scholarly journals Columbite U-Pb Geochronology of Kalu’an Lithium Pegmatites in Northern Xinjiang, China: Implications for Genesis and Emplacement History of Rare-Element Pegmatites

Minerals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 456 ◽  
Author(s):  
Yonggang Feng ◽  
Ting Liang ◽  
Ze Zhang ◽  
Yiqian Wang ◽  
Yi Zhou ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Rare Metal ◽  
Oscillatory Zoning ◽  
Granitic Magma ◽  
Rare Element ◽  
Inductively Coupled ◽  
Electron Probe Micro Analyzer ◽  
Sector Zoning ◽  
Icp Ms ◽  
History Of

The Kalu’an-Azubai pegmatite field, one of the most important rare-metal metallogenic regions in China, contains a large number of pegmatite dikes belonging to spodumene and lepidolite subtypes. Columbite-group minerals (CGMs) collected from three spodumene subtype pegmatites (No. 802, No. 803, and No. 805 pegmatites) were analyzed for major element contents using EPMA (electron probe micro-analyzer) and dated using LA-ICP-MS (laser ablation-inductively coupled plasma mass spectrometer). The crystallization ages of the CGMs from No. 802, No. 803, and No. 805 pegmatites are 209.5 ± 1.4 Ma (2σ), 198.3 ± 2.0 Ma (2σ), and 224.3 ± 2.9 Ma (2σ), respectively. Oscillatory zoning and/or sector zoning along with the associated mineral assemblages suggest that the dated columbite is of magmatic origin. The crystallization ages of the columbite grains thus represent the emplacement ages of the Li pegmatites. Therefore, our dating results indicate that there were three emplacement events of the Li-rich pegmatite-forming melts in a timeframe of ~30 Ma. In combination with previous studies, we conclude that the Li pegmatites were formed before the Be-Ta-Nb pegmatites (~194–192 Ma), which precludes the genesis of rare-metal pegmatites via fractional crystallization of a granitic magma in the Kalu’an-Azubai region.

scholarly journals The emplacement age of the Muntele Mare Variscan granite (Apuseni Mountains, Romania)

2009 ◽  
Vol 60 (6) ◽  
pp. 495-504 ◽  
Author(s):  
Ioan Balintoni ◽  
Constantin Balica ◽  
Monica Cliveţi ◽  
Li-Qiu Li ◽  
Horst Hann ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Variscan Orogeny ◽  
Weighted Mean ◽  
Apuseni Mountains ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Plasma Mass Spectrometry ◽  
History Of ◽  
The Alps ◽  
Last Stage

The emplacement age of the Muntele Mare Variscan granite (Apuseni Mountains, Romania)Like the Alps and Western Carpathians, the Apuseni Mountains represent a fragment of the Variscan orogen involved in the Alpine crustal shortenings. Thus the more extensive Alpine tectonic unit in the Apuseni Mountains, the Bihor Autochthonous Unit is overlain by several nappe systems. During the Variscan orogeny, the Bihor Unit was a part of the Someş terrane involved as the upper plate in subduction, continental collision and finally in the orogen collapse and exhumation. The Variscan thermotectonic events were marked in the future Bihor Unit by the large Muntele Mare granitoid intrusion, an S-type anatectic body. Zircon U-Pb laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) dating yielded a weighted mean age of 290.9 ± 3.0 Ma and a concordia age of 291.1 ± 1.1 Ma. U-Pb isotope dilution zircon analyses yielded a lower intercept crystallization age of 296.6 + 5.7/-6.2 Ma. These two ages coincide in the error limits. Thus, the Muntele Mare granitoid pluton is a sign of the last stage in the Variscan history of the Apuseni Mountains. Many zircon grains show inheritance and/or Pb loss, typical for anatectic granitoid, overprinted by later thermotectonic events.

Lithogeochemical characteristics of metasandstones of the Chetlas series (Chetlassky Kamen, Middle Timan)

2021 ◽  
pp. 3-12
Author(s):  
N. Y. Nikulova ◽  
◽  
O. V. Udoratina ◽  
I. V. Kozyreva
Keyword(s):  
Inductively Coupled Plasma ◽  
Volcanic Rocks ◽  
Rare Metal ◽  
Weathering Crust ◽  
Terrigenous Material ◽  
Inductively Coupled ◽  
Coastal Marine ◽  
Icp Ms ◽  
Middle Timan ◽  
Destruction Of Rocks

The lithological and geochemical features of the metasandstones of the Svetlinskaya and Vizingskaya formations of the Middle Late Riphean Chetlas series in the Middle Timan, which are a substrate of rare-metal-rare-earth mineralization in several ore occurrences of the Kosyus ore cluster, have been investigated. The interpretation of the results of traditional weight chemical and mass spectrometric inductively coupled plasma (ICP MS) analyses allowed us to identify differences in the material composition of metapesanics, mainly due to changes in the degree of sedimentation maturity of terrigenous material coming from the demolition areas. The composition of metasandstones in various ratios includes both weakly weathered products of destruction of volcanic rocks of intermediate/basic composition, and altered, including under conditions of the weathering crust, metaterrigenous formations. The accumulation of sediments took place in a shallow coastal-marine environment with changing hydrodynamics, which affected the rate of destruction of rocks in paleo-catchments.

Petrogenetic significance of LA-ICP-MS trace-element data on quartz from the Borborema Pegmatite Province, northeast Brazil

2011 ◽  
Vol 75 (5) ◽  
pp. 2703-2719 ◽  
Author(s):  
H. Beurlen ◽  
A. Müller ◽  
D. Silva ◽  
M. R. R. Da Silva
Keyword(s):  
Inductively Coupled Plasma ◽  
Border Zone ◽  
Northeast Brazil ◽  
Rare Element ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Coupled Substitution ◽  
Plasma Mass Spectrometry ◽  
Magma Fractionation ◽  
Quartz Core

AbstractQuartz from different zones within five granitic pegmatites of the rare-element class from the Borborema Pegmatite Province in northeast Brazil were analysed for fourteen trace elements using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The concentrations of Li (6—150 ppm), B (1—9 ppm) and Ge (1—23 ppm) in quartz show a positive correlation with Al (30—770 ppm). The concentrations of these elements increase from the border zone to the quartz core of pegmatites of the spodumene or lepidolite subtypes. The Ge concentrations in the quartz core are the highest so far reported in igneous quartz. In the less evolved pegmatites of the beryl-columbite subtype, the Al, Li, B, and Ge concentrations in quartz from all zones remain at the same level as the border and wall zones. The Ti concentrations in quartz from the core of the more evolved pegmatites are below 3 ppm (with Al >250 ppm), contrasting with 7—25 ppm (with Al <280 ppm) in samples from the border and wall zones of the less evolved and more evolved pegmatites. The concentrations of Al. Li, B, Ge, and Ti in quartz are therefore confirmed as good indicators of the degree of magma fractionation and analyses of pegmatite quartz cores can be used for exploration purposes to distinguish pegmatites with high metallogenic potential. Atoms of Li and Al are incorporated into quartz such that Li/Al ranges between 0.75 and 1.0. This suggests a coupled substitution of the form Si4+ ↔ (Li+ + Al3+). The other elements analysed either showed an erratic distribution (e.g. Be and P) or were below the respective limits of detection (Na, K, Rb, Ca, Sr, Mn, Fe) in most samples.

Lithium and trace-element concentrations in trioctahedral micas from granites of different geochemical types measured via laser ablation ICP-MS

2017 ◽  
Vol 81 (1) ◽  
pp. 15-33 ◽  
Author(s):  
Karel Breiter ◽  
Michaela Vaňková ◽  
Michaela Vašinová Galiová ◽  
Zuzana Korbelová ◽  
Viktor Kanický
Keyword(s):  
Laser Ablation ◽  
Inductively Coupled Plasma ◽  
Rare Metal ◽  
Major Elements ◽  
Massif Central ◽  
Inductively Coupled ◽  
Exchange Vector ◽  
Icp Ms ◽  
Parent Rocks ◽  
Plasma Mass Spectrometry

AbstractThe compositions of trioctahedral micas from 51 samples of granitoids with different geochemical affiliations and grades of differentiation from the Bohemian Massif, Central Europe, were analysed using electron microprobe (major elements) and laser ablation inductively coupled plasma mass spectrometry (Li, Sc, Ga, Ge, Nb, In, Sn, Cs, Ta, W, Tl). The micas form a continuous evolutionary series from phlogopite to zinnwaldite. The phlogopites and biotites from the I-type rocks are characterized by 5.5–5.7 Si, 2.4–2.6 Al, <0.1 Li atoms per formula unit [apfu] and Mg/(Mg + Fe) = 0.4–0.8. The biotites from the S-type granites usually contain 5.3–5.7 Si, 3.2–3.6 Al, 0.1–0.3 Li apfu and Mg/(Mg + Fe) = 0.15–0.4. The annites and zinnwaldites from the rare-metal granites contain 5.7–6.8 Si, 3.2–3.8 Al, 0.6–2.6 Li apfu and Mg/(Mg + Fe) < 0.1. The concentrations of F, Rb, Cs and Tl increase from the phlogopites and biotites to zinnwaldites: F 0.1 → 8 wt.%, Rb2O 0.05 → 1.7 wt.%, Tl 2 → 50 ppm and Cs 40 → 2000 ppm. The concentrations of Sn, Nb, Ta and W in phlogopites and biotites from the I- and S-type granitoids generally correlate with those of the parent rocks and reach values of (in ppm) 20–100 Sn, 20–250 Nb, 1–20 Ta and <5 W. The highest concentrations were found in the Li-annites in the relatively early facies of rare-metal granites (in ppm): 250–600 Sn, 400–600 Nb, 60–120 Ta and 50– 120 W. The zinnwaldites in the late rare-metal granites facies are impoverished in these elements, which is explained by contemporaneous crystallization of cassiterite and columbite. Lithium enters the crystal lattice of trioctahedral micas via the exchange vector Li3□Si3Fe–6Al–1up to concentrations of ∼2.5 wt.% Li2O (1.5 apfu Li). At higher Li concentrations, Li is incorporated through the exchange vector Li3Si1□–1Fe–2Al–1.

scholarly journals Pre-Alpine thermal history recorded in the continental crust from Alpine Corsica (France): evidence from zircon and allanite LA-ICP-MS dating

2020 ◽  
Vol 113 (1) ◽  
Author(s):  
Maria Di Rosa ◽  
Federico Farina ◽  
Pierre Lanari ◽  
Michele Marroni
Keyword(s):  
Inductively Coupled Plasma ◽  
Middle Eocene ◽  
Late Triassic ◽  
Field Observations ◽  
Early Permian ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Plasma Mass Spectrometry ◽  
History Of ◽  
Alpine Metamorphism

AbstractThe pre-Alpine history of the Venaco-Ghisoni Unit, a continental unit belonging to the Alpine Corsica (France), was reconstructed on the basis of U–Pb dating of zircon and allanite. Zircon was separated from a metagranitoid and an epidote-bearing metagabbro and analyzed by Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS). Magmatic ages ranging from 291 to 265 Ma were obtained for the metagranitoid samples and 276.9 ± 1.1 Ma for the epidote-bearing metagabbro. This geochronological dataset, combined with field observations, microstructural and cathodoluminescence analysis demonstrate that in the Early Permian, the Variscan basement of the Venaco-Ghisoni Unit was intruded first by the granitoid and then by the gabbro. Allanite was identified in the metagranitoid and exhibit an U–Pb age of 225 ± 8 Ma. We interpret this age as reflecting metamorphism associated to the Late Triassic rifting predating the opening of the Piemonte-Liguria Ocean. The absence of middle Eocene—Oligocene zircon and allanite overgrowths is compatible with the low metamorphic conditions (< 350–400 °C) recorded by the Venaco-Ghisoni Unit during Alpine metamorphism.

Tracing the life history of individual barramundi using laser ablation MC-ICP-MS Sr-isotopic and Sr/Ba ratios in otoliths

2005 ◽  
Vol 56 (5) ◽  
pp. 637 ◽  
Author(s):  
Malcolm McCulloch ◽  
Mike Cappo ◽  
James Aumend ◽  
Wolfgang Müller
Keyword(s):  
Life History ◽  
Laser Ablation ◽  
Inductively Coupled Plasma ◽  
Inductively Coupled ◽  
Elemental Abundances ◽  
Isotopic Compositions ◽  
Marine Habitats ◽  
Icp Ms ◽  
Plasma Mass Spectrometry ◽  
History Of

Otoliths preserve a continuous geochemical record of its life history, from the earliest natal stage through to adulthood. Using in situ laser ablation (UV) multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) measurements of Sr isotopic compositions together with elemental abundances (Ca, Sr, Ba and Mg), we show how it is possible to characterise the various types of habitats encountered throughout the lifecycle history of individual barramundi. Unlike trace element concentrations, which can be modulated by physiological processes, Sr isotopic compositions of otoliths provide a direct fingerprint of the water mass in which the fish lived. Elemental abundances, in particular Sr/Ba ratios are, however, shown to be especially sensitive to transitional environments, such as estuaries. The flexibility of the barramundi’s life history is confirmed by the present study, with the existence of both marine and freshwater nurseries, with some individuals spending their entire life cycle in fresh water, some entirely in marine and others moving between freshwater estuarine and marine habitats.

scholarly journals Episodic Precipitation of Wolframite during An Orogen: The Echassières District, Variscan Belt of France

Minerals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 923 ◽  
Author(s):  
Loïs Monnier ◽  
Jérémie Melleton ◽  
Olivier Vanderhaeghe ◽  
Stefano Salvi ◽  
Philippe Lach ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Time Lag ◽  
Rare Metal ◽  
Crustal Thickening ◽  
Variscan Belt ◽  
Massif Central ◽  
Magmatic Arc ◽  
Inductively Coupled ◽  
History Of ◽  
Middle Carboniferous

Monazite and rutile occurring in hydrothermally altered W mineralizations, in the Echassières district of the French Massif Central (FMC), were dated by U-Pb isotopic systematics using in-situ Laser ablation-inductively coupled plasma–quadrupole mass spectrometry (LA-ICP-MS). The resulting dates record superimposed evidence for multiple percolation of mineralizing fluids in the same area. Cross-referencing these ages with cross-cutting relationships and published geochronological data reveals a long history of more than 50 Ma of W mineralization in the district. These data, integrated in the context of the Variscan belt evolution and compared to other major W provinces in the world, point to an original geodynamic-metallogenic scenario. The formation, probably during the Devonian, of a quartz-vein stockwork (1st generation of wolframite, called wolframite “a”; >360 Ma) of porphyry magmatic arc affinity is analogous to the Sn-W belts of the Andes and the Nanling range in China. This stockwork was affected by Barrovian metamorphism, induced by tectonic accretion and crustal thickening, during the middle Carboniferous (360 to 350 Ma). Intrusion of a concealed post-collisional peraluminous Visean granite, at 333 Ma, was closely followed by precipitation of a second generation of wolframite (termed “b”), from greisen fluids in the stockwork and host schist. This W-fertile magmatic episode has been widely recorded in the Variscan belt of central Europe, e.g. in the Erzgebirge, but with a time lag of 10–15 Ma. During orogenic collapse, a third magmatic episode was characterized by the intrusion of numerous rare-metal granites (RMG), which crystallized at ~310 Ma in the FMC and in Iberia. One of these, the Beauvoir granite in the Echassières district, led to the formation of the wolframite “c” generation during greisen alteration.

scholarly journals Early Paleozoic zircon ages of the Higher Himalayan Gneisses of the Everest region and their Pan-African/Proto-Himalayan orogenic signature

2019 ◽  
Vol 59 ◽  
pp. 107-124 ◽  
Author(s):  
Masaru Yoshida ◽  
George E. Gehrels ◽  
Bishal N. Upreti ◽  
Santa M. Rai
Keyword(s):  
Inductively Coupled Plasma ◽  
Inductively Coupled ◽  
Pan African ◽  
Icp Ms ◽  
University Of Arizona ◽  
Plasma Mass Spectrometry ◽  
History Of ◽  
High Grade Metamorphism ◽  
Almost All ◽  
The University

The U-Pb analysis of zircons from two independent leucosome bodies belonging to the paragneiss of the Higher Himalayan Crystallines Sequence (HHCS) in the Everest region of eastern Nepal Himalaya was carried out using laser ablation-multi collector inductively coupled plasma-mass spectrometry (LA-MC-ICP-MS) at the University of Arizona, Tucson, USA. The analysis of zircons from sample 07EVT3 forms a discordia with upper and lower intercepts at 478±25 and 21.5±4.1 Ma with concordant ages of 488.5±9.2 and 20.9±0.9 Ma for cores and rims, respectively. Similarly, the analysis of zircons from sample U1206 forms a discordia with upper and lower intercepts at 515±20 and 34.8±2.7 Ma, and provides concordant ages of 463.9±10.9 and 24.6±0.6 Ma for cores and rims, respectively. No inherited zircon grains with older ages were found indicating that almost all these zircons must have formed along with the leucotomies during the ca. 500 Ma metamorphism of the protoliths. The high U/Th ratio, i.e. average 11.0 for zircons from sample 07EVT3 and 253.6 for sample U1206 also support a metamorphic origin of the zircons. The occurrences of zircons in the ca. 500Ma leucosomes in the HHCS strongly points that rocks in the Himalayan area had undergone to a high-grade metamorphism during the late Pan-African time. We call this metamorphism as the Proto himalayan metamorphism. More studies along this line will help to better understand and constrain the Pan-African orogenic history of the Proto-Himalayan Orogen within the Peri-Gondwana Orogenicterrains.

scholarly journals The origin and chronology of medieval silver coins based on the analysis of chemical composition

Nukleonika ◽  
2015 ◽  
Vol 60 (3) ◽  
pp. 657-663 ◽  
Author(s):  
Ewa Pańczyk ◽  
Bożena Sartowska ◽  
Lech Waliś ◽  
Jakub Dudek ◽  
Władysław Weker ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Inductively Coupled Plasma ◽  
Energy Dispersive ◽  
Inhomogeneous Surface ◽  
Variable Environment ◽  
X Ray ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Plasma Mass Spectrometry ◽  
History Of

Abstract Medieval Central Europe coins - the Saxon coins, also called as the Otto and Adelheid denarii, as well as the Polish ones, the Władysław Herman and Bolesław Śmiały coins - were examined to determine their provenance and dating. Their attribution and chronology often constitute a serious problem for historians and numismatists. For hundreds of years, coins were in uncontrolled conditions and in variable environment. Destructed and inhomogeneous surface were the effect of corrosion processes. Electron microscopy with energy dispersive X-ray analysis (scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS)), X-ray fluorescence (XRF) analysis (energy dispersive X-ray fluorescence (EDXRF) and total reflection X-ray fluorescence (TXRF)), and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) were applied. The results of these investigations are significant for our knowledge of the history of Central European coinage, especially of Polish coinage

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