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32981
Chemostratigraphic Analysis of Wufeng and Longmaxi Formation in Changning, Sichuan, China: Achieved by Principal Component and Constrained Clustering Analysis
Published 2021-10-01“…Thus, a three-stage geochemical evolution along the Changning section can be classified: (1) the siliceous and anoxic deposits of Wufeng Formation (CZ I–CZ III) with high TOC contents; (2) the siliceous and anoxic sedimentary rocks of bottom Longmaxi Formation with still higher TOC (CZ Ⅳ); (3) the calcarous-detrital and oxic sediments for the rest of Longmaxi Formation (CZ Ⅴ–CZ Ⅻ). …”
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32982
Migration of Natural Hydrogen from Deep-Seated Sources in the São Francisco Basin, Brazil
Published 2020-09-01“…Alternatively, ultramafic rocks that may have generated H<sub>2</sub> during their serpentinization are also documented in the basement. …”
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32983
Optimization of fluorine mine water treatment and fluorine removal mechanism using response surface methodology
Published 2022-12-01“…Surface water or groundwater flowing through fluorine-rich rocks can easily lead to excessive fluorine in water.Excessive fluoride in water can cause endemic fluorosis, damage of the ecological environment and restrict comprehensive utilization of water resources.In this study, based on a highly effective fluoride removal agent developed by the research group earlier, the box-Behnken method of response surface analysis was applied to design fluoride removal experiments where the influences of pH value, dosage of defluoridation reagent and fast stirring time on fluoride removal effect were optimized.This paper used X-Photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and Fourier transform infrared spectrum (FT-IR) to characterize the defluoridation reagent and the sludge produced after treatment, and discussed the mechanism of fluoride ion removal.The experimental results showed that F<sup>-</sup>could be reduced from the initial 20 mg/L to 0.453 mg /L under the optimal conditions of fluoride removal (pH value 6.11, dosage 4.15 mL, fast stirring time 10.90 min), which was basically consistent with the predicted value 0.445 mg /L of the model.The defluoridation reagent was mainly through the formation of Fe, Al, Si and O polynuclear polyhydroxyl complex, fluorine-ion exchange with hydroxyl and replace hydroxyl, then fluorine-ion was fixed in the polynuclear polyhydroxyl complex.Meanwhile, fluoride forms a tetrahedral structure of aluminum, silicon and oxygen, and locks fluorine ions in the tetrahedral structure to achieve fluoride removal.Compared with the current main treatment process using hydroxyapatite adsorption, the defluoridation reagent in this study has the advantages of simple treatment process, stable treatment effect and low treatment cost.…”
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32984
Deposition, Diagenesis, and Sequence Stratigraphy of the Pennsylvanian Morrowan and Atokan Intervals at Farnsworth Unit
Published 2021-02-01“…This paper presents a geological description of the rocks comprising the reservoir that is a target for both oil production and CO<sub>2</sub> storage, as well as the overlying units that make up the primary and secondary seals. …”
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32985
Fluid Redox Fingerprint of the CaCO<sub>3</sub>+Antigorite Dehydration Reaction in Subducted Metacarbonate Sediments
Published 2023-04-01“…Whereas previous studies have investigated antigorite dehydration in serpentinites (i.e., in a (C)AMFS-H<sub>2</sub>O system), this contribution is devoted to the CMFS-COHS carbonate system, which is representative of the metacarbonate sediments (or carbonate-dominated ophicarbonate rocks) that sit atop the slab. Thermodynamic modelling is used to investigate the redox effect of the carbonate-buffered antigorite dehydration reactions (i.e., brucite breakdown and antigorite breakdown) on electrolytic fluid geochemistry as a function of <i>P</i>-<i>T</i>-<i>f</i>O<sub>2</sub>. …”
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32986
Recognition of Volumetric Scattering of Lunar Regolith Media in the PSR via Fully Polarimetric SAR Data
Published 2022-01-01“…Scattering from surface, rocks should be excluded. Such flat regions are difficult to identify in the digital elevation model. …”
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32987
Chemical-Abrasion U-Pb zircon geochronology reveals 150 Myr of partial melting events in the Archean crust of the São Francisco Craton
Published 2022-09-01“…Field observations and CA-LA-ICP-MS U–Pb zircon ages and Hf isotope compositions obtained from migmatitic orthogneisses and granitoids from the Belo Horizonte Complex, southern São Francisco Craton, indicate a major period of partial melting and production of felsic rocks in the Neoarchean. Our observations show that the complex is an important site for studying partial melting processes of Archean crystalline crust. …”
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32988
New paleomagnetic data on the Permian-Triassic sedimentary sections of the Moscow syneclise
Published 2020-06-01“…Presumably, the reasons are (a) an inclination shallowing in the studied sedimentary rocks, (b) the presence of a significant contribution of non-dipole components to the main geomagnetic field about 250 million years ago, (c) local tectonics. …”
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32989
Petrogenesis of the late Cretaceous Turnagöl intrusion in the eastern Pontides: Implications for magma genesis in the arc setting
Published 2013-07-01“…It is of sub-alkaline affinity, belongs to the medium- to high-K calc-alkaline series, and displays features typical of I-type granites. The rocks of the intrusion are enriched in large-ion lithophile elements and light rare earth-elements with negative Eu anomalies (Eu/Eu* = 0.69–0.82), but are deficient in high-field-strength elements. …”
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32990
Ore Genesis of the Dongping Gold Deposit in the Northern Margin of North China Craton: Constraints from In-Situ Major, Trace Elemental Analysis of Magnetite and Pyrite
Published 2022-07-01“…The Dongping gold deposit in the Zhangxuan district is well known for its unique hosting of rocks and ore mineral assemblages. Magnetite and pyrite are common minerals that widely exist in ores of the Dongping deposit. …”
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32991
Sedimentological and geochemical evaluation of sandstones of the Ilaro formation, Dahomey Basin, Southwestern Nigeria : Insights into paleoenvironments, provenance, and tectonic se...
Published 2024-03-01“…Bivariate and discriminant plots from major elements and trace elements suggest the sandstones were non-marine and sourced from intermediate rocks. The sandstones were deposited in an oxic-dyoxic condition under a humid climate and passive or active continental margins. …”
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32992
Elemental and K-Ar Isotopic Signatures of Glauconite/Celadonite Pellets from a Metallic Deposit of Missouri: Genetic Implications for the Local Deposits
Published 2022-10-01“…In the course of attempting to date the host rocks of Viburnum metal deposits from the US state of Missouri, the purpose was here a detailed examination and contribution of the constitutive minerals of glauconite-rich pellets to the isotopic dating of these deposits. …”
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32993
Petrogenesis of Syn-Collisional Adakitic Granitoids and Their Copper Mineralization Potential in the North Qilian Suture Zone
Published 2023-06-01“…Geochemically, the granitoids resemble low-Mg adakitic rocks featured by elevated Sr/Y and (La/Yb)<sub>N</sub> ratios with depleted MgO, Cr, and Ni concentrations, suggesting minimal mantle contribution. …”
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32994
Silicates from Lherzolites in the South-Eastern Part of the Kempirsay Massif as the Source for Giant Chromitite Deposits (the Southern Urals, Kazakhstan)
Published 2022-08-01“…We provide results of a comprehensive mineralogical and microstructural study of relict lherzolites of the main ore field and fresh rocks from a deep structural borehole drilled in the south-eastern part of the Kempirsay massif. …”
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32995
<i>Allium ducissae</i> (<i>A.</i> subgen. <i>Polyprason</i>, Amaryllidaceae) a New Species from the Central Apennines (Italy)
Published 2022-02-01“…It grows in crevices on calcareous rocks, rocky slopes and grassy ledges in the subalpine belt, within two regional protected areas in the Lazio and Abruzzo administrative regions (Central Apennines, Italy). …”
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32996
Halogen-bearing metasomatizing melt preserved in high-pressure (HP) eclogites of Pfaffenberg, Bohemian Massif
Published 2024-03-01“…Chemical similarities between this melt and other metasomatizing melts measured in other eclogites from the Granulitgebirge and Erzgebirge, in addition to the overall similar enrichment in trace elements observed in other metasomatized mantle rocks from central Europe, suggest an extended crustal contamination of the mantle beneath the Bohemian Massif during the Variscan orogeny.…”
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32997
Imaging Karatungk Cu-Ni Mine in Xinjiang, Western China with a Passive Seismic Array
Published 2020-07-01“…Two high-velocity zones, distributed at 0.7–1.3 km depth in the northernmost and southernmost parts of the study area respectively, are interpreted to be igneous rocks related to early magma intrusion. Furthermore, the low-velocity zone at 0.7–1.3 km depth in the middle of the study area may be related to: a possible channel related to initial magma transport; mine strata or a potentially mineralized area. …”
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32998
Internal Transcribed Spacer and 16S Amplicon Sequencing Identifies Microbial Species Associated with Asbestos in New Zealand
Published 2023-03-01“…Samples from Auckland (North Island, New Zealand) asbestos cement, Auckland asbestos-contaminated soils, and raw asbestos rocks from Kahurangi National Park (South Island, New Zealand) were comprised of very different microbial communities. …”
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32999
Development characteristics of multi-scale fracture network systems in metamorphic buried hills
Published 2023-01-01“…Continuous networks associated with multi-scale fractures with good connectivity is critical for high-quality reservoirs as well as high and stable production in the tight metamorphic rocks. The multi-scale fractures in Bozhong 19–6 metamorphic buried hills were well characterized through integrating image logs, cores, thin-sections, and scanning electron microscope, etc. …”
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33000
Laser Raman Spectroscopic Study and LA-ICP-MS U-Pb Dating of Zircons from the Badaling Granitic Complex
Published 2016-09-01“…In this study, Laser Raman Spectroscopy and LA-ICP-MS were used to analyze zircons from the Badaling Granitic Complex rocks. Results show that the metamictization degree is low when the actual retained alpha dose (DαP) is no more than 0.75×1018 g-1 and the matrix effect is negligible. …”
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