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new K-feldspar parameterization is compared to the litera-ture data (Fig. 7d) it represents the variability of K-feldspar, as well as the curvature in the datasets. In particular, the.
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Feldspars with compositions close to KAlSi 3 O 8 are generally called K-feldspar, or K-spar. But, K-feldspar has three polymorphs with slightly different atomic arrangements: orthoclase, microcline, and sanidine. Photos of each are shown below in Figures 6.39, 6.40, and 6.41. In these photos the polymorphs have different colors, but color is ...
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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 range (Li and Li, 2011). Fortunately, the single-grain pIRIR dating of KF can solve the problem of insufficient bleaching by choosing the well or better bleached components ...
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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 compared with quartz ages. It is found that the g value correction method cannot give reliable ages due to the large errors induced during measurements.
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where K 0 and K 1 are the Na/K ratios in feldspars in the parent rocks and sediment, respectively; t represents the time interval; γ is the ratio of K 1 to K 0; and t Na-L and t K-L are the lifetimes of Na-containing and K-containing feldspars, respectively. According to this model, the change in the Na/K ratio in feldspars as a function of time for different combinations …
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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 al., 2021a).
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The data from Zolles et al. (2015) have been split into quartz samples that were milled for fresh surfaces and all the combined data (both milled and unmilled quartz). - "The ice-nucleating ability of quartz immersed in water and its atmospheric importance compared to K-feldspar"
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Quartz and feldspar are the two most abundant minerals in the continental crust. The rheology of quartz and feldspar has been used to approximate the rheology of the upper and the lower crust, respectively. However, compared with quartz and plagioclase, the rheology of K-feldspar (Kfs) is much less characterized. We present here systematic axial compression deformation …
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It was found that Na-rich feldspar containing body composition achieve full vitrification at lower temperature compared to K-rich feldspar containing composition with improved flexural strength. Differential thermal analysis-thermogravimetric analysis (DTA-TGA) confirms similar reaction steps for both the compositions up to 1000 • C, beyond ...
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feldspar minerals can be grouped, according to bulk compo-sition, into potassium-rich feldspar (K-feldspar) and Na- or Ca-rich species (plagioclase). While the series of plagioclase contains all fractions of Na and Ca, there is a mixing gap for K-feldspar. Only a limited fraction of KCcan be replaced by NaCor Ca2C. K-feldspar is subdivided into ...
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Although the concentration of most of trace elements is lower in K-feldspar compared to biotite, the chemical composition of K-feldspar still reflects the fractionation model of the MDG system (Figs. 14 d-f). Li, Rb, and Cs values increase with fractionation, however, Sr behaves contradictory that is attributed to its much greater compatibility ...
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Abstract In this study, a selective flotation process for the separation of K-feldspar from Na-feldspar was developed for the beneficiation of a Norwegian microcline-quartz pegmatite sample. 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 activated …
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NaOL is extensively adopted to the flotation processes as an anionic collector [23].However, a single NaOL cannot effectively separate and purify K-feldspar [24].Cetyltrimethyl ammonium chloride (CTAC) is a cationic surfactant that is resistant to heat, light, pressure, and strong acids and bases, and has the advantages of strong collection, good solubility, and less …
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The EDS analysis of the major elements of the minerals shows that the recrystallized grains (Site P1) are oligoclase. Compared with K-feldspar porphyroclasts, the oligoclase grains are featured by moderately high Na 2 O and CaO contents but low K 2 O and SiO 2 contents.
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Feldspar is the most abundant mineral in the Earth's crust, and the infra-red stimulated luminescence (IRSL) signal of feldspars has the potential to extend the luminescence dating range because of its high saturation dose of the order of ∼1 kGy (see Jain, 2014, for a recent overview).However, in typical potassium feldspar (K-feldspar) sediment samples used …
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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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K-feldspars. These measurements are compared with Monte Carlo simulations to identify best-fit values for ... The K-feldspar samples analyzed in this study were extracted from bedrock outcrops across the southern San Bernardino Mountains of Southern California. Young apatite (U-Th)/He ages (Spotila et al., 1998, ...
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Li and Wintle (1992) compared the thermal stability of the IRSL signal derived from fine-grained polymineral loess with signals from feldspar grains with different grain-sizes and chemical compositions. The results indicated that the IRSL signal in the fine-grained polymineral loess was less stable than that from the K-feldspar grains, but ...
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Moreover, a more hydrogen-rich syngas when using K-feldspar was produced (46% compared to 39% with olivine). Operating conditions in the FBG. Physico-chemical characterization of almond shells ...
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Because compared to K-feldspar, it's a relatively very slow reaction. And when we think about the reaction that's happening, the K-feldspar will be dissolving out. So you would have this K-feldspar dissolving out to become released calcium, which is very important nutrients, metals, cations. And then it would be also released aluminum plus SiO2 ...
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Abstract. Mineral dust particles are thought to be an important type of ice-nucleating particle (INP) in the mixed-phase cloud regime around the globe. While K-rich feldspar (K-feldspar) has been identified as being a particularly important component of mineral dust for ice nucleation, it has been shown that quartz is also relatively ice-nucleation active. Given quartz typically makes up …
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Request PDF | Coarse-grained K-rich feldspar and fine-grained polymineral IRSL dating of loess-palaeosol from the Chinese Loess Plateau: A comparison | In this study, the characteristics of ...
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1 1 The ice-nucleating ability of quartz immersed in water and its 2 atmospheric importance compared to K -feldspar 3 4 Alexander D. Harrison 1, Katherine Lever 1, Alberto Sanchez -Marroqu in1, Mark A. Holden 1,2*, 5 Thomas F. Whale 1,2, Mark D. Tarn 1, James B. McQuaid 1 and Benjamin J. Murray 1 6 1School of Earth and Environment, University of Leeds, Leeds, …
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The K-feldspar mineral is an insoluble potassium resource with a high potassium content and the most extensive and abundant reserves. To address the insufficient supply of soluble potassium fertilizers in China, the …
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Compared to quartz, the infrared stimulated luminescence (IRSL) signal from K-feldspar saturates at much higher dose, which has the higher dating limit. Though application of IRSL dating with K-feldspar was hampered by anomalous fading (Spooner, 1992), later studies showed that the post-infrared IRSL (pIRIR) signal stimulated at a higher ...
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For K-feldspar thermoluminescence (TL) glow curves, which comprise overlapping signals of different thermal stability, it is challenging to develop measurements that capture these parameter values. ... TL dose–response and fading measurements from bedrock-extracted K-feldspars. These measurements are compared with Monte Carlo simulations to ...
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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 luminescence dating. Our results show discrepancies between published and our measured K …
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3 65 K -rich feldspar extracts in which all grains have a homogeneous K -concentration of ~14 % (e.g. Huntley and Baril, 1997) . Therefore, the K -concentration used for int calculations of a sample should not automatically be assumed to be 14 .05 %. M ost of the time t he K -concentration used for int calculations is based on literature values (see section 2.2).
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The K-feldspar was selectively floated from Na-feldspar at pH 10.5–11.6 with NaOH as pH adjuster/modifier and Brij58 as frother, but without any additional collector other than the …
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Compared to K-feldspar, the K content could be a better proxy for constraining the δ 41 K of plagioclase. Our results demonstrate that the δ 41 K of K-feldspar is dependent on its …
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