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1
Karlina, Elin, Nina Djustiana, I. Made Joni, Renny Febrida, Camellia Panatarani e Akhyar Dyni Zakyah. "Analisis Mikrostruktur Partikel Zirkoniakalsia-silika (ZrO 2 -CaO-SiO ) Dari Pasir Zirkon Alam Indonesia Menggunakan Metode Spray Pyrolysis". Jurnal Material Kedokteran Gigi 6, n. 1 (1 marzo 2017): 23. http://dx.doi.org/10.32793/jmkg.v6i1.261.
Testo completoAbstract (sommario):
Indonesian Natural Sand, Zircon, is an Indonesia’s natural resource that contains zirconia, silica, titania and alumina. In Dentistry, zirconia as one of the content in natural zircon sand, have the potential to be the material for filler composites. The purpose of this research was to analyze the Zirconia-Calcium-Silicate Particle (ZrO2CaO-SiO2) synthesized from Indonesia natural sand, zircon, in microstructural way. Methods: By synthesizing ZirconiaCalcium-Silicate particle (ZrO2-CaO-SiO2) from Indonesia natural zircon sand, using spray pyrolysis method. A precursor solution that is used consists of zirconil nitrate (Zr (NO3) 2), sodium silicate (Na2SiO3), and calcium hydroxide (Ca (OH) 2). Variations in the temperature of the reactor that are used were 4000C, 4500C, and 5000C with a feed rate of 6 L / min and a piezoelectric frequency of 1.7 MHz. Result showed that the better content in zirconia-calcium-silicate is the one that was synthesized at a temperature of 4500C, based on the results of EDS, SEM and XRD. The composition that is obtained in the zirconia-calcium-silicate particle has a ratio of 1: 14: 4 with the size of 500-1000nm, and has a tetragonal crystal zirconium silicate structure and dicalcium monoclinic silicate. From this research it can be concluded that the result that was synthesized at a temperature of 4500C is adequate to use as a filler based on the characterization result of SEM and XRD.
2
Poernomo, Herry, Dwi Biyantoro e Maria Veronica Purwani. "Kajian Konsep Teknologi Pengolahan Pasir Zirkon Lokal yang Mengandung Monasit, Senotim dan Ilmenit". EKSPLORIUM 37, n. 2 (19 dicembre 2016): 73. http://dx.doi.org/10.17146/eksplorium.2016.37.2.3054.
Testo completoAbstract (sommario):
ABSTRAKKeberadaan zirkon (ZrSiO4) di alam kebanyakan berasosiasi dengan beberapa senyawa oksida berharga (SOB) seperti TiO2 dan oksida logam tanah jarang atau rare earth oxides (REO). Keterdapatan mineral alam di Indonesia yang mengandung zirkonium (Zr) dan REO tersebar di 13 wilayah mulai dari Provinsi Aceh sampai Papua Barat. Berdasarkan hal tersebut, maka tujuan penelitian adalah melakukan kajian integrasi teknologi pengolahan pasir zirkon lokal yang mengandung TiO2 dan REO. Penelitian dilakukan dengan menganalisis kandungan SOB dalam sampel pasir zirkon dari daerah Landak dan Tumbang Titi Kalimantan Barat serta Bangka menggunakan XRF. Berdasarkan kandungan SOB dalam pasir zirkon tersebut dapat diprediksi bahwa pasir zirkon dari daerah Landak dan Tumbang Titi Kalimantan Barat serta Bangka mengandung mineral zirkon (ZrSiO4), ilmenit (FeTiO3), monasit (LREE, Th)PO4, dan senotim (HREE, Y, Th)PO4. Berbasis jenis mineral tersebut diperoleh hasil kajian berupa diagram alir proses konsep teknologi konsentrat zirkon menjadi ZrO2 (zirkonia) dan ZrOCl2.8H2O (zirkonium oksiklorida) derajat industri serta zirkonia dan zirconium chemicals derajat nuklir, ilmenit menjadi TiO2, monasit menjadi Nd2O3 dan konsentrat Th(OH)4, senotim menjadi Y2O3, Gd2O3 dan konsentrat Th(OH)4 dalam satu kawasan pilot plant atau pabrik yang terintegrasi. Hasil kajian disimpulkan bahwa konsep pengolahan pasir zirkon lokal yang mengandung monasit, senotim, dan ilmenit dapat dilakukan secara terintegrasi dalam satu kawasan pabrik dengan hasil multi produk. Jika hal tersebut dapat direalisasikan di Indonesia dengan tambahan sistem pengolahan air limbah terpadu, maka selain aman bagi lingkungan juga dapat menghemat biaya produksi dan memberikan nilai tambah ekonomi bagi para pemegang izin usaha pertambangan zirkon. ABSTRACTThe existence of zircon (ZrSiO4) in the nature is mostly associated with some of the valuable oxide compounds (VOC), such as TiO2 and rare earth oxides (REO). The existence of natural minerals in Indonesia containing zirconium (Zr) and REO lies in 13 regions, ranging from Aceh to West Papua province. Based on those aforementioned aspects, the goal of this research is to conduct the study of integrated technology of local zircon sand processing containing TiO2 and REO. The study was conducted by analyzing the content of VOC in zircon sand samples from the areas of Landak and Tumbang Titi West Kalimantan and Bangka by using XRF. Based on the content of VOC in this zircon sand, it can be predicted that the zircon sand from the area of Landak and Tumbang Titi West Kalimantan and Bangka contains mineral zircon (ZrSiO4), ilmenite (FeTiO3), monazite (LREE, Th)PO4, and xenotime (HREE, Th)PO4. Based on these types of mineral, the flow chart of beneficiation technology process to increase the concentration of each mineral and the flow chart of zircon concentrate process into ZrO2(zirconia) and ZrOCl2.8H2O (zirconium oxychloride) industrial grade and zirconia and zirconium chemicals nuclear grade, ilmenite into TiO2, monazite into Nd2O3, and Th(OH)4 concentrate, xenotime into Y2O3, Gd2O3, and Th(OH)4 concentrate are obtained in one area of pilot plant or an integrated factory. The results of the study concluded that the concept of local processing of zircon sands containing monazite, xenotime, and ilmenite can be either integrated in the region with the results of multi-product plant. If it can be realized in Indonesia with the addition of an integrated waste water treatment system, then in addition to safe for the environment can also save on production costs and give economic added value for shareholders zircon mining permit
3
Wei, Zhang, e Nian Qiao Fang. "Chronology Research on Eocene Trachyte in Zoumaying, Sanshui Basin". Applied Mechanics and Materials 275-277 (gennaio 2013): 1571–74. http://dx.doi.org/10.4028/www.scientific.net/amm.275-277.1571.
Testo completoAbstract (sommario):
Trachyte in Zoumaying was erupted in Eocene by 40Ar-39Ar age-dating in previous studies. Multielement Geochemistry analysis and U-Pd radiochronology were introduced on zircons from trachyte in Zoumaying in this paper. The SiO2 and K2O+Na2O contents of trachytes vary between 58.59% to 68.99%, and 10% to 11%. About twenty zircons were selected from trachyte sample with fractures and zonal structure, and most of them were inheritable magmatic zircons. The result of radiochronology on zircon is 60Ma which is similar with the former result as 53.2±0.2Ma.
4
Sajima, Sajima. "Pelindian Natrium Zirkonat Menggunakan Asam Klorida Secara Catu". EKSPLORIUM 39, n. 1 (10 luglio 2018): 67. http://dx.doi.org/10.17146/eksplorium.2018.39.1.4369.
Testo completoAbstract (sommario):
Penelitian tentang teknologi pengolahan zircon terus dilakukan untuk mengikuti kebutuhan industri pasar. Pengolahan natrium zirkonat dengan pelindian menggunakan asam klorida sebagai pelarut telah dilkukan. Penelitian ini bertujuan mempelajari pengaruh ukuran butir, temperatur, dan kecepatan pengadukan terhadap zirkon terambil. Penelitian dilakukan dengan memasukkan pelarut (asam klorida 4 N) ke dalam reaktor, kemudian pelarut tersebut dipanaskan sambil diaduk. Umpan dengan ukuran butir tertentu dimasukkan ke dalam reaktor. Kondisi temperatur dan kecepatan pengadukan dijaga tetap. Setelah kondisi operasi tercapai, proses dihentikan kemudian disaring. Hasil penelitian dengan analisis XRF menunjukkan bahwa kondisi proses optimum dicapai pada ukuran butir 90 µm, temperatur 80 oC dan kecepatan pengadukan 200 rpm. Pada kondisi tersebut zirkon terambil sebesar 84.50 %. Research on zircone processing technology has been continued to follow industrial market needed. Treatment of sodium zirconate with leaching process using hydrochloric acid as solvent has been conducted. The aim of the study is to evaluate the effect of grain size, temperature, and speed of stirring on the extracted zircon. The research starting with introduced the solvent (chloride acid 4 N) into the reactor, then heated while stirring. The feed with a certain grain size was introduced into the reactor. The temperature and stirring conditions were kept steady. Once the operating conditions are reached, the process is stopped and then filtered. The results with XRF analysis showed that the optimum process conditions were achieved on 90 μm grain size, the temperature of 80oC, and stirring speed of 200 rpm. The amount of zircon that taken out were 84.50% on this conditions.
5
Krasnobaev, A. A., P. M. Valizer e N. N. Farrakhova. "Zircons of fenites of Ilmeno-Vishnevogorsky Complex (Southern Urals)". LITHOSPHERE (Russia) 21, n. 3 (8 luglio 2021): 306–22. http://dx.doi.org/10.24930/1681-9004-2021-21-3-306-322.
Testo completoAbstract (sommario):
Research subject. U-Pb zircon dating, as well as a petrological and geochemical study of pyroxene-amphibole-, pyroxeneamphibole- biotite- and biotite-bearing fenites from the Central Alkaline Band Ilmeno-Vishnevogorsky Complex.Methods. The age of zircons was determined by an ion mass spectrometer (SHRIMP II, Centre of Isotopic Research VSEGEI). The content of REE and trace elements was estimated by secondary ion mass spectrometer methods (CAMECA IMS-4F, Valiev Institute of Physics and Technology RAS).Results. The mineralogical and geochemical (U, Th, REE) features of zircons, as well as fenites, reflect their polygenic-polychronous nature. Most zircon crystals have a metastable matrix and are characterized by averaged REE contents between igneous and hydrothermal types. These crystals are distinguished from magmatic zircons by high LREE contents and low values of Ce anomalies, and from hydrothermal zircons – by differentiated REE distribution spectra. Three ages of zircon were established: 2066–1686 (PR1), 425–404 (S2) and 284–266 (P1) Ma. PR1 zircons reflect the primary features and the degree of changes in the fenite substrate. S2 zircons, limited only to the biotite- bearing fenite, correspond to the age of the miaskite formation process. The P1 zircons clearly reflect the metasomatic process of fenitization initiated by late shear deformations. The temperature of the phenitization processes (based on the Ti content in zircons) was estimated at 630–670°C for S2 and ≤ 600°C for P1 fenites, respectively.Conclusions. Central Alkaline Band fenites were formed by the metasomatic process of PR1 substrate fenitization in the late stage (P1) of shear strains, which are widely expressed in the Ilmeno-Vishnevogorsky Complex.
6
No, Sang-Gun, e Maeng-Eon Park. "The Geochronology and Geochemistry of Zircon as Evidence for the Reconcentration of REE in the Triassic Period in the Chungju Area, South Korea". Minerals 10, n. 1 (5 gennaio 2020): 49. http://dx.doi.org/10.3390/min10010049.
Testo completoAbstract (sommario):
The Chungju rare-earth element (REE) deposit is located in the central part of the Okcheon Metamorphic Belt (OMB) in the Southern Korean Peninsula and research on REE mineralization in the Gyemyeongsan Formation has been continuous since the first report in 1989. The genesis of the REE mineralization that occurred in the Gyemyeongsan Formation has been reported by previous researchers; theories include the fractional crystallization of alkali magma, magmatic hydrothermal alteration, and recurrent mineralization during metamorphism. In the Gyemyeongsan Formation, we discovered an allanite-rich vein that displays the paragenetic relationship of quartz, allanite, and zircon, and we investigated the chemistry and chronology of zircon obtained from this vein. We analyzed the zircon’s chemistry with an electron probe X-ray micro analyzer (EPMA) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The grain size of the zircon is as large as 50 µm and has an inherited core (up to 15 µm) and micrometer-sized sector zoning (up to several micrometers in size). In a previous study, the zircon ages were not obtained because the grain size was too small to analyze. In this study, we analyzed the zircon with laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS) for dating purposes. The REE patterns and occurrence of zircon in the quartz–allanite vein match well with previous reported recrystallized zircon, while the behavior of the trace elements shows differences with magmatic and hydrothermal zircon. The 206Pb/238U ages obtained from the zircon in the quartz–allanite vein are from 240.1 ± 2.9 to 257.1 ± 3.5 Ma and this age is included in the tectonic evolution period of the study area. Therefore, we suggest that the quartz–allanite veins in the Gyemyeongsan Formation were formed during the late Permian to early Triassic metamorphic period and the zircon was recrystallized at that time. The Triassic age is the first reported age with zircon dating in the Gyemyeongsan Formation and will be an important data-point for the study of the tectonic evolution of the OMB.
7
Zamyatin, D. A., S. L. Votyakov e Yu V. Shchapova. "JPD-analysis as a new approach for studying the zircon texture with micron spatial resolution with application to geochronology". Доклады Академии наук 485, n. 4 (22 maggio 2019): 479–83. http://dx.doi.org/10.31857/s0869-56524854479-483.
Testo completoAbstract (sommario):
The polygenic and polychronous character of zircon texture is the key source of information on the conditions of its growth and secondary alterations. In this research the JPD method of processing of the BSE and CL images including plotting of JPD histograms and JPD maps of grains was developed and applied for quantitative study of the internal texture of zircon grains with micron spatial resolution and for its use in geochronometry. The nomenclature for distinguished zones on the generalized diagram (BSE vs. CL) is suggested for zircons of a wide range of the conditions of its formation, age, size, texture types, and degrees of structure disordering. The JPD-analysis of zircon internal texture is applied for interpretation of the nature of variations in the BSE and CL intensities within an individual heterogeneous grain (on the quantitative level) and between different grains (on the qualitative level). The approach is suggested as the preliminary stage during geochronological studies increasing the reliability of the local electron microprobe and mass spectrometry isotope dating of the mineral.
8
Xu, Zhongjie, Yizhi Lan, Jintao Kong, Rihui Cheng e Liaoliang Wang. "Detrital zircon U–Pb dating of Late Triassic Wenbinshan Formation in southwestern Fujian, South China, and its geological significance". Canadian Journal of Earth Sciences 55, n. 8 (agosto 2018): 980–96. http://dx.doi.org/10.1139/cjes-2018-0007.
Testo completoAbstract (sommario):
Based on research of the petrology, geochemistry, and zircon U–Pb dating of detrital rocks in the Late Triassic Wenbinshan Formation in southwestern Fujian, and comparing the detrital zircon ages of Wenbinshan Formation with those of Late Paleozoic – Early Mesozoic main basins in South China, the sedimentary provenance of the Late Triassic in southwestern Fujian and its implications for changes in basin properties are discussed. The research results demonstrate that there is a major age peak at 222 Ma, two subordinate age peaks at 275 Ma and 1851 Ma, and two minor age peaks at 413 Ma and 2447 Ma in the detrital zircon age spectra of the upper samples (YGP–6) of the Wenbinshan Formation, whereas there are two major age peaks at 229 Ma and 1817 Ma and other minor age peaks 265 Ma 309 Ma, 415 Ma, 1968 Ma, and 2435 Ma in the detrital zircon age spectra of the lower samples (YGP–26) of the Wenbinshan Formation. The upper samples contain fewer old detrital zircons than the lower samples, but the upper and lower samples of Wenbinshan Formation are similar in major age composition, which indicates the main provenances of the upper and lower sediments are very similar. The source rocks are mainly sedimentary rocks and their provenances are derived from a source area of recycled orogenic belt and volcanic arc orogenic belt (acidic island arc). The detrital zircon composition of the Wenbinshan Formation is mainly composed of Paleoproterozoic zircon and Late Paleozoic – Early Mesozoic zircon. In the Paleoproterozoic, sedimentary provenances were mainly derived from the Wuyi Massif and partly from northwestern Fujian-southwestern Zhejiang. As for the period of Late Paleozoic – Early Mesozoic, the provenances of the Wenbinshan Formation were derived from magmatic active belts of the Early Indosinian Epoch of northern South China, eastern South China, and the Indosinian Period of northern South China and coastal areas of eastern South China. The similarities and differences between detrital zircon age peaks of the Wenbinshan Formation in southwestern Fujian and that of the main basins in South China during the period of Late Paleozoic – Early Mesozoic indicate that from eastern coastal areas of South China to the north and interior of South China, the age composition of basin sediments has changed from simple to relatively complex, and from young sediments to older sediments. There are similarities and differences in the detrital zircon compositions of the different basins, which can indicate differences in the nature of the basins.
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Syzdek, Joseph, David Malone e John Craddock. "Detrital Zircon U-Pb Geochronology and Provenance of the Sundance Formation, Western Powder River Basin, Wyoming". Mountain Geologist 56, n. 3 (1 agosto 2019): 295–317. http://dx.doi.org/10.31582/rmag.mg.56.3.295.
Testo completoAbstract (sommario):
This study uses detrital zircon U-Pb geochronology to investigate the provenance of the Jurassic Sundance Formation in the western Powder River Basin, Wyoming. Understanding the provenance of the Sundance Formation is critical as it was deposited during the transition from cratonic to synorogenic sedimentation derived from the Sevier-Laramide foreland. The Sundance in the western Powder River Basin consists of an oolitic limestone and green glauconitic sandstone at the base, green shales in the middle, and a yellow quartz arenite with coquina “oyster” beds at the top. U-Pb analyses of detrital zircons using LA-ICP-MS were conducted on two samples collected in the Bud Love Wildlife Habitat Management Area, 20 km northwest of Buffalo, WY. The two samples were taken from the upper and lower sandstone members of the Sundance Formation (n=289 concordant U-Pb zircon ages). The samples show a distinct difference in detrital zircon age spectra. The lower sandstone age spectrum ranges from 260-3172 Ma with 23% of the ages being Paleozoic, 71% being Proterozoic, and 6% being Archean. This lower stratum has detrital zircon age peaks at 343, 432, 686, 1039, 1431, 1662, 1748, 1941, 2433, and 3179 Ma. The lower sandstone shows an easterly Appalachian-Ouachita provenance, which persisted in the region beginning in the Carboniferous. In comparison to the upper strata, ages range from 157-2949 Ma and age peaks at 170, 243, 440, 545, 1082, 1467, 1681, and 1985 Ma. The maximum deposition age for the upper member is 160 Ma. Mesozoic aged grains make up 15.6% of the zircons, 14.7% were Paleozoic, 65.7% were Proterozoic, and 4% were Archean in age. The appearance of Mesozoic zircons in the upper sandstone marks the first significant appearance of westerly sourced zircons, and perhaps reflects the earliest uplift of the Sevier fold and thrust belt. Previous research has found this same signature in the Sundance but not in the underlying Triassic Chugwater Formation, resulting in a broad boundary of the change in sediment dispersal and the onset of the Sevier Orogeny between the Triassic and Jurassic. This study was conducted for a higher resolution to the provenance of the Sundance Formation and to further narrow the boundary of differing sedimentation from an eastern recycled to western synorogenic source.
10
Hartoyo, Hutomo Mandala, Veni Takarini, Renny Febrida, Elin Karlina e I. Made Joni. "Diametral Tensile Strength and Hardness Evaluation of Prototype Composite Based on Natural Zircon Sand Using Geopolymerization Method with Coupling Agent Variation". Key Engineering Materials 829 (dicembre 2019): 87–92. http://dx.doi.org/10.4028/www.scientific.net/kem.829.87.
Testo completoAbstract (sommario):
The widely use of dental composite triggers a lot of research to synthesize composite made from natural sources. One of the natural sources that could be used as a filler of composite is natural zircon sand from Indonesia. The physical properties of dental composite, such as Diametral Tensile Strength (DTS) and hardness could be affected by the filler of the composite. The aim of this research is to determine the value of diametral tensile strength and hardness of prototype composite with natural zircon sand-based filler by using geopolymerization method with various coupling agents. The procedures began from synthesizing Zirconia-Alumina-Silica filler from natural zircon sand using geopolymerization method with two different coupling agents, 3-mercapto propyltrimethoxysilane (3-MPTS) and 3-aminopropyltriethoxysilane (3-APTS), which then mixed with resin matrix to form composite resin, some of the samples were then subjected to a DTS test using Lloyd Universal Testing Machine (5.6 N initial load) until a crack/fracture was formed while some of them was subjected to a hardness test using Vickers Hardness Tester. The results showed the average DTS of dental composite using MPTS coupling agent was 13.78 MPa, while the average DTS of dental composite using APTS coupling agent was 8.90 MPa, and the average hardness result of dental composite coated by 3-MPTS was higher (20.68 VHN) than composite coated by 3-APTS (18.02 VHN). This difference could be affected by filler particle composition, filler surface area and also coupling agent variation. In conclusion, the tensile strength of the prototype resin composite sample group with the natural zircon sand filler using MPTS coupling agent was higher than the APTS coupling agent group.
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Ngadenin, Ngadenin, e Adhika Junara Karunianto. "Identifikasi Keterdapatan Mineral Radioaktif pada Granit Muncung Sebagai Tahap Awal untuk Penilaian Prospek Uranium dan Thorium di Pulau Singkep". EKSPLORIUM 37, n. 2 (19 dicembre 2016): 63. http://dx.doi.org/10.17146/eksplorium.2016.37.2.3101.
Testo completoAbstract (sommario):
ABSTRAKPulau Singkep adalah bagian dari jalur timah Asia Tenggara, yang salah satu litologinya tersusun oleh granit Muncung. Keberadaan granit tersebut memungkinkan adanya cebakan mineral radioaktif yang prospek terhadap uranium dan thorium. Penelitian ini bertujuan untuk mengidentifikasi keterdapatan mineral radioaktif pada granit Muncung sebagai tahap awal untuk penilaian prospek uranium dan thorium di Pulau Singkep. Metoda yang digunakan adalah pengambilan sampel batuan granit, analisis petrografi sampel granit Muncung, analisis kadar uranium dan thorium serta analisis butir sampel konsentrat dulang yang diambil di wilayah granit Muncung. Mineral radioaktif pada granit Muncung adalah monasit dan zirkon sedangkan pada konsentrat dulang adalah monasit, zirkon, dan senotim. Persentase monasit dalam konsentrat dulang adalah 1,1 – 59,53 %, zirkon 0,68 –55,07 % dan senotim 0,39 – 3,54 %. Kadar uranium dalam konsentrat dulang adalah 30 – 1.346 ppm dan kadar thorium 557 – 13.200 ppm. Disimpulkan bahwa daerah di sekitar granit Muncung dianggap cukup prospek uranium dan thorium dan dapat dikembangkan ke tahapan eksplorasi lebih detail. ABSTRACTSingkep Island is part of Southeast Asia tin belt, which is one of the lithologies, composed of granite Muncung. Existence of granite allows formed deposits of radioactive minerals that prospect of the uranium and thorium. This research goal is to identify radioactive minerals occurrences on granit Muncung in the initial stage for prospect assessment of uranium and thorium in Singkep Island. The Methodologies are granite sampling, petrography analysis of Muncung granite samples, uranium and thorium content analysis and grain size analysis of pan concentrate samples. Radioactive minerals in Muncung granite are monazite and zircon, while in pan concentrate they are monazite, zircon, and xenotime. The percentage of monazite, zircon, and xenotime in the pan concentrate are 1.1–59.53 %, 0.68–55.07 %, and 0.3–3.54 % respectively. The uranium and thorium content in the pan concentrate are 30–1,346 ppm and 557–13,200 ppm respectively. It concluded that the area around the Muncung granite considered prospect for uranium and thorium, and possibly developed into more detailed exploration stage.
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Dobrescu, Anca. "Pre-Variscan granitoids with adakitic signature at west Getic basement of the South Carpathians (Romania): constraints on genesis and timing based on whole-rock and zircon geochemistry". Geologica Acta 19 (14 aprile 2021): 1–17. http://dx.doi.org/10.1344/geologicaacta2021.19.4.
Testo completoAbstract (sommario):
Research on two strata-like intrusions from Slatina-Timiş (STG) and Buchin (BG) at West Getic Domain of the South Carpathians (Semenic Mountains) identified granitoids with adakitic signature in a continental collision environment. Whole-rock geochemical composition with high Na2O, Al2O3 and Sr, depleted Y (18ppm) and HREE (Yb 1.8ppm) contents, high Sr/Y (40), (La/Yb)N (10) ratios and no Eu anomalies overlaps the High-Silica Adakites (HSA) main characteristics, though there are differences related to lower Mg#, heavy metal contents and slightly increased 87Sr/86Sr ratios. Comparison with HSA, Tonalite-Trondhjemite-Granodiorite (TTG) rocks and melts from experiments on basaltic sources suggests partial melting at pressures exceeding 1.25GPa and temperatures of 800-900ºC (confirmed by calculated Ti-in zircon temperatures) as the main genetic process, leaving residues of garnet amphibolite, garnet granulite or eclogite type. The adakitic signature along with geochemical variations observed in the STG-BG rocks indicate oceanic source melts affected by increasing mantle influence and decreasing crustal input that may restrict the tectonic setting to slab melting during a subduction at low angle conditions. An alternative model relates the STG-BG magma genesis to garnet-amphibolite and eclogite partial melting due to decompression and heating at crustal depth of 60-50km during syn-subduction exhumation of eclogitized slab fragments and mantle cumulates. The granitoids were entrained into a buoyant mélange during collision and placed randomly between two continental units. U-Pb zircon ages obtained by LA-ICP-MS and interpreted as Ordovician igneous crystallization time and Variscan recrystallization imprint are confirmed by trace-element characteristics of the dated zircon zones, connecting the STG-BG magmatism to a pre-Variscan subduction-collision event. The rich zircon inheritance reveals Neoproterozoic juvenile source and older crustal components represented by Neoarchean to Paleoproterozoic zircons.
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Kelly, Colter J., Daniel E. Harlov, David A. Schneider, Simon E. Jackson e Renelle Dubosq. "Experimental fluid-mediated alteration of zircon under lower greenschist facies conditions". Canadian Mineralogist 58, n. 2 (1 marzo 2020): 247–65. http://dx.doi.org/10.3749/canmin.1900041.
Testo completoAbstract (sommario):
ABSTRACT The use of zircon in the dating of geological processes and tectonic events has become a standard approach in many aspects of Earth science research. As a result, understanding how zircon interacts with aqueous fluids during metasomatism has become increasingly important. The alteration of natural zircon is driven primarily by coupled dissolution–reprecipitation or by ion-exchange with an aqueous fluid. In this study, whole and intact, euhedral light-brown zircon crystals (100–250 μm in length; 2 mg) from the Oligocene Fish Canyon Tuff (FCT) were experimentally reacted with an alkali-bearing reactive fluid and a REE + P source (0.5 mg CePO4 or 0.5 mg YPO4). Experiments were conducted in sealed Au metal capsules at 350 °C and 100 MPa for 182 days. During the experiment, the zircon became colorless, indicating annealing of the radiation damage in the crystal. Two-dimensional element maps of the outermost 3 μm of unpolished zircon crystal surfaces were produced using a grind of contiguous 7 μm analytical spots via laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The chemical maps indicate that the surface of the zircon crystals from each experiment heterogeneously reacted with the fluid, such that the Ce and Y concentration of chemically modified areas increased (by an order of magnitude) in the CePO4-bearing and YPO4-bearing experiments, respectively, when compared with the chemical maps of unaltered zircon grain surfaces. Helium ion microscopy of polished crystals revealed discontinuous micron-scale altered domains at the crystal margin, consistent with the findings of the unpolished mapping technique. Interestingly, the Th and U concentration of the altered zircon grain surfaces were consistent with the unaltered zircon regardless of the experiment. Incorporation of REEs on the zircon grain surface likely occurred via the coupled substitution REE3+ + P5+ ↔ Zr4+ + Si4+. The results from these experiments imply that the surfaces of minimally metamict zircon can be chemically modified by alkali-bearing fluids via ion exchange under lower greenschist pressures and temperatures over relatively short time periods with respect to the geological time scale.
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Zhang, Wenhui, Liyuan Wang, Xupeng Lv, Xiaomin Li, Shuaiqi Yan e Juntao Nie. "Origin of Mesozoic Porphyritic Rocks and Regional Magmatic Evolution in the Zijinshan Ore Field of Fujian Province, China: Hf-O Isotope Characteristics of Magmatic Zircons". Minerals 10, n. 12 (20 dicembre 2020): 1143. http://dx.doi.org/10.3390/min10121143.
Testo completoAbstract (sommario):
Mesozoic porphyritic rocks from the Zijinshan area, southwestern Fujian Province, China, are andesitic to rhyolitic in composition. The whole-rock SiO2 contents of these rocks are between 62.5% and 78.1%. Magmatic zircon from the Mesozoic porphyritic rocks was determined via secondary-ionization mass spectrometry (SIMS) for the U-Pb age and Hf and O isotopes. The zircon U-Pb ages could be mainly divided into three age groups: Group 1: ~138.8 Ma; Group 2: 109.2~107.4 Ma; and Group 3: 99.7~98.2 Ma. The εHf(t) and δ18O values of the porphyritic zircons showed that the porphyritic rocks in Group 2 were more affected by mantle-derived magma. Combined with previous research results, the medium-acidic magmatism in the southwestern Fujian Province can be divided into eight periods: Paleoproterozoic, Mesoproterozoic, Middle Neoproterozoic, Silurian to Lower Devonian, Permian to Triassic, Middle Jurassic to early Lower Cretaceous, late Lower Cretaceous, and late Lower Cretaceous to early Upper Cretaceous. The Paleoproterozoic crust was the predominant magmatic source for the subsequent Mesoproterozoic to Jurassic magmatism, but the only melts that were closely related to mineralization were derived from partial melting of the Mesoproterozoic crust and a more depleted upper mantle.
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Sukirno, Sukirno, Sri Murniasih, Rosidi Rosidi e Samin Samin. "Evaluasi Ketidakpastian Pengukuran Multi-Unsur Dalam Mineral Zirkon Dengan Metode Analisis Aktivasi Neutron". EKSPLORIUM 36, n. 1 (30 maggio 2015): 45. http://dx.doi.org/10.17146/eksplorium.2015.36.1.2770.
Testo completoAbstract (sommario):
Evaluasi analisis multi-unsur yang disertai perhitungan ketidakpastian unsur pada mineral zirkon yang berasal dari Sampit, Kalimantan Tengah dan Pulau Bangka telah dilakukan dengan metode Analisis Aktivasi Neutron (AAN). Tujuan penelitian ini adalah menentukan komposisi dan nilai ketidakpastian multi-unsur dalam mineral zirkon untuk memenuhi persyaratan ISO/IEC guide 17025-2008 yang telah diterapkan pada laboratorium AAN. Analisis menggunakan spektrometri gamma dengan detektor HPGe menghasilkan 21 unsur terdeteksi yang dibagi menjadi tiga kelompok (mayor, minor, dan kelumit). Evaluasi ketidakpastian pengukuran perlu dilakukan untuk meningkatkan kualitas dan tingkat kepercayaan hasil analisis. Hasil pengujian tidak akan bermakna tanpa disertai perhitungan ketidakpastian. Oleh karena itu, dilakukan evaluasi nilai perhitungan ketidakpastian pada hasil analisis semua unsur yang terkandung dalam mineral zirkon. Hasil analisis kuantitatif tertinggi adalah zirkonium (Zr) dengan konsentrasi 38,986% dan mempunyai nilai ketidakpastian 0,33% sehingga nilai konsentrasi nyata adalah 38,986±0,33%, dalam oksida (ZrO2) mempunyai konsentrasi 52,661±0,45%. Unsur stibium (Sb) adalah unsur yang terdeteksi paling rendah dengan nilai konsentrasi dan ketidakpastian adalah 7±0,3 μg/g sedangkan dalam oksida (Sb2O3) mempunyai konsentrasi 17±0,9 μg/g. Komposisi oksida dan bahan kimia dalam mineral pasir zirkon yang lebih signifikan berasal dari Sampit dengan kandungan ZrO2+HfO2 (53-55%), F2O3 (5-6%), TiO2 (13-14%), Al2O3 (1,5-2%) dan SiO2. Unsur Si (SiO2) tidak dapat ditentukan dengan metode AAN sebab tampang lintang Si sangat kecil. The evaluation of multi-elements analysis has been carried out with calculation of element uncertainy in the zircon mineral from Sampit (Central Kalimantan) dan Bangka has been evaluated by the Neutron Activation Analysis (NAA) method. The purpose of this research is determination of composition and value of multi-elements uncertainty in the mineral of zircon to fulfil the requirements of ISO/IEC guide 17025-2008 that applied at NAA laboratory. The result of analysis using gamma spectrometry with a HPGe detector showed of 21 detected elements, divided into three groups (major, minor, and trace). Evaluation of uncertainty estimation should be done to increase quality and confidence rate of analysis results. The result of testing are not mean without calculation of uncertainty. Therefore, it was assessed the uncertainty measurement of all elements analysis in zircon mineral. The results of quantitative analysis is Zr with the highest concentration value of 38.986% and value of uncertainty is 0.331% so that value of real concentration is 38.986 ± 0.331%. In the form of oxide (ZrO2) has concentration of 52.661±0.45%. Sb element is the lowest element detected with value of concentration and uncertainty is 7±0,3 µg/g. In the form of oxide (Sb2O3) has concentration is 17±0.9 µg/g. The oxide composition and the must important of chemicals in the zircon sand mineral more significant from Sampit which quantitative composition areZrO2+HfO2 (53-55%), F2O3 (5-6%), TiO2 (13-14%), Al2O3 (1.5-2%) and SiO2. Elements ofSi(SiO2) can not be determinedbyNAAmethodbecauseSi cross-sections is verysmall.
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Ding, Xiang-Li, Lin Ding, Li-Yun Zhang, Chao Wang e Ya-Hui Yue. "Identification and Origin of Jurassic (~182 Ma) Zircon Grains from Chromitite within the Peridotite of the Jijal Complex, Kohistan Arc in North Pakistan". Minerals 10, n. 12 (3 dicembre 2020): 1085. http://dx.doi.org/10.3390/min10121085.
Testo completoAbstract (sommario):
The Jijal ultramafic–mafic complex in Pakistan probably preserves the most complete fragments of the petrological Moho. However, a few studies argue for multiple origins (including petrogenetic speculations and tectonic reconstructions) for different lithologies. One of the main reasons for this dispute is the lack of direct age information of the ultramafic rocks. Zircon grains, despite generally being exotic in ultramafic rocks, can provide significant insights into the petrogenetic process of the host ultramafic rocks. This study reports the first zircon U–Pb age and Lu–Hf and trace element data for zircon grains separated from chromitite lenses within the peridotite, which is commonly considered the lowermost part of the Jijal complex. These zircon grains yield concordant 206Pb/238U ages of ~182 ± 3 Ma, which is much older than the late Early Cretaceous age (<120 Ma) of the Jijal complex, and lying above it, the other complexes of the Kohistan paleo-arc. Furthermore, these Jurassic zircon grains present radiogenic εHf(t) values (+9.7 to +6.0) which are obviously lower than the values for the Cretaceous zircon grains of the Kohistan arc. From integrated analysis of the zircon trace element signatures (e.g., high Th, U, Th/U, and U/Yb ratios) and regional geology, we speculate that these zircon grains came from a ‘missing’ Early Jurassic arc akin to the Gangdese belt to the east, and entered the mantle by oceanic subduction processes. Although these Jurassic zircon grains cannot actually constrain the formation age of the chromitite as well as the peridotite, it reminds us that some cryptic pre-Cretaceous complexes and geodynamic processes were incorporated in building the oceanic crust of the Jijal intra-oceanic arc, or the mantle section (at least part of it) should probably belong to the Indus ophiolite mélange. Further research, particularly chronological studies on mantle (or ultramafic) rocks, as well as detailed geological mapping, should be carried out in the future for solving this issue.
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Smolkin, V. F., S. V. Mezhelovskaya e A. D. Mezhelovsky. "Sources of Pechenga structure terrigenous layers clastic material according to detrital zircon isotopic analysis data (SIMS SHRIMP-II, LA-ICP MS)". Доклады Академии наук 488, n. 6 (30 ottobre 2019): 645–50. http://dx.doi.org/10.31857/s0869-56524886645-650.
Testo completoAbstract (sommario):
The results of Pechenga ore-bearing Paleoproterozoic structure, located on the northern-western part of Kola region, research, are presented in this article. Secondary ions mass-spectrometry (SIMS) was used for U-Th-Pb-zircon age definition, on SRHIMP-II device and mass spectrometry with inductively associated plasm with LA-ICPMS ablation on ThermoQuest Finnigan MAT Neptune device. Televi Formation basalt conglomerates, Luchlompo Formation red colored gravelites and middle part Matert Formation high siliceous turbidites were tested. On U-Pb diagram with Concordia part of analytical points for zircon from conglomerates are approximated by Discordia with the top intersection 2792 7 Ma. All gravelite zircon grains are located on Concordia. The main part of their age values is within interval 2700-2820, the lesser - 2840-3000 Ma (with the maximums 2718, 2779, 2854, 2972). The single grains have the age from 3037 4 up to 3698 8 Ma. Concordant value 207Pb/206Pb age 2640 16 Ma is fixed for turbidite zircon. The sources of zircon for conglomerates and gravelites were the rocks of Northern zone Pechenga structure basement: gneisses of Kirkenes, Varanger and Svanvik Complexes (2715, 2803 and 2825 Ma) and high aluminous gneisses (2798-2830 Ma), for turbidites - Southern slope granitoides. The dominating role of zircon group with 2. 7 billion years proves a global growth of continental crust in this period. Ancient values of zircon age (3.0-3.7 billion years) of red colored gravelites are connected with the deeper erosion of the basement and outcrop of Eoarchaean and Mezoarchaean age rocks on erosive surface in Northern zone within the period of the first global Oxygen revolution (2.4-2.3 billion years).
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Yue, Wei, Xiyuan Yue, Lingmin Zhang, Xianbin Liu e Jian Song. "Morphology of Detrital Zircon as a Fingerprint to Trace Sediment Provenance: Case Study of the Yangtze Delta". Minerals 9, n. 7 (17 luglio 2019): 438. http://dx.doi.org/10.3390/min9070438.
Testo completoAbstract (sommario):
Deltaic areas and marginal seas are important archives that document information on regional tectonic movement, sea level rise, river evolution, and climate change. Here, sediment samples from boreholes of the Yangtze Delta and the modern Yangtze drainage were collected. A quantitative analysis of detrital zircon morphology was used to discuss the provenance evolution of the Yangtze Delta. This research demonstrated that a dramatic change in sediment provenance occurred in the transition from the Pliocene to Quaternary. Zircon grains in the Pliocene sediments featured euhedral crystals with large elongation (>3 accounted for 13.2%) and were closely matched to tributary samples in the Lower Yangtze (>3 accounted for 11.3%), suggesting sediment provenance from the proximal river basin. However, most detrital zircon grains of the Quaternary samples exhibited lower values of elongation and increased roundness (rounded grains were 9.4%), which was similar to those found in the modern Yangtze mainstream (rounded grains were 12.5%) and the middle tributaries (rounded grains were 7.0%). The decrease in zircon elongation and improvement of its roundness in the Quaternary strata implied that the Yangtze Delta received sediments of different provenance that originated from the Middle-Upper Yangtze basin due to the uplift of the Tibetan Plateau. Statistical analysis of detrital zircon morphology has proven useful for studying the source-to-sink of sediments.
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Meng, Xianghong, Yu Zhang, Duoyun Wang e Xue Zhang. "Provenance analysis of the Late Triassic Yichuan Basin: constraints from zircon U-Pb geochronology". Open Geosciences 10, n. 1 (21 marzo 2018): 34–44. http://dx.doi.org/10.1515/geo-2018-0003.
Testo completoAbstract (sommario):
AbstractLaser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) U-Pb dating has been performed on detrital zircons from the Chunshuyao Formation sandstone of Yichuan Basin. The ages of 85 detrital zircon grains are divided into three groups: 252-290 Ma, 1740-2000 Ma, and 2400-2600 Ma. The lack of Early Paleozoic and Neoproterozoic U-Pb ages indicates that there is no input from the Qinling Orogen, because the Qinling Orogen is characterized by Paleozoic and Neoproterozoic material. In combination with previous research, we suggest that the source of the Chunshuyao Formation is most likely recycled from previous sedimentary rocks from the North China Craton. In the Late Triassic, the Funiu ancient land was uplifted which prevented source material from the Qinling Orogen. Owing to the Indosinian orogeny, the strata to the east of the North China Craton were uplifted and eroded. The Yichuan Basin received detrital material from the North China Craton.
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Apriany, Karima, Fitria Rahmawati, Eddy Heraldy, Dani G. Syarif e Syoni Soepriyanto. "SYNTHESIS AND CHARACTERIZATION OF CERAMIC METAL Ni-YSZ PREPARED FROM LOCAL ZIRCON SAND AT VARIOUS Ni:YSZ COMPOSITION". ALCHEMY Jurnal Penelitian Kimia 13, n. 2 (1 settembre 2017): 217. http://dx.doi.org/10.20961/alchemy.13.2.2384.217-229.
Testo completoAbstract (sommario):
<p>This research synthesized a cermet Ni-YSZ, in which the YSZ (yttria stabilized-zirconia) was synthesized from the local zircon sand, ZrSiO<sub>4</sub>, as a side product of tin mining plant in Bangka island, Indonesia. The synthesized YSZ in this research is zirconia, ZrO<sub>2</sub> doped by 8 % mol of yttrium dioxide. The synthesis used solid state reaction method and the result was characterized its crystal structure and its cell parameters by XRD analysis equipped with Le Bail refinement, surface morphology analysis, and an impedance analysis to understand its ionic conductivity. The cermet Ni-YSZ was synthesized at a various composition of Ni:YSZ i.e., 20:80, 30:70, and 40:60 (b/b). The analysis shows that Ni-YSZ is in two phases of Ni and YSZ without any presence of a third phase. It indicates that there was no solid state reaction between Ni and YSZ during synthesis. In this Ni-YSZ cermet, the Ni phase in a cubic structure, and the YSZ is also in a cubic structure. Morphological study shows that the addition of Ni to YSZ allows the morphology to become more roughness with larger grain size. This research found that the Ni-YSZ 20:80 has highest ionic conductivity.</p>
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Ponomareva, Y. V., M. V. Ponomareva, A. V. Sadchikov e N. V. Zhelayeva. "A model of the tectonic development of Irtysh shear zone in terms of present day radioisotope data". Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu, n. 4 (2021): 5–9. http://dx.doi.org/10.33271/nvngu/2021-4/005.
Testo completoAbstract (sommario):
Purpose. To present the model of tectonic development of the Irtysh shear zone, based on recent uranium-lead dating for zircon. Methodology. The authors analyzed the results of studies of foreign and domestic scientists, conducted field research, sample preparation, carried out iso-tope studies using SHRIMP-2 and LA-ICP-MS technology; determined small elements by the fusion method using ICP. Findings. Based on more than ten uranium-lead dating for zircon using the local method and the given geological and structural data, model of the Irtysh shear zone tectonic development has been proposed Originality. A tectonic model has been developed and the age and structural relationships of the Irtysh shear zone with the Kalba-Narym zone based on uranium-lead zircon dating have been established. Practical value. The article considers the structural and age relationships of the Irtysh crush zone which prove its formation along the deep Irtysh fault in the course of a long multi-stage tectogenesis.
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Gazdanova, Irina, Fatima Gerieva e T. Morgoev. "Efficiency of application of “Epin-extra” and “Zircon” biostimulants on potato landings in agroecological conditions of Republic of North Ossetia-Alania". Agrarian Bulletin of the 199, n. 8 (31 agosto 2020): 2–8. http://dx.doi.org/10.32417/1997-4868-2020-199-8-2-8.
Testo completoAbstract (sommario):
Abstract. Recently, the trend of agricultural biologization has been gaining great importance. When cultivating crops, the use of biostimulants helps to improve the environment and produce environmentally friendly products. The purpose of the work is to identify the effectiveness of the use of biostimulants “Epin-extra” and “Zircon” in the cultivation of potatoes on the background of minimal doses of mineral fertilizers. Impact on productivity, morbidity and quality indicators of tubers. The novelty lies in the fact that for the first time in the agroecological conditions of the foothill zone of North Ossetia-Alania, the effectiveness of the use of the “Epin-Extra” and “Zircon” biostimulants on the indicators of productivity and quality of potato varieties was studied. Methods Accounting and observations were carried out according to generally accepted methods described in the “Educational-methodical guide for research in agronomy”. Results. As a result of the use of biostimulants “Epin-extra” and “Zircon” in combination with minimal doses of mineral fertilizers, they contribute to a reduction in the passage of the phenological phases of plants compared to the control by 8–9 days. The processing of potato tubers before planting “Epin-extra” and “Zircon” in combination with mineral fertilizers in minimum doses provided a high level of yield, on the Background 1 + “Epin-extra” variant by varieties: 33.7–39.1 t/ha. The biostimulants “Epin-extra” and “Zircon” possess not only growth-regulating properties, but also inhibit the development of diseases, in particular, increase plant resistance to late blight by 4.6–6.5 %.
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Sun, Yong-gang, Bi-le Li, Feng-yue Sun, Qing-feng Ding, Ye Qian, Liang Li, Qing-lin Xu e Yu-jin Li. "Geochronology, geochemistry, and Hf isotopic compositions of early Permian syenogranite and diabase from the northern Great Xing’an Range, northeastern China: petrogenesis and tectonic implications". Canadian Journal of Earth Sciences 57, n. 12 (dicembre 2020): 1478–91. http://dx.doi.org/10.1139/cjes-2019-0200.
Testo completoAbstract (sommario):
Geodynamic evolution in the late Paleozoic is significant for understanding the final amalgamation of the Central Asian Orogenic Belt (CAOB). No consensus has yet been reached regarding the late Paleozoic geodynamic evolution of the northern Great Xing’an Range (GXR) in northeastern China, the eastern CAOB. Furthermore, late Paleozoic syenogranite–diabase dyke association is present in the Xiaokele area in northern GXR. It provides an important opportunity to understand the nature of magmatism and the geodynamic evolution during this period. This paper presents new zircon U–Pb ages, zircon Hf isotopic compositions, and geochemical data of whole rocks for Xiaokele syenogranite and diabase. Zircon U–Pb dating suggests that the Xiaokele syenogranite (292.5 ± 0.9 Ma) and diabase (298.3 ± 1.5 Ma) were emplaced during the early Permian. The Xiaokele syenogranites have high SiO2 contents, low MgO contents, and enriched zircon εHf(t) values, suggesting that their primary magma was generated by the partial melting of the juvenile crustal material. The Xiaokele diabases have low SiO2 contents, high MgO contents, are enriched in large-ion lithophile elements, depleted in high-field-strength elements, and exhibit enriched zircon εHf(t) values. They derived from a lithospheric mantle source that had previously been metasomatized by slab-derived fluids. Combined with previous research results, we believe that the continent–continent collision between the Xing’an and Songliao blocks occurred during the late early Carboniferous – early late Carboniferous (330–310 Ma), and the two blocks were transformed into a post-collisional extensional setting during the latest Carboniferous – early Permian.
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Zhou, Xiao Hu, e Shi Chao Xu. "The Basement Features Research of Junggar Basin, China: A Review". Applied Mechanics and Materials 295-298 (febbraio 2013): 2740–43. http://dx.doi.org/10.4028/www.scientific.net/amm.295-298.2740.
Testo completoAbstract (sommario):
There are different understanding of long-standing and significant differences about the characteristic and age of the basement of Junggar Basin. And the existence of Precambrian crystalline basement and the nature of Paleozoic folded basement of the Junggar basin are under question. The research aims including the basin peripheral orogenic clastic zircon dating and the drilling samples. Those research playing a key role in rebuilding the tectonic framework, reconstructing the geological evolution of northern Xinjiang region; and provides the basis for geological research in the area of objective information, provides an important basis in the evolution of continental geology and dynamics; also available as a scientific theory and support to resource development, it is of great value in the exploration and evaluation of resources within the basin.
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Caracciolo, L., S. Andò, P. Vermeesch, E. Garzanti, R. McCabe, M. Barbarano, C. Paleari, M. Rittner e T. Pearce. "A multidisciplinary approach for the quantitative provenance analysis of siltstone: Mesozoic Mandawa Basin, southeastern Tanzania". Geological Society, London, Special Publications 484, n. 1 (27 febbraio 2019): 275–93. http://dx.doi.org/10.1144/sp484-2018-136.
Testo completoAbstract (sommario):
AbstractThis paper shows how heavy minerals and single-grain varietal studies can be conducted on silt (representing c. 50% of world's sediments) sediments to obtain quantitative data as efficiently as for sand-sized sediments. The analytical workflows include heavy mineral separation using a wide grain-size window (15–355 μ) analysed through integrated optical analysis, Raman spectroscopy, QEMSCAN microscopy and U–Pb dating of detrital zircon. Upper Jurassic–Cretaceous silt-sized sediments from the Mandawa Basin of central-southern Tanzania have been selected for the scope of this research. Raman-aided heavy mineral analysis reveals garnet and apatite to be the most common minerals together with durable zircon, tourmaline and subordinate rutile. Accessory but diagnostic phases are titanite, staurolite, epidote and monazite. Etch pits on garnet and cockscomb features on staurolite document the significant effect of diagenesis on the pristine heavy mineral assemblage. Multivariate statistical analysis highlights a close association among durable minerals (zircon, tourmaline and rutile, ZTR) while garnet and apatite plot alone reflecting independence between the three groups of variables with garnet increasing in Jurassic samples. Raman data for garnet end-member analysis document different associations between Jurassic (richer in A, Bi and Bii types) and Cretaceous (dominant A, Ci and Cii types) samples. U–Pb dating of detrital zircon and their statistical integration with the above-mentioned datasets provide further insights into changes in provenance and/or drainage systems. Metamorphic rocks of the early and late Pan-African orogeny terranes of the Mozambique Belt and those of the Irumide Belt acted as main source of sediment during the Jurassic. Cretaceous sediments record a broadening of the drainage system reaching as far as the Usagran–Ubendian Belt and the Tanzanian Archean Craton.
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Abdullah, Mohammad, Triwikantoro Triwikantoro, Chairatul Umamah e Herman Jufri Andi. "THE EFFECT OF PH AND CALCINATION TEMPERATURE ON THE ZrO2 PHASE FORMATION FROM NATURAL ZIRCON SAND OF KERENG PANGI". Jurnal Neutrino 13, n. 2 (16 giugno 2021): 39–48. http://dx.doi.org/10.18860/neu.v13i2.10507.
Testo completoAbstract (sommario):
In this research ZrO2 has been synthesized from Kereng Pangi zircon sand in Central Kalimantan through alkali fusion-coprecipitation method. Firstly, zircon sand (ZrSiO4) was purified to reduce impurities by magnetic separation, cleaned using an ultrasonic cleaner, soaked/leached with HCl 2 M for 12 hours and leached with HCl at 60 ºC for 3 hours. Secondly, alkali fusion was done with KOH as an alkali. This product was then washed by water and dried before leached with HCl 30% at 90 ºC for 30 minutes to precipitate and seperate Silica from Zircon. ZrO2 filtrate (ZrOCl2) precipitated with NH4OH at pH 4, pH 7, and pH 10 forms Zr(OH)4 gel. Zr(OH)4 gel was dried and characterized by DTA-TGA, which was then followed by calcination based on DTA TGA results at temperature ranges of 550 ºC - 700 ºC to produce ZrO2. XRD results show that single tetragonal phase of ZrO2 is formed in all variations of pH precipitation and calcination temperature. An analysis using MAUD software show that crystal size reduces as the increase in precipitation of pH. The crystal size results are 110 nm, 66 nm and 48 nm at pH 4, pH 7 dan pH 10 at 700 ºC, respectively. Moreover, XRF results show that ZrO2 with purity is at around 95.8 % at pH 4 and 96.3 % at pH 7 and pH 10.
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Liu, Deng, e Dai Yong Cao. "Regional Geology Background and Minerogenetic Series in Ongniud Banner of Inner Mongolia". Advanced Materials Research 734-737 (agosto 2013): 408–17. http://dx.doi.org/10.4028/www.scientific.net/amr.734-737.408.
Testo completoAbstract (sommario):
Ongniud Banner is located in the northern margin of the North China platform, possessing binary attribute of the greenville period orogenic belt and North China block. The authors reclassify geological unit through the rock stratigraphic correlation and isotope chronology. Achaean strata is mainly composed of quartz schist, chlorite schist, amphibole schist, and the rocks have been highly metamorphosed into the green schist facies, and its single particle zircon U-Pb age is 2645 ±86Ma, so it is assigned to North China block. Proterozoic strata is mainly composed of metamorphic complex including chlorite schist, marble, basalt, amphibolite, plagiogranite and olivine pyroxenolite, and its single particle zircon U-Pb age is 1620±160Ma, so it is assigned to Greenville period orogenic belt. According to 1:50000 stream sediment geochemical elementary assemblage characteristics, the authors discuss the metallogenic endowment and minerogenetic series of geological unit in research area.
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Zeh, Armin, Allan H. Wilson, Dominik Gudelius e Axel Gerdes. "Hafnium Isotopic Composition of the Bushveld Complex Requires Mantle Melt–Upper Crust Mixing: New Evidence from Zirconology of Mafic, Felsic and Metasedimentary Rocks". Journal of Petrology 60, n. 11 (1 novembre 2019): 2169–200. http://dx.doi.org/10.1093/petrology/egaa004.
Testo completoAbstract (sommario):
Abstract The origin of magmas that formed the Bushveld Complex remains highly debated in spite of many decades of intense research. Previous geochemical–petrological studies have shown a strong mantle derivation resulting ultimately in highly economic ore bodies of platinum group elements and chromium. However, geochemistry also points to the contribution of a significant crustal component, which may have been derived singly or in combination from a number of different sources. These include subcontinental lithospheric mantle that was enriched prior to Bushveld magma formation, possibly by subduction, assimilation of lower and upper crust during magma ascent, and contamination during magma chamber accretion within sedimentary rocks of the enclosing Transvaal Supergroup. In this study, the contributions of these various reservoirs will be evaluated by employing Hf isotopic data of well-characterized zircon grains in mafic, felsic and metasedimentary rocks, together with Zr–Hf bulk-rock compositions. The results reveal that magmatic zircon grains in mafic cumulate rocks from the floor to the roof of the c. 9 km thick Rustenburg Layered Suite (RLS) show essentially the same variations in εHf2·055 Ga from −7·5 to −10·2 as those of metamorphic zircon grains and overgrowths in the immediate surrounding quartzite and metapelitic rocks, as well as in granitic melt batches, granophyres, and the upper Rooiberg volcanics. The same values are also obtained by estimating the average Hf isotopic compositions of detrital zircon grains in many quartzite and metapelitic rocks from the surrounding Magaliesberg (εHf2·055 Ga = −6·2 to −10·8, six samples, maximum deposition age at 2080 Ma) and Houtenbeck formations (εHf2·055 Ga = −7·1 to −8·9, three samples, maximum deposition age at 2070 Ma), and by a six-point isochron of a garnet-schist from the Silverton Formation (εHft = −6·6 ± 0·7; age = 2059·4 ± 2·7 Ma). Zircon morphologies, zoning patterns, Hf isotopic data and petrological constraints furthermore reveal that metamorphic zircon was precipitated from aqueous fluids and/or felsic melts at temperatures between 550 and 900 °C, and that the Hf isotopic composition became homogenized during fluid transport in the contact aureole. However, results of numerical modelling indicate that fluid infiltration had only a minor effect on the Zr–Hf budget and Hf isotopic composition of the RLS, and that these parameters were mainly controlled by the mixing of melts derived from three major sources: (1) the asthenospheric mantle (>20 %); (2) enriched subcontinental lithospheric mantle (<80 %); (3) assimilation of significant amounts of crust (up to 40 %). The modelling furthermore suggests that assimilation of lower Kaapvaal Craton crust was minor (<15 %) during B1 (high-Mg andesite) magma formation, but up to 40 % during B3 (tholeiite) magma formation. The minor variation in εHft of zircon throughout the entire stratigraphy of the RLS resulted from the interplay of three dominant contributing factors: (1) intrusion of hot (>1200 °C) mantle-derived magmas with relatively low Zr–Hf concentrations having a similar εHf2·055 Ga of −8·5 ± 1·9 to that of upper crust rocks surrounding the RLS; (2) significant assimilation of volcanic and metasedimentary rocks with high Zr–Hf concentration; (3) mingling, mixing and/or diffusive exchange of Zr and Hf between crust and mantle-derived melts and aqueous fluids prior to late-magmatic crystallization of zircon at temperatures between 700 and 900 °C. This study shows that the combination of Zr–Hf bulk-rock data with Hf isotopic data of well-characterized zircon grains provides a powerful tool to quantify various mantle and crustal reservoirs of mafic layered intrusions, and allows new insights into magma chamber and related contact metamorphic processes.
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Peng, Yuan, Yongsheng Zhang, Eenyuan Xing e Linlin Wang. "Provenance and tectonic significance of the Zhongwunongshan Group from the Zhongwunongshan Structural Belt in China: insights from zircon geochronology". Open Geosciences 12, n. 1 (28 febbraio 2020): 25–43. http://dx.doi.org/10.1515/geo-2020-0003.
Testo completoAbstract (sommario):
AbstractThe Zhongwunongshan Structural Belt (ZWSB) locates between the Olongbruk Microblock of North Qaidam and the South Qilian Block in China, and it has important implication for understanding the tectonic significance of North Qaidam. Nowadays, there are few discussion on the Caledonian tectonothermal events of the Zhongwunongshan Structural Belt, and there exist different opinions on provenance and tectonic environment of the Zhongwunongshan Group in the ZWSB and its adjacent North Qaidam. In this study, a comprehensive analysis of the detrital zircon geochronological research was carried out on the Zhongwunongshan Group. The detrital zircon U-Pb dating results showed two major populations. The first was Neoproterozoic (966-725 Ma) with a ∈Hf(t) = −15.9 to 9.5, and the other was late Early Paleozoic (460-434Ma) with a ∈Hf(t) = −9.6 to −3.1. In combination with previous research, the dominated provenances were found to be the Neoproterozoic granitic gneiss of the Yuqia-Shaliuhe HP-UHP metamorphic belt and the late Early Paleozoic granite of the Tanjianshan ophiolite-volcanic arc belt in North Qaidam. The Zhongwunongshan Group was deposited in the back-arc sedimentary basin related to the Caledonian collisional orogeny during Middle Silurian-Early Devonian (434-407.9 Ma).
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Shardakova, G. Yu, e A. V. Korovko. "Vendian-Cambrian granites of the Salatim suture zone (the Northern Urals): Geochemistry of zircons, source composition, geochronological and geodynamical consequences". LITHOSPHERE (Russia) 21, n. 1 (4 marzo 2021): 32–54. http://dx.doi.org/10.24930/1681-9004-2021-21-1-32-54.
Testo completoAbstract (sommario):
Research subject. The composition and isotope systems of zircons and their host granites from the Krutorechensky complex (western part of the Main Uralian fault zone, Northern Urals) were investigated. Methods. The U-Pb age, trace element contents and Lu-Hf isotopes in the zircons under study were determined by LA-ICP-MS (Ulan-Ude, Ekaterinburg). TIMS was used to determine Sm-Nd isotopes in the rocks. Results and Discussion. It was shown that the morphology and composition of the main zircon group from granites confirm their magmatic origin and the absence of alteration. It means that the previously defined Vendian-Cambrian (542 Ma) age of the granites remains valid. The relics ancient (1043–122 Ma) cores were probably inherited from Isherim suite rocks. The source of such detrital grains could have been the rocks from the East-European platform basement. Young zircons (400 Ma) differing strongly from others in composition could have been formed around the already existing grains produced by a fluid generated under the action of plume activity. The source for granite melting was mainly of a crust nature: εNd(t) = –6, εHf(t) = –6…–9, initial ratio (87Sr/86Sr)i = 0.796943. In terms of lithology, the source rocks correspond to sandstones with a small admixture of clay components. The obtained information confirms the necessity to further investigate questions concerning the area of distribution and the age of the Sarankhapnorsk suite within the Krutorechensky complex, as well as the position of the eastern boundary of the Isherim block. Conclusion. The obtained results can be used in geological mapping.
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Lin, J. Q., F. Ding, C. H. Chen e T. Shen. "Zircon U–Pb geochronology, Hf isotope composition, and petrochemical characteristics of Paleocene granitoids in the western Gangdese Belt, Tibet". Russian Geology and Geophysics 62, n. 6 (1 giugno 2021): 666–84. http://dx.doi.org/10.2113/rgg20194131.
Testo completoAbstract (sommario):
Abstract —The research team studied the petrology, whole-rock geochemistry, zircon U–Pb age, and stable isotopic characteristics of the Rongguo Longba and Garongcuo granites of the Nuocang area to understand better the impact of Neo-Tethys ocean subduction and In-dia–Eurasia continental collision on Paleocene tectonomagmatic processes along the southern margin of the Gangdese Belt. The Rongguo Longba granite and Garongcuo granite porphyry formed at 61.86 and 62.17 Ma, respectively. The Nuocang granitoids are characterized by (1) high SiO2, NaO2, and Al2O3 contents and low FeOtot, MgO, and TiO2 contents; (2) LREE and LILE enrichment and HREE and HFSE (Nb, P, and Ti) depletion; and (3) obvious negative Eu anomalies. These features indicate that the Nuocang granites are of the high-K calc-alkaline and peraluminous granite types. Furthermore, their zircon Hf isotope characteristics suggest that the magma source region has an ancient crystalline basement. The basaltic andesitic crystal tuff is the product of garnet–peridotite partial melting and crust contamination from rising magma emplacement.
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Tan, Jun, Jun-Hao Wei, Shao-Qing Zhao, Yan-Jun Li, Yan Liu, Xiao-Yang Liu, Fei Zhang, Jin-Rong Gan e Zhi-Hua Wang. "Petrogenesis of Late Triassic high-Mg diorites and associated granitoids with implications for Paleo-Tethys evolution in the northeast Tibetan Plateau". GSA Bulletin 132, n. 5-6 (17 settembre 2019): 955–76. http://dx.doi.org/10.1130/b35225.1.
Testo completoAbstract (sommario):
Abstract Recent research on Paleo-Tethys tectonics has identified a huge late Paleozoic to Mesozoic igneous belt that extends more than 2500 km in the northeast Tibetan Plateau. However, the magma genesis and evolution in this belt remains a subject of considerable debate. This paper presents a combination of zircon U-Pb ages, mineral compositions, major and trace element concentrations, and Sr-Nd-Hf isotopic data for the plutons across the Zhiduo arc belt that marks the site connecting different tectonic-magmatic units. The studied rocks from one quartz diorite, two granodiorite plutons, and their mafic enclaves define a continuous compositional evolution varying from high- to medium-K calc-alkaline gabbroic diorite to granodiorite. Laser ablation–inductively coupled plasma–mass spectroscopy U-Pb analyses of zircons from these three plutonic suites and one mafic enclave yield Late Triassic ages of 222–217 Ma, establishing that the mafic and felsic magmas were nearly coeval. All these rocks are featured by zoned hornblende and plagioclase with Mg- and Ca-rich mantles or oscillatory change in compositions. They exhibit high and variable MgO (up to 4.88–5.66 wt%), Cr, and Ni contents except that one granitoid pluton (Dangjiangrong) possesses high Co (up to 145.0 ppm). They are characterized by subduction-type trace element patterns, with prominent positive Rb, Th, Pb, and K anomalies and negative Ba, Nb, P, and Ti. Together with continuous and heterogeneous Sr-, Nd-, and zircon Hf-isotopic compositions, it suggests that these Late Triassic high-Mg diorites and associated granitoids were generated through magma mixing and fractional crystallization accompanied by chemical exchange. Taking into account the magmatic record from nearby regions, we suggest that double-sided subduction and rollback of the subducting Paleo-Tethys oceanic slab is the main mechanism to generate geochemically-varied magmatism in the northeast Tibetan Plateau, and eventually close the Paleo-Tethys Ocean during much of the Late Triassic.
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Wang, Zhi, Weijian Yu e Fangfang Liu. "The Materialization Characteristics and Ratio of a New Soil Paste Filling Material". Advances in Civil Engineering 2020 (29 dicembre 2020): 1–8. http://dx.doi.org/10.1155/2020/6645494.
Testo completoAbstract (sommario):
In this paper, the research background is the filling and mining of the landscape mineral paste body in Baixian State, Guangxi, China. The strength test of the new paste filling material is carried out by the materials of coal zircon, red soil, and cement, the best ratio between the materials is obtained, and the hydration mechanism of the new paste filling material is studied by XRD diffraction instrument and SEM (scanning electron microscopy) test. The types of hydration products and microstructure forms of filling materials in different age periods are revealed. The test results show that the optimal ratio of the new paste filling material in the coal mine is the quality ratio of coal zircon: red soil: cement as 6 : 2 : 1, and the slurry concentration is 80%, which can not only meet the transportation requirements required by the filling process but also reduce the cost of filling, and with the extension of the maintenance age, the filling material produces more gel products, and the overall structure is more encrypted.
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CHERVYAKOVSKIY, Vasiliy Stanislavovich. "Geological features and the first isotopic data of volcanic rocks in the Iset river basin, East-Urals megazone". NEWS of the Ural State Mining University 1 (15 marzo 2021): 55–64. http://dx.doi.org/10.21440/2307-2091-2021-1-55-64.
Testo completoAbstract (sommario):
Relevance of the work. The Iset river basin contains the most extensive outcrops of volcanogenic formations of the Beklenishchevsky complex of the East Ural megazone, the age of which is determined as Early Carboniferous by the ratio of volcanic rocks with faunistically characterized sedimentary deposits. Volcanics here compose flows of andesite-basaltic and andesitic lavas and lava breccias. There are no geochronological dates specifying the age of the rocks, which makes it difficult to assess their role in the formation of the megazone. Therefore, isotopic dating of these formations is very important. Methods. The U – Pb age and data on the geochemistry of zircons were obtained by laser ablation (LA – ICP – MS). Purpose of the research is to study the features of the geological structure, the material composition of volcanic rocks in the Iset river basin, the geochemistry of zircons from andesites and the determination of their isotopic age. Results of the work and the scope of their application. Lava flows of andesites and basaltic andesites with minor amounts of basalts and dacites have tectonic contact with sedimentary rocks of the Early Carboniferous age. The distribution of rare elements in volcanics is typical of supra-subduction formations. Zircons in andesites are represented by prismatic and isometric crystals. Prismatic differences in the nature of the distribution of REE and the content of Li, Ti, Sr, Th, U refer to zircons of magmatic genesis, isometric – to “hydrothermal”. According to the U / Yb – Y ratios, the former correspond to the zircons of the ocean floor, while the latter are related to the continental ones. Isotopic dating of zircons from andesites was carried out for the first time. Their age was 311 million years. The data can be used in geological mapping, as well as in the compilation of large-scale geodynamic maps and diagrams. Conclusions. Volcanic rocks in the Iset river basin were formed in supra-subduction continental-marginal geodynamic conditions that took place in the Urals in the Carboniferous. The obtained value of the age of zircons from andesites, possibly, fixes the stage of their transformation. Keywords: East-Ural megazone, volcanic rocks, zircon, isotopic age.
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Viehmann, Sebastian. "Hf-Nd Isotopes in Archean Marine Chemical Sediments: Implications for the Geodynamical History of Early Earth and Its Impact on Earliest Marine Habitats". Geosciences 8, n. 7 (16 luglio 2018): 263. http://dx.doi.org/10.3390/geosciences8070263.
Testo completoAbstract (sommario):
The Hf-Nd isotope systems are coupled in magmatic systems, but incongruent Hf weathering (‘zircon effect’) of the continental crust leads to a decoupling of the Hf-Nd isotope systems in low-temperature environments during weathering and erosion processes. The Hf-Nd isotope record was recently dated back from the Cenozoic oceans until the Archean, showing that both isotope systems were already decoupled in seawater 2.7 Ga ago and potentially 3.4 Ga and 3.7 Ga ago. While there might have existed a hydrothermal pathway for Hf into Archean seawater, incongruent Hf weathering of more evolved, zircon-bearing uppermost continental crust that was emerged and available for subaerial weathering accounts for a significant decoupling of Hf-Nd isotopes in the dissolved (<0.2 µm) and suspended (>0.2 µm) fractions of Early Earth’s seawater. These findings contradict the consensus that uppermost Archean continental crust was (ultra)mafic in composition and predominantly submerged. Hence, Hf-Nd isotopes in Archean marine chemical sediments provide the unique potential for future research to trace the emergence of evolved continental crust, which in turn has major implications for the geodynamical evolution of Early Earth and the nutrient flux into the earliest marine habitats on Earth.
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Milovanov, Ivan Vladimirovich, Evgeniy Viktorovich Kandalov, Viktor Bisengalievich Narushev e Rima Zhambulovna Kozhagalieva. "Influence of growth stimulants and microfertilizers on the productivity of Carthamus tinctorius in the steppe zone of the Saratov Right Bank". Agrarian Scientific Journal, n. 4 (22 aprile 2021): 24–39. http://dx.doi.org/10.28983/asj.y2021i4pp24-39.
Testo completoAbstract (sommario):
In the course of the research, it was found out that the highest rates of photosynthetic activity of Carthamus tinctorius were noted in the variant where pre-sowing treatment of seeds with a growth stimulator zircon + treatment of crops in the budding phase with siliplant microfertilizer was carried out. In this variant, the leaf area of the best variety Ershovsky 4 was 35.3 thousand m2 / ha, dry aboveground biomass - 7.49 t / ha, photosynthetic potential - 1941 thousand m2 / ha·day; net productivity of photosynthesis - 3.86 g / m2·day. On average for 2018–2020, the highest yield of safflower oilseeds of the Ershovsky 4 variety reached 1.89 t / ha. The highest (1.74 t / ha) average annual yield of safflower oilseeds of Astrakhanskiy 747 variety was also obtained using a similar option. To ensure a consistently high productivity of Carthamus tinctorius agrocenoses in the arid conditions of the steppe zone of the Saratov Right Bank, it is recommended to expand the cultivation areas of the most adapted variety Ershovsky 4, using pre-sowing seed treatment with a zircon growth stimulator (30 ml / t) and processing crops in the budding phase with siliplant micronutrient fertilization (1 , 0 l / ha).
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Borisov, V. A., A. N. Khovrin, A. R. Bebris, N. A. Fillrose e G. F. Monahos. "THE EFFECT OF FERTILIZERS AND GROWTH REGULATORS ON YIELD AND QUALITY OF HYBRID ONION, GROWN IN ANNUAL CROPS UNDER DRIP IRRIGATION". Vegetable crops of Russia, n. 4 (27 luglio 2018): 89–93. http://dx.doi.org/10.18619/2072-9146-2018-4-89-93.
Testo completoAbstract (sommario):
In the studies of 2014-2016 years on rich medium-loamy alluvial soils of the Moscow region in the cultivation of hybrids of onions Pervenets F1, Bennito F1 and Poisk 012 F1 in drip irrigation conditions in an annual crop, the best yield of Repka 45.1 t/ha, 47.9 t/ha and 59.9 t/ha, respectively. The greatest effect was obtained from the complex application of N90P90K90 (main) in combination with plant fertilization with potassium nitrate and Zircon growth regulator during the period of intensive growth of vegetative mass and the beginning of bulb formation for late Bennito F1 hybrids and Poisk 012 F1, and for the medium-unrided hybrid the Pervenets F1 system was the best N90P90K90+Zircon. This system allowed to obtain a high yield of standard products (up to 93%) with good bio-chemical quality of the onion. New technologies of cultivation of onions in an annual crop with the complex use of drip irrigation, fertilizers and new hybrids of intensive type, allow in the conditions of the Central non-Chernozem zone to obtain the yield of onion-turnip at the level of 50-60 t/ha, with the output of standard products 80-93%. The best biochemical quality indicators of bulbs were obtained with the complex application of fertilizers with the growth regulator Zircon, with the cultivation of hybrids Pervenets F1 and Bennito F1, and hybrid Poisk 012 F1 is not mature enough in the Moscow region. From the conducted research it can be concluded that the studied hybrids of onion Pervenets F1, Bennito F1 and Poisk 012 F1 when grown in annual crops in terms of Non-Chernozem zone of the Russian Federation use better fertilizing than the main fertilizer.
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Nguyen, Tai Minh, Hoa Xuan Tran, Giang Thi Truong Nguyen, Cuong Chi Truong e Minh Pham. "U-Pb zircon and Hf composition of granite Song Ma block". Science and Technology Development Journal - Natural Sciences 2, n. 4 (14 agosto 2019): 167–75. http://dx.doi.org/10.32508/stdjns.v2i4.825.
Testo completoAbstract (sommario):
The granite of the Song Ma block mainly consists of two types of granite: biotite granite and hornblende-biotite granite. Biotite granites have the percent of plagioclase (35– 45%), K-feldspar (25–35%), quartz (~20%) and biotite (~10%). Biotite-hornblende granite with the content of plagioclase (40–50%), Kfeldspar (10–15%), hornblende (5–10%) and biotite (5%). Zircon crystals were selected from the granite of Song Ma block are V0741, V0856 and V1006 samples with the LA-ICPMS U-Pb analyses gave concordant ages concentrated at 257±4Ma, 262±3Ma and 241±6Ma (weighted mean). Those ages are older than the results of the previous research. The mineral assemblages and geochemical characteristics show the typical of I-type granites. The results of Hf isotope composition analysis give the value of εHf(t) from +7.3 to +13.9, which is proven the sources of the granite Song Ma block similar to the granite of Phan Si Pan zone, NW Viet Nam during the period from late Permian to early Triassic.
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Гущина, В. А., e Е. А. Кутихина. "RAW MATERIAL PRODUCTIVITY OF CALENDULA OFFICINALIS IN THE FOREST STEPPE OF THE MIDDLE VOLGA REGION". Niva Povolzh`ia, n. 4(58) (31 marzo 2021): 65–73. http://dx.doi.org/10.36461/np.2020.57.4.019.
Testo completoAbstract (sommario):
Регуляторы роста растений являются одной из самых перспективных групп пестицидов, достоинства которых состоят в том, что они безвредны, экологически безопасны и высокоэффективны при низких нормах расхода биологически активных веществ полифункционального действия. Препаратом, обладающим такими свойствами, является Циркон, производимый на основе растительного сырья эхинацеи пурпурной. В связи с этим, целью исследований является установление влияния способов применения Циркона на сырьевую продуктивность календулы лекарственной сорта Кальта в условиях неустойчивого увлажнения лесостепи Среднего Поволжья. На черноземно-луговой почве в 2018-2020 гг. коллекционного участка ФГБОУ ВО Пензенский ГАУ заложен однофакторный опыт по способам использования препарата. Самым засушливым по условиям увлажнения (ГТК – 0,61) был первый год проведения эксперимента, два следующих – характеризовались недостаточным увлажнением. Сбор сырья по годам исследований продолжался 43, 63, 87 дней соответственно. В среднем за три года стимулирование семян и растений Цирконом увеличило количество соцветий на 5…18 шт./растение, причем их максимум наблюдался от сочетания обработок. Наиболее продуктивными 63,3 г были растения, где дважды использовали препарат Циркон. Масса соцветий в контроле составила 48,4 г/растение. От некорневой подкормки она увеличилась на 5,2 г, а от предпосевной обработки семян на 12,1 г. Урожайность сырья, высушенного при температуре 45…50 ºС, находилась в пределах 1,79…2,72 т/га. Двукратное использование Циркона увеличило сырьевую продуктивность на 0,93 т/га. При однократном применении препарата урожайность возросла до 1,94…2,58 т/га. Причем обработка семян перед посевом оказалась более эффективной, чем некорневая подкормка. Plant growth regulators are one of the most promising groups of pesticides, the advantages of which are that they are harmless, environmentally safe and highly effective at low consumption rates of biologically active substances of multifunctional action. The preparation that has such properties is Zircon. It is produced on the basis of plant raw materials of Echinacea purpurea. In this regard, the purpose of the study is to establish the influence of Zircon-using methods on the raw material productivity of Calendula officinalis of the Kalta variety in the conditions of unstable moistening of the Middle Volga region forest-steppe. In 2018-2020, a single-factor experiment on the methods of using the preparation was conducted on the chernozem-meadow soil site of the Penza State Agrarian University. The first year of the experiment was the driest in terms of moisture conditions (HTC – 0.61). The next two years were characterized by insufficient moisture. Gathering raw materials during the years of research lasted 43, 63, 87 days, respectively. Over three research years, the Zircon stimulation of seeds and plants increased the number of inflorescences by 5...18 pcs./plant. It must be noted that their maximum was observed in a combination of treatments. The most productive (63.3 g) were plants where the Zircon preparation was used twice. The inflorescence mass in the control option counted to 48.4 g/plant. With foliar nutrition, it increased by 5.2 g, and with pre-sowing seed treatment – by 12.1 g. The yield of raw materials, dried at a temperature of 45 ... 50°C, counted in the range of 1.79...2.72 t/ha. The double application of Zircon increased the raw material productivity by 0.93 t/ha. With a single preparation application, the yield increased to 1.94...2.58 t/ha. It must be noted that the pre-sowing seed treatment was more effective than foliar fertilization.
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Bebris, A. R., V. A. Borisov, N. A. Fillrose, S. A. Maslovsky e G. F. Monahos. "INFLUENCE OF FERTILIZERS AND GROWTH REGULATOR ON THE CHANGE OF BIOCHEMICAL PROPERTIES OF HYBRIDS OF ONION DURING STORAGE". Vegetable crops of Russia, n. 4 (27 luglio 2018): 67–70. http://dx.doi.org/10.18619/2072-9146-2018-4-67-70.
Testo completoAbstract (sommario):
Research staff All-Russian Scientific Research Institute of Vegetable Growing – Branch of the Federal State Budgetary Scientific Institution Federal Scientific Vegetable Center in collaboration with Russian state agrarian University – Moscow Timiryazev agricultural Academy conducted research (2014-2016) on the effect of fertilizers and plant growth regulators on changes in the quality of onions of the Pervenets F1, Bennito F1 hybrids and Poisk 012 F1 during storage. As a result of research, the greatest effect was obtained from the complex application of N90P90K90 in combination with trace elements (tenso-cocktail) and a growth regulator Zircon. This system allowed to obtain high biochemical parameters of onions. At the end of the 7 months of storage (October-may), the highest dry matter and sugar content and the minimum nitrate content was observed in Pervenets F1 onions, as well as in hybrid Bennito F1. In the latematuring hybrid onions Poisk 012 F1 at the end of storage, the dry matter content decreased to 6,8-7,3%, sugars to 3,6-4,1%, vitamin "C" to 3,2-4,9 mg%, and nitrates increased to 92,1 mg/kg, which led to a decrease in product quality and large losses of onions from diseases and natural losses (up to 48-59%). The main reason for these losses was the lack of maturity of bulbs,low solids and sugars during harvest. It is obvious that for long-term storage it is necessary to use bulbs with a dry matter content of at least 10%. It was found out that feeding of onions during the beginning of the formation of food organizations with potassium nitrate, treatment with a growth regulator of Zircon and a complex of microelements of tenso-cocktail contributes to better preservation of the quality of onions.
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Crespo, Jorge, Elizabeth Holley, Katharina Pfaff, Madeleine Guillen e Roberto Huamani. "Ore Mineralogy, Trace Element Geochemistry and Geochronological Constraints at the Mollehuaca and San Juan de Chorunga Au-Ag Vein Deposits in the Nazca-Ocoña Metallogenic Belt, Arequipa, Peru". Minerals 10, n. 12 (11 dicembre 2020): 1112. http://dx.doi.org/10.3390/min10121112.
Testo completoAbstract (sommario):
The Mollehuaca and San Juan de Chorunga deposits are hosted in the poorly explored gold and copper trends of the Nazca-Ocoña metallogenic belt in Arequipa, Perú, which extends from Trujillo (9 °S) to Nazca-Ocoña (14 °S). The aim of this study is to characterize the age, occurrence, and distribution of quartz vein-hosted Au-Ag mineralization and associated trace elements (e.g., Hg, Pb, Cu, Zn, and Bi) in these deposits. Here, we present geological mapping, geochemical whole rock inductively coupled plasma (ICP)-MS data of the veins, petrographic observations, backscattered electron images, quantitative SEM-based automated mineralogy, and electron microprobe analyses (EMPA). Despite the fact that there are numerous small-scale gold mines in the Nazca-Ocoña metallogenic belt, there have been few studies that document the origin and geological evolution of these deposits or the implications for decision-making in exploration, metallurgical processing, and environmental management. In this research, we document the host rock age of the mineralized veins (129.2 ± 1.0 Ma; U-Pb in zircon), the mineralization age (95.86 ± 0.05 Ma; 40Ar/39Ar in secondary biotite), the occurrence and distribution of Au-Ag in the veins, the mineral zonation present in the vein system, and the zircon geochemistry, in order to provide tools for natural resource management in the metallogenic belt.
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Bracciali, Laura. "Coupled Zircon-Rutile U-Pb Chronology: LA ICP-MS Dating, Geological Significance and Applications to Sediment Provenance in the Eastern Himalayan-Indo-Burman Region". Geosciences 9, n. 11 (5 novembre 2019): 467. http://dx.doi.org/10.3390/geosciences9110467.
Testo completoAbstract (sommario):
U-Pb dating by LA ICP-MS is one of the most popular and successful isotopic techniques available to the Earth Sciences to constrain timing and rates of geological processes thanks to its high spatial resolution, good precision (absolute U/Pb age resolution of ca. 2%, 2s), rapidity and relative affordability. The significant and continuous improvement of instrumentation and approaches has opened new fields of applications by extending the range of minerals that can be dated by this method. Following the development and distribution to the community of good quality reference materials in the last decade, rutile U-Pb thermochronology (with a precision only slightly worse than zircon) has become a commonly used method to track cooling of deep-seated rocks. Its sensitivity to mid- to low-crustal temperatures (~450 °C to 650 °C) is ideal to constrain exhumation in active and ancient orogens as well as thermal evolution of slow-cooled terranes. Recrystallization and secondary growth during metamorphism and the presence of grain boundary fluids can also affect the U-Pb isotopic system in rutile. A growing body of research focusing on U-Pb dating of rutile by LA ICP-MS is greatly improving our understanding of the behavior of this mineral with regards to retention of radiogenic Pb. This is key to fully exploit its potential as a tracker of geological processes. The latest developments in this field are reviewed in this contribution. The combined application of U-Pb zircon and rutile chronology in provenance studies, particularly when complemented by lower-T thermochronometry data, allows the isotopic characterization of the sources across a wide range of temperatures. The benefits of applying detrital zircon-rutile U-Pb chronology as a coupled provenance proxy are presented here, with a focus on the Eastern Himalayan-Indo-Burman region, where a growing number of successful studies employs such an approach to help constrain river drainage and basin evolution and to infer feedback relationships between erosion, tectonics and climate.
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LV, Yingli, Qui-Thao Le, Hoang-Bac Bui, Xuan-Nam Bui, Hoang Nguyen, Trung Nguyen-Thoi, Jie Dou e Xuan Song. "A Comparative Study of Different Machine Learning Algorithms in Predicting the Content of Ilmenite in Titanium Placer". Applied Sciences 10, n. 2 (16 gennaio 2020): 635. http://dx.doi.org/10.3390/app10020635.
Testo completoAbstract (sommario):
In this study, the ilmenite content in beach placer sand was estimated using seven soft computing techniques, namely random forest (RF), artificial neural network (ANN), k-nearest neighbors (kNN), cubist, support vector machine (SVM), stochastic gradient boosting (SGB), and classification and regression tree (CART). The 405 beach placer borehole samples were collected from Southern Suoi Nhum deposit, Binh Thuan province, Vietnam, to test the feasibility of these soft computing techniques in estimating ilmenite content. Heavy mineral analysis indicated that valuable minerals in the placer sand are zircon, ilmenite, leucoxene, rutile, anatase, and monazite. In this study, five materials, namely rutile, anatase, leucoxene, zircon, and monazite, were used as the input variables to estimate ilmenite content based on the above mentioned soft computing models. Of the whole dataset, 325 samples were used to build the regarded soft computing models; 80 remaining samples were used for the models’ verification. Root-mean-squared error (RMSE), determination coefficient (R2), a simple ranking method, and residuals analysis technique were used as the statistical criteria for assessing the model performances. The numerical experiments revealed that soft computing techniques are capable of estimating the content of ilmenite with high accuracy. The residuals analysis also indicated that the SGB model was the most suitable for determining the ilmenite content in the context of this research.
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Wells, Hannah C., e Richard G. Haverkamp. "Characterization of the Heavy Mineral Suite in a Holocene Beach Placer, Barrytown, New Zealand". Minerals 10, n. 2 (21 gennaio 2020): 86. http://dx.doi.org/10.3390/min10020086.
Testo completoAbstract (sommario):
The placer deposit at Barrytown, New Zealand, has been worked for gold and is known for high levels of ilmenite that has not been exploited. Other heavy minerals are present but have not been well characterized, which is the purpose of this research. Sand grains were separated into the density fractions and the heavier fractions analyzed by laser ablation ICP-MS for elemental composition and by scanning electron microscopy (SEM) EDS in whole grains and polished sections. Grain size distributions were determined from SEM images of polished grain mounts. Elemental associations have been identified with different minerals. A wide range of ore minerals, or potential useful industrial minerals, have been shown to be present largely as individual sand grains. These include gold, ilmenite, garnet, zircon, monazite, allanite, uraninite, thorite, cassiterite, wolframite, scheelite, and columbite. The ilmenite contains many inclusions, consisting of silicates and phosphates and 100–400 ppm Nb. Scandium is found to be present in zircon at 100–600 ppm along with 3000 ppm Y. Monazite is depleted in Eu relative to chondrite and contains Ga and Ge at 1000–3000 ppm. Because the sand grains are mostly individual minerals, it is suggested that separation may be possible using a combination of density, electrostatic and magnetic methods to obtain almost pure mineral fractions. This knowledge should inform decisions on potential exploitation of the resource.
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Popuiac, Aurelia. "Rare Earths in Geological Formations of Central Region of the Dniester River Basin, Republic of Moldova". Advances in Geology 2015 (5 gennaio 2015): 1–13. http://dx.doi.org/10.1155/2015/713282.
Testo completoAbstract (sommario):
In the different varieties of crystalline basement of Archean and Proterozoic age and in Vendian (Ediacaran) basal layers of platform coverture in the Central Basin of the Dniester River were found relatively high concentrations of Lanthanum, Cerium, Yttrium, Ytterbium, and Scandium. Because the petrographic formations, which are genetic associated with RE elements in Dniester region are absent, the origin of these elements is unclear. At the same time, in the geological mapping, it was detect that geochemical aureoles of REE, found in the northern region of Republic of Moldova, are generated by accessory minerals monazite and zircon present in the rock of basement platform and fragments of crystalline rock in the composition of terrigenous formations from basal levels of sedimentary coverture. Probably mentioned minerals are brought from Ukrainian Crystalline Shield regions, in which are spread varieties of granitic rocks and alkaline pegmatite. It is not excluded that in these basal layers in the sedimentogenes processes and differentiation of detrital material to be formed the mechanic aureoles rich in monazite and zircon, which in turn can form significant concentrations of rare earths. To solve the perspective problem of detection of industrial mineral accumulations of RE in the central region of the Dniester River basin, it is necessary to conduct within this area detailed geological and geochemical research.
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YATSENKO, Ivan, Sergey SKUBLOV, Ekaterina LEVASHOVA, Olga GALANKINA e Sergey BEKESHA. "Composition of spherules and lower mantle minerals, isotopic and geochemical characteristics of zircon from volcaniclastic facies of the Mriya lamproite pipe". Journal of Mining Institute 242 (25 maggio 2020): 150. http://dx.doi.org/10.31897/pmi.2020.2.150.
Testo completoAbstract (sommario):
The article presents the results of studying the rocks of the pyroclastic facies of the Mriya lamproite pipe, located on the Priazovsky block of the Ukrainian shield. In them the rock's mineral composition includes a complex of exotic mineral particles formed under extreme reduction mantle conditions: silicate spherules, particles of native metals and intermetallic alloys, oxygen-free minerals such as diamond, qusongite (WC), and osbornite (TiN). The aim of the research is to establish the genesis of volcaniclastic rocks and to develop ideas of the highly deoxidized mantle mineral association (HRMMA), as well as to conduct an isotopic and geochemical study of zircon. As a result, groups of minerals from different sources are identified in the heavy fraction: HRMMA can be attributed to the juvenile magmatic component of volcaniclastic rocks; a group of minerals and xenoliths that can be interpreted as xenogenic random material associated with mantle nodules destruction (hornblendite, olivinite and dunite xenoliths), intrusive lamproites (tremolite-hornblende) and crystalline basement rocks (zircon, hornblende, epidote, and granitic xenoliths). The studied volcaniclastic rocks can be defined as intrusive pyroclastic facies (tuffisites) formed after the lamproites intrusion. Obviously, the HRMMA components formed under extreme reducing conditions at high temperatures, which are characteristic of the transition core-mantle zone. Thus, we believe that the formation of primary metal-silicate HRMMA melts is associated with the transition zone D".
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Chen, Ying Fu, Gen Hou Wang e Xian Le Duan. "Zircon SHRIMP Geochronology and Geochemistry of late Jurassic Volcanic Rocks in Huiyin Obo Area, Inner Mongolia, China". Advanced Materials Research 634-638 (gennaio 2013): 3527–36. http://dx.doi.org/10.4028/www.scientific.net/amr.634-638.3527.
Testo completoAbstract (sommario):
The primary object of this fundamental research is to reveal new study of Late Jurassic Manketou Obo Formation and Early Cretaceous Manitu Formation, Baiyingaolao Formation, in Huiyin Obo area, East Ujimqin County, Inner Mongolia. Several sets of experiments were carried out to test the validity of three formations’ age, and these forms can be contrasted with Chagannuoer Formation and Bulagehada Formation from “1/250000 Regional Geology Survey in Hesigewula Farm.” As a result of our study, we concluded that further research into the Mesozoic volcanic rocks on the Huiyin Obo is necessary.
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Montedo, Oscar Rubem Klegues, e Antonio Pedro Novaes de Oliveira. "Relationship between Surface Abrasion Wear and Brightness in Glazed Porcelainized Stoneware Tiles". ISRN Ceramics 2011 (8 settembre 2011): 1–8. http://dx.doi.org/10.5402/2011/548129.
Testo completoAbstract (sommario):
This paper reports the results of a research work whose main objective is related to the development of a technical solution that takes into account the relationship between the surface abrasion wear resistance and brightness of glazed ceramic tile products. Thus, glazes formulated from a glass-ceramic composition belonging to the LZSA system reinforced with crystalline particles of zircon were prepared and characterized with respect to their scratching and surface abrasion wear resistances and brightness. In this context, a bright (71.2 UB) porcelainized stoneware ceramic tile with high scratching resistance (9 Mohs), high surface abrasion wear resistance (PEI 5), and good staining resistance (Class 4) was obtained.
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Urednistvo, U. "Retracted: Magnesia-zircon brick: Evolution of microstructure, properties and performance with increasing sintering temperature". Science of Sintering 45, n. 3 (2013): 387. http://dx.doi.org/10.2298/sos1303387e.
Testo completoAbstract (sommario):
(retraction) This article has been retracted: please see Science of Sintering Policy on Article Withdrawal (http://www.iiss.sanu.ac.rs/forauthors.htm, see Withdrawal policy). This article has been retracted at the request of Mr. Bernd Buchberger, Head of Corporate Research and Development of the RHI AG Technology Center and Mr. Alfons Luftenegger, Head of Innovation and Intellectual Property Menagement of the RHI AG Technology Center, due to legal limitations, since the publication of this article was not authorized by RHI AG or any company within the RHI Group. <br><br><font color="red"><b> Link to the retracted article <u><a href="http://dx.doi.org/10.2298/SOS1302181G">10.2298/SOS1302181G</a></b></u>
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Kabanova, Svetlana Anatolyevna, Valery Anatolyevich Bortsov e Matvey Anatolyevich Danchenko. "Adaptation of foreign technologies of intensive cultivation of scots pine planting material in Kazakhstan". RUDN Journal of Agronomy and Animal Industries 15, n. 1 (15 dicembre 2020): 40–50. http://dx.doi.org/10.22363/2312-797x-2020-15-1-40-50.
Testo completoAbstract (sommario):
The purpose of the research was the adaptation of foreign technologies for intensive and accelerated cultivation of Scots pine planting material in Kazakhstan. Objects of research were annual seedlings of scots pine in forest nurseries of Pavlodar, Akmola, and North Kazakhstan regions. The experiments were established in 4 directions: application of dry growth regulators to soil, pre-sowing seed treatment with growth regulators, soaking seeds in stimulants and fungicide, pre-sowing watering of the soil with growth regulators. It was established that seed quality decreased significantly compared to the last year, only seeds from Pavlodar region had high indicators. Seeds from the nursery ‘Ertic Ormany’ had the highest average indicators of soil germination (58.7…67.8%). In ‘Bukhpa’, the highest germination was observed in seeds soaked with Zircon + Trichocin (3 + 2 hours). Baikal growth regulator and AridGrow slightly increased germination in the nursery of Arykbalyk branch of ‘Kokshetau’. In the forest nursery ‘Ertis Ormany’, the highest annual seedlings were obtained in variants with presowing treatment of scots pine seeds with stimulants and watering the soil with growth substances. The average height of experimental seedlings was 4.32 and 4.64 cm, respectively. The combined use of Zircon and Trichocin increased seedling growth in ‘Bukpa’ nursery to 1.42 cm, which was the highest value. It was revealed that the technologies used in neighboring countries for intensive cultivation of scots pine seedlings showed a positive effect only when using Citovit. According to other experiments, it was determined that seedlings of scots pine grown from seeds with pre-sowing treatment in Gumat+7 for 12 hours had the best growth indicators in height. Increased soil fertility through applying nitrogen, phosphorus fertilizers, soil activator AridGrow and KZ Cultury significantly accelerated growth of scots pine seedlings.