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Sun, Bo Xue, Zuo Ren Nie, Yu Liu, Zhi Hong Wang e Xian Zheng Gong. "Exergy-Based Model of the Depletion of Mineral Resources". Materials Science Forum 650 (maio de 2010): 1–8. http://dx.doi.org/10.4028/www.scientific.net/msf.650.1.
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The primary problem of eco-materials is how to judge whether a material is environmentally friendly or not, and the method of life cycle assessment is usually used to evaluate it. The depletion of mineral resources is a very important indicator of LCA, but its characterization is still filled with dispute. At present, the most commonly used method is CML, which is put forward by Leiden University, and its core idea is that using the ratio of exploitation amount and reserves of mineral resources as the degree of scarcity. Although being accepted by most of the scholars at work on LCA, CML doesn’t grasp the essence of the depletion of mineral resources. Recently, a new assessment method, injecting new ideas to the conventional life cycle assessment, combines exergy with LCA is arising, which can be used to solve some specific problems of LCA especially the depletion of mineral resources. In this paper, two results of elements’ exergy calculated by Rivero and Szargut respectively are compared, and the exergy of some natural minerals, which can be used in LCA and other minerals-related research, is calculated based on the data of Chinese mineral resources.
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Fisher, Beth A., Kyungsoo Yoo, Anthony K. Aufdenkampe, Edward A. Nater, Joshua M. Feinberg e Jonathan E. Nyquist. "Mineral surface area in deep weathering profiles reveals the interrelationship of iron oxidation and silicate weathering". Earth Surface Dynamics 11, n.º 1 (31 de janeiro de 2023): 51–69. http://dx.doi.org/10.5194/esurf-11-51-2023.
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Abstract. Mineral specific surface area (SSA) increases as primary minerals weather and restructure into secondary phyllosilicate, oxide, and oxyhydroxide minerals. SSA is a measurable property that captures cumulative effects of many physical and chemical weathering processes in a single measurement and has meaningful implications for many soil processes, including water-holding capacity and nutrient availability. Here we report our measurements of SSA and mineralogy of two 21 m deep SSA profiles at two landscape positions, in which the emergence of a very small mass percent (<0.1 %) of secondary oxide generated 36 %–81 % of the total SSA in both drill cores. The SSA transition occurred near 3 m at both locations and did not coincide with the boundary of soil to weathered rock. The 3 m boundary in each weathering profile coincides with the depth extent of secondary iron oxide minerals and secondary phyllosilicates. Although elemental depletions in both profiles extend to 7 and 10 m depth, the mineralogical changes did not result in SSA increase until 3 m depth. The emergence of secondary oxide minerals at 3 m suggests that this boundary may be the depth extent of oxidation weathering reactions. Our results suggest that oxidation weathering reactions may be the primary limitation in the coevolution of both secondary silicate and secondary oxide minerals. We value element depletion profiles to understand weathering, but our finding of nested weathering fronts driven by different chemical processes (e.g., oxidation to 3 m and acid dissolution to 10 m) warrants the recognition that element depletion profiles are not able to identify the full set of processes that occur in weathering profiles.
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Weitzman, M. L. "Pricing the Limits to Growth from Minerals Depletion". Quarterly Journal of Economics 114, n.º 2 (1 de maio de 1999): 691–706. http://dx.doi.org/10.1162/003355399556025.
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BLACK, J. R., C. B. AMMERMAN, P. R. HENRY e R. C. LITTELL. "INFLUENCE OF DIETARY MANGANESE ON TISSUE TRACE MINERAL ACCUMULATION AND DEPLETION IN SHEEP". Canadian Journal of Animal Science 65, n.º 3 (1 de setembro de 1985): 653–58. http://dx.doi.org/10.4141/cjas85-077.
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An experiment was conducted to investigate tissue trace mineral accumulation and depletion in sheep fed high dietary Mn in the form of reagent grade MnO. During the pre-trial phase, 32 wethers, 56 kg initially, were group-fed the basal corn-soybean meal diet (36 mg/kg Mn) for 8 days at which time eight sheep were slaughtered and tissues were taken to represent controls. For the remaining sheep, the experiment was divided into two phases of 6 wk and 12 wk; during the first phase (accumulation), the diet contained 8000 mg/kg supplemental Mn and during the second phase (depletion) the diet was the unsupplemented basal. Sheep were slaughtered at various intervals during both phases and tissue samples were taken. Manganese increased in all tissues measured during accumulation but decreased rapidly during the depletion phase. In general, liver and kidney Zn and Cu increased during the accumulation phase but tissue Fe decreased during this phase. MnO appeared to be a relatively safe supplemental source of Mn for sheep. Key words: Manganese, trace minerals, tissue minerals, sheep
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Çolak, Ayşenur, Bertrand Laratte, Birol Elevli e Semra Çoruh. "Abiotic Depletion of Boron: An Update Characterization Factors for CML 2002 and ReCiPe". Minerals 12, n.º 4 (31 de março de 2022): 435. http://dx.doi.org/10.3390/min12040435.
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The risk of resource depletion for future generations of humanity is often cited as an important issue. The choice of impact categories and characterization models for resource extraction in LCA is no more precise than other impact categories and models. This means that more discussion is needed on the use of resources. In this article, the potential depletion of Boron and Boron minerals (Colemanite, Ulexite, Tincal) are studied. These minerals have a big role for the world and for Turkey; however, this resource is limited. Using the life cycle assessment methodology, one can estimate the resource depletion through the indicator “abiotic resource depletion”. Several models can evaluate this indicator, but the most used models are ReCiPe and CML (that is the previous attempt of ReCiPe) methods. Here, we estimated the damage that is done to natural resource scarcity. The values that are calculated by these two methods were compared to identify the potential evolution of the model and to observe the gap between these two models. The ReCiPe method refers to the average amount of extra ore that is produced in the future to extract 1 kg of boron ore or boron minerals resource. On the other hand, The CML method depends on the final reserve amount in terms of depletion. The results show no depletion shortly for boron ore and boron minerals. Correlation coefficients were calculated in the ReCiPe method, and ‘high uncertainty’ was estimated since R2 < 0.8. This research highlights the fact that there is the necessity to propose different impact factors for the various minerals and not only for boron (that is done today).
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Zhang, Yan Jiao, Feng Gao e Zhi Hong Wang. "Updated Resource Depletion Characterization Factors for Life Cycle Assessment-Case Studies on Iron and Steel Production in China". Materials Science Forum 847 (março de 2016): 358–65. http://dx.doi.org/10.4028/www.scientific.net/msf.847.358.
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In this study, the CML model for resource depletion was updated based on the current status of the mineral resources and the characteristics of relevant statistics in China; and the characterization factors of resource depletion were determined for the majority of natural minerals which are most used in materials industry. Besides, case studies on iron and steel production (BF-BOF and EAF process) were carried out to demonstrate the valid of the modified and localized resource depletion model. The results show that in terms of category, the development of Chinese steel industry is mainly based on the depletion of the natural iron ore and fluorite. The results also show that for BF-BOF process, abiotic resource depletion potential (ADP) in 2012 is 5.26 times of that in 2004; and for the EAF process, ADP in 2012 is 23.6 times of that in 2004. Therefore, the information of ADP needs to be updated at intervals of time.
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Oziegbe, E. J., V. O. Olarewaju e O. O. Ocan. "MINERAL CHEMISTRY AND GEOCHEMISTRY OF HYPERSTHENE-BEARING DIORITE FROM ERUSU AKOKO, SOUTHWESTERN NIGERIA". Malaysian Journal of Geosciences 4, n.º 1 (7 de fevereiro de 2020): 13–18. http://dx.doi.org/10.26480/mjg.01.2020.13.18.
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Samples of mafic intrusive rock were analyzed for their mineralogical and chemical properties. The textural relationship was studied using the petrographic microscope, elemental composition of minerals was determined using the Electron Microprobe and the whole rock chemical analysis was done using the XRF and ICP-MS. The following minerals were observed in order of abundance; pyroxene, amphibole, plagioclase, biotite, opaque minerals, quartz and chlorite, with apatite and zircon occurring as accessory mineral. Two types of pyroxenes were observed; orthopyroxene (hypersthene) and clinopyroxene. Texturally, amphiboles have inclusions of plagioclase and pyroxene. The plagioclase has undergone sericitization. The chemical composition of the pyroxene is En51.95Fs44.53Wo3.52, biotite has Fe/(Fe+Mg):0.42, Mg/(Fe+Mg):0.59, and plagioclase is Ab63.5An34.55Or1.95. Whole rock chemistry shows a chemical composition; SiO2: 45.15 %, Al2O3: 14.04 %, Fe2O3: 16.01 %, MgO: 5.65 %, CaO: 7.58 % and TiO2: 3.59 %. There is an enrichment of LREE and a depletion of HREE. Based on the minerals, mineral chemistry and the geochemistry of the studied rock, the rock is mafic and hydrous minerals formed by hydration recrystallization of pyroxene. The rock has extensively retrogressed but has not been affected by any form of deformation.
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Haglund, David G. "La nouvelle géopolitique des minéraux : Une étude sur l’évolution de l’impact international des minéraux stratégiques". Études internationales 13, n.º 3 (12 de abril de 2005): 445–71. http://dx.doi.org/10.7202/701383ar.
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This article explores changes in the international political significance of "strategic minerals" over the past half-century. The method of analysis is comparative historical, or "diachronic", and the major issues examined are: 1) minerals as a cause of international conflict; 2) minerals as a factor contributing to the military potential of states; and 3) the question of mineral scarcity. In addition to the above issues, the author analyzes two central concepts, "geopolitics" and "strategic minerals" . He concludes that while it does make sense to speak of a "new geopolitics of Minerals" in the post-1973 era, there are nevertheless important ways in which recent strategic-minerals issues resemble those of the earlier period under examination, the interwar years (and, in particular, the 1930s). What does not seem to have changed in respect of strategic minerals since the 1930 s is that access to them continues ultimately to be a function of political processes, and therefore the access question remains what it was, a matter of geopolitical concern. Where there have been differences in the relevance of strategic minerals, these have mainly consisted in: 1) the declining importance of minerals as a major contributory factor in the breakdown of world order; 2) the lessening of what had formerly been a deterministic equation between mineral possession and military potential; and 3) the increased salience in the post-1973 era of the perception that access will be affected by the growing scarcity of minerals, whether due to the actual depletion of reserves or politically induced supply disruptions.
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Elsayed, Omnia, Nahla Abd El Ghaffar, Abdel Moneim Mahmoud e Ismail Ismail. "Significant Enrichment of Rare Earth Element Concentrations in Stream Sediments of Sharm El-Sheikh Area, Southern Sinai-Egypt: Geochemical Prospecting and Heavy Mineral Survey". Iraqi Geological Journal 56, n.º 1B (28 de fevereiro de 2023): 1–15. http://dx.doi.org/10.46717/igj.56.1b.1ms-2023-2-9.
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Economic rare earth element bearing-heavy mineral accommodation in alluvial deposits (stream sediments) is a well-known process caused by varying rates of weathering and transportation of heavy minerals and sediments, which is significant in geochemical exploration. In the present work, stream sediment samples from Wadi Lethi, Sharm El-Sheikh, were systematically collected. The collected stream sediments were investigated mineralogically and geochemically using collaborative techniques. The separated heavy fractions have been analyzed for trace elements and Rare Earth Element. Important heavy minerals identified are monazite, sphene, apatite, garnet, xenotime, magnetite, ilmenite, and hematite, with subordinate riebeckite, epidote, and chlorite. Geochemical analyses of the separated heavy minerals revealed an abnormal concentration of total Rare Earth Element that was more than eleven times higher than in the studied area's granitic rocks. The Rare Earth Elements trends of these minerals depict the enrichment of light rare earth elements and the depletion of heavy rare earth elements, as well as the typical negative Eu anomaly found in granitic magma.
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Mitra, Sam. "Depletion, technology, and productivity growth in the metallic minerals industry". Mineral Economics 32, n.º 1 (12 de novembro de 2018): 19–37. http://dx.doi.org/10.1007/s13563-018-0165-8.
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Jin, Yujian, Lihong Yu e Yan Wang. "Green Total Factor Productivity and Its Saving Effect on the Green Factor in China’s Strategic Minerals Industry from 1998–2017". International Journal of Environmental Research and Public Health 19, n.º 22 (9 de novembro de 2022): 14717. http://dx.doi.org/10.3390/ijerph192214717.
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Improving green total factor productivity (GTFP) is a fundamental solution to help the strategic mineral industry to achieve green and sustainable development. This study incorporates the dual negative externalities of resource depletion and environmental pollution into the GTFP measurement to capture the ‘green’ elements. By employing a truncated third-order (TTO) translog cost function and the feasible generalized least squares (FGLS) approach, we evaluate the GTFP growth performance and its components in China’s strategic minerals industry from 1998 to 2017. Moreover, we explore the bias of technological progress toward the resource and environmental factors to grasp the green factor saving effects. The results show that: (1) during the sample period, the average GTFP growth rate of China’s strategic minerals industry was 0.46%, but there were variances between mineral sectors. Nevertheless, after 2012, the GTFP of all mineral sectors experienced different degrees of decrease. (2) The main driver of adjustments in GTFP growth shifted from technological progress to changes in scale efficiency, with technological progress contributing less to GTFP growth. This is particularly evident in the metal and energy minerals sectors. (3) Green technological progress is biased toward saving environmental factor input but enhancing resource extraction. Therefore, the current development of China’s strategic minerals industry falls into a non-sustainable mode of being environmentally friendly but not resource-saving.
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Adediyan, Aderopo Raphael, Uchenna Kingsley Chigozie e Venus Nmakanmma Obadoni. "Foreign Direct Investment and External Debt Impacts Assessment on Environmental Resources Depletion in Nigeria". Ekonomické rozhľady – Economic Review 50, n.º 4 (15 de dezembro de 2021): 361–80. http://dx.doi.org/10.53465/er.2644-7185.2021.4.361-380.
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The public interest in justness, equity and fairness in the use of environmental resources between the present and future generations have raised concern about the current depletion rate of environmental resources in Nigeria. Several socioeconomic factors are involved. Worrisome however is the inflow of foreign direct investment and external debt escalation in recent years in the economy. Importantly, we asked, do they contribute to the depletion of environmental resources in Nigeria? In that, we modelled the implications of growth in FDI and external debt on four cases of environmental resources depletion (forestry, solid minerals, fisheries, and crude oil resources productions). The estimated results suggested that though the depletion rate of environmental resources like crude oil depends largely, over the long run and short run, on the movement in FDI inflow, critical to the level of depletion of the forest is the short run effect of external debt. Furthermore, the depletion level of fisheries responds positively only to a change in FDI with a lag in the short run. In terms of solid minerals, we found a long run impact of external debt. Therefore, provided the impact of a rise in FDI and external debt on the depletion of environmental resources is subject to the particular resource and time in Nigeria, selective policies based on the FDI and external debt management is appropriately adequate to control the level of depletion of environmental resources in Nigeria for the benefit of the future generation.
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Lutyński, Marcin, Piotr Sakiewicz e Sylwia Lutyńska. "Characterization of Diatomaceous Earth and Halloysite Resources of Poland". Minerals 9, n.º 11 (31 de outubro de 2019): 670. http://dx.doi.org/10.3390/min9110670.
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The mining industry of Poland is based mostly on coal and copper ores. Strict carbon emissions and the depletion of deposits will slowly phase out coal. Therefore, metallic ores and other mineral raw materials will dominate the extractive industry of Poland. Current measured resources of the largest deposits of halloysite and diatomaceous earth in Poland are over 0.5 Mt and 10 Mt, respectively. Halloysite and diatomaceous earth samples from halloysite Dunino deposits and Jawornik diatomaceous earth deposits (composed mostly of diatomaceous skeletons (frustules)) were subjected to mineralogical analysis, scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM-EDS) nanostructural, chemical, elemental, and mineral content analysis. Both these minerals have similar properties, i.e., sorption capacity and cation exchange capacity, and are used mostly for the same purposes, e.g., adsorbents, filler material, and filtration. Samples of Dunino halloysite consist of minerals such as halloysite, kaolinite, hematite, magnetite, quartz, magnesioferrite, rutile, ilmenite, geikielite, goyazite, gorceixite, and crandallite, with little impurities in the form of iron oxides. Occasionally, halloysite nanoplates (HNP) nanotubes (HNT) were found. Diatomaceous earth is composed mainly of silica-containing phases (quartz, opal) and clay minerals (illite and kaolinite). The frustules of diatoms are mostly centric (discoid) and have radius values of approximately 50–60 μm. Large resources of these minerals could be used in the future either for manufacturing composite materials or highly advanced adsorbents.
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Temple, J. T., e J. N. Walsh. "Use of element-mineral correlations to investigate fractionation of rare earth elements in fine-grained sediments". Mineralogical Magazine 58, n.º 393 (dezembro de 1994): 533–41. http://dx.doi.org/10.1180/minmag.1994.058.393.01.
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AbstractRelative concentrations of elements in the minerals of fine-grained sediments can be inferred from element-mineral correlation coefficients. The technique is applied to the distribution of REE in Middle Ordovician shales from South Wales analysed by ICPAES, Leco C/S125 and XRD. Phosphate and chlorite show mid-REE enrichment; muscovite + biotite shows mid-REE depletion. The complementarity of the chlorite and muscovite + biotite patterns may be due to fractionation during diagenetic recrystallisation. Partial correlation analysis is used to infer the presence of zircon.
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Prior, T., D. Giurco, G. Mudd, L. Mason e J. Behrisch. "Resource depletion, peak minerals and the implications for sustainable resource management". Global Environmental Change 22, n.º 3 (agosto de 2012): 577–87. http://dx.doi.org/10.1016/j.gloenvcha.2011.08.009.
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Seifert, Karl E., e Sarah A. Chadima. "Depletion of heavy rare-earth elements in metamorphic minerals from Adirondack anorthosites". Geology 17, n.º 11 (1989): 1004. http://dx.doi.org/10.1130/0091-7613(1989)017<1004:dohree>2.3.co;2.
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Irifune, Tetsuo, Toru Shinmei, Catherine A. McCammon, Nobuyoshi Miyajima, David C. Rubie e Daniel J. Frost. "Iron Partitioning and Density Changes of Pyrolite in Earth’s Lower Mantle". Science 327, n.º 5962 (3 de dezembro de 2009): 193–95. http://dx.doi.org/10.1126/science.1181443.
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Phase transitions and the chemical composition of minerals in Earth’s interior influence geophysical interpretations of its deep structure and dynamics. A pressure-induced spin transition in olivine has been suggested to influence iron partitioning and depletion, resulting in a distinct layered structure in Earth’s lower mantle. For a more realistic mantle composition (pyrolite), we observed a considerable change in the iron-magnesium partition coefficient at about 40 gigapascals that is explained by a spin transition at much lower pressures. However, only a small depletion of iron is observed in the major high-pressure phase (magnesium silicate perovskite), which may be explained by preferential retention of the iron ion Fe3+. Changes in mineral proportions or density are not associated with the change in partition coefficient. The observed density profile agrees well with seismological models, which suggests that pyrolite is a good model composition for the upper to middle parts of the lower mantle.
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Rogozhnikov, Denis A., Andrey A. Shoppert e L. M. Karimova. "Investigating of Nitric Acid Leaching of High-Sulfur Copper Concentrate". Solid State Phenomena 299 (janeiro de 2020): 968–73. http://dx.doi.org/10.4028/www.scientific.net/ssp.299.968.
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This article describes the problems of deterioration of the quality of processed raw materials due to depletion of mineral resources. It is proposed to use nitric acid for the processing of complex refractory low-grade concentrates containing non-ferrous and noble metals. It was found that the studied concentrate contains: sphalerite (26.9 %), pyrite (22.0 %), chalcopyrite (19.9 %), silica (13.9 %), alumina (5.5 %), galena (1.7 %), oxidized forms of iron (Fe2O3) (12 %). Gold and silver are associated with sulfide minerals. Typical reactions of interaction of these minerals with nitric acid are considered. A sufficiently high thermodynamic probability of these reactions in a wide temperature range is established. With the use of mathematical methods, the optimal conditions of the process of nitric acid leaching are selected: the ratio of L:S = 5:1; the concentration of nitric acid 10 mol/L; the duration of the process is 60 minutes. In this case, the extraction of copper, zinc, iron and sulfur into the solution was 99.00 %, 99.84 % 98.60 %, 88.51 %, respectively.
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Syed, Shameer, Xingxing Wang, Tollamadugu N. V. K. V. Prasad e Bin Lian. "Bio-Organic Mineral Fertilizer for Sustainable Agriculture: Current Trends and Future Perspectives". Minerals 11, n.º 12 (29 de novembro de 2021): 1336. http://dx.doi.org/10.3390/min11121336.
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Chemical (synthetic) fertilizers used indiscriminately for improved production pose a major threat to long-term soil fertility, the soil environment, and its components. The soil microbial community, however, plays a major and important role in fostering soil health and plant growth. While the use of synthetic fertilizers has a profound impact on plant growth, it also significantly alters the makeup of the microbial community towards a detrimental low, especially N and P fertilizers. Sustainable farming practices can reduce the depletion of natural resources and maintain both productivity and soil fertility. The use of minerals that contain fertilizer nutrients in their native state is a very promising approach to reducing emissions associated with the processing chemical industries. Organic material from natural sources (food waste, manure from livestock, agricultural biomass, etc.) acts as a source of microbial culture and encourages the release of nutrients into the soil during mineral weathering. The combination of nutrient-bearing minerals and their biological weathering agents together with organic matter has the potential to remediate, restore, and sustain depleted agricultural soils. Therefore, in this review, we emphasize the significance of sustaining agricultural productivity and microbial diversity in the rhizosphere, the two vital aspects of modern agricultural systems, through bio-organic mineral fertilizers.
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Kim, Dong-Shik, Steven Thomas e H. Scott Fogler. "Effects of pH and Trace Minerals on Long-Term Starvation of Leuconostoc mesenteroides". Applied and Environmental Microbiology 66, n.º 3 (1 de março de 2000): 976–81. http://dx.doi.org/10.1128/aem.66.3.976-981.2000.
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ABSTRACT Laboratory experiments have definitively shown that exopolymer-producing bacteria have the potential to modify the flow of fluids in oil reservoirs to enhance oil production. Once injected into the reservoir, they will be subjected to a wide range of pH values and to starvation resulting from nutrient depletion. For successful field implementation it is necessary to have a fundamental understanding of these effects on the viability of bacteria. This paper addresses the effects of pH and trace minerals on cell viability of Leuconostoc mesenteroides during carbon source depletion. Two different carbon sources were used to grow cells before transferring the cells to starvation conditions: sucrose and a combination of glucose and fructose. These substrates were chosen because L. mesenteroides produces a significant amount of water-insoluble exopolymers (dextran) under sucrose-fed conditions, which may enhance cell survival under harsh conditions. The effects of dextran on the cell viability were tested at different pH values with and without trace minerals. The rate of cell death followed an exponential-decay law for different values of the solution pH. The optimal solution pH for survival was pH 5, whereas cells died rapidly at pH 3 and below and at pH 13 and above. The sucrose-fed cells showed a greater viability than cells fed glucose and fructose for all pH ranges tested. The results indicated that water-insoluble exopolymers help cells survive for longer periods of time under starvation conditions. The effects of trace minerals on cell culturability were tested at two pH values, 4.5 and 7. For both cases, cells showed a greater culturability (smaller decay rate constant) in the presence of trace minerals than without trace minerals. It was also found that the effects of trace minerals on cell culturability were greater for glucose-fructose-fed cells than for sucrose-fed cells. The Michaelis pH function theory was used for comparing the relationships between the cell decay rate and pH.
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Chatterjee, D., Datta SC e Manjaiah KM. "Transformation of short-range order minerals in maize (Zea mays L.) rhizosphere". Plant, Soil and Environment 60, No. 6 (2 de junho de 2014): 241–48. http://dx.doi.org/10.17221/800/2013-pse.
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Under nutrient stress, low molecular weight organic acids are released in rhizosphere, which dissolve the crystalline layered silicate minerals and subsequently some short range order (SRO) minerals may be formed. To analyze this hypothesis, a controlled greenhouse experiment was conducted with three contrasting soils belonging to Alfisols, Inceptisols and Vertisols order in two phases, viz. Sorghum-sudangrass depletion and test crop experiment on maize. The SROs were measured by selective dissolutions. The results indicate that, NaOH extractable amorphous ferri-alumino silicate was higher in rhizosphere, whereas mild extractant extractable SRO dissolution was increased due to fertilization and rhizospheric effect. Fourier transform infrared band showed changes in 3400–3600/cm region (adsorbed water) and Si-O stretching vibration (1000/cm). This information will provide a new insight in formation of SROs under the rhizospheric environment.
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Xu, Kai, Xiaofeng Wang, Chunfang Kong, Ruyi Feng, Gang Liu e Chonglong Wu. "Identification of Hydrothermal Alteration Minerals for Exploring Gold Deposits Based on SVM and PCA Using ASTER Data: A Case Study of Gulong". Remote Sensing 11, n.º 24 (13 de dezembro de 2019): 3003. http://dx.doi.org/10.3390/rs11243003.
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Dayaoshan, as an important metal ore-producing area in China, is faced with the dilemma of resource depletion due to long-term exploitation. In this paper, remote sensing methods are used to circle the favorable metallogenic areas and find new ore points for Gulong. Firstly, vegetation interference was removed by using mixed pixel decomposition method with hyperplane and genetic algorithm (GA) optimization; then, altered mineral distribution information was extracted based on principal component analysis (PCA) and support vector machine (SVM) methods; thirdly, the favorable areas of gold mining in Gulong was delineated by using the ant colony algorithm (ACA) optimization SVM model to remove false altered minerals; and lastly, field surveys verified that the extracted alteration mineralization information is correct and effective. The results show that the mineral alteration extraction method proposed in this paper has certain guiding significance for metallogenic prediction by remote sensing.
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Yildiz, A., e İ. Dumlupunar. "Mineralogy and geochemical affinities of bentonites from Kapıkaya (Eskişehir, western Turkey)". Clay Minerals 44, n.º 3 (setembro de 2009): 339–60. http://dx.doi.org/10.1180/claymin.2009.044.3.339.
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AbstractThere are numerous bentonite deposits, formed by the alteration of volcanic rocks, in the Kapıkaya area (Eskişehir, western Turkey). These deposits can be classified into three groups according to their stratigraphical levels. X-ray diffraction (XRD), scanning electron microscope (SEM), major, rare-earth and trace-element analyses of bentonites and their parent rocks from the Kapıkaya area were used to evaluate the mineralogical and geochemical properties of bentonites and their parental affinities. Mineral assemblages resulting from bentonite deposits consist mostly of clay minerals, gypsum, cristobalite/opal-CT, quartz, feldspar, calcite and dolomite. The clay minerals are represented mainly by dioctahedral smectite and lesser amounts of illite and chlorite. The enrichment and depletion of the elements indicates open-system alteration conditions. The enrichments in MgO, Fe2O3, TiO2, Co, Pb, Zn, and Ni are related to the precipitation of hydrothermal solutions channelled throughout ultramafic sources. The main differences in mineralogy and geochemistry of bentonites from the Kapıkaya area are in the smectite composition and the contents of major, rare-earth and other trace elements. The data obtained show that the types of parent rock the influenced the mineralogical and geochemical compositions of the bentonites.
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Arkhipova, Yuliya, e Anna Bardal. "Transport and economic problems of subsoil use in the Russian Far East". E3S Web of Conferences 192 (2020): 03003. http://dx.doi.org/10.1051/e3sconf/202019203003.
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The Russian Far East possesses significant reserves of minerals. Mineral resources are rich in species diversity. The development of resources is faced with several problems, such as the depletion of active proven reserves in the exploited fields; high costs of transporting raw materials and finished products to processing sites or end-user markets; lack of availability of deposits; significant financial investments in the construction of new transport routes, etc. This means a transition from the extraction of raw materials to obtaining a product with a high stage of processing and the construction of transport routes. In this article, the authors examined the structure of investments in fixed assets by type of economic activity in the subjects of the Far Eastern Federal District. The values of the volumes of reserves and production of major minerals (for 2018) are presented, and resources are allocated based on which it is necessary to develop processing industries in the region. A comparison is made of the transport accessibility of options for locating a metallurgical plant in the Far East. The conclusion about the need for state support of resource projects and the development of measures to improve the conditions for investment has been substantiated.
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El-Nakhel, Christophe, Danny Geelen, Jolien De Paepe, Peter Clauwaert, Stefania De Pascale e Youssef Rouphael. "An Appraisal of Urine Derivatives Integrated in the Nitrogen and Phosphorus Inputs of a Lettuce Soilless Cultivation System". Sustainability 13, n.º 8 (10 de abril de 2021): 4218. http://dx.doi.org/10.3390/su13084218.
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Reinforcing and optimizing sustainable food production is an urgent contemporary issue. The depletion of natural mineral resources is a key problem that is addressed by recycling mined potassium and phosphorus, and nitrogen, whose production depends on very high energy input. A closed-loop approach of fertilizer use asserts the necessity for efficient management and practices of organic waste rich in minerals. Human-derived urine is an underutilized yet excellent source for nitrogen fertilizer, and, in this study, processed urine fertilizer was applied to greenhouse soilless cultivation of lettuce (Lactuca sativa L.) cv. Grand Rapids. Biomass increase, biometric parameters, soil plant analysis development (SPAD) index, minerals, and organic acids content of lettuce were analyzed. From eight different urine fertilizer products generated, K-struvite, urine precipitate-CaO, and the liquid electrodialysis (ED) concentrate supported the growth of lettuce similar to that of commercial mineral fertilizer. ED concentrate application led to the accumulation of potassium (+17.2%), calcium (+82.9%), malate (+185.3%), citrate (+114.4%), and isocitrate (+185.7%); K-struvite augmented the accumulation of magnesium (+44.9%); and urine precipitate-CaO induced the highest accumulation of calcium (+100.5%) when compared to the control, which is an added value when supplemented in daily diet. The results underlined the potential of nitrogen- and phosphate-rich human urine as a sustainable source for the fertilization of lettuce in soilless systems.
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Luo, Bin, Junbo Liu, Quanjun Liu, Chao Song, Li Yu, Shimei Li e Hao Lai. "A Mechanism for the Adsorption of 2-(Hexadecanoylamino)Acetic Acid by Smithsonite: Surface Spectroscopy and Microflotation Experiments". Minerals 9, n.º 1 (26 de dezembro de 2018): 15. http://dx.doi.org/10.3390/min9010015.
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Zinc is mostly extracted from oxidized zinc and zinc sulfide minerals, and this process involves flotation as a key step. While it is easier to float the sulfide mineral, its consumption and depletion has led to an increased reliance on oxidized zinc minerals, including smithsonite. Hence, the development of efficient ways of collecting smithsonite by flotation is an important objective. Herein, we describe the use of 2-(hexadecanoylamino)acetic acid (HAA), a novel surfactant, as a collector during smithsonite flotation. The mechanism and flotation performance of HAA during smithsonite flotation was investigated by total organic carbon (TOC) content studies, zeta potential measurements, Fourier-transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS) analyses, combined with microflotation experiments. The flotation results revealed that HAA was an excellent collector in pulp over a wide pH range (9–12) and at a relatively low concentration (2 × 10−4 mol/L), at which a recovery of close to 90% of the smithsonite mineral was obtained. TOC content studies revealed that the good flotation recovery was ascribable to large amounts of collector molecule adsorbed on the smithsonite surface, while zeta potential measurements showed that the HAA was chemically adsorbed onto the smithsonite. FTIR and XPS analyses revealed that the HAA collector molecules adsorbed onto the smithsonite surface as zinc–HAA complexes involving carboxylate moieties and Zn sites on the smithsonite surface in alkaline solution.
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Caixao, J. J. Z. "Mining industry in Mozambique". Gornye nauki i tekhnologii = Mining Science and Technology (Russia) 6, n.º 2 (14 de julho de 2021): 114–20. http://dx.doi.org/10.17073/2500-0632-2021-2-114-120.
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At present time,Mozambiqueis called the “Rising Star of South Africa” mainly due to the rapid development of its mining industry. Mineral resources sector ofMozambiqueis one of the most dynamically developing sectors of the country’s economy.China,BrazilandIndiahave recently become the main partners forMozambique. Recently, a number of projects is being implemented in the country, for example, Auroch Minerals Manica Gold in gold production. Increasing coal production is connected with commissioning of the Moatize open pit, which is being developed by Brazilian Vale Company, as well as Benga mining company owned by Indian ICVL consortium. The analysis of the extraction of certain mineral types inMozambiquepresented in the paper demonstrates general picture of mining industry development in the country. The analysis findings allow identifying the causes of negative phenomena in the industry, manifesting themselves in decreasing production of certain types of minerals. For instance, the main reasons for the decline in coal production were dropping labor productivity, deterioration of mining conditions, and depletion of the most accessible coal reserves, extractable by open pit mining. In this regard, development of underground mining methods providing for opening of deep deposits by vertical shaft sets is highly relevant. The experience of the neighboringRepublicofSouth Africashows that, in the mining and geological conditions of the south of the African continent, highspeed shaft sinking methods accelerating deposit development can be successfully applied.
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Egorova, Irina, e Boris Mikhailov. "Objective method for analysis of mineral resources supply on the example of Russia". Ores and metals, n.º 4 (10 de janeiro de 2022): 6–21. http://dx.doi.org/10.47765/0869-5997-2021-10025.
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A forecast of nonfuel mineral production in Russia is
considered, based on the integration of the expected life
of specific deposits currently exploited and developed. It
is shown that mineral safety is fully ensured for copper,
nickel, lead, tungsten and tin, whose reserves are sufficient
for their extraction, at least at the current level, for
40–50 years and there are real prospects for its significant
growth. The sufficiency of other minerals is much
lower: for molybdenum and chromium, it is limited to
about 30 years, and the extraction of zinc and uranium
in Russia may significantly decrease in 20 years. The situation
is more difficult with the most liquid solid minerals,
like gold and diamonds. The commissioning of mining
enterprises at the developed gold deposits can ensure
a rapid growth in the production of the precious
metal in the coming years. However, at the beginning of
the next decade, the resource base depletion of the Olimpiada
field and a number of other exploited deposits is
predicted. The projects currently implemented for the
development of new fields do not compensate for the lost
capacity. This may account for a long-term (until the beginning
of the 2050s) decline in the Russian gold production,
which may be halved against the current level by
the end of this period. Such a scenario can only be avoided
with the intensification of geological exploration in
the coming years. The earlier decrease in the number of
diamonds mined in Russia, associated with the depletion
of reserves of exploited pipes, is predicted (since 2025).
Unless new deposits are discovered and developed, the
domestic production of precious stones will steadily decline
and, in the 2040s, may be reduced fourfold.
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SALSKI, Wojciech. "VARIATIONS IN THE AMOUNT OF MINERAL RESOURCES AND MINING PRODUCTION OF POLAND AFTER WORLD WAR II". Biuletyn Państwowego Instytutu Geologicznego 473, n.º 473 (20 de dezembro de 2018): 67–92. http://dx.doi.org/10.5604/01.3001.0012.7710.
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The paper presents the estimates of Polands’s reserves of mineral raw materials after World War II until 2005. This refers to energy minerals (methane, natural gas, oil, black and brown coals), metal ores (iron, copper, lead and zinc) and chemical mineral raw materials (sulphur, rock salt). The period of 1960–1980 was characterised by a dynamic increase of the reserves. In many cases, it was an effect of discoveries of new large deposits, and even large mineral-rich areas. The amount of reserves increased three to four times compared with its volume in 1960. For instance, sulphur reserves increased seven times, natural gas – sixteen times. Discoveries of new deposits as well as intense mining have caused a change in geographical distribution of the main mining centres. However, the last 15 years have been characterised by a depletion of reserves and a drop in the mining extraction. Mining of iron ores and sulphur has been abandoned, and lead and zinc deposits have been significantly depleted. Generally, the role of the potential of mineral raw materials has greatly weakened in the national economy.
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Uliganets, Serhii I., Sergii Yu Syrovets, Nataliia S. Koroma e Mykola A. Molochko. "A geographical dimension of resource endowment of Ukrainian territories". Journal of Geology, Geography and Geoecology 30, n.º 3 (7 de outubro de 2021): 589–96. http://dx.doi.org/10.15421/112154.
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Given the multidisciplinary nature of this research, it is important to develop a common understanding of the security and complexity of the rational consumption of available minerals. Considerations for the availability and depletion of minerals are part of a diverse range of research focused on sustainable development, in areas such as resource critical shortage, life cycle assessment and material flow analysis. Mineral resources are non-renewable resources that provide humanity with a wide range of goods and services. Although their value has been recognized for millennia, their large-scale industrial production did not grow until after World War II due to efficient industrial production processes and rapidly growing demand due to demographic growth, urbanization and economic wealth growth in developed countries. The proposed research confirms the high level of supply of the territory of Ukraine with mineral resources. The objective idea of mineral and self-sufficiency of Ukraine, its inclusion in the top groups of the states most provided with the most valuable types of minerals is strengthened and the high level of availability of mineral resources in Ukraine in terms of its economic and geographical areas and regions is confirmed. At the same time, a number of mineral deposits in modern social and economic conditions are preserved and not used. For the first time, a cartographic interpretation of the periodic table of chemical elements (D. I. Menedeleev's table) is given, which is reinforced by data on the distribution of mineral resources and minerals in terms of selected groups of regions within the administrative regions of Ukraine. There are 33 chemical elements extracted from more than 100 mineral deposits. The provisions and conclusions of the article testify the mineral self-sufficiency of Ukraine and can act as a lever for developing strategies for socio-economic development of the United Territorial Communities (UTC) of Ukraine, which today are the new centers of management of territories and its resources. D. I. Mendeleev's table and its mineral content are positioned as an objective factor in the specialization of Ukraine and the international geographical division of labour. It is noted that the main advantages of the Periodic Table of Chemical Elements, including its structure, logic, objectivity, a system in relation to the economic and geographical regions of Ukraine are considered as an element of monitoring the mineral component of natural resources of the country, the lever of further development of exploratory geology and geomorphology. The information obtained from this research ultimately influences the future policies of the territories and its plans for the balanced use of available mineral reserves and can be used to promote the sustainable use of mineral resources in the regions.
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Pal, Y., R. J. Gilkes e M. T. F. Wong. "Soil factors affecting the availability of potassium to plants for Western Australian soils: a glasshouse study". Soil Research 39, n.º 3 (2001): 611. http://dx.doi.org/10.1071/sr00030.
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A glasshouse experiment was conducted with 41 surface and 8 subsurface soils to measure their potassium (K) supply capacities and K depletion of soils by ryegrass growth for 260 days and harvesting at ~40-day intervals. Dry matter yield ranged from 0.22 g to 25.4 g/kg soil, cumulative K uptake ranged from 0.006 to 1.49 cmol/kg soil, and values of K concentration (%) in the first cut herbage ranged from 0.40% to 5.97%. Some of the light-textured soils were so impoverished in K that symptoms of K deficiency appeared during the first growth period. Water-soluble K + exchangeable K accounted for 43–100% of cumulative K uptake by the ryegrass. Multiple regression analysis indicated that 68% of the variation in dry matter yield and 90% of the variation in K uptake may be predicted by the exchangeable K content of these soils. The 6 harvests of ryegrass extracted only 0.21–12.07% of total K from these soils, which was not sufficient to cause discernible mineralogical changes in most soils. For some soils vermiculite was formed at the expense of illite/mica by K release to plants. For soils containing vermiculite but no other K-bearing clay minerals, vermiculite peaks broadened on K depletion by plants. Major proportions of total K in these soils are present in silicate minerals, yet only minor amounts are released to plants by very slow weathering processes. For soils that do not contain any K bearing clay minerals, very minor amounts of feldspar may have dissolved to release K.
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Mulopo, Jean, e L. Schaefer. "Biological regeneration of ferric (Fe3+) solution during desulphurisation of gaseous streams: effect of nutrients and support material". Water Science and Technology 71, n.º 11 (30 de março de 2015): 1672–78. http://dx.doi.org/10.2166/wst.2015.144.
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This paper evaluates the biological regeneration of ferric Fe3+ solution during desulphurisation of gaseous streams. Hydrogen sulphide (H2S) is absorbed into aqueous ferric sulphate solution and oxidised to elemental sulphur, while ferric ions Fe3+ are reduced to ferrous ions Fe2+. During the industrial regeneration of Fe3+, nutrients and trace minerals usually provided in a laboratory setup are not present and this depletion of nutrients may have a negative impact on the bacteria responsible for ferrous iron oxidation and may probably affect the oxidation rate. In this study, the effect of nutrients and trace minerals on ferrous iron oxidation have been investigated and the results showed that the presence of nutrients and trace minerals affects the efficiency of bacterial Fe2+oxidation. The scanning electron microscopy analysis of the geotextile support material was also conducted and the results showed that the iron precipitate deposits appear to play a direct role on the bacterial biofilm formation.
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Setti, M., L. Marinoni e A. López-Galindo. "Mineralogical and geochemical characteristics (major, minor, trace elements and REE) of detrital and authigenic clay minerals in a Cenozoic sequence from Ross Sea, Antarctica". Clay Minerals 39, n.º 4 (dezembro de 2004): 405–21. http://dx.doi.org/10.1180/000985503540143.
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AbstractThe mineralogy and geochemistry of the clay fraction of Victoria Land Basin (Ross Sea, Antarctica) sediments was investigated, to determine the origin of clay minerals and the features of authigenic smectite. The investigated core (CRP-3) is ~800 m long, mostly of Oligocene age. The clay fraction of the upper sequence consists of mica, chlorite and detrital smectite, while that of the central and lower part is largely made up of authigenic smectite. Authigenic smectites are ditrioctahedral, with a composition close to saponite, while detrital smectites such as Al-Fe beidellites are dioctahedral. Authigenic smectites have no illite mixed layers, show a higher degree of crystallization, higher MgO, Fe2O3, V, Cr, Co, Ni and Sc contents and lower SiO2, Al2O3, K2O, TiO2, Ba, Rb and Zr contents with respect to detrital clay minerals, and a clear depletion of LREE with respect to HREE. Authigenic smectite formed from the alteration of volcanic materials and clay minerals.
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Sutarto, Sutarto, Adi Sulaksono, Dema Laksana T., Anggita Mahyudani, Ajimas Setiahadiwibowo P. e Muhammad Nurcholis. "REE content of volcanic rocks and their weathered horizons in the Muria Volcanic Complex, Central Java, Indonesia". Bulletin Mineralogie Petrologie 30, n.º 1 (2022): 28–37. http://dx.doi.org/10.46861/bmp.30.028.
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We investigated bedrock samples and their weathered horizons collected from the Muria Volcanic Complex (MVC), Central Java, Indonesia. In addition to petrographic study, samples were analysed using X-ray diffraction (XRD), inductively coupled plasma-atomic emission spectroscopy (ICP-AES), and inductively coupled plasma-mass spectrometry (ICP-MS) for mineral composition, major elements, and trace elements, respectively. Bedrock samples (n = 10) from the MVC have ΣREE ranging from 364 to 739 ppm (avg. 579 ppm). Basanite (n = 2) and phonotephrite (n = 2) are consistently high in ΣREE (659 - 739 ppm) compared with basaltic trachyandesite, trachyandesite, and trachyte. Apatite is the only REE-bearing mineral observed in basanite and phonotephrite (up to ~1 vol.%). The ΣREE is positively corelated with P2O5, which inversely corelates with SiO2. The weathered horizons contain clay minerals that consist primarily of kaolinite ± halloysite. The REE content of the weathered horizons (n = 7) is up to 183 ppm higher than those of the bedrocks. The decrease in CaO and P2O5 indicates a fractionation of apatite at early stage of magma evolution, resulting in the depletion in the ΣREE content in the residual melt. We suggest that apatite is the major host of REE in the MVC alkali-rich, silica-undersaturated volcanic rocks, as evidenced by our petrographic and geochemical data. We also suggest that the increase in ΣREE in the weathered horizon is due to the presence of clay minerals, particularly kaolinite and halloysite.
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Othman, D. Ben, N. T. Arndt, W. M. White e K. P. Jochum. "Geochemistry and age of Timiskaming alkali volcanics and the Otto syenite stock, Abitibi, Ontario". Canadian Journal of Earth Sciences 27, n.º 10 (1 de outubro de 1990): 1304–11. http://dx.doi.org/10.1139/e90-140.
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Tephrites and trachytes of the Timiskaming volcanics from the Kirkland Lake area (Ontario) and syenites and a granite from the nearby Otto Stock are characterized by extreme enrichment of incompatible elements coupled with relative depletion of Nb, Ti, and to a lesser extent Zr and Y.The volcanic rocks have a whole-rock Sm–Nd isochron age of 2740 ± 117 Ma (2σ error), and minerals separated from the Otto Stock, a Sm–Nd age of 2544 ± 50 Ma. Conventional and ion probe U–Pb analyses of zircons from the Otto Stock yielded an upper intercept age of 2700 ± 19 Ma, whereas the more concordant ion probe analyses had a mean 207Pb/206Pb age of 2671 ± 8 Ma (2σ). The latter is interpreted as the age of emplacement of both the volcanics and the pluton, and the Sm–Nd mineral isochron age is thought to reflect a period of later disturbance, probably during regional metamorphism.A high initial εNd of 2.5 ± 1.5 for Kirkland Lake volcanics indicates long-term isotopic depletion of their source. This value is the same as that for volcanic rocks throughout the Abitibi belt and indicates that any chemically enriched material in the source cannot have been much older than the volcanics themselves. An environment remote from older continents is inferred.
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JOSHI, VIVEK, A. G. BHANUPRAKASH, R. S. K. MANDAL, S. ALAM, V. K. GUPTA e UMESH DIMRI. "Oxidative stress and imbalance of serum trace mineral metabolism contribute to bovine respiratory disease in dairy calves". Indian Journal of Animal Sciences 88, n.º 3 (26 de março de 2018): 295–99. http://dx.doi.org/10.56093/ijans.v88i3.78267.
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Bovine respiratory disease (BRD) is the most common infectious cause of clinical disease and death in young calves. The study was undertaken to scrutinize a relationship between tissue damage by oxidative stress, concentrations of serum trace minerals and clinical status of calves during BRD. The method of clinical scoring and thoracic auscultation were used to screen and select infected calves. In this study, comparison of lipid peroxides (LPO), antioxidant enzymes and serum trace minerals was done between BRD infected and healthy subjects (18 calves in each group). The infected group was further divided into 3 subgroups according to clinical scores (CS) (5,6,7). The blood LPO levels were significantly higher in BRD infected calves. The antioxidative activities of superoxide dismutase, reduced glutathione, catalase and serum uric acid were significantly lower in BRD infected calves. The concentrations of trace minerals (copper, zinc, selenium) were significantly reduced during BRD. All hematobiochemical parameters varied proportionately with the CS of infected calves. These findings demonstrated simultaneous occurrence of increased oxidative stress and depletion of antioxidative trace minerals during BRD in calves. A strong correlation exists between severity of oxidative stress and CS of calves.
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Burwash, Ronald A., Thomas Chacko, Karlis Muehlenbachs e Youcef Bouzidi. "Oxygen isotope systematics of the Precambrian basement of Alberta: implications for Paleoproterozoic and Phanerozoic tectonics in northwestern Alberta". Canadian Journal of Earth Sciences 37, n.º 11 (1 de novembro de 2000): 1611–28. http://dx.doi.org/10.1139/e00-090.
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We have conducted a regional survey of the oxygen isotope compositions of drill core samples from the Precambrian basement of the Alberta sedimentary basin. The majority of samples have whole-rock δ18O (SMOW) values between +7 and +11, as is typical of crustal rocks. However, there are also a significant number of samples with δ18O values less than +5. In these samples, high-grade minerals such as pyroxene, amphibole, and biotite commonly show retrograde alteration to chlorite and (or) epidote. The majority of low-δ18O samples are from a 250 x 50 km zone in northwestern Alberta, which we refer to as the Kimiwan isotope anomaly. The anomaly is significant in that the most reasonable explanation for generating such a laterally extensive zone of rocks, with δ18O values below +5, is through high-temperature interaction with surface-derived fluids in an extensional tectonic setting. We propose, therefore, that the low-δ18O samples define a hitherto unrecognized extensional zone in the Alberta basement. Available geochronological data indicate that fluid-rock interaction and associated 18O depletion occurred at ca. 1800 Ma. Oxygen and hydrogen isotope data on mineral separates from this zone indicate that the surface fluids responsible for 18O depletion were of meteoric origin. Seismic reflection profiles acquired during the Lithoprobe Alberta Basement Transect reveal the presence of basement faults spatially associated with the zone of 18O depletion. We propose that these faults were extensional in nature at ca. 1800 Ma. Periodic reactivation of these basement structures during the Phanerozoic played an important role in the development of faults in the overlying sedimentary basin.
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Teveldal, S., P. Jørgensen e A. O. Stuanes. "Long-term weathering of silicates in a sandy soil at Nordmoen, southern Norway". Clay Minerals 25, n.º 4 (dezembro de 1990): 447–65. http://dx.doi.org/10.1180/claymin.1990.025.4.04.
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AbstractWeathering processes have been studied in a podzol profile developed on sand during a postglacial period of 9400 years. Due to disintegration of rock fragments, the particle-size distribution has changed markedly in the upper part of the profile, and minerals have been transferred from sand fractions to silt and clay fractions. The most important weathering processes are the total breakdown of trioctahedral chlorite and biotite, and the transformation of dioctahedral mica (muscovite-phengite) to a regularly interstratified mineral, and further to Al-vermiculite or smectite. By using quartz as an internal standard, the annual loss due to weathering was found to be 3·2 g/m2. The release of elements due to silicate weathering was calculated from depletion curves, and the average annual release of Na + K + Mg + Ca for the postglacial period was 19 mEq/m2.
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Kühnel, Radko A., e Sjerry J. van der Gaast. "Humidity Controlled Diffractometry and its Applications". Advances in X-ray Analysis 36 (1992): 439–49. http://dx.doi.org/10.1154/s0376030800019066.
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AbstractHumidity sensitive mineral phases change their structure when humidity varies resulting in X-ray pattern changes in intensity, position, and shape of lines. These structural changes in hydrous minerals are induced by dehydration and rehydration, which can lead to phase transformations or to steady depletion which may result in a total structure collapse. By means of X-ray diffraction with a special attachment, such reactions can be followed. The controlled relative humidity is provided in situ, in a closed cell, by a flow of moistened helium gas which is flushed through the cell during the XRD analysis. Humidity diffractometry allows studies of reaction rates of dehydration-rehydration reactions and their reversibilities, as well as effects of additives and impurities on these reactions. Potential applications in basic research and in industry are demonstrated using montmorilionite, ettringites, sodium carbonates and calcium sulfates.
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Venturelli, Sascha, Christian Leischner, Thomas Helling, Olga Renner, Markus Burkard e Luigi Marongiu. "Minerals and Cancer: Overview of the Possible Diagnostic Value". Cancers 14, n.º 5 (28 de fevereiro de 2022): 1256. http://dx.doi.org/10.3390/cancers14051256.
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Cancer is the second leading cause of death worldwide and is expected to increase by one-third over the next two decades, in parallel with the growing proportion of the elderly population. Treatment and control of cancer incidence is a global issue. Since there is no clear way to prevent or cure this deadly malignancy, diagnostic, predictive, and prognostic markers for oncological diseases are of great therapeutic value. Minerals and trace elements are important micronutrients for normal physiological function of the body. They are abundant in natural food sources and are regularly included in dietary supplements whereas highly processed industrial food often contains reduced or altered amounts of them. In modern society, the daily intake, storage pools, and homeostasis of these micronutrients are dependent on certain dietary habits and can be thrown out of balance by malignancies. The current work summarizes the data on minerals and trace elements associated with abnormal accumulation or depletion states in tumor patients and discusses their value as potential tumor-associated biomarkers that could be introduced into cancer therapy.
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ALEXANDROVA, Tatyana, Anastasia AFANASOVA e Nadezhda NIKOLAEVA. "LOW- GRADE STRUCTURES OF NOBLE AND NON- FERROUS METALS AND METHODS OF THEIR SELECTIVE SEPARATION". Sustainable Development of Mountain Territories 13, n.º 2 (30 de junho de 2021): 161–69. http://dx.doi.org/10.21177/1998-4502-2021-13-2-161-169.
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There is a worldwide trend of increasing the share of extraction and processing of low-grade minerals, but their extraction and processing volumes are still low. There are several reasons for this: high mining and transportation costs, imperfect techniques and technological difficulties in enrichment and processing of refractory and low-quality minerals. Due to the depletion of reserves of easily beneficiated raw materials and to compensate for the growing shortage of high-quality minerals, the Russian mining industry development strategy provides for the involvement of new and unconventional types of deposits into production. Examples of such deposits are deposits of carbonaceous raw materials (black shale, refractory sulphide carbon-bearing ores, impactites, etc.) containing carbon of varying degrees of metamorphism. On the basis of the most modern mineralogical, physical, nuclear and chemical methods of research of composition, structure and properties of the carbonaceous raw materials at the micro- and nanolevel, the composition of the productive mineral matter, physical, chemical and thermodynamic laws of separation of valuable mineral components and the basic technological processes to obtain the finished product for valorization of the unconventional carbonaceous mineral raw materials were determined with maximum reliability. One of the possible reasons of difficulty of beneficiation of carbonaceous raw materials is the fine phenocrysts in graphite which can be solved by using the flotation process. Contrast of surface properties of minerals with similar technological properties can be increased by application of different energy effects (MEMI, MIO, microwave, electrochemical treatment etc.) at successive stages of raw material transformation, regulation of pulp conditioning conditions (duration and intensity of agitation, heat treatment of pulp) as well as by development and application of selective reagent regimes. The special feature of flotation as a method of extraction of noble and rare metals is the ability to extract valuable metals not only in their native free form, but also in close association with sulphides and carbon. Flotation with the use of intensifying influences made it possible to transfereven low-sized structures of noble and rare metals, which are not extracted by conventional methods of cyanidation, gravitation enrichment and amalgamation, into the concentrate. One of the ways to increase the efficiency of the flotation process is preliminary modification of the additive which is introduced in addition to the main reagents of the sinter - “carrier material”.
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Albertyan, Aida Pogosovna. "Development of the mineral resource complex as an increase in the geopolitical status of Russia". Мировая политика, n.º 1 (janeiro de 2022): 48–58. http://dx.doi.org/10.25136/2409-8671.2022.1.37713.
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The state of the mineral resource complex is one of the foundations of the functioning and development of Russia in the context of the global geopolitical struggle. The geopolitical status of the state today largely depends on how the country will be able to respond to the challenges associated with the depletion of traditional mining areas and the beginning of a new stage of energy transition. In this article, the author provides an overview of the mineral resource complex of Russia, and also analyzes the dependence of the geopolitical status on the state of the mineral resource complex. According to the results of the study, the author concludes that the mineral resource potential of Russia, although it is one of the largest in the world, at the same time, there is a problem of shortage of certain types of minerals (manganese, chromium, titanium, bauxite, zirconium, beryllium, lithium, rhenium, rare earths of the yttrium group, hydrofluoric spar, bentonites for foundry production, feldspar raw materials, kaolin, large-leaf muscovite, iodine, bromine) and the country's dependence on imports. The deficit is caused by both the growth of consumption of certain types of minerals, and low quality, as well as poor development of some domestic deposits. In order to successfully develop Russia, the country needs to increase the volume and improve the quality of the mineral resource base that can meet the demand of high-tech and technological sectors of the economy (military-industrial complex, dual-use systems, medicine, etc.).Increasing the volume and improving the quality of the country's mineral resource base is possible due to the development of new areas and the search for new, high-quality deposits of strategic and scarce mineral raw materials. In this connection, the author examines in detail the cooperation in the field of mineral resources development in the Republic of Kazakhstan, in the Socialist Republic of Vietnam, as well as with the People's Republic of China. In carrying out this research, the author applied the methods of content analysis, historical and systemic.
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Liu, Zhixiang, Xiaoqing Dai, Shan Yang e Yuxi Liu. "Experimental Platform Development of Similar Simulation and Mechanical Test for Undersea Metal Mining". E3S Web of Conferences 206 (2020): 03032. http://dx.doi.org/10.1051/e3sconf/202020603032.
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With the depletion of shallow metal resources in the land, the development of seabed resources has become a new direction. In order to achieve safe and efficient exploitation of seabed metal mineral resources, a similar simulation test platform was established for seabed mining of metal minerals in this paper. Similar simulation materials and the best material ratios were selected to make simulated specimens. A series of mechanical pressurization devices and model sample were prototyped and submarine simulation mining test was conducted. During the simulation mining test, stress and strain changes and microscopic observations of crack evolution were monitored by the static strain test system. These indicators revealed the characteristics of ore-rock mechanical change in the development of submarine mental resources. By exploring the best safe thickness of seabed resource mining, it provides effective data reference for subsequent seabed resource development, so as to realize safe and efficient mining.
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Ali, Sarmad A. "Petrography and Geochemistry of Gabbroic Rock from the Penjwin Ophiolite, Kurdistan Region, Northeastern Iraq". Iraqi Geological Journal 54, n.º 2E (30 de novembro de 2021): 24–37. http://dx.doi.org/10.46717/igj.54.2e.3ms-2021-11-19.
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The gabbroic rocks as a part of Zagros ophiolite are exposed in northeastern Iraq, Penjwin area. These rocks with granular to ophitic textures are widely distributed without metamorphic halos. The main minerals are plagioclase (An90-99), olivine, clinopyroxene (Wo27-47 En 45-64 Fs8-14) and orthopyroxene (Wo2 En78 Fs20) respectively based on the abundances. The major elements show a broad range of compositional variations, with SiO2 (46.2–50.9 wt. %), and low concentrations Na2O (0.15–0.62 wt. %), K2O (0.01–0.03 wt. %) and TiO2 (0.06–0.2) and high concentrations, Al2O3 (6.4–19.75 wt. %), total Fe2O3 (6.29–11.6 wt. %), MgO (9.63–24.5 wt. %), CaO (8.02–18 wt. %) and low alkali contents (Na2O + K2O = 0.16–0.65 wt. %). On Ti-V diagram, all of the gabbroic samples have Ti/V less than 10 and consequently fall in the low Ti- Island arc tholeiitic. Whole rocks chemistry shows a depletion of High field strength elements in comparison with the primitive mantle with an arched upward rare earth elements pattern, characterized by light rare earth elements depletion (La N/Sm N = 0.05–0.8) and enrichment in the High field strength elements. Whole rocks chemistry, mineral paragenesis and chemistry of these rocks are more consistent with tholeiitic magma series. Based on our findings in this research, the primary magma has been produced from the depleted mantle with a high degree of partial melting.
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Thomas, David. "A Study on the Mineral Depletion of the Foods Available to us as a Nation over the Period 1940 to 1991". Nutrition and Health 17, n.º 2 (abril de 2003): 85–115. http://dx.doi.org/10.1177/026010600301700201.
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In 1927 a study at King's College, University of London, of the chemical composition of foods was initiated by Dr McCance to assist with diabetic dietary guidance. The study evolved and was then broadened to determine all the important organic and mineral constituents of foods, it was financed by the Medical Research Council and eventually published in 1940. Over the next 51 years subsequent editions reflected changing national dietary habits and food laws as well as advances in analytical procedures. The most recent (5th Edition) published in 1991 has comprehensively analysed 14 different categories of foods and beverages. In order to provide some insight into any variation in the quality of the foods available to us as a nation between 1940 and 1991 it was possible to compare and contrast the mineral content of 27 varieties of vegetable, 17 varieties of fruit, 10 cuts of meat and some milk and cheese products. The results demonstrate that there has been a significant loss of minerals and trace elements in these foods over that period of time. It is suggested that the results of this study cannot be taken in isolation from recent dietary, environmental and disease trends. These trends are briefly mentioned and suggestions are made as to how the deterioration in the micronutrient quality of our food intake may be arrested and reversed.
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Lippy, Brittany A., Blake K. Wilson e Colton A. Robison. "The Effects of Varying Levels of Trace Mineral Supplementation on Feedlot Cattle Performance and Carcass Characteristics". Journal of Animal Science 99, Supplement_2 (1 de maio de 2021): 28. http://dx.doi.org/10.1093/jas/skab096.050.
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Abstract The objective of this experiment was to determine the effects of 4 levels of trace mineral supplementation on feedlot cattle. Two hundred and forty Angus crossbred steers (n = 48, BW = 291 ± 27 kg) were stratified by arrival BW and source and randomly assigned to 1 of 4 experimental treatments in a randomized complete block design (12 pens/ treatment; 5 steers/pen). Cattle went through a 35 d depletion period prior to the administration of treatments where cattle received a supplement that included zero trace minerals and was formulated to meet or exceed other nutrient requirements not met by the ration. Cattle were administered treatments after transition to the finishing ration. The treatments included a negative control (CON) which contained no added trace minerals, a requirement treatment (1X) in which cattle received added trace minerals at requirement levels indicated by NASEM (Co 0.15 mg/kg, Cu 10 mg/kg, Fe 50 mg/kg, I 0.5 mg/kg, Mn 20 mg/kg, Se 0.1 mg/kg, Zn 30 mg/kg; NASEM 2016), a 2 times requirement levels (2X) treatment, and a treatment at four times requirement (4X) levels recommended by the NASEM. Iron was kept constant at 50 mg/kg for 1X, 2X, and 4X treatments. Due to feeding laws, Selenium was included at 0.1, 0.2, and 0.3 mg/kg for 1X, 2X, and 4X respectively. Treatment levels were chosen based on the 2015 Feedlot Consulting Nutritionist Survey. There was no difference in BW, ADG, overall DMI and G:F over the course of the experiment (Linear P ≥ 0.12; Quadratic P ≥ 0.17; CON vs Supplements P ≥ 0.47) There was no difference in marbling score, yield grade, back fat, REA, HCW, or dressing percentage between treatments (Linear P ≥ 0.23; Quadratic P ≥ 0.36; CON vs Supplements P ≥ 0.30). In conclusion, the lack of or addition of supplemented trace minerals at or above indicated requirement levels has no effect on cattle performance or carcass characteristics.
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Nikol’sky, Alexander M., Sergey A. Shchukin e Anton I. Konurin. "JUSTIFICATION OF UNDERGROUND TECHNOLOGY OF PLACER GOLD MINING IN THE FAR NORTH". Interexpo GEO-Siberia 2, n.º 3 (21 de maio de 2021): 342–53. http://dx.doi.org/10.33764/2618-981x-2021-2-3-342-353.
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A significant part of placer mineral deposits in the Arctic zone of Russia urges the need for its strategic development in the near and medium term. Applicably to underground mining of placer gold deposits, the problems of safe and efficient extraction of minerals by mines in the conditions of the Far North are considered. A substantiated choice of uncovering and mining technology for gold-bearing sand strata is proposed in the context of rational planning of mining operations associated with minimizing material and labor costs for uncovering and extracting a part of the deposit, as well as completeness of reserves depletion during the operational period. Safe parameters of structural elements of room mining systems have been determined by geomechanical assessments. Methods for additional support of the roof of mined-out rooms are proposed. The indicators of losses and dilution of gold-bearing sands in accordance with the sources of their formation were determined by the graphoanalytical method.
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Maksimova, Victoria, Eugenia Krasavtseva, Yevgeny Savchenko, Petr Ikkonen, Irina Elizarova, Vladimir Masloboev e Dmitry Makarov. "Study of the composition and properties of the beneficiation tailings of currently produced loparite ores". Записки Горного института 256 (10 de novembro de 2022): 642–50. http://dx.doi.org/10.31897/pmi.2022.88.
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The increase in demand for rare earth metals and the depletion of natural resources inevitably causes the need to search for alternative unconventional sources of rare metal raw materials. The article presents the results of a study of the composition and properties of the beneficiation tailings of currently produced loparite ores. Sieve, mineralogical, chemical, and radionuclide analyses were carried out. The average content of loparite in tailings was determined. Using scanning electron microscopy, minerals-concentrators of rare earth elements in the loparite ore beneficiation tailings were diagnosed. The distribution of valuable components and thorium in the tailings was determined depending on the particle size class. The radium-thorium nature of radioactivity was established, the values of the effective specific activity of the samples were calculated. We concluded that it is necessary to develop an integrated technology for processing the beneficiation tailings of loparite ore, due to the complex and heterogeneous mineral and chemical composition of the tailings material.
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LINDH, ANDERS, e HELENA NÄSSTRÖM. "Crystallization of orbicular rocks exemplified by the Slättemossa occurrence, southeastern Sweden". Geological Magazine 143, n.º 5 (16 de agosto de 2006): 713–22. http://dx.doi.org/10.1017/s001675680600210x.
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The orbicular rock at Slättemossa, southeastern Sweden, has a quartz monzodioritic composition. The cores of the orbicules crystallized directly from the orbicule-forming magma; cores made up of xenoliths have not been observed. Outside the core follow first an inner mafic, a felsic and then an outer mafic shell. The orbicules occur in a matrix, which is similar to the core. They grew simultaneously and show an almost perfect parallelism in evolution. After initial ‘normal’ crystall-ization of the magma, superheating probably triggered by a sudden addition of volatiles destroyed earlier formed nuclei and also affected the already crystallized part of the rock. Cooling caused heterogeneous nucleation and rapid crystallization, which formed the inner mafic shell. This is enriched in mafic minerals, especially biotite, compared to the core. At the same time the grain size becomes significantly smaller. Depletion in mafic components, possibly intensified by a sudden change in physical conditions, destabilized biotite and amphibole crystallization, causing oversaturation in plagioclase components, forming a felsic shell having a sharp boundary with the mafic shell. Plagioclase is extremely altered. Mafic minerals were then stabilized, probably due to depletion of plagioclase components, and an outer mafic shell formed. With the return to homogeneous nucleation, matrix formation concluded the crystallization. Orbicules might have moved in the magma causing some squeezing of magma surrounding the orbicules, but major movements involved the settling of the whole package of orbicules and matrix in the surrounding non-orbicular magma.
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Li, Ai, Jian Wang e Yue Song. "Petrology, mineral chemistry, and geochemistry of Late Triassic Ni–Cu ore-bearing mafic–ultramafic intrusions, Hongqiling, northeastern China: petrogenesis and tectonic implications". Canadian Journal of Earth Sciences 56, n.º 2 (fevereiro de 2019): 111–28. http://dx.doi.org/10.1139/cjes-2018-0014.
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The Hongqiling magmatic Ni–Cu sulfide deposit, situated on the southern margin of the eastern Central Asian Orogenic Belt (CAOB), is composed of over 30 mafic–ultramafic intrusions. These ore-bearing intrusions are composed mainly of harzburgite, lherzolite, websterite, orthopyroxenite, and norite (gabbro). The constituent minerals are olivine, diopside, bronzite, calcic-hornblende, plagioclase, and spinel with orthopyroxene as a dominant mineral in these intrusions. These ore-bearing intrusions are not Alaskan-type complexes. Spinel and clinopyroxene both exhibit different chemical compositions from those in the Alaskan-type complexes. The rocks that make up the intrusions have high contents of MgO (average value = 25.20 wt.%) and low TiO2 (average value = 0.58 wt.%). The high MgO contents of the minerals and the high Mg# (71) of the calculated melt in equilibrium with olivine demonstrate that the parental magma of the Hongqiling mafic–ultramafic intrusions was a high-Mg tholeiitic magma. The Hongqiling ore-bearing mafic–ultramafic intrusions and the calculated “trapped liquids” for the olivine-orthopyroxene cumulate rocks are all enriched in large-ion lithophile elements and depleted in high field strength elements. The Ce/Pb, Ta/La, Th/Yb, and (La/Sm)PM values and the depletion of Nb and Ta suggest that the magma experienced crustal contamination. The Hongqiling ore-bearing intrusions display many similarities with mafic–ultramafic intrusions that formed in a post-collisional extensional environment in the western CAOB (e.g., Huangshanxi). Common features include their whole-rock compositions and mineral chemistry. Combined with the evolutionary history of the eastern segment of the CAOB, we believe that the Late Triassic Hongqiling mafic–ultramafic intrusions formed in a post-collisional extensional environment.