Dunite (>90 vol% olivine) is the predominant rock type on the eastern edge of the Polaris intrusion (Fig. 3 a).The nature of contacts between dunite and other ultramafic rocks is variable (Nixon et al., 1997; Nott et al., 2020a, Nott et al., 2020b).Dunite commonly exhibits gradational contacts with olivine wehrlite (65–90 vol% olivine) and wehrlite …
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However, a few studies focusing on olivine dissolution in seawater have been reported. Montserrat et al. (2017) reported that olivine dissolution in artificial and natural seawater caused a significant increase in alkalinity and dissolved inorganic carbon (DIC) due to CO 2 sequestration. It has been predicted that dissolved ions such as …
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Introduction. The study of olivine-hosted melt inclusions trapped at depth by growing olivine crystals, before a rising magma has the opportunity to degas completely, presents an exceptional opportunity to directly measure pre-eruptive volatile concentrations of basaltic rocks, thereby allowing characterization of the source and …
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A wide range in H2O concentrations has been discovered, with the highest amount of 4.2wt.% found in olivine grains from a lava flow in the Malheur Gorge area, which erupted several million years after the hypothesized initial impingement of the Yellowstone Hotspot against the lithosphere of the North American Plate.
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Qualitative proposals to control atmospheric CO2 concentrations by spreading crushed olivine rock along the Earth's coastlines, thereby accelerating weathering reactions, are presently attracting ...
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Materials. Commercially available olivine sand (Mg 2–x Fe x SiO 4) and lab-grade quartz (SiO 2) were used in slurry dissolution experiments.The olivine sand (particle size quantiles: D10 = 91 μm, D50 = 143 μm, D90 = 224 μm) had a molar Mg-to-Fe ratio of 0.94:0.06, characterizing the olivine as forsterite-94 (Fo 94).The Ni content was …
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Abstract Trace concentrations of H2O in olivine strongly affect diverse mantle and magmatic processes. H2O in olivine has been difficult to accurately quantify due to challenges in sample preparation and measurement, as well as significant uncertainties in standard calibrations. Here we directly compare secondary-ion mass …
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Thin amorphous films (1-2 nm) at olivine grain boundaries in mantle xenoliths from San Carlos, Arizona ... high energy grain boundaries. In the following, Al2O3, TiO2 and CaO are considered as impurities because their concentration in olivine usually is very low (.0.1 wt%). The concentration of CaO might be slightly higher. The mean value and ...
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Complex core-rim zoning of Mg-Fe-Ni-Ca-Cr-Al-P in high-Mg olivine crystals from a tuff ring of Shiveluch volcano, Kamchatka, enables reconstruction of the entire olivine crystallization history ...
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Olivine dissolution plays an important role in environmental science and technology, from controlling global element circulation to carbon capture for climate change mitigation. Most studies have been …
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The rheological properties of amorphous olivine thin films deposited by pulsed laser deposition have been studied based on ambient temperature …
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Recharge caused partial dissolution and renewed growth of Fo 90 olivine and resulted in the formation of identical overgrowths on a variety of olivine cores.
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The D bulk Ca is calculated using the Ca concentration of experiment melts (with SiO 2 < 57 wt%) and residual solid phases during partial melting (Table S1). Olivine phenocrysts, which are the first minerals to crystallize from mantle-derived magma, have the potential to record the compositions of primary melt.
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1. Introduction. Olivine is a family of minerals with an orthorhombic structure and a general composition of (Mg, Fe) 2 SiO 4.The Mg 2 SiO 4 magnesium-rich end-member is called forsterite, and the Fe 2 SiO 4 iron-rich end-member is called fayalite. With an iron composition close to 10 %, olivine is the main constituent of the Earth's mantle …
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[1] We report analyses of hydrogen abundance in experimentally annealed and natural mantle minerals using FTIR and use these data to establish calibration lines for measurement of H 2 O …
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A second major reason to review olivine dissolution rates is that its reactivity is relatively simple. Its structure is comprised of isolated Si O 4 4− tetrahedra linked by divalent cations. As such, its dissolution mechanism is less complex than most other naturally occurring multi-oxide silicates (Oelkers, 2001a).As there are no Si-O-Si …
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Isotopic depth profiles were also conducted on an unzoned olivine cuboid that was coated with a 26 Mg-and 56 Fe-enriched olivine thin film (of ∼ 800 nm) in order to investigate top-to-bottom ...
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Hydrogen concentration profiles across olivine reveal that H loss during decompression was limited to the outermost rims, and yield dehydration durations of 15–417 min. Based on the water ...
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The specimens were first mechanically polished down to a thickness of 30 μm. To reach electron transparency, the sample foils mounted on Mo …
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We have determined Fe–Mg diffusion coefficients in olivines from different sources (Nanga Parbat, Pakistan and San Carlos, Arizona, USA) at atmospheric pressure as a function of composition, oxygen fugacity (10−5–10−12 Pa) and temperature (700–1200°C) using thin films produced by pulsed laser deposition and RBS to analyze …
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The leaching of Ca2+ from the Ca-olivine surface is a ligand exchange process that results in a much lower energy barrier with 103 times faster dissolution rate compared to the leaching of Mg2 ...
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Introduction. Olivine, a silicate with composition (Mg,Fe) 2 SiO 4, is the major constituent (60 to 80 %) of the Earth's mantle up to ca. 410 km deep where it transforms into a high-pressure polymorph, called wadsleyite. The mechanical properties of olivine are of primary importance in geodynamics since this mineral controls the …
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O to refer to the concentration of structurally bound H in a crystal, and where appropriate, H + for discussing the diffusing species. Olivine typically has only trace concentrations of H 2 O (0–60 ppm), yet because it is the dominant upper-mantle mineral, it plays a prominent role in mantle dynamics (Demouchy and Bolfan-Casanova 2016).
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Trace concentrations of H2O in olivine strongly affect diverse mantle and magmatic processes. H2O in olivine has been difficult to accurately quantify due to challenges in sample preparation and measurement, as well as significant uncertainties in standard calibrations. Here we directly compare secondary-ion mass spectrometry …
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Olivine in the host rock entrapped in a shock-induced melt vein initially transformed into polycrystalline ringwoodite through a nucleation and growth mechanism. ... However, its Fe concentration ...
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To address this question we determined H 2 O, CO 2, F, Cl and S concentrations in olivine-hosted melt inclusions of high-Mg volcanic rocks of the Siberian Traps Large Igneous Province that bracket the main pulse of volcanism at about 252–250 Ma, and can be classified as melanephelinites and meimechites. Both rock types belong …
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The strength of olivine at low temperatures and high stresses in Earth's lithospheric mantle exerts a critical control on many geodynamic processes, including lithospheric flexure and the formation …
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Semantic Scholar extracted view of "Volatile concentrations in olivine-hosted melt inclusions from the Columbia River flood basalts and associated lavas of the Oregon Plateau: Implications for magma genesis" by J. A. Cabato et al.
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The conclusion of Hangx and Spiers (2009), commenting on Schuiling and Krijgsman (2006), that in the coastal zone up to 2100 years may be needed for 300 μ olivine sand to be chemically weathered under the uptake of CO 2 grossly understates the uptake rate in natural settings, where flora, fauna and physical processes accelerate the …
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with the host olivine, primarily impacting the MgO concentration, and in complicated cases, by volatiles diffusing in or out, or simply getting degassed through cracks in the host olivine.
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