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Various additives are introduced to drilling mud to control its flow behavior in drilling operations under the desired conditions. These additives can cause increased drilling costs and environmental damage. In recent years, natural materials have mainly been used in drilling mud to reduce the increasing costs. In this study, amorphous silica was obtained by alkaline extraction method from pumice and quartzite, having a large reserve in Turkiye. Amorphous silica, which is cost-effective and easy to supply, was used in the drilling mud and rheological and filtration tests of the fluids. The results obtained from the study indicate that drilling mud with 8, 9, and 10 % of amorphous silica exhibits promising results.

The production of synthetic iron castings in Russia comprises 50% of all alloys produced; therefore, increasing their smelting efficiency is an urgent task in the industry. This process depends primarily on the efficiency of industrial frequency induction crucible furnaces using acid lining. In the present study, the properties of quartzite, which forms the basis of such a lining, were investigated. An analysis of the proposed variants for changing the composition of the acid lining for use at temperatures of 1550–1600 °C was conducted. Following the preliminary temperature treatment of raw quartzite, which was then subjected to a sintering regime, we determined the conditions under which it was possible to obtain a phase state, allowing for the operation of the lining at temperatures above 1450 °C. We determined the use of an electrocorundum of two fractions as an additive to the traditional composition of the acid lining. The industrial testing of a new liner composition for the smelting of synthetic cast iron in an induction crucible melting furnace with a single steel scrap-metal filling was assessed, which required the use of an increased amount of carburizing agent. The positive results obtained can be explained by the study of the spent lining, which withstood 345 smelting methods of genophasic rent analysis. The results of the test are based on the results obtained in a study conducted on the finished coating of the product.

In Juazeiro de Piauí and Castelo do Piauí, two cities in northeast Brazil, mined morisca rock is widely used in civil construction for external coating applications. Aiming at a sustainable practice for its extraction, which includes the economical use of the tailings from its mining, this work presents a solution for the use of discarded materials from processing morisca from Piauí. In this context, an analysis of the results of using morisca as a substitute for clay materials for applications in red ceramics are presented. For the analyses, XRF, XRD, microgranulometry, limits of consistency, TG, DTG, and a set of technological tests inherent to ceramic materials were used. It was concluded that morisca powder is viable as a clay substitute for red ceramic applications.

Brazil has immense potential in the production of quartz and its gem varieties, consequently generating huge amounts of waste. This research aims to utilize the amethyst quartz tailings from the Alto Bonito mine-Brazil accumulated for decades in waste dumps, through a specific study of cementitious mortar production, considering the mineralogical and chemical characterization; evaluation the use of tailings as a fine aggregate for mortar production; estimate the technical feasibility through mechanical tests and; characterize of specimens by SEM after breakage. The tailings are quartz associated with mica. Quartz is polycrystalline with medium to fine grain, being SiO2 the main component. The comminuted tailings showed a very fine fineness modulus, affecting the formulations. With cement:tailings (1:3) traces the mechanical tests show 5.65 Mpa and 1.05 Mpa to compressive and flexural strength respectively, slightly below the reference. The fine-sized and metamorphic morphology of the tailings affects the mechanical strength of the mortar. The process adopted in the production of mortars with total replacement of the fine aggregate have a great impact contributing to the reduction of waste in dumps, minimizing the environmental impact of mining, in addition to benefiting the Amethyst Miners Cooperative.

This paper presents an attempt to use crushed quartzite as a substitute to crushed basalt, which is since more than sixty years the most systematically used aggregate on all the Senegalese territory to formulate the bituminous mixes for pavement. This massive use induced a decrease of basalt reserves and it is urgent to find other substitution materials. This article reports an attempt to valorize crushed massive quartzite from Bakel in the region of Tambacounda in Senegal. The studies carried out on a mixture of quartzite composed of 23% of 8/14, 25% of 3/8 and 52% of 0/4 and bitumen 35/50 showed that this quartzite material complies with the rules and practices currently in force in Senegal.

The analysis of modern research in the direction of water mineralization during water treatment is carried out. The possibility of mining waste usage for water mineralization after treatment, in particular by reverse osmosis, is considered and substantiated. An experiment in which mining waste was placed in a container with distilled water in the proportion of 100 g of rock per 1 liter of water was carried out. Distilled water was infused during the day. Waste from the crushed stone production process was obtained from PJSC «Tovkachivskyi MPP». The studied rock has the following composition: quartzite – 90–98 %, pyrophyllite – 1–9 %, ore mineral – 0,3–1 %. A study of the chemical composition of water after mineralization was done. It is established that the ratio of mass particles «rock-water» as 1:10 allows us to saturate the water with such useful elements as Calcium, Magnesium, Sodium, Potassium, Silicon, as well as fluorides. However, it should be noted that the content of Iron, Manganese and polyphosphates is also increasing. Determining the optimal ratio of «rock-water», which would allow saturating the water with useful elements and ions, while ensuring compliance with water State sanitary rules and regulations 2.2.4-171-10, is the subject of further research.

We experimentally determined the hydraulic properties of fractures within various rock types, focusing on a variety of Variscan rocks. Flow-through experiments were performed on slate, graywacke, quartzite, granite, natural fault gouge, and claystone samples containing an artificial fracture with a given roughness. For slate samples, the hydraulic transmissivity of the fractures was measured at confining pressures, pc, at up to 50 MPa, temperatures, T, between 25 and 100 °C, and differential stress, σ, acting perpendicular to the fracture surface of up to 45 MPa. Fracture transmissivity decreases non-linearly and irreversibly by about an order of magnitude with increasing confining pressure and differential stress, with a slightly stronger influence of pc than of σ. Increasing temperature reduces fracture transmissivity only at high confining pressures when the fracture aperture is already low. An increase in the fracture surface roughness by about three times yields an initial fracture transmissivity of almost one order of magnitude higher. Fractures with similar surface roughness display the highest initial transmissivity within slate, graywacke, quartzite and granite samples, whereas the transmissivity in claystone and granitic gouge material is up to several orders of magnitude lower. The reduction in transmissivity with increasing stress at room temperature varies with composition and uniaxial strength, where the deduction is lowest for rocks with a high fraction of strong minerals and associated high brittleness and strength. Microstructural investigations suggest that the reduction is induced by the compaction of the matrix and crushing of strong asperities. Our results suggest that for a given surface roughness, the fracture transmissivity of slate as an example of a target reservoir for unconventional EGS, is comparable to that of other hard rocks, e.g., granite, whereas highly altered and/or clay-bearing rocks display poor potential for extracting geothermal energy from discrete fractures.

The article presents the results of geological and structural studies of the northwestern part of the Gargan quartziferous province, wherein the Bural-Sardyk deposit is located. The early views on this deposit of high-quality siliceous raw materials have been amended using the new data. This deposit is associated with quartzites of the Meso-Proterozoic Irkut formation and discordantly overlaps the Gargan block. According to the detailed study results on the cover of the Oka-Urik interfluve area, its structure is predetermined by physical and mechanical properties of the rocks, and the degree of rock dislocation depends on the rock viscosity. Most of its section is composed of viscous quartzites that create the structural framework of the study area. Such viscous rocks are not prone to folding. An alternative is detachment taking place concordantly to layering. The only interlayer is composed of limestones that underwent intense plastic deformation reflected in multi-folding. Actually, limestones mark a zone of plastic detachment. The authors propose an interpretation of the formation of the deposit structure. The main deformation event was preceded by the sediment transformation stage in conditions of diagenesis and catagenesis due to the influence of a lithostatic load. Primary recrystallization under lithogenesis led to the formation of high-purity silicon rocks. At the next stage, the rocks were subjected to longitudinal compression in the PT conditions of green-shale metamorphism. This stage is mainly evidenced by sublayer detachments. In parallel with that process, quartzites experienced super-plastic flow and recrystallization, which led to the formation of super-quartzites. The bodies of super-quartzites tend to be layered and less discordant. Such a structural position suggests the possibility of detecting latent manifestations of super-quartzites at different levels in the quartzites of the Irkut formation. Tectonic detachments are observed in the sedimentary cover and do not reach the foundation. Based on these features, there are reasons to use the thin-skinned tectonic model. Rock deformation occurred under stress oriented from the northwest to the southeast. This is indicated by the position of the axial surfaces of the folds, as well as the orientations of the maximum compression axis and the crystallographic axes of quartz. Macro- and microstructural data indicate that the tectonic transport of matter was directed to the southeast. The research results were used for compiling a new geological map of the deposit.

Skiferdriften i Alta har historie tilbake til 1850-tallet, de første hundre årene i hovedsak som en sidenæring til jordbruk. Utover 1900-tallet ble markedet for produkter av altaskifer stadig større, og skiferdriften vokste til å bli en viktig næring. Andelslaget Alta Skiferbrudd ble stiftet i 1933. Alle skiferdrivere var og er selvstendig næringsdrivende, men medlemskap i andelslaget har alltid vært en forutsetning for å delta i skiferdriften. Skiferforekomstene i Alta ligger på statlig grunn, og Alta Skiferbrudd forpakter rettighetene til å drive steinbrudd på vegne av medlemmene. Skiferdrift er et håndverk som krever mye kunnskap og erfaring, men lite investeringer for å gi et godt økonomisk utbytte. Etterkrigstidens industri- og distriktspolitikk nådde også skifernæringen i Alta, og i perioden fra 1950 til 1980 ble det startet flere bedrifter som hadde som formål å modernisere og effektivisere skiferdriften. Dette skjedde med liten forankring i skiferdrivernes organisasjon, og uten å ta hensyn til drivernes opparbeidede kunnskap om skifer og skiferarbeid. Det var Utbyggingsfondet for Nord-Norge, Distriktenes utbyggingsfond og Industridepartementet som i stor grad styrte planlegging og gjennomføring og som støttet prosjektene økonomisk. Det var store forventninger til resultatene, men de uteble. Artikkelen diskuterer noen forklaringer til hvorfor de store statlige prosjektene slo feil gang på gang, og årsakene til at den «tradisjonelle skiferdriften» – som den ble kalt i de statlige utredningene, fremdeles er en av Altas viktigste næringer.

The increase in rates of habitat loss requires an understanding of how biodiversity is distributed. Campo rupestre is an old, climatically buffered, and infertile landscape located in Brazil. Considered a biodiversity hotspot, the campo rupestre is mainly threatened by mining activity that requires a large operating area. Campo rupestre is known for its restricted distribution area and high abiotic heterogeneity, which modulates species coexistence and richness. To recognise the association between habitat type and plant communities, we propose to describe the floristic composition of herbaceous and shrub components in four habitats of the campo rupestre comprising quartzite and ferruginous substrate. We classified habitat types by the main surface soil features. In each habitat, we sampled ten 100-m2 plots to access information on the shrub and ten 1-m2 plots for the herbaceous component. Altogether we sampled 153 species, belonging to 38 families. The cluster analysis ordered by Sorensen metric indicates a clear distinction of species composition in the shrub component in the four habitats. However, the floristic composition of the herbaceous component was similar between the four habitats but showed a distinction when contrasting with the substrate type. Our results highlight the local taxonomic distinction between habitat types and substrates, indicating that the ecological distinction among substrate types of the campo rupestre cannot be overlooked in conservation and restoration actions.

The angle and shape of lithic tool edges have long been used as a method of inferring prehistoric tool function. However, accurately measuring and characterizing edge angles of lithic tools is notoriously difficult. Studies using goniometers, calipers, or morphometrics often rely on two-dimensional representations of edges. Furthermore, there have been limited attempts to quantitatively document stone tool edges based on surface metrology, most notably edge curvature. In this study, we use microCT to capture models of the complex geometry, or ‘freeform’ surfaces, of experimental quartzite flakes from Olduvai Gorge (Tanzania) to document and mathematically calculate edge curvature using multiscalar length-scale analysis. Through this analysis, we also explore the quantification of re-entrant (overhang) features on lithic edge cross-sections. On lithic tools, especially coarse-grained rocks with complex surface topographies, such as quartzite, traditional techniques for edge angle measurement are incapable of capturing re-entrant features on edge profiles. Here we present the first archaeological study that addresses the measurement of these re-entrant features, using novel length-scale and curvature analysis methods of calculating edge angles for complex freeform surfaces. With these new methods for measuring edge angles, we can consider the impact of complex geometry, including re-entrant features, on the function of lithic tools in the past., Permission to export Olduvai quartzite was authorized by COSTECH and Department of Antiquities, Tanzania, and de la Torre was funded by an ERC-Advanced Grant (BICAEHFID, No. 832980). Bartkowiak’s, Mendak’s, and Wieczorowski’s contribution to the research was funded by the Polish Ministry of Science and Education as a part of a research subsidy, project number: 0614/SBAD/1547. Macdonald’s research was supported by the National Science Foundation (grant number 1727357). Key’s work on this research was supported by the Royal Society (RGS\R1\211318)

First of all, the smelting equipment is the most important component of a foundry’s main production process and therefore requires constant reproduction. This is ensured by timely and high-quality maintenance and repair, the cost of which is 8–12% of the total costs. The technical and economic conditions of the enterprise itself depend on this, as the productivity of workers during production is directly related to the technical condition of the equipment and its downtime for repairs. An important factor in ensuring a melting furnace’s reproduction is a replacement of the worn lining, which leads to downtime of the smelting furnace and reduces the efficiency of its operation. The amount of torque required depends directly on the compound used. The quality of the manufacturing and sintering process of the lining, which provides the necessary durability, is affected by the heat capacity of the materials used when they are affected by the melting temperature of the alloys. In the present work, using the BRUKER D8 ADVANCE diffractometer, the Shimadzu XRF-1800 spectrometer and the STA 449 F1 Jupiter synchronous thermal analyzer, we probed the changes in the heat capacity of quartzite and PKMVI-3 under the action of temperatures of 200–1550 °C. This technology allows the manufacture of a lining that maintains high stability during operations at 1550–1600 °C melting modes.

Up to now, little was known about the Middle Palaeolithic from the Hérault Valley (France). Recently, systematic surveys have led to the discovery of several surface stations on river terraces. Some of these have yielded stone tools made from unusual raw materials, such as, brecciated quartzites and jasper-like rocks, as well as quartz and rare flints. These rocks are found in primary position in the Montagne Noire area, and are also available in the alluvial deposits of the Hérault and its tributaries in the form of more or less rounded cobbles. These raw materials are very heterogeneous even within a single cobble. Their inter and intra-variability has been found to have induced specific knapping strategies as hominins adapted to - or took full advantage of - their special petrographic characteristics. Here we present data from three Middle Palaeolithic open-air stations (Les Geissières, Saint-Saturnin and Camillo) to illustrate adaptive knapping strategies performed by Neanderthals. In addition to the technological analysis, experiments were also conducted to test some of the identified methods, such as bipolar-on-anvil, with the aims of: 1) evaluating flake production efficiency and 2) recognizing specific traces left on the products by this method. This enabled us to better identify archaeological artefacts in this particular alluvial context. The study shows the use of stone reduction methods that allowed the knappers to adapt to the constraints posed by the raw materials: Discoid sensu lato (bifacial, unifacial, partial), Clactonian and bipolar-on-anvil. Methods more diagnostic of the Middle Palaeolithic, such as the Levallois and typo-Levallois or various Kombewa methods were used on finer grained raw materials. There are a few retouched flake tools and some pebble tools (mainly choppers). These assemblages show us that, despite the influence of the raw materials (which is more of a constraint than a limit), Neanderthals achieved their goals through a variety of methods. These surface stations make it possible to better perceive adaptive strategies in the Middle Palaeolithic in Languedoc-Roussillon, in a context where the Levallois techno-complexes prevail.

The characterization of the Pouma-Cameroon quartzite deposit with the aim of determining its lateral extension along the Douala-Yaounde axis required, among other things, the examination of the petrographic and morpho-structural domain as well as the determination of the electrical properties of the formations in the study area. 24 vertical electrical sounding points were carried out using a Schlumberger type electrode configuration; also, 7 manual auger boreholes were carried out, these resulted on one hand in the following types of curves: KH, QH, AKH, H, HK, AK, HA, A; and on the other hand to lithological logs with a clayey sandy texture, gravelly clayey sand to lateritic. The calculation of the densities as well as the petro-structural studies made it possible to confirm the geological context of the study area. The various results obtained permitted us to locate the fresh quartzite formation at the center of the study area. It stretches along the Douala-Yaounde axis over 1871.4 m for the fresh formation and 1991 m for the slightly altered formation.

The analysis of modern research in the direction of water mineralization during water treatment is carried out. The possibility of mining waste usage for water mineralization after treatment, in particular by reverse osmosis, is considered and substantiated. An experiment in which mining waste was placed in a container with distilled water in the proportion of 100 g of rock per 1 liter of water was carried out. Distilled water was infused during the day. Waste from the crushed stone production process was obtained from PJSC «Tovkachivskyi MPP». The studied rock has the following composition: quartzite – 90–98 %, pyrophyllite – 1–9 %, ore mineral – 0,3–1 %. A study of the chemical composition of water after mineralization was done. It is established that the ratio of mass particles «rock-water» as 1:10 allows us to saturate the water with such useful elements as Calcium, Magnesium, Sodium, Potassium, Silicon, as well as fluorides. However, it should be noted that the content of Iron, Manganese and polyphosphates is also increasing. Determining the optimal ratio of «rock-water», which would allow saturating the water with useful elements and ions, while ensuring compliance with water State sanitary rules and regulations 2.2.4-171-10, is the subject of further research., Проведено аналіз сучасних досліджень у напрямі мінералізації води в процесі водопідготовки. Розглянуто та обґрунтовано можливість використання відходів гірничого виробництва для мінералізації води після очищення, зокрема зворотнім осмосом. Проведено експеримент, у межах якого в ємність із дистильованою водою поміщались відходи гірничого виробництва у пропорції 100 г породи на 1 дм3 води. Дистильована вода настоювалася протягом доби. Відходи процесу виробництва щебеню отримано від ПрАТ «Товкачівський ГЗК». Досліджувана порода має такий склад: кварцит – 90–98 %, пірофіліт – 1–9 %, рудний мінерал – 0,3–1 %. Проведено дослідження хімічного складу води після мінералізації. Встановлено, що співвідношення масових часток «порода – вода» в пропорції 1:10 дозволяє наситити воду такими корисними елементами, як Кальцій, Магній, Натрій, Калій, Силіцій, а також фторидами. Однак варто зауважити, що вміст Феруму, Мангану та поліфосфатів також зростає. Визначення оптимальної пропорції «порода – вода», яка б дозволила максимально наситити воду корисними хімічними елементами та іонами й водночас забезпечити її відповідність ДСАНПІН 2.2.4-171-10, є предметом подальших досліджень.

The objective of this work was to test the hypothesis that weathering-resistant surface layers found in intensively hammered petroglyphs at many sites worldwide and on other heavily battered metamorphosed rocks are the result of kinetic energy-induced tribological reactions. The methods of material testing included extensive fieldwork and in-situ studies at an Indian site that had been subjected to fluvial battery in the distant geological past; the removal of numerous surface and subsurface samples; and their analysis by several laboratory methods. These included binocular light microscopy, scanning electron microscopy, thin sectioning and elemental composition determination of crucial sites. It was confirmed that samples show evidence of crystallization by ductility of formerly amorphous silica cement in quartzite, yielding a tectonite of fully crystalline quartz. This finding confirms that the surficial application of very high levels of kinetic energy to certain rock types that are susceptible to metamorphosis can yield exceptionally weathering-resistant surface layers. This phenomenon has not been described before. Although it was first observed in rock art it is now thought to occur much more widely in numerous geological contexts, such as at fault mirrors, in the form of what has been regarded as glacial polish and on ventifacts.

Quality of raw materials, including quartz sand and quartzite, varies from one deposit to another. Furthermore, the material quality determines in which industrial branches it can be used after certain preparation processes. Potential applications of quartz raw materials are: in the construction and refractory industry, ceramics and glass industry, then in metallurgy, foundry and also in production of water treatment filters. Geological investigations of the central Serbia region, in the Rekovac municipality, resulted in identification of occurrence of quartz sand ("Ursula") and quartzite ("Velika Kruševica"). Preliminary laboratory tests and characterization of the quartz sand size fraction -0.63+0.1 mm confirmed the possibility of applying this size fraction in the construction materials industry, while the quartzite can be used in refractory, glass and metallurgy industries. After determining the geological reserve of quartz sand "Ursula" and quartzite "Velika Kruševica", detailed investigations are required. Quality conditions from the aspect of chemical composition and physical properties of quartz sand and quartzite are mostly clearly defined by a special standard for this purpose. On the other hand, there are also application areas where standards does not exist, but users define their quality conditions. This example is with the application of quartz sand in the production of water glass. Chemical composition as well is not always the determining factor for the application of quartz raw material. For example, for quartz sand used for sandblasting, grain form is essential. From the economic analysis point of view, the prices of quartz raw materials vary depending on their chemical and physical properties. After all, what needs to be pointed out is the fact that these raw materials are very widespread in nature and that their exploitation is quite simple. After the raw material is excavated, it is stored and further sieved, washed, dried and processed according to customer requirements. All of these processes are cheaper than preparing, for example, limestone, and significaly cheaper than preparation of metal ores. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR 34013]

The efficiency of the production of foundry products depends on the reliable operation of the melting furnace including, therefore, the durability of its lining. The most common material adopted for the production of an acid furnace crucible lining is quartzite, in which during the pretreatment (heating to 800 °C followed by holding), a tridymite phase appears that maintains a constant volume at 840–1470 °C for a long time and provides high lining durability of 300–350 melts, but only when using melting temperature regimes not exceeding 1500 °C. However, the absence of iron scrap leads to the smelting of synthetic iron from only one steel scrap using higher melting temperatures (1550–1570 °C), which sharply reduces the lifetime of the lining to 220 melts. This work is devoted to research aimed at establishing technology for the pretreatment with the original quartzite, which ensures the formation of a phase state that successfully withstands elevated temperatures for a long time. The studies were carried out using a Bruker D8 ADVANCE diffractometer and a Shimadzu XRF-1800 X-ray wave-dispersive spectrometer. The work consisted of drying samples of the original quartzite at temperatures of 200 and 800 °C with subsequent exposure to temperatures of 200, 400, 600, 870, 1000, 1200, 1470 and 1550 °C. As a result, the conditions for pretreatment of quartzite were established, during which during its further use, a cristobalite phase can be obtained, which makes it possible manufacture a high-temperature lining that ensures its high durability. The introduction of this technology will ensure the efficiency of the production of foundry products for enterprises operating induction crucible furnaces at industrial frequency.

In the present study, the thermoluminescencecharacteristics of natural quartzite collected from Karaisalı (Adana) in Turkeywere investigated after β irradiation at room temperature with the purpose touse as radiation dosimetry. The glow curve of quartzite mineral shows two peaksat 110 oC and 250 oC and a shoulder at 375 oC,explicitly. The resulting peaks, which were examined using the computer glowcurve deconvulation (CGCD) method, were deconvuluted and kinetic parameters(activation energy Ea,frequency factor (s) and kineticdegree (b)) were determined. AfterCGCD methods, it was seen that the glow curve suporposed at least eightpeaks. Additionally, kinetic parameterswere determined using by Arrhenius plot obtained from initial rise (IR) method.In this study, it is shown that there is a correspondence between kineticparameters calculated by IR method and peaks deconvoluated by CGCD technique inlow temperature region (P1-P3). Additionally, reusability test was conducted toinvestigate its usability as a dosimetric material, and a change of 2% wasobserved in the results of 10 repeated times. Besides to the characterizationof this sample X-ray diffraction (XRD) and scanningelectron microscopy (SEM) - energy dispersive X-ray (EDX) results wereinvestigated., Bu çalışmada, Türkiye’de Karaisalı (Adana)’dantoplanan doğal kuvarsit kayacının termolüminesans karakteristiği, bir radyasyondozimetresi olarak kullanmak amacıyla oda sıcaklığında β ışınlaması yapıldıktansonra incelenmiştir. Kuvarsit mineralinin ışıma eğrisi belirgin bir şekilde 110oC ve 250 oC'de iki tepe noktası ve 375 oC 'debir omuzu göstermektedir. Bilgisayarla Işıma Eğrisi Ayrıştırma (CGCD) yöntemikullanılarak tepeler ayrıştırılmış ve kinetik parametreler (aktivasyon enerjisiEa, frekans faktörü (s) ve kinetik derece (b)) belirlenmiştir. CGCD yöntemindensonra, bu ışıma eğrisinin en az sekiz tepeden oluştuğu görülmüştür. Ayrıca IRyönteminden elde edilen Arrhenius grafiği yöntemiyle kinetik parametrelerbelirlendi. Bu çalışmada, düşük sıcaklıktaki tepe değerleri için CGCD tekniğiile ayrılan tepeler ile (P1-P3) IR yöntemi ile hesaplanan kinetik parametrelerarasında bir ilişki olduğu gösterilmiştir. Ek olarak, dozimetrik materyalolarak kullanılabilirliğini araştırmak için tekrar kullanılabilirlik testiyapılmış ve 10 kez tekrarlanan sonuçlarda % 2'lik bir değişim gözlenmiştir. Buçalışmaların yanında kuvarsit örneğinin karakterizasyonu için X-ışını kırımı(XRD) ve taramalı elektron mikroskobu (SEM-) enerji yayılımlı X-ışını analizi(EDX) sonuçları incelendi.

Raw material characterization in Paleolithic archaeology has widened our knowledge of Middle Paleolithic societies. Procurement of raw material, specifically flint, has allowed the tracing of the mobility of both stones and people, as well as selective processes to obtain specific types or even extraction activities. The analysis of quartzite has also developed in recent years, providing an opportunity to better understand prehistoric societies. This study characterizes the procurement strategies implemented by Middle Paleolithic people in the mountainous region of the Picos de Europa. To this end, we present a comprehensive characterization of potential catchment areas: massive outcrops, conglomerates, and river deposits. The exploitation of quartzite at the sites of El Habario and El Arteu allows us to understand the territorial management of this mountainous area through the combination of selective processes and mobility mechanisms in lower and middle altitudes. These perspectives enable us to view the mountainous region not as a barrier but as an environmental mosaic managed by Middle Paleolithic groups. This study shows strategies that bring together direct and embedded procurement based on both intensive and extensive searches. These discourses are more closely related to the daily life of people than those only considering the mobility of people and objects., A comprehensive geoarchaeological research project based on the integration of a geographic information system, field survey, stereomicroscopy, and thin‐section petrography, is presented to characterize potential procurement areas of quartzite. The application of this methodology in the Deva, Cares, and Güeña valleys and in three different geological contexts; massive outcrops, conglomerates, and secondary deposits, suggest potential acquisition processes of lithic resources. The analysis of the quartzite assemblages of El Habario and El Arteu unveils complex management of terrain based on a mobility mechanism that connects middle altitude plateaus with open and lower river valleys, as well as intensive and extensive procurement mechanisms of raw material., Education Department of the Government of the Basque Country, The Spanish Ministry of Science Project, The Consolidated Research Group in Prehistory of the Basque Country University

A comprehensive understanding of geological, structural geological, hydrogeological and geotechnical features of the host rock are essential for the design and performance evaluation of surface and underground excavations. The Hungarian National Radioactive Waste Repository (NRWR) at Bátaapáti is constructed in a fractured granitic formation, and Telfer Gold Mine in Australia is excavated in stratified siltstones, sandstones and quartzites. This study highlights relationships between GSI chart ratings and calculated GSI values based on RMR rock mass classification data. The paper presents linear equations for estimating GSI from measured RMR89 values. Correlations between a and b constants were analyzed for different rock types, at surface and subsurface settings.

This article deals with material research of selected types of quartz and quartzites in order to determine the priority of their use in the production of ferrosilicon and pure silicon, respectively. The highest quality quartzes and quartzites are commonly used in metallurgy, but not all types of these silicon raw materials are suitable for the production of ferrosilicon and pure silicon, despite their similar chemical composition. Behavior differences can be observed in the process conditions of heating and carbothermic production of ferrosilicon and silicon. These differences depend, in particular, on the nature and content of impurities, and the granularity (lumpiness) and microstructure of individual grains. The research focused primarily on determining the physicochemical and metallurgical properties of silicon raw materials. An integral part of the research was also the creation of a new methodology for determining the reducibility of quartzes (or quartzites), which could be used for real industrial processes and should be very reliable. The results of the laboratory experiments and evaluation of the physicochemical and metallurgical properties of the individual quartzes (or quartzites) are presented in the discussion. Based on comparison of the tested samples’ properties, their priority of use was determined. This research revealed the highest quality in quartzite from Sweden (Dalbo deposit) and Ukraine (Ovruč deposit) and quartz from Slovakia (Švedlár deposit). The use of these raw materials in industrial conditions is expected to result in the achievement of better production parameters, such as higher yield and product quality and lower electricity consumption.

PhD (Environmental Sciences), North-West University, Potchefstroom Campus The Griqualand West Centre (GWC) of plant endemism harbours a unique flora of which 24 species are endemic. Heterogeneous geology, climate and topography are considered drivers of the unique flora and local endemism. However, these drivers have not yet been investigated and our understanding of the effects thereof on vegetation dynamics remains poor. Four mountain ecosystems, each underlain by different rock types and with distinct climatic patterns, provided a setting to investigate the effects of ecological drivers shaping vegetation dynamics of this semi-arid area. Therefore, the primary aim of this study was to disentangle the effects of rainfall and geology, through soil properties related to the underlying geological parent material, as drivers of floristic patterns, plant diversity and structure, biomass production, and the relationship between diversity and biomass production. The objectives of this study were to (i) redefine the borders of GWC to establish which mountain ranges fall within the centre by using a MaxEnt spatial model based on geology, climate and topography in combination with distribution data of GWC endemics, (ii) describe the flora within the newly redefined borders of GWC based on dominant plant families and -species, indicator plant species, endemic species and species composition, (iii) compare soil properties, rainfall, plant diversity and structure between mountain ecosystems to test whether mountains, within the newly defined borders of GWC, differ significantly from each other, (iv) determine whether soil properties, rainfall or a combination thereof act as drivers of plant diversity and structural differences between mountains, (v) test for differences in total biomass production (above ground green plant material and debris), live biomass production (only live green above ground plant material) and respective plant functional group (PFG) biomass production between the four mountain rangelands, (vi) relate differences to specific soil properties and rainfall to identify the strongest drivers of biomass production, (vii) investigate diversity-biomass relationships for total plant species and for species representing different PFGs, and (viii) present an optimal range of biomass production at which herbaceous species diversity can be maintained at regional scale. Results obtained from this study revealed that each mountain plant community was characterised by unique herbaceous plant communities with specific indicator plant species, driven by soil properties and rainfall. Herbaceous plant composition, density, height, cover and shrub frequencies were related to a combination of soil properties and mean annual rainfall. However, plant diversity, and grass, lignified forb and tree frequencies, as well as woody plant height and canopy area, could only be related to soil properties. Grasses, lignified forbs and herbaceous forbs contributed to biomass production in descending order. At regional and local scales, diversity-productivity relationships followed non-linear trends. However, optimum biomass production was reached at highest diversity. Semi-arid mountain landscapes in GWC provide important ecosystem services through their unique plant diversity. It is necessary to follow a holistic, multi-disciplinary conservation and management approach to not only manage for species diversity, but to conserve the underlying environmental drivers in semi-arid mountain plant communities. Doctoral

Sinningia rupicola (Gesneriaceae), espécie ameaçada de extinção e classificada como endêmica de canga do Quadrilátero Ferrífero é aqui apresentada sob uma abordagem ecológica, baseada na análise de dados referentes a registros realizados em duas Reservas Particulares do Patrimônio Natural (RPPN) da empresa Vale, situadas no Quadrilátero Ferrífero, Estado de Minas Gerais, Brasil: Capanema e Poço Fundo. O estudo visou caracterizar a população da espécie quanto ao número de indivíduos, área de ocupação (AOO), extensão de ocorrência (EOO) e aspectos ambientais dos locais de registros relacionados à topografia, cobertura vegetal e litologia, além de avaliação do substrato, micro-habitat e fenologia. Foram registrados 1.397 indivíduos, sendo 1.254 na RPPN Capanema e 143 na RPPN Poço Fundo. As populações foram registradas colonizando rochas Quartzíticas, em altitudes que variaram entre 1.400 e 1.600 m. As populações foram caracterizadas como predominantemente saxícolas, encontradas em floração entre janeiro e março e com frutos entre fevereiro e março. Os resultados obtidos neste estudo demonstram a ocorrência de Sinningia rupicola em litologias variadas, o que sugere que a distribuição da espécie em ambientes naturais é mais ampla do que a até então presumida. RESUMO Sinningia rupicola (Gesneriaceae), an endangered species classified as endemic to the cangas of the Quadrilátero Ferrífero is presented here under an ecological approach. It was based on data analysis of two populations sampled in the Private Natural Heritage Reserves (RPPN) Capanema and Poço Fundo belonging to the company Vale S.A., located at the Quadrilátero Ferrífero, state of Minas Gerais, Brazil. The study aimed to characterize the populations of the species regarding the number of individuals, area of occupancy (AOO), extent of occurrence (EOO) and the environmental aspects of the record sites. The populations were related to topography, hydrography, vegetation cover and lithology, as well as substrate, micro-habitat and phenology evaluation. In total, it was registered 1,397 individuals, 1,254 at RPPN Capanema and 143 at RPPN Poço Fundo. The populations were found occurring on quartzitic rocks, at altitudes ranging from 1,400 to 1,600 m. The populations were characterized as predominantly saxicolous, flowering between January and March and with fruits between February and March. The results obtained in this study demonstrate the occurrence of Sinningia rupicola in varied lithologies suggesting that its occurrence in natural environments may be wider than previously assumed.

The expediency of replacing natural quartz Sands, whose reserves are gradually exhausted, by rock screenings as part of fine-grained concretes is shown. In particular, the characteristics of granite and quartzite crushing screenings in comparison with quartz river sand are presented, as well as the results of studying the strength and abrasion of the fine-grained concrete obtained. To exclude the effect of the grain composition on the properties of concrete, aggregate samples were pre-fractionated, and the conditions for producing concrete (cement consumption, water-cement ratio, concrete mix mobility) were the same. It was found that quartz sand having rounded grains with a relatively smooth surface promotes the formation of dense particle packing and increases the strength of fine-grained concrete by 9-14%, but at the same time reduces the abrasion of similar standard samples by 20-30% compared to screenings crushing of granite and quartzite. The maximum abrasion resistance showed concrete containing quartzite screening. Quartzite – metamorphic (metasomatic) dense rock crushing which produces angular particles with a rough surface. The absence of dense packaging reduces the compressive strength of concrete samples containing quartzite aggregate compared to quartz sand. At abrasion of similar samples in a thin layer the resistance to sliding of filler particles one relative to another increases. Therefore, when choosing crushed rock fines instead of natural quartz Sands, it is important to consider the purpose of the designed fine-grained concrete. Keywords: crushing screenings, quartz sand, granite, quartzite, fine-grained concrete, strength, abrasion

The development of artificial stone from the agglutination of polymeric resin using industrial wastes can be a viable alternative from a technical, economic, and sustainable point of view. The main objective of the present work was to evaluate the physical, mechanical, and structural properties of artificial stones based on quartzite waste added into a synthetic, epoxy, or biodegradable polyurethane polymer matrix. Artificial stone plates were produced through the vacuum vibration and compression method, using 85 wt% of quartzite waste. The material was manufactured under the following conditions: 3 MPa compaction pressure and 90 and 80 °C curing temperature. The samples were characterized to evaluate physical and mechanical parameters and microstructure properties. As a result, the artificial stone plates developed obtained ≤0.16% water absorption, ≤0.38% porosity, and 26.96 and 10.7 MPa flexural strength (epoxy and polyurethane resin, respectively). A wear test established both artificial quartzite stone with epoxy resin (AS-EP) and vegetable polyurethane resin (AS-PU) high traffic materials. Hard body impact resistance classified AS-EP as a low height material and AS-PU as a very high height material. The petrographic slides analysis revealed that AS-EP has the best load distribution. We concluded the feasibility of manufacturing artificial stone, which would minimize the environmental impacts that would be caused by this waste disposal. We concluded that the production of artificial rock shows the potential and that it also helps to reduce environmental impacts.

In this study, we develop ceramic formulations based on quartzite and scheelite tailings collected from mining companies in the northeast of Brazil (Rio Grande do Norte State). New ceramic samples (27 wt% of kaolin, 29 wt% of plastic clay, 11 wt% of quartzite tailing, and 0&ndash, 8 wt% scheelite tailing) were uniaxially pressed in two steps (20 MPa and 50 Mpa for 20 s), dried at 110 &deg, C for 24 h, and sintered at 1150 &deg, C, 1200 &deg, C, and 1250 &deg, C. The main mineralogical phases (mullite, quartz, calcite, and anorthite) of the sintered samples were identified using X-ray diffraction (XRD). After evaluation of the physical-mechanical properties (water absorption, linear shrinkage, apparent porosity, and flexural strength), it was observed that the incorporation of scheelite tailing by up to 8 wt% did not significantly alter the properties of samples sintered at all temperatures. Our results indicate that the new ceramics formulations developed have strong potentials in manufacturing sustainable materials such as ceramic tiles and porcelain stoneware.

Van Staden N, Siebert SJ, Cilliers DP, Wilsenach D, Frisby AW. 2020. Floristic analysis of semi-arid mountain ecosystems of the Griqualand West centre of plant endemism, Northern Cape, South Africa. Biodiversitas 21: 1989-2002. The Griqualand West Centre (GWC) is one of 13 centres of plant endemism in South Africa. Despite its unique flora, it remains poorly conserved and studied. A recent study identified an extensive geographical core area for the GWC, but endemic plant species were found to be absent from certain parts within these borders. To address this, we refined the current GWC borders based on an ecological niche model, which predicted that endemic species are restricted to four mountain ranges within GWC. Mountain floras within these refined borders were then floristically compared to assess whether they are hotspots of endemicity. Floristically, the Asteraceae, Fabaceae, Malvaceae, and Poaceae were the dominant plant families. Mountain ecosystems differed from one another at species level, with indicator species explaining the compositional differences. Distribution patterns of indicator species were determined by mean annual precipitation, Ca: Mg ratios, soil pH, cation exchange capacity, iron, and sand content. These environmental factors are possible drivers of niche partitioning, environmental filtering and habitat specialization in each mountain ecosystem. Limestone and banded ironstone habitats were identified as conservation priority areas, since they contained the highest numbers of rare and threatened GWC restricted-range species, of which six were narrow endemics.

International audience; Montmorencian sandstone macrolithic industries have aroused interest within the scientific community ever since the first finds at the end of the 19th century. Questions related to their use and chronocultural attribution are still relevant, especially following the discovery of specific tools (called Montmorencian-type tools) within some mesolithic campsites.The aim of our study is to identify the role of the Montmorencian-type tools within the Mesolithic material culture. Their geographical distribution reveal a "technical phenomenon" of regional or even supra-regional scale during the first Mesolithic. Analyses show that they are standardised tools, used on hard mineral material. Experimental tests results are compatible with their use as retouchoirs for the process of knapping bladelets by the microburin technique.Similar tools, sharing technological and morphological characteristics but unfinished, are found within the production sites i.e. Montmorencian sites, and some campsites. The modalities of the geographical diffusion of these specific tools has yet to be determined. Our work has also led to the identification of lithic artefacts related to axe productions in Montmorencian sites in the strict sense Therefore, in our opinion, Montmorencian should no longer designate specific sites as both Mesolithic and Neolithic populations are the authors of what appears to be mixed industries.; Les industries macrolithiques en grès, appelées montmorenciennes, ont depuis les premières découvertes à fin du XIXe siècle interpellé les chercheurs. Les problématiques liées à leur utilisation et à leur attribution chronoculturelle sont toujours d'actualité, notamment suite à la découverte d'outils, nommés outils de type montmorencien, au sein de certains habitats mésolithiques.C'est pour définir leur place au sein de la culture matérielle du Mésolithique que nous avons repris l'étude de ces outils trouvés en contexte d'habitat. Leur répartition géographique caractérise un « phénomène technique » d'ampleur régionale, voire suprarégionale au cours du premier Mésolithique. Les analyses montrent qu'il s'agit d'outils typés, employés sur une matière minérale dure et des tests expérimentaux nous orientent vers une utilisation comme retouchoirs pour la fracturation des lamelles par la technique du microburin.On trouve des pièces similaires, morphologiquement et technologiquement, mais inachevées sur des sites « producteurs », c'est-à-dire principalement sur les sites montmorenciens sensu stricto et sur quelques habitats, alors que les modalités liées à leur diffusion à travers les territoires restent à définir. Nous avons aussi pu mettre en évidence sur certains sites montmorenciens sensu stricto des productions de haches, nous amenant à reconsidérer le Montmorencien qui ne désigne plus selon nous un faciès spécifique, en raison d'un mélange de productions tant mésolithiques que néolithiques.

At present, quartzite is widely used across many industries. The properties of quartzite significantly affect the technology used during the preparation of the raw materials as well as the technology used for manufacturing the final product, which may be intended for further operation at different temperatures. The purpose of the study was to create a scheme for the transformation of quartzite that would describe the changes in the parameters of its lattice parameter upon heating and would offer guidance regarding the drying technology and technology required to obtain tridymite. A Bruker D8 Advance diffractometer was used to study changes in the phase composition of quartzite at the temperatures of 200, 400, 600, 879, 1000, 1200, 1470, and 1550 °C. A detailed scheme of transformations of PKMVI-1 quartzite with a SiO2 content of at least 97.5% at normal pressure was proposed for crystalline modifications formed during its heating. As a result of this research, the changes in the parameters of the lattice parameter—such as the average interplanar distance davg, the volume of the unit cell Vavg, the density of the unit cell Davg, and the molecular weight Mavg—were established.

The first layers of rock underground are in thermal contact with the external atmosphere mainly through infiltrating meteoric water. This relatively cool zone absorbs rising geothermal energy, which heats the water. If the aquifer consists of gypsum, halite or quartzite, the water at those depths is usually salt-saturated, so the increase in temperature renders the water aggressive again. This in turn leads to rock dissolution and formation of phreatic conduits. This way, the geothermal flow creates caves that do not necessarily reach the surface. This paper analyzes the speed of the excavation, which, in different types of rocks, depends only slightly on temperature and meteoric precipitation. The time scale of this speleogenesis appears to be similar to that of other known cave systems. These processes are probably able to greatly increase the permeability around underground radioactive waste storage in halite.

The 2 to 5 km thick, sandstone‐dominated (>90%) Jura Quartzite is an extreme example of a mature Neoproterozoic sandstone, previously interpreted as a tide‐influenced shelf deposit and herein re‐interpreted within a fluvio‐tidal deltaic depositional model. Three issues are addressed: (i) evidence for the re‐interpretation from tidal shelf to tidal delta; (ii) reasons for vertical facies uniformity; and (iii) sand supply mechanisms to form thick tidal‐shelf sandstones. The predominant facies (compound cross‐bedded, coarse‐grained sandstones) represents the lower parts of metres to tens of metres high, transverse fluvio‐tidal bedforms with superimposed smaller bedforms. Ubiquitous erosional surfaces, some with granule–pebble lags, record erosion of the upper parts of those bedforms. There was selective preservation of the higher energy, topographically‐lower, parts of channel‐bar systems. Strongly asymmetrical, bimodal, palaeocurrents are interpreted as due to associated selective preservation of fluvially‐enhanced ebb tidal currents. Finer‐grained facies are scarce, due largely to suspended sediment bypass. They record deposition in lower‐energy environments, including channel mouth bars, between and down depositional‐dip of higher energy fluvio‐ebb tidal bars. The lack of wave‐formed sedimentary structures and low continuity of mudstone and sandstone interbeds, support deposition in a non‐shelf setting. Hence, a sand‐rich, fluvial‐tidal, current‐dominated, largely sub‐tidal, delta setting is proposed. This new interpretation avoids the problem of transporting large amounts of coarse sand to a shelf. Facies uniformity and vertical stacking are likely due to sediment oversupply and bypass rather than balanced sediment supply and subsidence rates. However, facies evidence of relative sea level changes is difficult to recognise, which is attributed to: (i) the areally extensive and polygenetic nature of the preserved facies, and (ii) a large stored sediment buffer that dampened response to relative sea level and/or sediment supply changes. Consideration of preservation bias towards high‐energy deposits may be more generally relevant, especially to thick Neoproterozoic and Lower Palaeozoic marine sandstones.

Crystal preferred orientation of 47 samples of quartzite and eight samples of associated marbles from the Bergell Alps have been analyzed with time-of-flight neutron diffraction and EBSD. The results show a clear distinction of texture types for quartzites transformed from Triassic sandstones and quartz layers in gneiss. Textures of Triassic quartzites are overall weak and display a maximum of c-axes perpendicular to the foliation or a crossed girdle perpendicular to the lineation. Pole figures for positive rhombs {10 1 ¯ 1} show a maximum perpendicular to the foliation and negative rhombs {01 1 ¯ 1} generally display a minimum. Based on polycrystal plasticity models this texture type can be attributed to a combination of basal and rhombohedral slip. Asymmetry of the distributions is attributed to simple shear and local strain heterogeneities. The relatively weak texture is partially caused by muscovite limiting dislocation motion and grain growth, as well as adjacent layers of marble that accommodate significant strain. Most quartz layers in gneiss, including mylonites, display a texture with a-axes parallel to the lineation and a c-axis maximum in the intermediate fabric direction. This texture type can be attributed to dominant prismatic slip. Many samples are recrystallized and recrystallization appears to strengthen the deformation texture. The study shows good agreement of neutron diffraction and EBSD. Neutron diffraction data average over larger volumes and maximum pole densities are generally lower and more representative for the bulk material. With EBSD the microstructure and mechanical twinning can be quantified.

usc Certain parts of Ghana (Eastern and Volta region) are predominantly covered by neoproterozoic Dahomeyide rocks which occurred during the Pan-African Orogeny event in West Africa. To understand the petrological, geochemical and structural evidence of this geologic event, a detailed geological mapping exercise was conducted in some parts of the Eastern and Volta regions of Ghana. The aim of this research is to understand the local geology of these areas and how it best fits the regional geology of Ghana and its implications in the Pan-African Orogenic event. The evidences presented in this study show that the rocks in these areas are mainly metamorphic, which are granitic augen gneiss, biotite gneiss and quartzite. The gneisses were proposed to belong to the basement Dahomeyan, while the quartzites belong to the Togo Structural Unit. It was also inferred that the rocks have been deformed mainly by brittle and ductile deformation, resulting in structures such as foliations, fractures and joints observed in the quartzites and gneisses within the area of study. The structures within the study area have a general attitude of north-east–south-west with some few structures trending in the north-west–south-east directions. Again, it was inferred that the rocks from the Dahomeyan structural unit are highly metamorphosed and deformed as compared to the rocks from the Togo structural unit. The granitic augen gneiss and biotite gneiss have rock-forming minerals such as biotite, K-feldspar, quartz, muscovite, plagioclase and hornblende in varying proportions, whereas the quartzites are predominantly composed of glassy quartz crystals. Refereed/Peer-reviewed

The Monte Bracco area (Western Alps, northern Italy) is located in the Dora Maira Massif, a geological unit belonging to the inner part of the Penninic Domain, extending more than 1000 km2 in the central sector of Cottian Alps. Monte Bracco is an isolated relief, mainly formed by ortho- and paragneisses, whose foliation is gently NW dipping. Some levels of quartzites, some metres thick, are cropping out only towards the uppermost part of Monte Bracco, and have been quarried as famous ornamental stones (“Bargiolina”). There are four main commercial and chromatic varieties: golden yellow (the most valuable), pale yellow, olive green, grey and white (the most common). The main technical characteristic of the “Bargiolina” is the regular schistosity, due to the presence of thin, plane parallel white mica layers; because of this feature it is possible to obtain very thin natural split slabs (1-2 cm). Under the optical microscope, the rock shows a fine and quite homogeneous grain size, a granular – lepidoblastic texture, with regular spaced schistose domains (up to mylonitic); small amounts of slightly altered K-feldspar (orthoclase) give to the rock a micro-augen texture. The main rock-forming minerals (XRD-QPA and SEM-EDS) are quartz (65 – 85 wt.%), white mica (up to 15 wt.%), potassic feldspar (5 – 10 wt.%) and traces of plagioclase and chlorite. Typical accessory minerals are zircon, rutile, titanite, hematite and limonite, whereas K-feldspar is often altered in kaolinite. The different colours are linked to the different abundance and degree of oxidation of secondary minerals, guided by fracture density and distribution. The “Bargiolina”, known and used since the prehistoric age as substituting material for chert, and celebrated by Leonardo da Vinci (1511), has been exploited at least since the XIII century, peaking in the XX century (up to 300 kt/year), used as internal and external facing, because of its excellent technical proprieties (freeze-thaw resistance, flexural strength up to 40 MPa, low water absorption, excellent wear resistance). These valuable features decreed its success when it was massively used in the construction of basilicas and noble palaces by famous architects of Piedmontese Baroque: Filippo Juvarra (1678 – 1736) used it in the flooring of the side wings of the hunting lodge of Stupinigi and in the cloister of the Superga Basilica. In the second half of the XIX and at the beginning of the XX century, the quartzite was marketed in Northern Italy and exported to Russia and South America. Waste materials were also used for abrasives (even for toothpaste), due to the abundance of quartz. Nowadays, only two quarries are involved in the exploitation of “Bargiolina”. The yield rate is about 20%; consequently 80% of the exploited material are rock wastes, disposed in quarry dumps. The poor exploitation planning of the past, which unfortunately involved the best portions of the rock body, led to only partly exploited quarry benches, with a residual yield rate of only 4-8%. The huge amount of quarry waste and the quartz-rich composition suggest interesting applications, especially for refractories and ceramic materials.

Обнаруженный в 2008 году А.А. Клюкойтем памятник археологии Васильевский Кордон 27 исследовался в 2016–2018 гг. В раскопе общей площадью 195 м² удалось выявить шесть древних сооружений и четыре погребения. Было обнаружено большое количество энеолитической керамики: среднестоговской и волосовской культур, посуда ксизовского типа. Обращает на себя внимание наличие большого количества находок, свидетельствующих об охоте и рыбной ловле на памятнике. Сопровождающий кремнёвый инвентарь представлен орудиями, имеющими отношение как к хозяйственной деятельности, так и к охотничьему вооружению, с преобладанием последних. В хозяйственных сооружениях, погребениях и культурном слое обнаружено 68 каменных наконечников стрел и дротиков. Также выявлено 2248 остатков животного происхождения. Из них 1389 – кости млекопитающих, 595 – птиц, 61 кость рептилии и 138 фрагментов раковин моллюсков. На памятнике впервые для Верхнего Подонья зафиксировано присутствие животноводства, при этом птицеводство отсутствовало. Тем не менее наличие в материалах костей диких видов млекопитающих, птиц, рыб и черепах подтверждает значение охоты и рыбалки как основного (но уже не единственного) источника пищи на поселении. При этом из кости изготовлены только четыре орудия охоты: острия и гарпуны по два обломка. Стоит отметить интересный факт – наличие рыболовных керамических грузиков для сетей, выточенных из стенок разбитых сосудов. Археологическая коллекция памятника Васильевский Кордон 27 относится преимущественно к эпохе позднего энеолита и датируется 3–2 четвертью IV тыс. до н.э., The settlement and grave field Vasilyevskiy Kordon 27 was discovered by A.A. Klukoit in 2008 and it was investigated from 2016 to 2018. In the excavation within the area of 195 sq. m. six ancient buildings and four burials were identified. A large number of Eneolithique ceramics of the Srednestogovskaya and Volosovskaya culture as well as Ksizovski type vessels were discovered. A huge number of finds testify to the hunting and fishing on the monument. The accompanying flint inventory is represented by tools related to both economic activity and hunting weapons, with the latter predominating. In the outbuildings, burials and cultural layer 68 stone arrowheads and darts were found. 2245 residues of animal origin were also revealed. There are 1386 mammalian bones, 595 birds, 61 reptile bones and 138 fragments of mollusk shells among them. It is interesting to note that there were ceramic fishing weights carved from the broken vessels. On the monument animal husbandry was noted for the Upper Don for the first time, while poultry farming was absent. Bones of wild species of mammals, birds, fish and turtles confirm the importance of hunting and fishing as the main (but not the only) source of food in the settlement. At the same time, only four hunting tools were made of bone: two edges and two fragments of harpoons. The archaeological collection of the settlement Vasilyevskiy Kordon 27 refers mainly to the late Eneolithic period and dates the 3–2 quarter of the IV Millennium BC.

The Bargiolina quartzite from Monte Bracco (western Alps, northern Italy) represents one of the most important historical ornamental stones of the Piedmont region. Known and used since the prehistoric age as substituting material for chert, it was celebrated by Leonardo da Vinci, and exploited at least since the XIII century, peaking in the XX century. It was extensively used in the construction of basilicas and noble palaces by famous architects of Piedmontese Baroque, for internal and external stone cladding. There are four main commercial and chromatic varieties, and the main technical feature is the regular schistosity, to obtain very thin natural split slabs. The different varieties have a homogeneous mineralogical composition and microstructure: A fine and homeoblastic grain size, and a granular&mdash, lepidoblastic texture, with regularly spaced schistose domains. The main rock-forming minerals are quartz, phengite, small amounts of K-feldspar and traces of plagioclase and chlorite. The yield rate of quarries is about 20%, and the poor exploitation planning of the past led to only partly exploited quarry benches, with a very poor residual yield. The large amount of quartz-rich quarry waste and the presence of kaolin-rich gneisses suggests the potential for novel applications in the field of industrial minerals.

Fil: Kohan, Patricio. Universidad de Buenos Aires. Facultad de Filosofía y Letras. Instituto de Arqueología; Argentina. The transition period between the middle and late Holocene in the Puna of Jujuy (3500-2000 years BP) accounts for a variety of technological, social and cultural changes within the human groups that inhabited it. The passage from a hunting-gathering strategy to a productive strategy had an impact in every activity sphere, including technology. Such is the case of Morro Blanco, an archaeological site most notable for its rock art and lithic assemblages. The relationship between both lines of evidence has been recently analysed, having identified an artefactual assemblage designated as potentially engraving tools, related to the manufacture of petroglyphs. When analysing the aforementioned assemblage, the presence of artefacts and tools manufactured almost exclusively in quartzite was noted. The present article evaluates the presence of this raw material in the sites, determining whether there was an intentional selection process. The main objective of this article is to delve into the first step of the manufacturing process of the potential engraving tools from a technological point of view, emphasising the importance quartzite had in the process of intentionally selecting lithic raw materials suitable for this tools, supporting the hypothesis that this tools were in fact used to manufacture engravings. El periodo de transición entre el Holoceno Medio y Tardío en la Puna de Jujuy (3500-2000 años AP) da cuenta de una variedad de cambios a nivel tecnológico, social y cultural dentro de los grupos humanos que la habitaron. El pasaje de una estrategia basada en la caza y recolección hacia una estrategia productiva tuvo un impacto en todas las esferas de actividades, incluyendo la tecnológica. Tal es el caso de Morro Blanco, un sitio arqueológico notable por su arte rupestre y conjuntos líticos. La relación entre ambas líneas de evidencia ha sido recientemente ana-lizada, habiendo identificado un conjunto artefactual designado como instrumentos potencialmente grabadores, relacionado con la manufactura de petroglifos. Al analizar dicho conjunto, se advirtió el registro de artefactos e instrumentos realizados casi exclusivamente en cuarcita. El presente trabajo evalúa la presencia de esta materia prima, para determinar si hubo un proceso de selección de la misma. El objetivo principal del artículo es ahondar en la primera etapa del proceso de manufactura de los instrumentos potencialmente grabadores desde un punto de vista tecnológico, señalando la relevancia que tuvo la cuarcita en un proceso de selección intencional de materias primas idóneas para estos instrumentos, apoyando la hipótesis de que estos instrumentos fueron utilizados para ejecutar grabados.

В статье на примере Михайловского месторождения рассмотрен ряд гипотез образования железистых кварцитов Курской магнитной аномалии. Рассматриваются терригенно-осадочная, вулканогенно-осадочная, метасоматическая, магматогенная, а также и космогоническая гипотезы образования железистых горизонтов докембрия. В статье излагаются результаты изучения генетических условий происхождения железистых кварцитов путём проведения вакуумно-декриптометрических исследований и утверждается, что железистые кварциты имеют полигенное происхождение., The paper presents a number of hypotheses on the formation of ferruginous quartzites of the Kursk Magnetic Anomaly (KMA) on the example of the Mikhailovsky field. Terrigenous-sedimentary, volcanogenic-sedimentary, metasomatic, magmatogenic, and cosmogonic hypotheses of the formation of glandular precambrian glandular horizons are considered. The article presents the results of a study of the genetic conditions of the origin of ferruginous quartzites by conducting vacuum-deciptometric studies. According to the results, it is revealed that ferruginous quartzites are of polygenic origin., №12(78) (2018)

A packed bed for solar energy storage in the form of sensible heat has been investigated using two-phase continuous model. The system contains Quartzite as the filler material and Palm oil as the heat transfer fluid. The aim of this work is to propose an eco-friendly storage system which uses natural concrete and certified sustainable oil for medium temperature thermal storage. Using the developed model, the performance of the Palm oil has been compared with two different synthetic oils which has shown that the Palm oil could efficiently be used as a heat transfer fluid for a working temperature below 300 °C.

The Middle Palaeolithic site of Lagoa do Bando is an open air site in a lacustrian context located at 570 m a.s.l. in the municipality of Mação in the center of Portugal. The site was discovered in 2011, during an emergency excavation, and resulted on the recovery of a Middle Palaeolithic lithic assemblage mainly composed of fine grained quartzite implements of expedient, discoid and Levallois technology. Use wear analysis was conducted on 41 artifacts formed through discoid and Levallois technology. Twenty one of these artifacts revealed use wear traces. Ten of them show traces of wood work, five have traces of butchering activities, three present traces of meat processing and two present undetermined traces. The site is located at an atypically high elevation for an open air site and there is evidence of a high rate of woodworking activity, rare in the Middle Palaeolithic occupations. The woodworking activities are possibly linked to the exploitation of woody local resources (maybe for the construction of hunting blinds) and not only with to the manufacture and maintenance of spears and shafts. These results converge with the interpretation of this site as a temporary hunting site integrated in a complex pattern of occupation of the area between the river valleys and the top of low mountains.

We conducted complex comparative mineralogical and spectroscopic researches on the quality of quartz raw from the quartzites and associated rocks at the Big Tyuters Island in the Gulf of Finland (Baltic Sea). Various geological and mineralogical studies of quartzites, which were rare in the eastern part of the Baltic shield, and related iron-alumina metasomatites, and also breaking them granitic dykes, revealed the features that they were secondary quartzites formed in the process of carbon dioxide metasomatism under the influence of volcanic fluids. The quartzites are well-processed by a number of characteristics, and according to ESR (electronic spin resonance) data they contained a relatively small amount of Al, Ge, Ti isomorphic impurities and could raise a commercial interest.

Plasma furnace processing has the potential to transform solar cell production. If informed decisions regarding silicon ore and mineral exploration can be made such that waste streams are also of high economic value, then production is ultimately more environmentally integrated. This study presents results from a spot check of the Kinnikinic Quartzite, ~4.5 km east of Arco, Butte County, Idaho (43.639091&deg, &minus, 113.243295&deg, ), for ore quality. The mineralogical and geochemical characteristics are explored within the context of a planned plasma furnace project at the sampled site and are compared to previous consulting reports. X-ray diffraction analysis detected only quartz, while scanning electron microscopy identified quartz grains, secondary quartz cement, trace amounts of potassium feldspar, minor iron oxides, and secondary illite. The bulk chemical characterization of 20 samples (including repeats) reports several wt. % variation in SiO2 from 96.47 to 99.66. Other notable chemical components include Al2O3, K2O, CaO, and Rb, all consistent with the presence of potassium feldspar (and illite). Gold concentrations vary from below detection (n = 12 out of 20) to a maximum concentration of 0.086 ppm. Total sum REE concentrations vary from 13 to 143 ppm. Conservatively and optimistically, assuming ideal extraction and recovery in plasma furnace operation, a resulting waste stream would have approximately 15.2 ppm (0.488 oz./metric ton) gold and 3400 ppm REE in the average waste. Gold (and REE extraction) may, however, be complicated by the presence of Fe and Cu if cyanide approaches were implemented. Gold concentrations are significantly lower than reported in previous work, warranting further characterization of this unit locally and regionally in order to characterize ore potential. This study works to demonstrate the possibility of evaluating other potential silicon ore units, such as the St. Peter Sandstone in Illinois and Missouri, for the co-production of materials in support of an emerging green economy.

In order to investigate the weathering characteristics of rocks in response to freeze-thaw conditions in northern latitudes, we analysed meteorological data from the Ny-&Aring, lesund region in Norway, and observed changes in the physical and mechanical properties of rocks of dolomite and quartzite. To assess the effects of freeze-thaw weathering on these rock properties, 900 cycles of long-term freeze-thaw tests were conducted for the sampled rocks in two locations. P-wave velocity, absorption, shore hardness, and the uniaxial compressive strength of the sampled rocks were measured at every 150 cycles in order to analyse physical and mechanical mediator variables of freeze-thaw weathering. It was found that an increasing number of freeze-thaw cycle on the sampled rocks decreases uniaxial compressive strength, shore hardness, and P-wave velocity and increases absorption.

Rad je nastao iz potrebe za reinterpretacijom okresane kamene industrije Đerdapskog mezolita u svetlu novih podataka dobijenih projektima terenskih istraživanja na obe obale Dunava, savremenim metodama fizičko-hemijskih analiza i revizijama stratigrafija, materijalne kulture i bioarheoloških ostataka. Da bi se dobio uvid u odluke i izbore zajednica i pojedinaca iz prošlosti, kameni artefakti su analizirani sa aspekta teorije optimalnog traganja i kroz granični model neolitizacije. Artefakti su posmatrani ne samo sa aspekta prilagođavanja ljudskog delovanja na promenea u okruženju, već i sa aspekta razmene predmeta i dobara, prenošenja informacija i uloge u ritualnim aktivnostima. U radu su razmotreni podaci dobijeni novom analizom okresanih artefakata sa Lepenskog vira i Vlasca i ranije objavljeni podaci o nalazima sa lokaliteta sa obe obale Dunava. Novi podaci su prikupljani primenom stand7ardne tehno-tipološke analize ali u okviru sirovinskih kategorija, izdvojenih na osnovu makroskopskih karakteristika. Prvi put u Srbiji je obavljena i analiza tehnike odbijanja, a preduzeta je i prostorna analiza radi uvida u aktivnosti zajednica u naselju... This thesis emerged from the need for reinterpretation of the knapped stone industry of the Iron Gates Mesolithic. Namely, new data came to light, obtained by field research projects on both banks of the Danube, contemporary methods of physical and chemical analyses and revisions of stratigraphy, material culture and bio-archeological remains. In order to gain insight into the decisions and choices of communities and individuals from the past, stone artefacts were analyzed from the perspective of Optimal Foraging theory and through the ‘border model’ of neolithization. Artefacts are not only viewed as a means of adapting human activities to changes in the environment, but also as exchanged objects and goods that transmitted information and had an important role in ritual activities. The thesis analyzes data obtained by a new inspection of the knapped artefacts from Lepenski Vir and Vlasac and previously published data on findings from the sites from both banks of the Danube. New data were collected using standard techno-typological analysis within raw material categories based on macroscopic characteristics. For the first time in Serbia, an analysis of the technique of reduction was done, and a spatial analysis was undertaken to reconstruct the activities of the communities in the settlement...

Site Form, Site 28BU522, for Joint Base McGuire-Dix-Lakehurst.