K isotopic fractionation in K-feldspar: Effects of mineral …

a significant role in the K isotopic behavior of K-feldspar. The correlations of δ. 41. K with SiO. 2. and Al. 2. O. 3. contents are attributed to the difference in K-O bond strengths. Compared to K …

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K-feldspar

The three principle varieties of K-feldspar are microcline (low temperature), orthoclase (medium temperature), sanidine (high temperature). Other, rare, related feldspar varieties include …

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Lecture Notes

delineates a hill-shaped, two-feldspar (or no feldspar!) region at intermediate compositions. The curve bounding this region is called a solvus. The solvus marks the limit of solubility of the Ab …

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Origin of K-feldspar megacrysts of Quxu batholith in Gangdese …

Compared with the common occurrence of K-feldspar megacrysts in the intrusive plutons, there are relatively few K-feldspar megacrysts in volcanic rocks (e.g., Cheng et al., …

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K isotopic fractionation in K-feldspar: Effects of mineral chemistry

The correlations of δ 41 K with SiO 2 and Al 2 O 3 contents are attributed to the difference in K-O bond strengths. Compared to K-feldspar, the K content could be a better …

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Advances in in-situ Rb-Sr dating using LA-ICP-MS/MS

The higher 87 Rb/ 86 Sr of K-feldspar compared to those of plagioclase make it possible to derive a robust Kfs-Pl isochron age of 1691 ± 74 Ma (MSWD = 2.4; Fig. 9 b), while …

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COMPARISON OF THREE K-FELDSPAR LUMINESCENCE …

from K-feldspar compared with OSL dating from Quartz. Firstly, The IRSL signals from K-feldspar are much brighter than the OSL signal from quartz. It enables high precision of luminescence …

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Comparing the accuracy and precision of luminescence

Grains of K-feldspar used to determine equivalent doses (D e) were extracted by treating each sample with a 10% v/v dilution of 37% HCl and with 20% v/v of H 2 O 2 to …

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Comparison of feldspar dating protocols for loess samples older …

Besides the slower decay rate of the K-feldspar IRSL signal compared to quartz OSL signals (Godfrey-Smith et al., 1988), K-feldspar has unbleachable signals even after a …

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COMPARISON OF THREE K-FELDSPAR LUMINESCENCE …

K-feldspar apparent ages using routine single aliquot regenerative-dose (SAR) protocol, K-feldspar ages using g value correction method and ages from isochron dating method were …

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Illite distribution and morphology explaining basinal variations in

Porosity, permeability are compared with K-feldspar and albite abundances and the dominant illite morphology. The deviated well, Gert-4, is presented by uncorrected measured …

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EGUsphere

We evaluate different methods for the potassium (K) concentration determination in feldspars and the impact of the K-concentrations on dose rate calculations for feldspar …

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(PDF) How much K is oK? – Evaluating different methods for K

For luminescence dating of potassium-rich (K) feldspars, the presence of 40K within the K-feldspar grains contributes significantly to the internal dose rate of the sample.

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Rounding of Quartz and K-Feldspar Sand From Beach to Dune …

Sand samples were collected from seven different locations along the California and Oregon coastlines where beach sediments and eolian coastal dunes are in close proximity …

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Feldspar

Plagioclase Orthoclase: Feldspar is a name given to a class of aluminum-containing silicates which are sometimes called light silicates or "nonferromagnesian silicates" since they don't contain iron or magnesium. The …

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Rheology of dry K-feldspar aggregates at high temperature and …

We present here systematic axial compression deformation experiments on a relatively dry (22 ± 2 wt ppm) synthetic Kfs aggregates (Or81 Ab 19) at strain rates of 10 −4 …

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Evaluating different methods for K

we determine the K -concentration of a set of ten density -separated sand -sized K -feldspar samples of different geological origin 25 and chemical composition using four different …

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Dynamic collapse and regrowth of the Antarctic Ice Sheet in the …

The use of 40 Ar/ 39 Ar as a detrital provenance tool is well-established, though it is relatively seldom applied to K-feldspar due to the lower closure temperature compared to other …

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Mechanistic understanding of Curium(III) sorption on natural K-feldspar

This is a similar increase compared to K-feldspar powder studies at similar Eu(III) concentration, where between pH 5.5 and 6.9 uptake increased by a factor of 2.5 (Neumann et …

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Evaluation of Non-Exchangeable Potassium Release from K …

Non-exchangeable potassium that is mainly placed with in layers of K-bearing minerals, such as K feldspar and mica, is considered as an important source of potassium for …

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A green K-fertilizer using mechanical activation to improve the

Furthermore, prior mechanical activation of the K-feldspar led to substantial increases of up to 172% in K release (reaching 326.86 mg L −1), compared to the original …

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Microwave-assisted Decomposition of K-feldspar at Low …

19 Jianhai Zhao et al.: Microwave-assisted Decomposition of K-feldspar at Low Temperature in Acids System Hydrothermal decomposition of potassium feldspar was often carried out in …

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USGS Scientific Investigations Report 2017-5118: Geochemical …

Thus, the concentration of K feldspar is markedly different among the different glacial lobes depending on provenance, with higher K feldspar concentrations in 'red' till compared to 'gray' …

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Understanding the flotation separation of Na and K feldspars in …

The K-feldspar flotation was performed in alkaline environment (pH 10.5–11.6) with only the addition of NaOH as a modifier and non-ionic Brij58 as a frother, on a fluorine-amine …

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Single-grain K-feldspar pIRIR dating of the Longwanling handaxe …

Compared to quartz OSL, pIRIR dating of K-feldspar, though possibly affected by insufficient bleaching, has the advantage of much higher signal intensity and a longer dating …

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Equilibrium partitioning and isotopic fractionation of nitrogen …

This has previously been shown to be an issue for comparing natural Kspar-mica K isotope fractionation (Huang et al., 2023) compared with theoretical DFT calculations (Li et al., …

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Syngas Quality in Fluidized Bed Gasification of Biomass

Moreover, a more hydrogen-rich syngas when using K-feldspar was produced (46% compared to 39% with olivine). The relevance of selecting an appropriate bed material in …

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The Geochemical Characteristics of Zircon and K-Feldspar …

Notably, substantial discrepancies exist in the U-Pb ages and Pb isotopic compositions of detrital zircons and K-feldspar from the lower Yellow River compared to those …

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FELDSPARS AND OTHER FRAMEWORK SILICATES

Range of feldspar compositions found in nature determined by the sizes and charges on Na, Ca, K. In general, a mineral structure will accept a mixture of cations if the cations have the same …

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K isotopic fractionation in K-feldspar: Effects of mineral …

Compared to K-feldspar, the K content could be a better proxy for constraining the δ41K of plagioclase. Our results demonstrate that the δ41K of K-feldspar is dependent on its mineral …

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K isotopic fractionation in K-feldspar: Effects of mineral chemistry

The correlations of δ41K with SiO2 and Al2O3 contents are attributed to the difference in K-O bond strengths. Compared to K-feldspar, the K content could be a better proxy for constraining …

WhatsApp: +86 18221755073

K isotopic fractionation in K-feldspar: Effects of mineral …

a significant role in the K isotopic behavior of K-feldspar. The correlations of δ41K with SiO 2 and Al 2 O 3 contents are attributed to the difference in K-O bond strengths. Compared to K …

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Rubidium isotope compositions of biotite in granites record …

This stability can be attributed to the contrasting behaviors of K-feldspar and biotite: K-feldspar preferentially enriches the heavier Rb isotope (87 Rb) compared to biotite (Fig. 5 c). …

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Ca diffusion in K-Feldspar

The single datum for albite is about 3 orders of magnitude faster than Ca diffusion in K-feldspar. The faster diffusivities of Ca in plagioclase vs. K-feldspar may be a consequence of …

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The complexity of sediment recycling as revealed by common Pb …

Since K-feldspar is a common rock forming mineral in many felsic plutonic rocks, which also generally contain abundant accessory zircon (as compared to, for example mafic …

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First investigation of the luminescence dating of loess in the …

Compared to quartz, infrared stimulated luminescence (IRSL) signals from K-feldspar have higher saturation doses and upper dating limits (Smedley, 2018).Furthermore, K …

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