Log in

Relevant bibliographies by topics / K-rich melt / Journal articles

To see the other types of publications on this topic, follow the link: K-rich melt.

Journal articles on the topic 'K-rich melt'

Author: Grafiati

Published: 1 April 2023

Last updated: 31 July 2025

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 journal articles for your research on the topic 'K-rich melt.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

Solovova, I. P., and A. V. Girnis. "Silicate–carbonate liquid immiscibility and crystallization of carbonate and K-rich basaltic magma: insights from melt and fluid inclusions." Mineralogical Magazine 76, no. 2 (2012): 411–39. http://dx.doi.org/10.1180/minmag.2012.076.2.09.

Full text

Abstract:

AbstractThis paper reports an investigation of the crystallization products of K-rich silicate and carbonate melts trapped as melt inclusions in clinopyroxene phenocrysts from the Dunkeldyk alkaline igneous complex in the Tajik Republic. Heating experiments on the melt inclusions suggest that the carbonate melt was formed by liquid immiscibility at 1180°C and ∼0.5 GPa. The carbonate-rich inclusions are dominated by Sr-bearing calcite, and rich in incompatible elements. Most of the silicate minerals are SiO2-poor and rich in K, Ba and Ti. Leucite, kalsilite and aegirine are the earliest magmati

APA, Harvard, Vancouver, ISO, and other styles

2

Lloyd, F. E., A. D. Edgar, D. M. Forsyth, and R. L. Barnett. "The paragenesis of upper-mantle xenoliths from the Quaternary volcanics south-east of Gees, West Eifel, Germany." Mineralogical Magazine 55, no. 378 (1991): 95–112. http://dx.doi.org/10.1180/minmag.1991.055.378.08.

Full text

Abstract:

AbstractGroup I xenoliths, orthopyroxene-rich and orthopyroxene-free, contain Cr-spinel and clinopyroxene ± phlogopite, and occur together with Group II clinopyroxenites ± Ti-spinel ± phlogopite in K-mafic pyroclastics southeast of Gees. The petrography and clinopyroxene chemistry of orthopyroxene-rich (opx-rich sub-group) Group I xenoliths is consistent with an ‘original’ harzburgitic mantle that has been transformed to lherzolite by the addition of endiopside. In harzburgites, orthopyroxenes are reacting to diopside + olivine + alkali-silicate melt, and, by inference, the orthopyroxene-free

APA, Harvard, Vancouver, ISO, and other styles

3

Panina, L. I., A. T. Isakova, and E. Yu Rokosova. "The Monticellite-Bearing Rocks of the Krestovskaya Intrusion: the Genesis According to Melt Inclusion Study." Петрология 31, no. 1 (2023): 81–100. http://dx.doi.org/10.31857/s0869590323010077.

Full text

Abstract:

The investigation of monticellitolites and olivine-monticellite rocks from the Krestovskaya Intrusion shows that the principal minerals (olivine and monticellite) contain higher amount of MgO than same minerals in olivinites and kugdites of the Intrusion. In the studied rocks olivine contains 90–93 mol. % Fo and monticellite has 41.6–42.3 mol. % Fo whereas in olivinites and kugdites olivine and monticellite contains 86–87 mol. % Fo, and 37.2–41.2 mol. % Fo, respectively. Melt inclusion study in minerals of monticellite rocks evidenced that the monticellite rocks of the Krestovskaya Intrusion w

APA, Harvard, Vancouver, ISO, and other styles

4

Kozieł, T., J. Latuch, and A. Zielińska-Lipiec. "Structure of the Amorphous-Crystalline Fe66Cu6B19Si5Nb4 Alloy Obtained by the Melt-Spinning Process." Archives of Metallurgy and Materials 58, no. 2 (2013): 601–5. http://dx.doi.org/10.2478/amm-2013-0044.

Full text

Abstract:

This paper presents structure investigations of the rapidly cooled Fe66Cu6B19Si5Nb4 alloy. A proper selection of chemical composition enabled in-situ formation of the amorphous-crystalline composite during the melt spinning process. Liquid phase separation into the Fe-rich and the Cu-rich phases was confirmed. The microstructures of alloy, melt-spun from 1723 and 1773 K, are composed of the Fe-rich amorphous matrix and Cu-rich spherical crystalline precipitates. For the higher melt-ejection temperature, no coarse precipitates could be observed. Amorphous nature of the Fe-rich matrix was confir

APA, Harvard, Vancouver, ISO, and other styles

5

Xu, Man, Zhicheng Jing, Suraj K. Bajgain, et al. "High-pressure elastic properties of dolomite melt supporting carbonate-induced melting in deep upper mantle." Proceedings of the National Academy of Sciences 117, no. 31 (2020): 18285–91. http://dx.doi.org/10.1073/pnas.2004347117.

Full text

Abstract:

Deeply subducted carbonates likely cause low-degree melting of the upper mantle and thus play an important role in the deep carbon cycle. However, direct seismic detection of carbonate-induced partial melts in the Earth’s interior is hindered by our poor knowledge on the elastic properties of carbonate melts. Here we report the first experimentally determined sound velocity and density data on dolomite melt up to 5.9 GPa and 2046 K by in-situ ultrasonic and sink-float techniques, respectively, as well as first-principles molecular dynamics simulations of dolomite melt up to 16 GPa and 3000 K.

APA, Harvard, Vancouver, ISO, and other styles

6

HAMADA, MORIHISA, and TOSHITSUGU FUJII. "H2O-rich island arc low-K tholeiite magma inferred from Ca-rich plagioclase-melt inclusion equilibria." GEOCHEMICAL JOURNAL 41, no. 6 (2007): 437–61. http://dx.doi.org/10.2343/geochemj.41.437.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Shen, Xiao, Shuiqing Liu, Xin Wang, et al. "Effect of Cooling Rate on the Microstructure Evolution and Mechanical Properties of Iron-Rich Al–Si Alloy." Materials 15, no. 2 (2022): 411. http://dx.doi.org/10.3390/ma15020411.

Full text

Abstract:

The mechanical properties of iron-rich Al–Si alloy is limited by the existence of plenty of the iron-rich phase (β-Al5FeSi), whose unfavorable morphology not only splits the matrix but also causes both stress concentration and interface mismatch with the Al matrix. The effect of the cooling rate on the tensile properties of Fe-rich Al–Si alloy was studied by the melt spinning method at different rotating speeds. At the traditional casting cooling rate of ~10 K/s, the size of the needle-like β-Al5FeSi phase is about 80 μm. In contrast, the size of the β-Al5FeSi phase is reduced to 500 nm and th

APA, Harvard, Vancouver, ISO, and other styles

8

Nosova, Anna A., Ludmila V. Sazonova, Alexey V. Kargin, Elena O. Dubinina, and Elena A. Minervina. "Mineralogy and Geochemistry of Ocelli in the Damtjernite Dykes and Sills, Chadobets Uplift, Siberian Craton: Evidence of the Fluid–Lamprophyric Magma Interaction." Minerals 11, no. 7 (2021): 724. http://dx.doi.org/10.3390/min11070724.

Full text

Abstract:

The study reports petrography, mineralogy and carbonate geochemistry and stable isotopy of various types of ocelli (silicate-carbonate globules) observed in the lamprophyres from the Chadobets Uplift, southwestern Siberian craton. The Chadobets lamprophyres are related to the REE-bearing Chuktukon carbonatites. On the basis of their morphology, mineralogy and relation with the surrounding groundmass, we distinguish three types of ocelli: carbonate-silicate, containing carbonate, scapolite, sodalite, potassium feldspar, albite, apatite and minor quartz ocelli (K-Na-CSO); carbonate–silicate ocel

APA, Harvard, Vancouver, ISO, and other styles

9

Hurai, V., M. Huraiová, P. Konečný, and R. Thomas. "Mineral-melt-fluid composition of carbonate-bearing cumulate xenoliths in Tertiary alkali basalts of southern Slovakia." Mineralogical Magazine 71, no. 1 (2007): 63–79. http://dx.doi.org/10.1180/minmag.2007.071.1.63.

Full text

Abstract:

AbstractTwo types of carbonatic cumulate xenoliths occur in alkali basalts of the northern part of the Carpatho-Pannonian region, Central Europe. One is dominated by Ca-Fe-Mg carbonates with randomly distributed bisulphide globules (Fe1+xS2, x = 0–0.1), Mg-Al spinel, augite, rhönite, Ni-Co-rich chalcopyrite, and a Fe(Ni,Fe)2S4 phase. The second, carbonatic pyroxenite xenolith type, is composed of diopside, subordinate fluorapatite, interstitial Fe-Mg carbonates, and accessory K-pargasite, F-Al-rich ferroan phlogopite, Mg-Al spinel, albite and K-feldspar. All accessory minerals occur in ultrapo

APA, Harvard, Vancouver, ISO, and other styles

10

Balcone-Boissard, Hélène, Don R. Baker, Benoit Villemant, Jean Cauzid, Georges Boudon, and E. Deloule. "Br diffusion in phonolitic melts: Comparison with fluorine and chlorine diffusion." American Mineralogist 105, no. 11 (2020): 1639–46. http://dx.doi.org/10.2138/am-2020-7372.

Full text

Abstract:

Abstract Bromine diffusion was measured in two natural phonolitic melts: (1) a K2O-rich (~10 wt%) one synthesized from the white pumice phase of the 79 AD eruption of Vesuvius (Italy), and (2) a Na2O-rich (~10 wt%) one corresponding to the most differentiated melt of the 12 000 BC eruption of the Laacher See (Germany). Experiments were performed at 0.5 and 1.0 GPa, 1250 to 1450 °C, at anhydrous and hydrous (2.65 ± 0.35 wt% of dissolved water) conditions. Experiments conducted with the diffusion-couple technique in the piston cylinder were performed with only bromine diffusing and with the simu

APA, Harvard, Vancouver, ISO, and other styles

11

Vapnik, Ye. "Melt inclusions in granitoids of the Timna Igneous Complex, Southern Israel." Mineralogical Magazine 62, no. 1 (1998): 29–40. http://dx.doi.org/10.1180/002646198547440.

Full text

Abstract:

AbstractHigh temperature microthermometry and Scanning Electron Microprobe (SEM) analyses were used to study natural magmatic remnants in quartz crystals in granitoids from the Timna Igneous Complex, southern Israel, and to constrain physicochemical parameters during their crystallization. For the porphyritic granite, alkali granite and quartz monzodiorite, liquidus temperatures are 710–770, 770–830 and 770–840°C, respectively; solidus temperatures are 690–770, 710–790 and 770°C, respectively. Pressures during crystallization and water content in the magmas were determined using the phase diag

APA, Harvard, Vancouver, ISO, and other styles

12

Salvioli-Mariani, E., L. Toscani, and D. Bersani. "Magmatic evolution of the Gaussberg lamproite (Antarctica): volatile content and glass composition." Mineralogical Magazine 68, no. 1 (2004): 83–100. http://dx.doi.org/10.1180/0026461046810173.

Full text

Abstract:

AbstractThe lamproite of Gaussberg is an ultrapotassic rock where leucite, olivine and clinopyroxene microphenocrysts occur in a glass-rich groundmass, containing microliths of leucite, clinopyroxene, apatite, phlogopite and rare K-richterite.Abundant silicate melt inclusions occur in olivine, leucite and, rarely, in clinopyroxene microphenocrysts. Raman investigations on melt inclusions showed the presence of pure CO2 in the shrinkage bubbles. On the other hand, the glass of the groundmass is CO2-poor and contains up to 0.70 wt.% of dissolved H2O, as estimated by infrared spectra. It is infer

APA, Harvard, Vancouver, ISO, and other styles

13

Sokol, A. G., A. V. Korsakov, and A. N. Kruk. "The Formation of K-Cymrite in Subduction Zones and Its Potential for Transport of Potassium, Water, and Nitrogen into the Mantle." Geochemistry International 62, no. 12 (2024): 1322–31. https://doi.org/10.1134/s0016702924700745.

Full text

Abstract:

Abstract The conditions of the formation of K-cymrite in volatile-rich pelite and partially devolatilized mica quartz–muscovite–chlorite schist were experimentally investigated at pressures of 5.5, 6.3, and 7.8 GPa and temperatures ranging from 900 to 1090°C corresponding to hot subduction geotherm. Experimental samples at these P–T conditions formed assemblage of solid phases (Grt + Coe + Phe + Cpx + Ky, with accessory Po + Ru + Zrn ± Mnz) and water-enriched supercritical fluid–melt. Analysis of the obtained data indicates that the stability of phengite and its potential replacement by K-cymr

APA, Harvard, Vancouver, ISO, and other styles

14

SHAW, CLIFF S. J., and ALAN D. EDGAR. "Post-entrainment mineral–melt reactions in spinel peridotite xenoliths from Inver, Donegal, Ireland." Geological Magazine 134, no. 6 (1997): 771–79. http://dx.doi.org/10.1017/s001675689700784x.

Full text

Abstract:

Spinel lherzolite and harzburgite xenoliths hosted in an alkali basalt dyke near Inver, Donegal, Ireland show abundant evidence of interaction between xenolith minerals and the host melt. Of particular interest are primary Cr-diopside and spinel with sieve-textured coronas. Coronas on primary Cr-diopside are up to 3 mm wide and are associated with veinlets of devitrified glass. The coronas comprise secondary Cr-diopside with vermicular, interstitial alkali feldspar and chlorite grains up to 100 µm in size. The inclusion-free Cr-diopside cores are Al- and Na-rich whereas the coronas are Al- and

APA, Harvard, Vancouver, ISO, and other styles

15

Limtrakun, P., Khin Zaw, C. G. Ryan, and T. P. Mernagh. "Formation of the Denchai gem sapphires, northern Thailand: evidence from mineral chemistry and fluid/melt inclusion characteristics." Mineralogical Magazine 65, no. 6 (2001): 725–35. http://dx.doi.org/10.1180/0026461016560004.

Full text

Abstract:

AbstractThe Denchai gem sapphire deposits in Phrae Province, northern Thailand are closely associated with late Cenozoic alkaline basaltic rocks. The sapphires occur in alluvial placer deposits in palaeo-channels at shallow depths. Electron microprobe analysis of minor and trace element contents (Fe, Ti, Cr, Ga and V) of the sapphires indicate the following oxide abundances: Fe2O3 (0.32–1.98 wt.%), TiO2 (0.01–0.23 wt.%), Cr2O3 (<0.01 wt.%), Ga2O3 (0.01–0.03 wt.%) and V2O5 (<0.03 wt.%). Optical studies of sapphires revealed three types of primary fluid/melt inclusions. CO2-rich inclusions

APA, Harvard, Vancouver, ISO, and other styles

16

Morin, David, Réjean Hébert, and Louise Corriveau. "Mesoproterozoic deep K-magmatism recorded in a megacryst- and xenolith-bearing minette dyke, western Grenville Province." Canadian Journal of Earth Sciences 42, no. 10 (2005): 1881–906. http://dx.doi.org/10.1139/e05-083.

Full text

Abstract:

The 1.07 Ga Rivard minette dyke transported thousands of exotic (xenoliths) and cogenetic (cognate nodules) clasts from deep lithospheric levels of the Grenville Province. Nodules related to the clinopyroxene- and biotite-phyric host consist of megacrystic clinopyroxene and K-feldspar and mica-rich pyroxenite. Clinopyroxene megacrysts record high-pressure and high-temperature crystallization, crystal recycling, or magma mixing, whereas Ba-rich K-feldspar megacryst possibly represent near-solidus phenocrysts crystallized from evolved K-rich magmas. Mica-pyroxenite xenoliths are interpreted as p

APA, Harvard, Vancouver, ISO, and other styles

17

Henderson, C. M. B., and W. J. Pierozynski. "An experimental study of Sr, Ba and Rb partitioning between alkali feldspar and silicate liquid in the system nepheline–kalsilite–quartz at 0.1 GPa P(H2O): a revisitation and reassessment." Mineralogical Magazine 76, no. 1 (2012): 157–90. http://dx.doi.org/10.1180/minmag.2012.076.1.157.

Full text

Abstract:

AbstractThe partitioning of Sr, Ba and Rb between alkali feldspar and melt has been determined at 0.1 GPa water vapour pressure, mainly on one Na-rich series and one K-rich series within the system nepheline-kalsilite-quartz. Experiments were also carried out with small amounts of the anorthite molecule or peralkaline components (Na, K metasilicates). The compositions of the alkali feldspars and coexisting quenched glasses were determined by electron microprobe analysis. Except for some peralkaline compositions, the crystal/liquid partition coefficients for Sr and Ba are always >1; the crys

APA, Harvard, Vancouver, ISO, and other styles

18

Ellis, D. J., and M. Obata. "Migmatite and melt segregation at Cooma, New South Wales." Earth and Environmental Science Transactions of the Royal Society of Edinburgh 83, no. 1-2 (1992): 95–106. http://dx.doi.org/10.1017/s0263593300007781.

Full text

Abstract:

ABSTRACTThe Cooma Complex of southeastern New South Wales comprises an andalusite-bearing S-type granodiorite surrounded by migmatites and low-pressure metamorphosed pelitic and psammitic sediments. The migmatite formed by the melting reaction:Biotite + Andalusite + K-feldspar + Quartz + V = Cordierite + Liquidat about 350–400 MPa , 670-730°C.The melanosome consists of biotite + cordierite + andalusite + K-feldspar + plagioclase + quartz + ilmenite, whereas the leucosome consists of cordierite + K-feldspar + quartz with extremely rare biotite and plagioclase. In a closed system, freezing of th

APA, Harvard, Vancouver, ISO, and other styles

19

Guo, Wentao, Zhi Wang, Zengwu Zhao, and Wenfeng Wang. "Research on the melt behavior of rare-earth-rich iron minerals by direct reduction." Metallurgical Research & Technology 117, no. 1 (2020): 118. http://dx.doi.org/10.1051/metal/2020009.

Full text

Abstract:

The evolution of mineral phase structure during the reduction and melting separation of an rare earth (RE)-rich iron mineral (RER-IM) is investigated. The results show the iron oxides are reduced to their metallic iron or FeO at 1373 K. When reduction time is 180 min, the reduction degree is 84%. Both bastnaesite (RE(CO3)F) and monazite (REPO4) are transformed into Ca2RE8(SiO4)6O2 during carbothermic reduction at 1373 K. The mineral with a reduction degree of 84% is melt-separated in a graphite crucible at 1773 K for 20 min, the resulting slag contains 20.64% RE2O3, with RE existing in the for

APA, Harvard, Vancouver, ISO, and other styles

20

Xu, Z., P. D. Han, L. Chang, A. Asthana, and D. A. Payne. "Electron microscopy studies of high Tc phase development in melt-quenched Bi-Ca-Sr-Cu oxides." Journal of Materials Research 5, no. 1 (1990): 39–45. http://dx.doi.org/10.1557/jmr.1990.0039.

Full text

Abstract:

A Bi-Ca-Sr-Cu oxide composition (2:4:2:5) was rapidly solidified from the melt, and the crystallization behavior examined on heat-treatment. Annealing conditions were 865°C for up to 11 days. The high Tc 2223 phase (105 K) evolved from the 2122 phase (80 K), which in turn developed from the 2021 phase (12 K). The high Tc phase developed only in the presence of a liquid phase at 865 °C. Lattice imaging was used to follow the conversion of 2122 phase to 2223. Data are reported for syntactic intergrowths, which became less frequent with time at temperature. EDS results are consistent with the con

APA, Harvard, Vancouver, ISO, and other styles

21

Altenberger, Uwe, Ana-Elena Concha-Perdomo, Daniel Humberto Larrota-Rincón, Christina Günter, and Melanie Lorenz. "Tracing magmatic footprints: Influence of a CO2-rich melt on the mineral assemblage of the San José del Guaviare Syenite, SE Colombia." Andean Geology 51, no. 3 (2024): 425. http://dx.doi.org/10.5027/andgeov51n3-3691.

Full text

Abstract:

A combined optical and electron microscopy (SEM, EDS, and EPMA) study was conducted on ten rock samples from the Proterozoic San José del Guaviare Syenite (SJGS), southeastern Colombia, to utilize minor and trace minerals in interpreting the magmatic evolution of these silica undersaturated rocks. The major minerals of the sampled syenites are nepheline, Fe-rich clinopyroxene, amphibole, alkali feldspar, and biotite. The minor minerals are titanite, calcite, cancrinite, and sodalite. Trace minerals are the niobium- or rare earth element-rich minerals pyrochlore, columbite, euxenite, britholite

APA, Harvard, Vancouver, ISO, and other styles

22

Xu, Man, Zhicheng Jing, James A. Van Orman, Tony Yu, and Yanbin Wang. "Density of NaAlSi2O6 Melt at High Pressure and Temperature Measured by In-Situ X-ray Microtomography." Minerals 10, no. 2 (2020): 161. http://dx.doi.org/10.3390/min10020161.

Full text

Abstract:

In this study, the volumetric compression of jadeite (NaAlSi2O6) melt at high pressures was determined by three-dimensional volume imaging using the synchrotron-based X-ray microtomography technique in a rotation-anvil device. Combined with the sample mass, measured using a high-precision analytical balance prior to the high-pressure experiment, the density of jadeite melt was obtained at high pressures and high temperatures up to 4.8 GPa and 1955 K. The density data were fitted to a third-order Birch-Murnaghan equation of state, resulting in a best-fit isothermal bulk modulus K T 0 of 10.8 −

APA, Harvard, Vancouver, ISO, and other styles

23

Heeb, B., S. Oesch, P. Bohac, and L. J. Gauckler. "Microstructure of melt-processed Bi2Sr2CaCu2Oy and reaction mechanisms during post heat treatment." Journal of Materials Research 7, no. 11 (1992): 2948–55. http://dx.doi.org/10.1557/jmr.1992.2948.

Full text

Abstract:

Phase compositions and microstructures of melt processed 2212 were studied. 2212 starting powder was cooled from temperatures between 910 °C and 1100 °C in air at rates ranging from 350 K/min to 0.083 K/min. The solidification sequence was established for all cooling rates. Under all conditions the Bi-free (Sr, Ca)CuO2 (01x1) is the primary phase. The one-layer solid solution 11905 nucleates on this phase. The residual liquid solidifies to a glassy state, decomposes into the eutectic of Cu2O and Bi2Sr2.1Ca0.9Ox, or reacts with the primary phase and the 11905 forming 2212 at high, intermediate,

APA, Harvard, Vancouver, ISO, and other styles

24

Kolbe, Matthias, J. R. Gao, and S. Reutzel. "Solidification of Co-Cu Alloys in the Metastable Miscibility Gap under Low Gravity Conditions." Materials Science Forum 508 (March 2006): 455–60. http://dx.doi.org/10.4028/www.scientific.net/msf.508.455.

Full text

Abstract:

Liquid Cu-Co shows a metastable miscibility gap where the homogeneous melt separates into the Co-rich L1-liquid and the Cu-rich L2-liquid. The required undercooling of the melt of > 120 K can be achieved by containerless methods as electromagnetic levitation, laser melting or drop tube processing. Due to the large undercooling, rapid solidification of the melt is favoured and preserves microstructure features of the metastable (liquid) phases. In Co-84.0 at% Cu alloy the L1- phase nucleates in the Cu-rich majority phase L2 as a dispersion of spherical droplets. Convective flow in the liquid

APA, Harvard, Vancouver, ISO, and other styles

25

Cherneva, Zlatka, Milena Georgieva, Elena Stancheva, and Ianko Gerdjikov. "High-pressure garnet-bearing migmatites from the Chepelare area, Central Rhodope." Geologica Balcanica 37, no. 1-2 (2008): 47–52. http://dx.doi.org/10.52321/geolbalc.37.1-2.47.

Full text

Abstract:

The association of Ca-rich garnet and Na-rich plagioclase in migmatites is a proper indicator for high-pressure melting. Garnet-bearing leucosome and aplitoid gneiss from the Mechi Chal peak in the Chepelare area of the Central Rhodope comprise a mineral assemblage produced by high-pressure melting: Ca-rich garnet (grossular 22–33 %), Na-rich antiperthitic plagioclase (An15–20), perthitic K-feldspar, quartz, and minor back reaction biotite replacing garnet rims. The approximate conditions of melt crystallization are in the range 1.6–1.9 GPa/800–850°C that is well above the P–T estimates availa

APA, Harvard, Vancouver, ISO, and other styles

26

Zhang, Zhonghua, Xiufang Bian, Yan Wang, and Kuibo Yin. "Microstructure selection map for rapidly solidified Al-rich Al–Sr alloys." International Journal of Materials Research 94, no. 8 (2003): 903–7. http://dx.doi.org/10.1515/ijmr-2003-0161.

Full text

Abstract:

Abstract The effect of rapid solidification on the microstructure of Al-5Sr, Al-10Sr and Al-23Sr (wt.%) alloys has been investigated using X-ray diffraction and transmission electron microscopy. The phases present in the melt-spun Al –Sr alloys are the equilibrium phases a-Al and tetragonal Al4Sr. The microstructure of the melt-spun Al –Sr alloys is quite different from that of the ingot-like alloys. Microstructure selection map is established for the rapidly solidified Al-rich Al –Sr alloys, in light of the microstructure together with the estimated cooling rates. The undercooling obtained th

APA, Harvard, Vancouver, ISO, and other styles

27

Bhattacharya, Abhijit. "Deformation-driven emplacement-differentiation in the Closepet pluton, Dharwar Craton, South India: an alternate view." Geological Society, London, Special Publications 489, no. 1 (2019): 261–74. http://dx.doi.org/10.1144/sp489-2019-315.

Full text

Abstract:

AbstractIn the Late Archean north-trending Closepet pluton, trains of euhedral K-feldspar phenocrysts and matrix-supported idiomorphic K-feldspar crystals in the central part of the pluton define oblique-to-pluton margin steep-dipping east/ENE-trending magmatic fabrics. The magmatic fabric is defined by phenocryst-rich and phenocryst-poor layers, with the euhedral porphyries continuous across the layers. The fabrics are near-orthogonal to the gently-dipping gneissic layers in the host gneisses. The fabrics curve adjacent to locally-developed north/NNE-trending melt-hosted dislocations parallel

APA, Harvard, Vancouver, ISO, and other styles

28

Kreuzer, Lucas P., Fan Yang, Sandro Szabo, Zach Evenson, Andreas Meyer, and Winfried Petry. "Relationship of the atomic dynamics and excess volume of a copper rich Cu76Ti24 alloy melt." High Temperatures-High Pressures 52, no. 2 (2023): 165–73. http://dx.doi.org/10.32908/hthp.v52.1353.

Full text

Abstract:

We investigate the atomic dynamics of a Cu-rich Cu76Ti24 alloy between 1223 K and 1453 K using the quasi-elastic neutron scattering technique. The obtained mean Cu/Ti self-diffusion coefficient D exhibits an Arrhenius-like temperature dependence with an activation energy of 0.46�0.02 eV per atom. Compared with those of the pure elements at a given temperature, D is slower than that for pure Cu, but similar to pure Ti. This slowing down of the liquid dynamics upon alloying has been observed for most binary alloy systems. However, in this study, the packing fraction of the Cu-Ti alloy is lower t

APA, Harvard, Vancouver, ISO, and other styles

29

Álvarez-Valero, Antonio M., John F. Pernet-Fisher, and Leo M. Kriegsman. "Petrologic History of Lunar Phosphates Accounts for the Water Content of the Moon’s Mare Basalts." Geosciences 9, no. 10 (2019): 421. http://dx.doi.org/10.3390/geosciences9100421.

Full text

Abstract:

We present reaction balancing and thermodynamic modeling based on microtextural observations and mineral chemistry, to constrain the history of phosphate crystallization within two lunar mare basalts, 10003 and 14053. Phosphates are typically found within intercumulus melt pockets (mesostasis), representing the final stages of basaltic crystallization. In addition to phosphates, these pockets typically consist of Fe-rich clinopyroxene, fayalite, plagioclase, ilmenite, SiO2, and a residual K-rich glass. Some pockets also display evidence for unmixing into two immiscible melts: A Si-K-rich and a

APA, Harvard, Vancouver, ISO, and other styles

30

Blancher, S. B., P. D'Arco, M. Fonteilles, and M. L. Pascal. "Evolution of nepheline from mafic to highly differentiated members of the alkaline series: the Messum complex, Namibia." Mineralogical Magazine 74, no. 3 (2010): 415–32. http://dx.doi.org/10.1180/minmag.2010.074.3.415.

Full text

Abstract:

AbstractThe change in chemical composition trend of magmatic nepheline through magma evolution has been characterized from the alkaline series of the Messum complex in which nepheline occurs in a succession of different mineral parageneses from mafic-rich (theralites) to strongly evolved felsic-rich rock types (nepheline syenites). The nepheline compositions are dependent on those of coexisting feldspar(s). They record an evolution parallel to that of the melt schematized according to experimental phase diagrams, from initially Ca-rich compositions in equilibrium with calcic plagioclase toward

APA, Harvard, Vancouver, ISO, and other styles

31

Wiafe-Akenteng, Dennis, Vladimir Menushenkov, Igor Shchetinin, and Alexander Savchenko. "Effect of aging on the magnetic properties of rapidly quenched Nd-rich Nd-Fe alloys." EPJ Web of Conferences 185 (2018): 04020. http://dx.doi.org/10.1051/epjconf/201818504020.

Full text

Abstract:

The FexNd100-x (x = 14, 28) alloys were successfully prepared by melt-spinning. Hysteretic and thermomagnetic properties of the as-melt-spun alloys and short-aged ribbons were investigated. Both ribbons exhibit a soft magnetic behavior at room temperature but at 5 K, the coercive force (Hci) proliferated to 8.6 kOe and 11.7 kOe, respectively. Thermomagnetic measurements, Zero Field Cooling (ZFC) and Field Cooling (FC), demonstrated that the rise in magnetization of the ribbons at temperatures lower 34 K is associated with ferromagnetism of fcc Nd-Fe solid solution clusters. Positive effect of

APA, Harvard, Vancouver, ISO, and other styles

32

Foley, Stephen, and Maik Pertermann. "Dynamic Metasomatism Experiments Investigating the Interaction between Migrating Potassic Melt and Garnet Peridotite." Geosciences 11, no. 10 (2021): 432. http://dx.doi.org/10.3390/geosciences11100432.

Full text

Abstract:

Dynamic metasomatism experiments were performed by reacting a lamproite melt with garnet peridotite by drawing melt through the peridotite into a vitreous carbon melt trap, ensuring the flow of melt through the peridotite and facilitating analysis of the melt. Pressure (2–3 GPa) and temperature (1050–1125 °C) conditions were chosen where the lamproite was molten but the peridotite was not. Phlogopite was formed and garnet and orthopyroxene reacted out, resulting in phlogopite wehrlite (2 GPa) and phlogopite harzburgite (3 GPa). Phlogopites in the peridotite have higher Mg/(Mg + Fe) and Cr2O3 a

APA, Harvard, Vancouver, ISO, and other styles

33

Cima, M. J., X. P. Jiang, H. M. Chow, et al. "Influence of growth parameters on the microstructure of directionally solidified Bi2Sr2CaCu2Oy." Journal of Materials Research 5, no. 9 (1990): 1834–49. http://dx.doi.org/10.1557/jmr.1990.1834.

Full text

Abstract:

Laser-heated float zone growth was used to study the directional solidification behavior of Bi–Sr–Ca–Cu–O superconductors. The phases that solidify from the melt, their morphology, and their composition are altered by growth rate. Highly textured microstructures are achieved by directional solidification at all growth rates. The superconducting phase is found always to have the composition Bi2.5Sr2CaCu2.2Oy when grown from boules with composition 2:2:1:2 (BiO1.5:SrO:CaO:CuO). Planar growth fronts of Bi2.5Sr2CaCu2.2Oy are observed when the temperature gradient divided by the growth rate (G/R) i

APA, Harvard, Vancouver, ISO, and other styles

34

Geng, Huiyuan, Jialun Zhang, Tianhong He, Lixia Zhang, and Jicai Feng. "Microstructure Evolution and Mechanical Properties of Melt Spun Skutterudite-based Thermoelectric Materials." Materials 13, no. 4 (2020): 984. http://dx.doi.org/10.3390/ma13040984.

Full text

Abstract:

The rapid solidification of melt spinning has been widely used in the fabrication of high-performance skutterudite thermoelectric materials. However, the microstructure formation mechanism of the spun ribbon and its effects on the mechanical properties are still unclear. Here, we report the microstructure evolution and mechanical properties of La–Fe–Co–Sb skutterudite alloys fabricated by both long-term annealing and melt-spinning, followed by sintering approaches. It was found that the skutterudite phase nucleated directly from the under-cooled melt and grew into submicron dendrites during th

APA, Harvard, Vancouver, ISO, and other styles

35

Mikhailenko, Denis, Alexander Golovin, Andrey Korsakov, Sonja Aulbach, Axel Gerdes, and Alexey Ragozin. "Metasomatic Evolution of Coesite-Bearing Diamondiferous Eclogite from the Udachnaya Kimberlite." Minerals 10, no. 4 (2020): 383. http://dx.doi.org/10.3390/min10040383.

Full text

Abstract:

A coesite-bearing diamondiferous eclogite from the Udachnaya kimberlite (Daldyn field, Siberian craton) has been studied to trace its complex evolution recorded in rock-forming and minor mineral constituents. The eclogite sample is composed of rock-forming omphacite (60 vol%), garnet (35 vol%) and quartz/coesite (5 vol%) and contains intergranular euhedral zoned olivine crystals, up to 200 µm long, coexisting with phlogopite, orthopyroxene, clinopyroxene (secondary), K-feldspar, plagioclase, spinel, sodalite and djerfisherite. Garnet grains are zoned, with a relatively homogeneous core and a m

APA, Harvard, Vancouver, ISO, and other styles

36

Golovin, Alexander V., Alexey A. Tarasov, and Elena V. Agasheva. "Mineral Assemblage of Olivine-Hosted Melt Inclusions in a Mantle Xenolith from the V. Grib Kimberlite Pipe: Direct Evidence for the Presence of an Alkali-Rich Carbonate Melt in the Mantle Beneath the Baltic Super-Craton." Minerals 13, no. 5 (2023): 645. http://dx.doi.org/10.3390/min13050645.

Full text

Abstract:

This report deals with the first mineralogical examination of secondary crystallized melt inclusions (CMIs) in healed cracks within olivine in a mantle peridotite xenolith from the V. Grib kimberlite pipe (Arkhangelsk diamondiferous province). In contrast to micro/nano-inclusions in diamonds, the studied CMIs are quite large (up to 50 µm), so that the mineral composition of the CMIs can be determined via conventional analytical approaches, e.g., Raman spectroscopy and scanning electron microscopy. Garnet peridotite is a coarse-grained mantle rock that equilibrates at 3.3 GPa and 750 °C (corres

APA, Harvard, Vancouver, ISO, and other styles

37

Urrutia-Fucugauchi, Jaime, Ligia Pérez-Cruz, Rafael Venegas-Ferrer, and Pablo Sánchez-Solis. "The Chicxulub crater drilling program – continuous coring, well logging and core analyses reviewed." Geologica Acta 23 (February 20, 2025): 1–21. https://doi.org/10.1344/geologicaacta2025.23.3.

Full text

Abstract:

Continuous core recovery, core scanning and logging are used for borehole characterization and petrophysical analyses in the Chicxulub drilling projects. The crater formed by an asteroid impact on the Yucatan platform ~66Ma ago, marking the Cretaceous/Paleogene (K/Pg) boundary. The K/Pg boundary clay layer, characterized by the Ir and platinum group element anomaly, has been studied worldwide. The crater has a ~200km rim diameter and is covered by up to ~1km of carbonate sediments, with studies based on geophysical surveys, drilling and ejecta deposits. The Yaxcopoil-1 borehole, drilled in the

APA, Harvard, Vancouver, ISO, and other styles

38

GROSSE, PABLO, ALEJANDRO J. TOSELLI, and JUANA N. ROSSI. "Petrology and geochemistry of the orbicular granitoid of Sierra de Velasco (NW Argentina) and implications for the origin of orbicular rocks." Geological Magazine 147, no. 3 (2009): 451–68. http://dx.doi.org/10.1017/s0016756809990707.

Full text

Abstract:

AbstractThe Velasco orbicular granitoid is a small (65 × 15 m), irregularly-shaped body that crops out within the Huaco granite, central Sierra de Velasco, NW Argentina. It consists of ellipsoid-shaped orbicules of 3 to 15 cm length immersed in an aplitic to pegmatitic matrix. The orbicules are formed by a core made up of a K-feldspar megacryst, partially to totally replaced by plagioclase, an inner shell of radial and equant plagioclase crystals, a layer of tangentially oriented biotite laths, and an outer shell of plumose plagioclase crystals, containing diffuse rings of tangentially oriente

APA, Harvard, Vancouver, ISO, and other styles

39

Rosatelli, G., F. Wall, and M. J. Le Bas. "Potassic glass and calcite carbonatite in lapilli from extrusive carbonatites at Rangwa Caldera Complex, Kenya." Mineralogical Magazine 67, no. 5 (2003): 931–55. http://dx.doi.org/10.1180/0026461036750152.

Full text

Abstract:

AbstractThe ∽16 Ma Rangwa Caldera Complex, part of the large Kisingiri nephelinite-carbonatite volcano, Homa Bay District, western Kenya (0º34’S; 34º09’E) contains carbonatitic lapilli and ash tuffs, agglomerate and tuffisite, and a number of intrusive calcite carbonatites. A detailed petrographic and electron microprobe study has been performed on 20 fresh samples from the collection at The Natural History Museum, London.Most of the juvenile lapilli and ash particles are either predominantly composed of devitrified silicate glass (now biotite/phlogopite but probably also originally potassic s

APA, Harvard, Vancouver, ISO, and other styles

40

Kozlov, Evgeniy, Ekaterina Fomina, Mikhail Sidorov, et al. "The Petyayan-Vara Carbonatite-Hosted Rare Earth Deposit (Vuoriyarvi, NW Russia): Mineralogy and Geochemistry." Minerals 10, no. 1 (2020): 73. http://dx.doi.org/10.3390/min10010073.

Full text

Abstract:

The Vuoriyarvi Devonian carbonatite–ijolite–pyroxenite–olivinite complex comprises several carbonatite fields: Neske Vara, Tukhta-Vara, and Petyayan-Vara. The most common carbonatites in the Tukhta-Vara and Neske-Vara fields are calciocarbonatites, which host several P, Fe, Nb, and Ta deposits. This paper focuses on the Petyayan-Vara field, in which the primary magmatic carbonatites are magnesian. The least altered magnesiocarbonatites are composed of dolomite with burbankite and are rich in REE (up to 2.0 wt. %), Sr (up to 1.2 wt. %), and Ba (up to 0.8 wt. %). These carbonatites underwent sev

APA, Harvard, Vancouver, ISO, and other styles

41

Johannes, Wilhelm, and François Holtz. "Melting of plagioclase in granite and related systems: composition of coexisting phases and kinetic observations." Earth and Environmental Science Transactions of the Royal Society of Edinburgh 83, no. 1-2 (1992): 417–22. http://dx.doi.org/10.1017/s0263593300008087.

Full text

Abstract:

ABSTRACTMelting experiments with plagioclases were performed in the systems Ab-An, Ab-An-H2O, Qz-Ab-An-H2O, and Qz-Or-Ab-An-H2O-CO2. The experimental products were analysed by electron microprobe, and the kinetics of the reactions were studied qualitatively.Melting of the plagioclase in the system Ab-An (P = 1 atm, T = 1420°C) is very fast in the first minutes but becomes slower with increasing run duration and is incomplete even after 1000 hours. The Ab/An fractionation between melt and residual plagioclase is similar to that described by Bowen (1913).Melting kinetics of plagioclase in the sy

APA, Harvard, Vancouver, ISO, and other styles

42

Tornos, Fernando, Francisco Velasco, and John M. Hanchar. "The Magmatic to Magmatic-Hydrothermal Evolution of the El Laco Deposit (Chile) and Its Implications for the Genesis of Magnetite-Apatite Deposits." Economic Geology 112, no. 7 (2017): 1595–628. http://dx.doi.org/10.5382/econgeo.2017.4523.

Full text

Abstract:

Abstract The geology and geochemistry of the El Laco iron oxide deposit (Central Andes, Chile) support a genesis related to the ascent, degassing, and subvolcanic emplacement of an unusual oxidized silica-poor but water-and iron-rich melt that took place during the growth of the host Pliocene-Holocene andesitic volcano. The model proposed in this paper for the evolution of the deposit involves the formation of a shallow telescoped magmatichydrothermal system with complex melt-fluid unmixing in a vertical column of less than 1 km. The dominant mineralization occurs as large stratabound apatite-

APA, Harvard, Vancouver, ISO, and other styles

43

Grima-Gallardo, P., A. Velásquez, G.E. Delgado, and E. Pérez-C. "Synthesis, X-Ray Diffraction, Scanning Electron Microscopy, Differential Thermal Analysis and Magnetic Susceptibility of the alloy (CuAlSe$_2$)$_{1-x}$(TaSe)$_x$ with $x=0.5$." Ciencia en Revolución 7, no. 21 (2021): 37–45. https://doi.org/10.5281/zenodo.5721457.

Full text

Abstract:

Polycrystalline samples of the alloy (CuAlSe$_2$)$_{1-x}$(TaSe)$_x$ with $x=0.5$ were prepared by the melt and anneal method and characterized by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Differential Thermal Analysis (DTA), and Magnetic Susceptibility (MS) techniques. It was found that this alloy is composed of two main phases, one poor and another rich in Ta, and traces of TaSe$_2$. The sample shows a weak ferromagnetic behavior with \hbox{$T_c > 300$ K}, a characteristic that can be useful for room-temperature ferromagnetic devices.

APA, Harvard, Vancouver, ISO, and other styles

44

Suzuki, Ryoji, Yuta Watanabe, Hisanori Yamane, Mamoru Kitaura, Kento Uchida, and Yuta Matsushima. "Crystal structure of silver carbonate iodide Ag10(CO3)3I4." Acta Crystallographica Section E Crystallographic Communications 77, no. 7 (2021): 734–38. http://dx.doi.org/10.1107/s2056989021006022.

Full text

Abstract:

The title silver carbonate iodide, Ag10(CO3)3I4, decasilver(I) tris(carbonate) tetraiodide, was recently reported as a precursor of the new superionic conductor Ag17(CO3)3I11. Ag10(CO3)3I4, was prepared by heating a stoichiometric powder mixture of AgI and Ag2CO3 at 430 K. A single-crystal suitable for X-ray diffraction analysis was obtained by slow cooling of a melt with an AgI-rich composition down from 453 K. Ag10(CO3)3I4 exhibits a layered crystal structure packed along [10\overline{1}], in which Ag atoms are intercalated between the layers of hexagonally close-packed I atoms, and CO3 grou

APA, Harvard, Vancouver, ISO, and other styles

45

Dolníček, Zdeněk, Michal Kovář, and Jana Ulmanová. "Axinit a doprovodné minerály z lokality Jezuitský rybník východně od Golčova Jeníkova (moldanubikum, Česká republika)." Bulletin Mineralogie Petrologie 28, no. 2 (2020): 437–53. http://dx.doi.org/10.46861/bmp.28.437.

Full text

Abstract:

A new occurrence of axinite at the locality Jezuitský rybník near Sirákovice (ENE from Golčův Jeníkov), situated in rocks of the Variegated (Drosendorf) Series (Moldanubian Zone of the Bohemian Massif), is a nice example of contaminated pegmatite in a Ca-skarn with intense superimposed hydrothermal overprint. Axinite [axinite-(Fe) to axinite-(Mg)] forms young hydrothermal infill of pocket/fissure in pegmatite cutting a brecciated Ca-skarn. The hydrothermal assemblage includes amphibole II (actinolite to ferro-actinolite), albite, K-feldspar II, chlorite, epidote (locally containing 0.20 - 0.30

APA, Harvard, Vancouver, ISO, and other styles

46

Gilg, H. A., B. Weber, J. Kasbohm, and R. Frei. "Isotope geochemistry and origin of illite-smectite and kaolinite from the Seilitz and Kemmlitz kaolin deposits, Saxony, Germany." Clay Minerals 38, no. 1 (2003): 95–112. http://dx.doi.org/10.1180/0009855033810081.

Full text

Abstract:

AbstractResidual clays that developed on Permian and Carboniferous glass-rich silicic volcanic rocks (pitchstones, ignimbrites) at the Seilitz and Kemmlitz kaolin deposits, Saxony, Eastern Germany, contain locally abundant lath-shaped illite-rich illite-smectite mixed-layer minerals (I-S). Analyses by XRD and TEM-AES reveal a large illite percentage (>∼90%) and R3 ordering in I-S from Seilitz (>∼90%) and smaller illite percentage (∼70%) and R1 ordering in I-S from Kemmlitz. The clays never suffered a deep burial and there is no geological, petrographic or fluid inclusion evidence for aeo

APA, Harvard, Vancouver, ISO, and other styles

47

Gulick, Sean P. S., Timothy J. Bralower, Jens Ormö, et al. "The first day of the Cenozoic." Proceedings of the National Academy of Sciences 116, no. 39 (2019): 19342–51. http://dx.doi.org/10.1073/pnas.1909479116.

Full text

Abstract:

Highly expanded Cretaceous–Paleogene (K-Pg) boundary section from the Chicxulub peak ring, recovered by International Ocean Discovery Program (IODP)–International Continental Scientific Drilling Program (ICDP) Expedition 364, provides an unprecedented window into the immediate aftermath of the impact. Site M0077 includes ∼130 m of impact melt rock and suevite deposited the first day of the Cenozoic covered by <1 m of micrite-rich carbonate deposited over subsequent weeks to years. We present an interpreted series of events based on analyses of these drill cores. Within minutes of the impact

APA, Harvard, Vancouver, ISO, and other styles

48

Bulanova, G. P., W. L. Griffin, and C. G. Ryan. "Nucleation environment of diamonds from Yakutian kimberlites." Mineralogical Magazine 62, no. 3 (1998): 409–19. http://dx.doi.org/10.1180/002646198547675.

Full text

Abstract:

AbstractThe micro-inclusions located in the genetic centre of Yakutian diamond monocrystals have been studied using optical (anomalous birefringence, photoluminescence, cathodoluminescence) and microanalytical (electron-microprobe, proton-microprobe, scanning electron microscope) methods. Most diamonds nucleated heterogeneously on mineral seeds, that lowered the energy barrier to nucleation. Nucleation of peridotitic diamonds occurred on a matrix of graphite+iron+wüstite, in an environment dominated by forsteritic olivine and Fe-Ni sulfide. Nucleation of eclogitic diamonds occurred on a matrix

APA, Harvard, Vancouver, ISO, and other styles

49

Handini, Esti, Toshiaki Hasenaka, Nicholas D. Barber, Tomoyuki Shibata, Yasushi Mori, and I. Wayan Warmada. "Geochemistry of shield stage basalts from Baluran volcano, East Java, Sunda arc." Journal of Applied Geology 7, no. 2 (2022): 64. http://dx.doi.org/10.22146/jag.73697.

Full text

Abstract:

We report petrography and geochemistry of basaltic lava flows from the shield stage of Baluran, a Quaternary volcanic center in the rear of East Java, Sunda Arc, Indonesia. These basalts contain abundant plagioclase, clinopyroxene, olivine, and minor magnetite. Geochemically, they resemble other medium-K calc alkaline basalts from eastern Java’s volcanoes, but they are less enriched in light ion lithophile elements (LILE) and Pb. The predicted primary basalt of Baluran lavas can be sourced to a more primitive primary melt composition which may also generate medium-K calc-alkaline magmas in the

APA, Harvard, Vancouver, ISO, and other styles

50

Arefiev, Anton V., Anton Shatskiy, Altyna Bekhtenova та Konstantin D. Litasov. "Quench Products of K-Cа-Mg Carbonate Melt at 3 and 6 GPa: Implications for Carbonatite Inclusions in Mantle Minerals". Minerals 12, № 9 (2022): 1077. http://dx.doi.org/10.3390/min12091077.

Full text

Abstract:

Alkali-rich carbonate melts are found as inclusions in magmatic minerals, mantle xenoliths, and diamonds from kimberlites and lamproites worldwide. However, the depth of their origin and bulk melt composition remains unclear. Here, we studied quench products of K-Cа-Mg carbonate melt at 3 and 6 GPa. The following carbonates were detected at 3 GPa: K2CO3, K2Cа(CO3)2 bütschliite (R32/m), o-K2Cа3(CO3)4 (P212121), K2Cа2(CO3)3 (R3), K2Mg(CO3)2 (R3m), Mg-bearing calcite, dolomite, and magnesite. At 6 GPa, the variety of quench carbonate phases includes K2CO3, K2Cа(CO3)2 bütschliite (R32/m), d-K2Cа3(

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!