric quality of the block to be assessed more accurately than currently possible. The sensitivity analysis of these factors showed that the change in angle relative to the change in spacing has the greater effect on the geometric quality. The proposed factors displayed a good performance in a comparison analysis of four sites of the Dareh Bokhari travertine quarry complex located in Mahallat, Markazi province, Iran. Based on the results, blocks at sites 2 and 4 have the lowest and the highest geometric quality, respectively, which is in accordance with the operational conditions at the respective sites. Moreover, comparison of the values of factor q obtained from applying various cutting planes indicated that to maximally increase block production capacity, the current cutting direction at site 4 should be adjusted 33° eastward.

Geocultural landscaping: Guidelines and conceptual framework to design future scenarios of exploited lands

The environmental recovery of quarried areas is increasingly a landscaping first-order issue in many countries and relevant lessons can be learned from each case history, depending upon factors such as the terrain nature and landscape consolidation over time. The case of the Tivoli travertine quarries near Rome (Acque Albule Basin, Italy) is addressed with a multidisciplinary approach and analytic data indicating sustainable and resilient future solutions. Geological data are analyzed to know the resources and natural hazards of this territory. Historical landscape analyses are next accomplished to know the cultural heritage and evolution of man-nature interactions. Eventually, the present land use and 3D landscape are considered to know the current setting. This territory is characterized by natural hazards including earthquakes, degassing, subsidence, and river flooding, and by resources such as abundant thermal waters. Historical analyses show the occurrence of a significant cultural heritage including two UNESCO world heritage sites. The present landscape is characterized by deep quarries and unplanned urbanization. The integration of geological data with historical information provides a new knowledge forming a geocultural database that must be taken into consideration for future planning. Based on these results, general landscape and urban guidelines are proposed for the future recovery of this intensively-quarried and -urbanized territory. The main lesson learned from the Tivoli case history is twofold: (1) the integration and feedback between multiple disciplines and professionals (architects and geologists) working together on environmental improvements and (2) the careful view of the past territory and meticulous analysis of existing buildings and urban landscapes are the key to sustainably interpret the future landscape. The main novelty of this lesson is the improvement of the concept of cultural landscape (UNESCO: http://whc.unesco.org/en/culturallandscape/) and its expansion toward geological issues and man-geology/nature interactions. In an urban-saturated territory that is also geologically-worn by human activities (e.g., Acque Albule Basin), restoring guidelines must comply with the partly-new concept of geocultural landscaping, which consists of a sustainable and resilient planning based on the study and understanding of natural-geological hazards, natural and cultural resources, and man-nature relationships over large spaces and long terms (4D). A general conceptual framework for geocultural landscaping is eventually proposed.

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

This study compares and contrasts the travertine depositional facies of two of the largest sites of travertine formation, located in very different geological contexts, i.e. the modern Mammoth Hot Spring (MHS) system in the active volcanic complex of Yellowstone National Park (USA) and the Pleistocene Cakmak quarry, a well-exposed example of the Ballik travertines in the extensional Denizli Basin (Turkey). New, 2D to 3D facies maps of both travertine systems, combined with microscopy, assist in proposing an integrated spring depositional model, based on the existing MHS facies model, understanding general controls on meter to kilometer scale travertine deposit architecture and its preservation, and provide quantitative estimates of facies spatial coverage and slope using GIS. The comparison resulted in the distinction of eight facies, grouped in five downstream facies zones from Vent to Distal Slope. Notwithstanding the different geological context of both travertine systems, observations show that several of the facies are strikingly comparable (draping Apron and Channel Facies, top-slope Pond Facies, crystalline Proximal Slope Facies and Distal Slope Facies), whereas other facies do not have a precise, exposed equivalent (Vent Facies, pavement Apron and Channel Facies, extended Pond facies and phyto Proximal Slope Facies). Combining observations of active springs at MHS with the Cakmak vertical travertine quarry exposures demonstrates that lateral and vertical facies transitions are a sensitive record of changes in the spring dynamics (flow intensity and paths) that become well-preserved in the geological record, and can be recognized as prograding, aggrading, retrograding trends or erosive surfaces, traceable over tens to hundreds of meters. Quantification of facies specific coverage at MHS shows that Proximal and Distal Slope Facies deposits cover as much as ∼90% of the total mapped surface area. In addition, only ∼7% of the surface is found to be marked by a waterfilm related to an active flowing spring. Slope statistics reveal that strong slope breaks can often be related to transgressive Apron and Channel Facies belts and that variable, but steep slopes (up to 40°) are dominated by Proximal Slope Facies, in agreement with the Cakmak exposures. Integrating travertine facies and architecture of deposits formed in distinct geological contexts can improve the prediction of general spring facies distributions and controls in other, modern and ancient, subsurface travertine systems.

Investigating fracture–cracked systems with geophysical methods in Bayburt Kıratlı travertine

There are many outcropping masses on the K?ratl? travertine fields where a new or open quarry is planned to be exploited. In this study, ground penetrating radar (GPR) and vertical electrical sounding (VES) have been applied on these fields in order to identify massive or weathered blocks and fracture?cracked systems in a short time and at low cost. GPR data were acquired on two areas, named Ocakustu (Ocakustu 1, Ocakustu 2) and Alarduc (Alarduc 1, Alarduc 2), using a 100?MHz unshielded and 250?MHz shielded antennas on 35 profiles. Generally, radargrams obtained from GPR profiles revealed massive or weathered blocks and fracture?cracked systems of these fields. The quarry operation was stopped in Ocakustu 1 due to the intensely fracture?cracked and weathered structures of the travertine field imaged by GPR. Detailed information was not obtained under the topping layer of 4?m from GPR sections?on Ocakustu 2 area. Therefore, VES was also performed along four profiles which made it possible to define the areal extension and thickness of the lithotype in this site. Electrical resistivity tomography (ERT) sections?have been generated by the inversion of the VES data. The subsurface geometries with resistivity values in the area were determined from these sections. Massive blocks with high resistivity could be seen at depths of 2?10?m and 10?20?m below the surface on these results and it was suggested that the quarry should be extended these parts. In addition, according to the GPR data, fracture?cracked blocks were present in Alarduc where a travertine quarry is thought to be operated. The places that will be started and orientated to quarry can be determined with respect to radargrams on Alarduc 1. Ultimately, the exploitation of a quarry was not recommended due to the extremely fracture?cracked systems found in Alarduc 2.

Dating the Homo erectus bearing travertine from Kocabaş (Denizli, Turkey) at at least 1.1 Ma

Since its discovery within a travertine quarry, the fragmentary cranium of the only known Turkish Homo erectus, the Kocabaş hominid, has led to conflicting biochronological estimations. First estimated to be ∼500 ka old, the partial skull presents a combination of archaic and evolved features that puts it as an intermediate specimen between the Dmanisi fossils (Homo georgicus) and the Chinese Zhoukoudian skulls (Homo erectus) respectively dated to 1.8 to ∼0.8 Ma. Here we present a multidisciplinary study combining sedimentological, paleontological and paleoanthropological observations together with cosmogenic nuclide concentration and paleomagnetic measurements to provide an absolute chronological framework for the Upper fossiliferous Travertine unit where the Kocabaş hominid and fauna were discovered. The 26Al/10Be burial ages determined on pebbles from conglomeratic levels framing the Upper fossiliferous Travertine unit, which exhibits an inverse polarity, constrains its deposition to before the Cobb Mountain sub-chron, that is between 1.22 and ∼1.5 Ma. The alternative match of the normal polarity recorded above the travertine with the Jaramillo subchron (lower limit 1.07 Ma) may also be marginally compatible with cosmogenic nuclides interpretation, thus the proposed minimum age of 1.1 Ma for the end of massive travertine deposition. The actual age of the fossils is likely to be in the 1.1–1.3 Ma range. This absolute date is in close agreement with the paleoanthropological conclusions based on morphometric comparisons implying that Kocabaş hominid belongs to the Homo erectus s.l. group that includes Chinese and African fossils, and is different from Middle and Upper Pleistocene specimens. Furthermore, this date is confirmed by the large mammal assemblage, typical of the late Villafranchian. Because it attests to the antiquity of human occupation of the Anatolian Peninsula and one of the waves of settlements out of Africa, this work challenges the current knowledge of the Homo erectus dispersal over Eurasia.

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.

Optimum cutting wire assembly in dimension stone quarries

Production process in dimension stone quarries has a close relationship with the diamond beads efficiency and their number in unit length (density parameter). This study intends to find out the governing relationship between these parameters and cutting efficiency according to empirical findings in Targh travertine quarry. In addition, it's been tried to figure out the optimum operating condition in order to maximize the efficiency. To do so, along with the number of beads in unit length, other parameters such as cutting length and time have been recorded through the whole lifetime of cutting wire. The collected data have been compiled statistically in order to obtain the optimum cutting dimensions, cutting capacity and efficiency and the optimum number of beads in unit length. The results showed that the optimum mode of cutting wire assembly occurs using 31 diamond beads per meter. Besides, diamond beads have the highest efficiency at the middle third of their lifetime.

Natural contamination by As and heavy metals in soil, their bio-accumulation and potential sources: the case of a travertine limestone quarry, Greece

AbstractThe first mineralogical and geochemical investigation of the travertine limestone, soil and corresponding plants associated with the Neogene basin of Varnavas, NE Attica, revealed a significant enrichment in the metalloid As. The total concentrations of As ranged from 61 to 210 ppm in limestone and 33 to 430 ppm in the associated soil demonstrating a wide variation of values. Calcite is a common authigenic mineral within travertine limestone, forming fine uniform micritic aggregates, having As and Mg concentrations lower than detection limits of EDS analysis. Clastic dominated minerals are quartz (both fine- and coarse-grained), muscovite, clinochlore, illite, pyrite, galena, arsenides, rutile, sphene, zircon, REE-minerals and albite. Goethite and Fe-Mn-oxides occur between calcite grains. The presence of fossilized micro organisms, resembling foraminifera, in travertine limestone combined with hydrous Fe-Mn-oxides, suggests a possible marine transgression during the evolution of the basin.The As content in plants ranges from 1.1 to 28 ppm As in shoots, and 0.8 to 114 ppm As in roots. The translocation factor, which is defined as the ratio of metal concentration in the shoots to the roots, is relatively low (average 0.33%) suggesting that the internal transport of metals from the roots to shoots was restricted. The bioaccumulation factor, which is defined as the ratio of metal concentration in the plants to that in soil, exhibits a wide range from relatively low (5.2–9.0% for As, Fe, Cr, Ni and Pb), much higher (56–67% for Cu and Zn) and exceptionally high (160% for Mo). A significant correlation between the translocation factors for Fe and As may confirm that Fe-Mn oxides/hydroxides represent the major sorbing agents for As in soils. The presented data, due to As contamination in travertine limestone, soil and plants, suggest a potential environmental risk not only for that part of Greece but in general for similar depositional environments.