Quartz Components Research Articles

Chronology of a sedimentary sequence from the land–ocean interaction zone in the North Jiangsu Basin

The North Jiangsu Basin (NJB), located in the western part of the North Jiangsu-South Yellow Sea Basin, is a critical region providing invaluable archives about the evolution processes of the land-ocean interchange and climatic environments in a coastal zone. Chronology is of crucial importance to reconstruct the timing of sea-level eustacy, and shoreline changes, as well as the evolution of the regional environment by means of numerical dating to determine the age of sedimentary strata in the sea–land interaction zone of the NJB. However, sediment dating in the NJB remains controversial due to limitations in the quantity and quality of chronological data. Therefore, the sediments in the Jianhu Gangxi (GX) profile of the NJB were analyzed in this study by applying both fine-grained quartz optically stimulated luminescence (OSL) dating and 14C dating. The results were used to discuss the processes of regional environment evolution. The OSL dating of fine-grained quartz components in sediments was found to be a reliable method to determine deposition ages of sediments in the land-sea interaction zone in the NJB. The combination of OSL and accelerator mass spectrometry 14C dating techniques allowed a reliable and high-resolution chronological framework for the GX profile. Since the last glaciation, the sedimentary environment in the eastern portion of the NJB changed significantly. In particular: (1) between 13 and 7.25 ka B.P, the area of interest was dominated by lacustrine deposition within a stable sedimentary environment with low deposition rates; (2) from 7.25 to 6.45 ka B.P, marine transgression events occurred, and the deposition rate increased rapidly in an area of land-sea interaction; (3) after 6.45 ka B.P, a regression event occurred, and the study area transformed into a lowland lake environment.

Separation and Identification of Minerals Composing the Silica Sands (Southwestern Tunisia)

Separation and identification of minerals composing the Tunisian silica sands have been conducted by acid etching and hot filtration/sedimentation (HFS) without affecting the quartz component. It was found that the hot acid etching process is an effective method to separate quartz and clay minerals in the silica sand. The SEM micrographs of the silica sand show rough surface and some cracks with irregular shapes. The surface becomes clean and smooth after acid etching process. After chemical dissolution, the clay minerals were recovered by hot filtration following by sedimentation at low temperature. FT-IR, EDS maps, and secondary electron (SE) analyses of separated clay minerals reveal the presence of Fe2O3, montmorillonite, and kaolinite minerals. The LIBS analysis of clay minerals shows the presence of Al, Fe, Ca, Al, and Mg. The sequential etching process can be introduced in the purification methods as an effective way to separate quartz from clay minerals.

A Fiber-Optic Sensor for Simultaneous Temperature and Pressure Measurements Based on a Fabry–Perot Interferometer and a Fiber Bragg Grating

This paper presents a sensor for simultaneous pressure and temperature measurements, which is made entirely of quartz components and uses a Fabry–Perot interferometer and a fiber Bragg grating (FBG). This combination allows simultaneous temperature and pressure measurements, as well as the reduction of the contribution of temperature to the pressure measurement. The sensitive element is a quartz-glass membrane manufactured by etching. The sensitivity of the sensor to the pressure is 50 nm/bar; the sensitivity to the temperature is 4.6 nm/°C on the Fabry–Perot interferometer side and 10 pm/°C on the FBG side. It has been shown that the FBG can be used as a thermal compensating element.

Analyzing the causes of crack formation in porcelain and the ways to eliminate them

The studies deal with the porcelain products produced by casting finely-dispersed slips into gypsum molds. The causes of the occurrence of cracks on the edges of products after bisque and glazed firing were established and the ways of their elimination were proposed. As a result of the comprehensive research into the basic ceramic mass of the assigned composition and products from it, a series of the technological factors that cause cracking were determined. Determining the fineness of grinding of production slips of various batches showed that the residue on sieve No. 0063 ranged from 0.7 to 3.5 %. The direct correlation between the occurrence of cracks in products and an elevated indicator of the residue that contributed to the stratification of a ceramic slip in the process of settling in gypsum molds was established. This led to the emergence of internal stresses in the structure of a potsherd. It was established that another factor that caused cracking of products was the existence in the composition of the ceramic mass of large quartz grains, which in the heating-cooling process are capable of modification transformations. In addition, the low temperature of bisque firing did not contribute to the completion of the process of dehydration of clay and mica minerals, which strengthened the internal stresses in a potsherd. The research revealed that to ensure qualitative indicators of ceramic products, it is necessary not only to control the residue on a sieve but also to take into consideration the distribution of the fractional composition of a ceramic slip, while the content of the quartz component of 30–63 µm should not exceed 12 % by weight. This contributes to the formation of a dense homogeneous potsherd with a high content of a mullite phase. As a result of the research, it was also proposed to change the temperature of bisque firing from 660 to 800 °C. It is at this temperature that the processes of dehydration of layered silicates are completed and the shrinkage processes are stabilized. The obtained results can be applied at the typical production of household products from low-temperature porcelain

Geochemistry of Famennian to Visean Metapelites from the Iberian Pyrite Belt: Implications for Provenance, Paleo-Redox Conditions and Vectoring to Massive Sulfide Deposits

Massive sulfide deposits of the Iberian Pyrite Belt (IPB) document the progression of ore-forming processes in the SW Iberian Variscides, throughout uppermost Devonian to Early Carboniferous. Sulfide ores are usually hosted in volcanic-dominated or shale-dominated successions belonging to the Volcano-Sedimentary Complex (VSC; Late Famennian to Late Visean). Yet, several important orebodies at Neves-Corvo are sitting within upper sections (Famennian) of the early deposited Phyllite–Quartzite Group (PQG). Four key sectors of the Portuguese segment of IPB were revisited and 262 samples collected to characterize the geochemical features of metapelites from PQG and VSC sequences in barren and fertile settings. The selected sectors include active (Neves-Corvo and Aljustrel) and old (Lousal) mines, besides promising brownfield (Gaviao) and greenfield (Sesmarias) prospects, and other lithostratigraphic sections without known mineralization. The composition of PQG and VSC metapelites is similar and mainly controlled by a mixture of clayey-derived and quartz sandy-derived components largely resulting from different sources of granitic to granodiorite/quartz diorite composition. A third component of local volcaniclastic origin could be significant in many samples of upper VSC sections. Mineral transformations during diagenesis and/or hydrothermal alteration/mineralization partially overprinted the primary composition. During sedimentation/diagenesis, prevalent redox conditions were mostly confined to oxic environments, at places transiting to sub-oxic. Subsequent multistage interaction with reducing hydrothermal fluids (to which the sulfide mineralization is related) generated heterogeneous anoxic signs. Consistent increases in Fe2O3/TiO2, (Cu + Zn + Pb)/Sc and (As + Sb)/Sc ratios to values above 10 represent a valuable footprint toward ore horizons.

Wietrzenie mrozowe wybranych skał tatrzańskich w świetle badań laboratoryjny = Frost weathering of selected Tatra rocks in the light of laboratory tests

The aim of the work described here was to determine the rate of frost weathering for selected types of rock, and the manner in which this proceeds. The authors attempts to answer questions regarding progress with the disintegration of a given type of rock over time; the size and shape of weathered grains; the role played by fissures in rock and rock texture; and further relevant properties like compressive and tensile strength, porosity and water absorption. The rock samples used in laboratory testing were collected in the catchment area of the Chochołowski Stream in the Western Tatra Mountains of Poland. The seven types of rock analysed were white and brown granite, organodetric limestone, fine-grained conglomerate, dolomite breccia, quartzite sandstone and amphibolite. Samples were subjected to simulated frost weathering via the impact of repeated thermal cycles across a temperature range of -5 to +10°C. The simulation was carried out at the Low Temperatures Laboratory of the Institute of Geography and Spatial Management of Kraków’s Jagiellonian University, using a CI/1400/LT/2D cooling device. As testing was in progress, changes in the states of samples were determined through the measurement of dry and saturated mass and water absorption, as well as the speed at which an ultrasonic wave passed through. By reference to results for these measures, it was possible to calculate the frost weathering index after Matsuoke, i.e.:Rf= (Vp0-Vpk)/(Vp0*k) [cykle -1],where Vp0 is wave speed at cycle 0 (in km/s), Vpk is wave speed at cycle k (km/s) and k is the number of cycles. Rock dissolution tests and measurements of the products of weathering were also carried out. Values obtained for the index were used to rank the rocks tested for their resistance to frost weathering, as was the percentage of material in the initial mass that became subject to rock weathering. The least-resistant rock proved to be dolomite breccia, and the most-resistant amphibolites and quartzite sandstones. The rankings of other rocks varied in line with the indicative parameter referred to. The testing of physical properties suggested several reasons for high resistance to frost weathering among the analysed types of rock from the Western Tatras, i.e. the limited (<5%) open porosity noted for all types, limited water absorption, high compressive and tensile strength, compactness and homogeneity, low densities of fissures in samples in their initial state, almost complete filling of pores with matrix (e.g. in sandstone and conglomerate), re-filling of cracks (e.g. in limestone), and a significant component of resistant quartz. No effect of rock texture on resistance to frost weathering could be observed, but the presence of carbon matrix and carbonate rock fragments is important. The latter dissolve steadily, creating more favourable conditions for physical weathering (e.g. of amphibolites and conglomerates). The occurrence of mineral veins within rocks determines disintegration routes (e.g. in conglomerates). Given that rocks were subjected to an average of 850 repeated thermal cycles in the laboratory, the simulation achieved was of approx. 50 years of frost weathering under natural conditions in the study area. Experiments of this kind thus offer insight into processes running very slowly under natural conditions.

Изучение гидролиза и осадкообразования в кислотных составах на основе сульфаминовой кислоты

This article presents the results of a study of the hydrolysis of sulfamic acid and the elaboration of acidic compositions that are characterized by reduced sedimentation compared to mud acid. The effect of complexing compounds on the hydrolysis of sulfamic acid is considered, the hydrolysis of sulfamic acid and sulfamates is compared, and the secondary sedimentation of sulfamic acid and mud acid compositions is compared using the formation of hexafluorosilicates. The hydrolysis intensity of sulfamic acid and ammonium sulfamate was determined by the mass of sediments formed during the reaction of hydrolysis products with calcium chloride. The mass of calcium sulfate formed is proportional to the rate of hydrolysis of sulfamic acid. The process of dissolution of the quartz component of the terrigenous formation was studied using the gravimetric method. Differences in influence of EDTA, HEDP, and NTP on sedimentation prevention of the products of sulfamic acid hydrolysis were studied by the example of reactions with Ca2+. It was shown that compositions with NTP are characterized by a lower sediments formation. The ratio of NTP concentration and the hydrolysis rate of sulfamic acid is shown. Differences in the hydrolysis rate of compositions based on sulfamic acid and sulfamates were determined at a temperature of 80°C. It was shown that sulfamates are characterized by a lower rate of hydrolysis. Differences in quartz solubility were determined for compositions based on sulfamic and sulfuric acids, differences in the reactions kinetics were shown. It has been established that acid compositions based on sulfamic acid are characterized by less sedimentation rate being compared with acid compositions based on hydrochloric acid by the example of hexafluorosilicates formation.

Textures of auriferous quartz-sulfide veins and 40Ar/39Ar geochronology of the Rushan gold deposit: Implications for processes of ore-fluid infiltration in the eastern Jiaodong gold province, China

The Rushan gold deposit, located in the eastern part of the world-class Jiaodong gold province, contains the largest gold resource within a single fault-controlled quartz vein in China. Processes involved in auriferous quartz vein deposition are not clear, and the precise gold mineralization age remains controversial for this deposit. New 40Ar/39Ar dating data on sericite from ores and altered rocks suggest that the Rushan gold deposit formed between ca. 122 Ma and 117 Ma, which overlap or are slightly younger than those of gold deposits in northwestern Jiaodong province. The age differences between samples from different locations indicate that the quartz veins on the margin of the orebody may be younger than those in the center, suggesting a single and protracted gold mineralization event lasting for about 5 My. Differences between gold mineralization ages and emplacement/cooling ages of the ore-hosting Kunyushan granite imply that they are not genetically related and that the Kunyushan granite is unable to provide any thermal input to the mineralization system. This also applies to the Sanfoshan monzonite as it marginally postdated gold mineralization and lacks any spatial association with it.Internal textures of high-angle shear veins and low-angle extension veins indicate that episodic fluctuations from supralithostatic to hydrostatic fluid pressure triggered the multiple ore-controlling fault ruptures induced by breach of supralithostatic fluids under a seismogenic regime. In this model, the controlling fault starts to slip with both reverse and sinistral kinematics, and dilatational zones are created. The ore-forming fluids then migrate upwards along the fault, due to the large pressure difference between the dilatational zones and the deep parts of the fault, causing hydraulic fracture in the host rocks and earlier quartz veins. Large volumes of quartz, pyrite, and other ore components are precipitated due to fluid immiscibility caused by pressure fluctuations, and new quartz veins form along both sides of the earlier quartz veins. The fault is now sealed by these new quartz veins and the fluid pressure starts to build until the next breach cycles. Orebodies with complex internal textures were thus deposited incrementally in these cycles, closely fitting the classic fault-valve model, in this case under a weak regional NW-SE transpressional stress.

Evidence for provenance change in deep sea sediments of the Bengal Fan: A 7 million year record from IODP U1444A

Previously published geochemical and mineralogical data have revealed conflicting views on the provenance of the deep-sea sediments in the Bengal Fan. Here we report results of a study for a 330-m sequence consisting of both turbitide and semi-pelagic sediments recovered at the Site U1444A during the IODP 353 Expedition. A novel technique using the optically and thermally stimulated luminescence (OSL and TL) signatures from quartz and K-feldspar has been employed to characterise the mineral compositions of the sediments. We show that the quartz luminescence sensitivity clearly differentiates the four sedimentary units. There is a distinct increase of quartz luminescence sensitivity in Unit 2 during the time interval of ~3.5–0.5 Ma. Analyses of the luminescence signal components in quartz and the ratio of the K-feldspar and quartz also point to a change in Unit 2 relative to the other three units. We interpret such changes in the mineralogical compositions through the sequence as reflecting a change in the provenance over the last 7 million years in the western Bengal Fan. We attribute the quartz with enhanced luminescence sensitivity in Unit 2 to the contribution from the sources associated with Indian rivers. We infer that the delivery of the sediments from Indian peninsula to IODP Site U1444A is facilitated by a weakening in the turbidite deposition which is dominated by weathering products from the Himalayas. We speculate that the relatively high elevation of the 85°E Ridge may act against the flow through and the associated deposition of turbidity current originated from the Himalayas.

Identification of sand dune sources in the east Sistan, Iran by using mineralogical and morphoscopic characterization of sediments

Sedimentation in the dune fields of the Sistan Plain of Iran is the result of deposition of fine-grained sediment downstream of the Helmand River. Due to poor adhesion and low moisture content of soil particles, and the strong renowned Levar wind, dune fields mostly of Barchan and Nebkha types are created. This study aims to assess the physical, morphological and mineralogical characteristics of surface (S) and sub-surface (S-S) sediments and their genetic relationships with the aeolian sand surface. For this purpose, 48 S and S-S sand samples were prepared from Niatak Corridor (NC) east of Sistan and were analyzed to determine their physical and mineralogical properties by dry sieving, scanning electron microscopy (SEM) and optical microscopy methods. Results show that the physical characteristics of S and S-S sand particles, such as sorting, roundness, minimum elongation projection, Riley sphericity, morphoscopic and mineralogical characteristics, have no significant difference. The study of thin sections showed that all samples generally contain quartz, feldspar, calcite, gypsum and lithic components. This confirms that the source of S sand dunes is local and consists of the buried layers of sands in the close vicinity. Therefore, the Hamoun Lake are most likely not a source of regional sands. The local existence of Yardang also supports the conclusion of this research.

Characterization of quartz in the Wufeng Formation in northwest Hunan Province, south China and its implications for reservoir quality

Quartz is one of the most important and common minerals in marine shales. This is especially true for the Wufeng-Longmaxi and Niutitang Formations in south China. However, the type, origin and formation mechanism of the quartz in these marine shales are as yet unclear. Thirteen samples of Ordovician shale from the Wufeng Formation in northwest Hunan Province were collected for this study. The quartz within the Wufeng shale was characterized through a series of experiments employing scanning electron microscopy with cathodoluminescence, nitrogen physisorption, X-ray diffraction, and geochemical analysis. The results were then used to assess the implications of the quartz component for reservoir quality. Three quartz types were identified based on scanning electron microscopy and cathodoluminescence imaging. Type I quartz has a relatively large grain size and exhibits bright luminescence, indicative of a terrigenous origin, whereas Type II and Type III quartz is authigenic and has dull or no luminescence. Type II quartz has small grain sizes and may be mainly biogenic in origin. This type of quartz may have formed during early diagenesis, with the silica being sourced from the dissolution of siliceous organisms. Type III quartz generally appears as dark rims on Type I quartz grains; the silica may have been derived from clay mineral alteration, with quartz-formation occurring during middle or late diagenesis. The authigenic quartz (Types II and III quartz) likely formed as a cement and would be expected to generate brittle behavior. The shale with a high content of authigenic quartz has a high Young's modulus and low Poisson's ratio. The biogenic authigenic quartz (Type II quartz) was pore-filling and formed during shallow burial. It would thus have been able to resist further compaction and provide a rigid framework within which the primary pores in the shale could be preserved, controlling the distribution of organic matter and the development of organic pores. The biogenic authigenic quartz has positive relationships with porosity and pore volume and specific surface area. Shale that was high in biogenic quartz had high porosity and adsorption capacity. The characterization of quartz in marine shales has significance for shale gas exploration and development and provides a new angle for evaluating the fracability and storage capacity of shale gas reservoirs.

Environmental Research and Geochemical Evaluation of Recent Bottom Sea Sediments North and North –East of Lesvos Island, Greece

An environmental and geochemical investigation of 33 surficial sediments of the continental shelf north and north east of Lesvos Island Greece was undertaken to study the mineralogy and geochemistry of the sediments and understand the distribution and sources of various major and trace elements. Texturally all the sediments contain high amounts of mud and clay indicating a uniform facies at depths between 30m - 300m. The sediments are a mixture of terrigenous components (albite, K-feldspar, muscovite, quartz, illite, amphibole and biogenic components (calcite, Mgcalcite, aragonite). Pyrite and glauconite are ascribed to diagenesis. There are four distinctive groups of elements each of which includes related elements, derived from different natural sources on land or in the marine basin. The first group (Ca, Sr) reflects the biogenous carbonate fraction and is negatively correlated against every other element determined. A second (Si, Al, Fe, Na, K, Ti, Ba and Zr) group reflects the aluminosilicate minerals derived from the alteration of volcanic rocks, and a third group (Mg, Ni, Cr, C and Zn) reflects the aluminosilicate minerals derived from the alteration of ultrabasic rocks (peridotites) and the organic carbon. The group of Fe, Mn, Zn and Y is a diagenetic association reflecting the distribution of these elements with pyrite. The association of Cu with Zn reflects a mineralization control in the sediment area. Finally, La and Ce are associated with the K-bearing minerals, while P is related to K and Fe-finegrained minerals. The concentrations of heavy metals in the sediments are normal comparing to the contents of other AEGEAN SEA sediments and are due to natural lithogenic sources.

Analysis of the Factors that Influence Diagenesis in the Terminal Fan Reservoir of Fuyu Oil Layer in the Southern Songliao Basin, Northeast China

AbstractThe diagenesis mechanism and the physical properties of a terminal fan reservoir are determined by nuclear magnetic resonance (NMR), X-ray diffraction and scanning electron microscopy. The main provenance directions are NE and SE, and the two oppositely directed fans converge to form a small catchment basin. The mudstone color is red or purplish red, which accounts for 60% of the total rock. The sandstones are lithic-feldspar sandstones and feldspar-lithic sandstones, with a smaller quartz component relative to the adjacent sandstone formations. The reservoir mainly consists of intergranular pores (51%), intragranular pores (22%), corrosion pores (20%), micro-fractures (5%) and clay matrix pores (2%). The porosity of the reservoir is only 13%, and the throats are fine with high displacement pressure. The diagenetic processes included compaction, cementation, replacement, and dissolution, and the most influential factor on the reservoir porosity was compaction. The detrital rock cement mainly consists of clay minerals (48%), quartz (23%), carbonate (19%), feldspar (7%) and dawsonite (3%). Among them, the mixed I/S layer has the most content and the most important cementation. In addition, a small amount of dawsonite is found in the pores of the sandstone, which is a unique mineral that is related to the background of inorganic CO2. The main diagenesis factors that affected this sandstone’s porosity were compaction, early quartz overgrowth and calcite cementation, which reduced the porosity from 40% to approximately 8%. Although dissolution and fracture increased the porosity (from 8% to 26%), clay- and carbonate-mineral cementation during the late diagenesis period had a dramatic effect, forming a typical low-porosity and low-permeability reservoir.

Abnormal open-hole natural gamma ray (GR) log in Baikouquan Formation of Xiazijie Fan-delta, Mahu Depression, Junggar Basin, China

Abstract Based on large amounts of cores, open-hole conventional logs and mineral components analysis, abnormal natural gamma ray (GR) log showing high values in conglomerates and low values in fine-grained sediments, are described and explained in Baikouquan Formation of Xiazijie Fan-delta, Mahu Depression, Junggar Basin. After observing cores, normalizing the GR log and correcting depth errors between both, the GR log values of individual grain-sized lithology are extracted and counted. When grain-size decreases, the average GR values of different sized grains increase generally. The GR values of conglomerates are mostly between 50 and 80 API, while the values of fine-grains are mainly between 70 and 100 API. However, abnormal GR log features exist in the cores and wells of Baikouquan Formation prevalently. A great deal of high radioactive intermediate-acid volcanic minerals, such as volcanic tuff, felsite, andesite, granite, rhyolite, et al., distribute widely in the conglomerates, which results in abnormal high GR values in conglomeratic intervals. Low radioactive quartz components exit widely in high percentage in mudstones, which is the primary mineral explanation for the abnormal low GR values in reddish-brown siltstones and sandstones intervals.

Different components of the quartz OSL signal resolved by the TM-OSL method

Recently it has been shown that the thermally modulated optically stimulated luminescence (TMOSL) method, which is based on optical stimulation during linear heating of the sample, can be used successfully to extract the individual OSL components during the experimental stage. Such a possibility is important in OSL dating of sediments, where using the OSL component that is most easily bleached in nature is the prerequisite for correct results. The TM-OSL measurements help also to correlate the optical depth of a trap with its thermal depth which enables to determine the thermal stability of traps active in the OSL process. This is especially significant in thermochronometry where the prediction of the temperature and time dependence of the stimulation processes in mineral grains is the main problem. It has been showed that the fast component of OSL in quartz can be separated from the others by optical stimulation with the wavelength of 620 nm. Here, it is shown how the slower OSL components in quartz can be measured individually using the TM-OSL method with the wavelengths of stimulation light in the range 450–620 nm. The growth curves for these components and results of the first tests of their thermal stability are presented.

The Through-Dyed Autoclaved Silicate Concretes with the Use of Thermally Activated Iron Ore Raw Materials Refinement Tailings

The iron ore raw materials refinement waste is not virtually used after the wet magnetic separation and is accumulated in special hydraulic constructions – tailing dumps. This work considers the opportunity of using the heat-treated tailings as loading pigments for through-dyed autoclaved silicate concretes production. The heat-treated tailings were added to the raw mix instead of quartz sand. The concrete samples of light-pink shades of color were obtained. It has been demonstrated that the activation processes, taking place at heat treatment of tailings, as well as the influence of iron oxides acting as a mineralizer at high temperatures, create the increased imperfection of the quartz component’s structure. This increases the synthesis rate of new formations – the low-basic calcium silicate hydrates – and increases the strength properties of the samples with optimal compositions by 70-75% as compared to the control sample.

Chemical and mineralogical investigations of lime plasters of medieval structures of Hampi, India

ABSTRACTThe historical lime plasters of World Heritage Site of Hampi were analyzed using X-ray fluorescence (XRF), petrological microscope, granulometric analysis, X-ray Diffraction (XRD), Fourier transform Infrared spectroscopy (FTIR), and Scanning Electron Microscopy (SEM). The studies indicated presence of aragonite and vaterite, i.e., the polymorphs of calcite in the lime platers of Hampi. The crystallization of calcite has significantly been influenced by self-healing of lime due to wet and dry cycle in the presence of magnesium that promoted formation of calcite polymorphs. The increasing solubility of metastable calcite led to loss of plaster by water dissolution. Granulometric analysis revealed inclusion of sub-angular to sub-rounded medium-sized aggregate grains of granitic origin and the sediments were medium transported before its deposition in fluvial river basin. The cementation index and mineralogical composition point use of air lime/sub-hydraulic lime admixed with non-hydraulic components sourced differently for Hampi plaster. Petrological analysis confirmed the plaster rich in essential minerals like quartz, orthoclase, plagioclase, and other clay components. The presence of chlorite and cristobalite revealed from SEM studies may be resultant minerals from the river sand of Tungabhadra. The scientific studies yielded information about the mineralogical, micro-structural, and chemical composition of the Hampi plasters useful to tailor compatible lime plaster for future conservation works.

A Novel Method for Preparing a Batch of Silicate Glasses Using Sodium and Potassium Hydroxides

A novel method for preparing a batch of silicate glasses containing crystalline quartz, glass formers, modifiers, intermediates, and auxiliary components, including the physicochemical activation of high-melting batch components with the use of alkali metal hydroxides, is developed. The optimal technological parameters are determined and the general scheme for obtaining an agglomerate by the proposed method is presented. It is found that moisturizing the activated components of a glass batch with a KOH solution having a minimal concentration of 0.5% strengthens the agglomerate of the glass batch in comparison with moisturizing by water.

Prediction of Sandstone Reservoir Composition, Porosity and their Variations by Using Well Logging Data, in the Process of CO2-EOR and Geological Storage of CO2

In the process of CO2-EOR and post-EOR, CO2 injection broke the original physical and chemical balance in reservoirs, and caused the complex CO2-brine-rock interactions, meanwhile, it leaded to the variations of rock composition, clay mineral, porosity, pore structure, water salinity, water type and pore fluid. By analyzing the model, core experimental study, field implementation of detection and so on, many scholars studied the CO2-brine-rock interactions and the variations of rock composition, porosity and others. The results showed that CO2 injection would lead to quartz, feldspar, carbonate mineral and clay mineral component dissolution and to the formation of new minerals, which would lead to the decrease of the reservoir porosity. The implementation of ECS time-lapse logging was helpful to predict the variation of rock composition. Neutron and acoustic time-lapse logging were helpful to predict the porosity variation.

Finding of the first fossil seep in the emerged coast of Central Chile (33°56’ S). Characterization and implications.

This study presents the main characteristics of the first fossil hydrocarbon seep documented on the emerged coast of Central Chile. The Navidad Paleoseep (NPS) is an outcrop of carbonate and fossil organisms preserved on the beach of the Navidad locality. The carbonate structure is oriented N45° W, perpendicular to the coastline and discordant with sub horizontal Miocene sequences found in the area. This type of authigenic carbonate accumulation, originates on the sea floor as the result of anaerobic oxidation of methane, generated by low temperature fluids released through seaf loor fractures. The NPS consists mainly of calcium carbonate in the form of matrix and crystallized precipitate. Based on textural features, dominant facies of the outcrop were defined as mudstone and ackestone. The associated mineralogy consists of magnesian calcite, predominantly as micrite matrix, minor components of quartz, albite, amphibole, orthoclase, microcline and fragments of volcanic lithics are also identified. The NPS also contains a variety of fossils, such as bivalves, gastropods, tube worms, teredolites, microbialites and others. The occurrence of Lucinoma promaucana in the paleoseep, evidences a temporal and spatial correlation with the Navidad Formation i.e., would ranges from lower to middle Miocene. The δ13C values vary between -41.4‰ in the matrix and -29.5‰ PDB in bivalve shells, representing the typical negative δ13C values seen in hydrocarbon seeps.