Timing of magmatic-hydrothermal activity in the Variscan Orogenic Belt: LA-ICP-MS U–Pb geochronology of skarn-related garnet from the Schwarzenberg District, Erzgebirge

AbstractHere, we present in situ U–Pb laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) ages of andradite-grossular garnet from four magmatic-hydrothermal polymetallic skarn prospects in the Schwarzenberg District, Erzgebirge (Germany), located in the internal zone of the Variscan Orogenic Belt. Within the geochronological framework of igneous rocks and hydrothermal mineralization in the Erzgebirge, the obtained garnet ages define three distinct episodes of Variscan skarn formation: (I) early late-collisional mineralization (338–331 Ma) recording the onset of magmatic-hydrothermal fluid flow shortly after the peak metamorphic event, (II) late-collisional mineralization (~ 327–310 Ma) related to the emplacement of large peraluminous granites following large-scale extension caused by orogenic collapse and (III) post-collisional mineralization (~ 310–295 Ma) contemporaneous with widespread volcanism associated with Permian crustal reorganization. Our results demonstrate that the formation of skarns in the Schwarzenberg District occurred episodically in all sub-stages of the Variscan orogenic cycle over a time range of at least 40 Ma. This observation is consistent with the age range of available geochronological data related to magmatic-hydrothermal ore deposits from other internal zones of the Variscan Orogenic Belt in central and western Europe. In analogy to the time–space relationship of major porphyry-Cu belts in South America, the congruent magmatic-hydrothermal evolution in the internal zones and the distinctly later (by ~ 30 Ma) occurrence of magmatic-hydrothermal ore deposits in the external zones of the Variscan Orogenic Belt may be interpreted as a function of their tectonic position relative to the Variscan collisional front.

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Antimony and Nickel Impurities in Blue and Green Copper Pigments

Minerals ◽

10.3390/min11111236 ◽

2021 ◽

Vol 11 (11) ◽

pp. 1236

Author(s):

Sylwia Svorová Pawełkowicz ◽

Barbara Wagner ◽

Jakub Kotowski ◽

Grażyna Zofia Żukowska ◽

Bożena Gołębiowska ◽

...

Keyword(s):

Inductively Coupled Plasma ◽

Ore Deposits ◽

Copper Ore ◽

Inductively Coupled ◽

Parish Church ◽

Icp Ms ◽

Plasma Mass Spectrometry ◽

Quantitative Analyses ◽

First Time

Impurities in paint layers executed with green and blue copper pigments, although relatively common, have been studied only little to date. Yet, their proper identification is a powerful tool for classification of paintings, and, potentially, for future provenance studies. In this paper, we present analyses of copper pigments layers from wall paintings situated in the vicinity of copper ore deposits (the palace in Kielce, the palace in Ciechanowice, and the parish church in Chotków) located within the contemporary borders of Poland. We compare the results with the analyses of copper minerals from three deposits, two local, and one historically important for the supply of copper in Europe, i.e., Miedzianka in the Holy Cross Mountains, Miedzianka in the Sudetes, and, as a reference, Špania Dolina in the Slovakian Low Tatra. Optical (OM) and electron microscopy (SEM-EDS), Raman spectroscopy, and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) have been used for a detailed investigation of the minute grains. Special attention has been devoted to antimony and nickel phases, as more unusual than the commonly described iron oxides. Analyses of minerals from the deposits helped to interpret the results obtained from the paint samples. For the first time, quantitative analyses of copper pigments’ impurities have been described.

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The Giant Chalukou Porphyry Mo Deposit, Northeast China: The Product of a Short-Lived, High Flux Mineralizing Event

Economic Geology ◽

10.5382/econgeo.4818 ◽

2021 ◽

Author(s):

Qingqing Zhao ◽

Degao Zhai ◽

Ryan Mathur ◽

Jiajun Liu ◽

David Selby ◽

...

Keyword(s):

High Precision ◽

Inductively Coupled Plasma ◽

Hydrothermal Activity ◽

Ore Deposits ◽

Ionization Mass ◽

Inductively Coupled ◽

Fine Grained ◽

Porphyry Cu ◽

Icp Ms ◽

Porphyry Mo Deposit

Abstract Whether giant porphyry ore deposits are the products of single, short-lived magmatic-hydrothermal events or multiple events over a prolonged interval is a topic of considerable debate. Previous studies, however, have all been devoted to porphyry Cu and Cu-Mo deposits. In this paper, we report high-precision isotope dilution-negative-thermal ionization mass spectrometric (ID-N-TIMS) molybdenite Re-Os ages for the newly discovered, world-class Chalukou porphyry Mo deposit (reserves of 2.46 Mt @ 0.087 wt % Mo) in NE China. Samples were selected based on a careful evaluation of the relative timing of the different vein types (i.e., A, B, and D veins), thereby ensuring that the suite of samples analyzed could be used to reliably determine the age and duration of mineralization. The molybdenite Re-Os geochronology reveals that hydrothermal activity at Chalukou involved two magmatic-hydrothermal events spanning an interval of 6.92 ± 0.16 m.y. The first event (153.96 ± 0.08/0.63/0.79 Ma, molybdenite ID-N-TIMS Re-Os age) was associated with the emplacement of a granite porphyry dated at 152.1 ± 2.2 Ma (zircon laser ablation-inductively coupled plasma-microscopic [LA-ICP-MS] U-Pb ages), and led to only minor Mo mineralization, accounting for <10% of the overall Mo budget. The bulk of the Mo (>90%) was deposited in less than 650 kyr, between 147.67 ± 0.10/0.60/0.76 and 147.04 ± 0.12/0.72/0.86 Ma (molybdenite ID-N-TIMS Re-Os ages), coincident with the emplacement of a fine-grained porphyry at 148.1 ± 2.6 Ma (zircon LA-ICP-MS U-Pb ages). The high-precision Re-Os age determinations presented here show, contrary to the finding of a number of studies of porphyry Cu and Cu-Mo systems, that the giant Chalukou porphyry Mo deposit primarily formed in a single, short-lived (<650 kyr) hydrothermal event, suggesting that this may also have been the case for other giant porphyry Mo deposits.

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Development and Application of Nanoparticle-Nanopolymer Composite Spheres for the Study of Environmental Processes

Frontiers in Toxicology ◽

10.3389/ftox.2021.752296 ◽

2021 ◽

Vol 3 ◽

Author(s):

Robert J. Rauschendorfer ◽

Kyle M. Whitham ◽

Star Summer ◽

Samantha A. Patrick ◽

Aliandra E. Pierce ◽

...

Keyword(s):

Inductively Coupled Plasma ◽

Large Scale ◽

Analytical Techniques ◽

Inductively Coupled ◽

The Past ◽

Icp Ms ◽

Sensitivity And Selectivity ◽

Plasma Mass Spectrometry ◽

Wide Scale ◽

Synthetic Copolymer

Plastics have long been an environmental contaminant of concern as both large-scale plastic debris and as micro- and nano-plastics with demonstrated wide-scale ubiquity. Research in the past decade has focused on the potential toxicological risks posed by microplastics, as well as their unique fate and transport brought on by their colloidal nature. These efforts have been slowed by the lack of analytical techniques with sufficient sensitivity and selectivity to adequately detect and characterize these contaminants in environmental and biological matrices. To improve analytical analyses, microplastic tracers are developed with recognizable isotopic, metallic, or fluorescent signatures capable of being identified amidst a complex background. Here we describe the synthesis, characterization, and application of a novel synthetic copolymer nanoplastic based on polystyrene (PS) and poly(2-vinylpyridine) (P2VP) intercalated with gold, platinum or palladium nanoparticles that can be capped with different polymeric shells meant to mimic the intended microplastic. In this work, particles with PS and polymethylmethacrylate (PMMA) shells are used to examine the behavior of microplastic particles in estuarine sediment and coastal waters. The micro- and nanoplastic tracers, with sizes between 300 and 500 nm in diameter, were characterized using multiple physical, chemical, and colloidal analysis techniques. The metallic signatures of the tracers allow for quantification by both bulk and single-particle inductively-coupled plasma mass spectrometry (ICP-MS and spICP-MS, respectively). As a demonstration of environmental applicability, the tracers were equilibrated with sediment collected from Bellingham Bay, WA, United States to determine the degree to which microplastics bind and sink in an estuary based of grain size and organic carbon parameters. In these experiments, between 80 and 95% of particles were found to associate with the sediment, demonstrative of estuaries being a major anticipated sink for these contaminants. These materials show considerable promise in their versatility, potential for multiplexing, and utility in studying micro- and nano-plastic transport in real-world environments.

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Trace Elements in Magnetite from the Pagoni Rachi Porphyry Prospect, NE Greece: Implications for Ore Genesis and Exploration

Minerals ◽

10.3390/min9120725 ◽

2019 ◽

Vol 9 (12) ◽

pp. 725 ◽

Cited By ~ 4

Author(s):

Constantinos Mavrogonatos ◽

Panagiotis Voudouris ◽

Jasper Berndt ◽

Stephan Klemme ◽

Federica Zaccarini ◽

...

Keyword(s):

Trace Elements ◽

Laser Ablation ◽

Trace Element ◽

Inductively Coupled Plasma ◽

Ore Deposits ◽

Hydrothermal Conditions ◽

Northern Greece ◽

Icp Ms ◽

Accessory Phase ◽

Granodiorite Porphyry

Magnetite is a common accessory phase in various types of ore deposits. Its trace element content has proven to have critical implications regarding petrogenesis and as guides in the exploration for ore deposits in general. In this study we use LA-ICP-MS (laser ablation-inductively coupled plasma-mass spectrometry) analyses of trace elements to chemically characterize magnetite from the Pagoni Rachi Cu–Mo–Re–Au porphyry-style prospect, Thrace, northern Greece. Igneous magnetite mostly occurs as euhedral grains, which are commonly replaced by hematite in fresh to propylitic-altered granodiorite porphyry, whereas, hydrothermal magnetite forms narrow veinlets or is disseminated in sodic/potassic-calcic altered (albite + K-feldspar + actinolite + biotite + chlorite) granodiorite porphyry. Magnetite is commonly associated with chalcopyrite and pyrite and locally exhibits martitization. Laser ablation ICP-MS analyses of hydrothermal magnetite yielded elevated concentrations in several trace elements (e.g., V, Pb, W, Mo, Ta, Zn, Cu, and Nb) whereas Ti, Cr, Ni, and Sn display higher concentration in its magmatic counterpart. A noteworthy enrichment in Mo, Pb, and Zn is an unusual feature of hydrothermal magnetite from Pagoni Rachi. High Si, Al, and Ca values in a few analyses of hydrothermal magnetite imply the presence of submicroscopic or nano-inclusions (e.g., chlorite, and titanite). The trace element patterns of the hydrothermal magnetite and especially the decrease in its Ti content reflect an evolution from the magmatic towards the hydrothermal conditions under decreasing temperatures, which is consistent with findings from analogous porphyry-style deposits elsewhere.

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Development of a laser ablation ICP-MS method for the analysis of fluid inclusions associated with volcanogenic massive sulfide deposits

Geochemistry Exploration Environment Analysis ◽

10.1144/geochem2020-043 ◽

2021 ◽

pp. geochem2020-043

Author(s):

Madison A. Schmidt ◽

Matthew I. Leybourne ◽

Jan M. Peter ◽

Duane C. Petts ◽

Simon E. Jackson ◽

...

Keyword(s):

Laser Ablation ◽

Fluid Inclusions ◽

Inductively Coupled Plasma ◽

Massive Sulfide ◽

Ore Deposits ◽

Volcanogenic Massive Sulfide ◽

Metals And Metalloids ◽

Inductively Coupled ◽

Icp Ms ◽

Vms Deposits

There is increasing acceptance of the presence of variable magmatic contributions to the mineralizing fluids in the formation of volcanogenic massive sulfide (VMS) deposits. The world-class Windy Craggy Cu-Co-Au deposit (>300 MT @ 2.12 wt.% Cu) in northwestern British Columbia is of interest because, unlike most VMS deposits, quarts fluid inclusions from within the deposit range from relatively low to intermediate salinity (most 6-16 wt.% equivalent). In this study we used an excimer (193 nm) laser ablation system interfaced to a quadrupole inductively coupled plasma mass spectrometer to quantify key metals and metalloids that are considered by many to be indicative of magmatic contributions to hydrothermal ore deposits. Although LA-ICP-MS signals from these low-salinity inclusions are highly transient, we were able to quantify Na, Mg, K, Ca, Mn, Fe, Co, Cu, Zn, Sr, Sn, Ba, Ce, Pb and Bi consistently – of the 34 elements that were monitored. Furthermore, Cl, Sb, Cd, Mo, Rb, Br, and As were also measured in a significant number of inclusions. Comparison of the fluid inclusion chemistry with unaltered and altered mafic volcanic and sedimentary rocks and mineralized samples from the deposit indicate that enrichment in the main ore metals (Cu, Zn, Fe, Pb) in the inclusions reflects that of the altered rocks and sulfides. Metals and metalloids that may indicate a magmatic contribution typically show much greater enrichments in the fluid inclusions much greater over the host rocks at the same Cu concentration; in particular Bi, Sn and Sb are significantly elevated when compared to the host rock samples. These data are consistent with the ore-forming fluids at Windy Craggy having a strong magmatic contribution.

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Isotopic composition and geochemical features of ores of Dzhusa pyrite-polymetallic deposit (South Urals)

Moscow University Bulletin. Series 4. Geology ◽

10.33623/0579-9406-2019-4-78-83 ◽

2019 ◽

pp. 78-83

Author(s):

E. I. Yartsev ◽

I. V. Vikentyev ◽

N. I. Eremin

Keyword(s):

Isotopic Composition ◽

Inductively Coupled Plasma ◽

Sulfur Isotopes ◽

Ore Deposits ◽

South Urals ◽

Sulfur Isotopic Composition ◽

Inductively Coupled ◽

Icp Ms ◽

Highly Sensitive ◽

First Time

The sulfur isotopic composition was studied for the main morphological types and generation of sulfides composing the ore of the Dzhusinsky deposit, and the content of trace elements was analyzed using the highly sensitive method of mass spectrometry with inductively coupled plasma and laser sampling (LA-ICP-MS). Both types of studies were performed for ore deposits for the first time. According to the geochemistry of sulfur isotopes, its deep magmatic source was reconstructed, which made a predominant contribution to the ore-forming fluid. Using the modules of the STATISTICA, correlations were calculated and the patterns of distribution of micro impurities in sulfide minerals were revealed.

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Tracing metal sources for the giant McArthur River Zn-Pb deposit (Australia) using lead isotopes

Geology ◽

10.1130/g47001.1 ◽

2020 ◽

Vol 48 (5) ◽

pp. 478-482 ◽

Cited By ~ 1

Author(s):

Joséphine Gigon ◽

Etienne Deloule ◽

Julien Mercadier ◽

David L. Huston ◽

Antonin Richard ◽

...

Keyword(s):

Large Scale ◽

Secondary Ion Mass Spectrometry ◽

Lead Isotopes ◽

Hydrothermal Systems ◽

Ore Deposits ◽

Source Rocks ◽

Metal Sources ◽

First Time ◽

Hydrothermal Ore Deposits ◽

Secondary Ion

Abstract Giant hydrothermal ore deposits form where fluids carrying massive amounts of metals scavenged from source rocks or magmas encounter conditions favorable for their localized deposition. However, in most cases, the ultimate origin of metals remains highly disputed. Here, we show for the first time that two metal sources have provided, in comparable amounts, the 8 Mt of lead of the giant McArthur River zinc-lead deposit (McArthur Basin, Northern Territory, Australia). By using high-resolution secondary ion mass spectrometry (SIMS) analysis of lead isotopes in galena, we demonstrate that the two metal sources were repeatedly involved in the metal deposition in the different ore lenses ca. 1640 Ma. Modeling of lead isotope fractionation between mantle and crustal reservoirs implicates felsic rocks of the crystalline basement and the derived sedimentary rocks in the basin as the main lead sources that were leached by the ore-forming fluids. This sheds light on the crucial importance of metal tracing as a prerequisite to constrain large-scale ore-forming systems, and calls for a paradigm shift in the way hydrothermal systems form giant ore deposits: leaching of metals from several sources may be key in accounting for their huge metal tonnage.

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The Role of Continental Crust in the Formation of Uraninite-Based Ore Deposits

Minerals ◽

10.3390/min10020136 ◽

2020 ◽

Vol 10 (2) ◽

pp. 136 ◽

Cited By ~ 2

Author(s):

Stefanie R. Lewis ◽

Antonio Simonetti ◽

Loretta Corcoran ◽

Stefanie S. Simonetti ◽

Corinne Dorais ◽

...

Keyword(s):

Trace Element ◽

Inductively Coupled Plasma ◽

Ore Deposits ◽

Source Attribution ◽

Rock Composition ◽

Isotopic Signatures ◽

Element Abundances ◽

Inductively Coupled ◽

Spatially Resolved ◽

Icp Ms

This study reports trace element abundances and Pb, Sr, and U isotopic signatures of uraninite from a variety of ore deposits in order to establish baseline forensic information for source attribution of raw, natural U-rich samples. Trace element concentrations, reported here, provide insights into uraninite crystal substitution mechanisms and possible crustal sources of U, including mobility of trace elements between pristine versus altered fractions. Spatially resolved laser ablation (LA) multicollector (MC) inductively coupled plasma mass spectrometry (ICP-MS) analyses were used to determine secondary 207Pb-206Pb isochron ages, and these were validated by corroborative results obtained by solution mode (SM) MC-ICP-MS for the same sample. Secondary Pb-Pb isochron ages obtained, in this study, indicate that uraninite alteration occurs shortly after ore mineralization. Initial 87Sr/86Sr values correlate in general with host craton age, and therefore suggest that uraninite ore formation is closely linked to the nature of the bedrock geology. The δ238U values are explained by invoking multiple physicochemical conditions and parameters such as temperature, nuclear field shift, oxidation, and source rock composition. The δ234U values indicate that the uraninites, investigated here, have undergone recent alteration, but the latter has not perturbed the Pb-Pb secondary isochron ages.

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Apatite U-Pb dating at UNAM laboratories: analytical protocols and examples of its application

Revista Mexicana de Ciencias Geológicas ◽

10.22201/cgeo.20072902e.2019.1.749 ◽

2019 ◽

Vol 36 (1) ◽

pp. 27-37 ◽

Cited By ~ 1

Author(s):

Carlos Ortega-Obregón ◽

Fanis Abdullin ◽

Luigi Solari ◽

Peter Schaaf ◽

Gabriela Solís-Pichardo

Keyword(s):

Mass Spectrometry ◽

Inductively Coupled Plasma ◽

Ore Deposits ◽

Ionization Mass ◽

Medium Temperature ◽

Rock Samples ◽

Inductively Coupled ◽

Advantages And Disadvantages ◽

Icp Ms ◽

Analytical Protocols

Apatite is the most common phosphate mineral in the Earth’s crust and can be found in practically all magmatic and metamorphic rocks, as well as in ancient and recent sediments and in certain ore deposits. Its effective closure temperature of 450–550 °C for the U-Pb system makes apatite an important natural medium-temperature thermochronometer that can be dated by both laser ablation inductively coupled plasma mass spectrometry (LA–ICP-MS) and isotope dilution thermal ionization mass spectrometry (ID–TIMS) techniques. Due to its low U content, coupled with high Pb contents incorporated during crystallization (also called common lead), apatite U-Pb dating is analytically challenging, and requires robust analytical protocols to achieve reliable ages. In this experimental study we obtained apatite U-Pb ages from six rock samples employing LA–ICP-MS (at Laboratorio de Estudios Isotópicos, Centro de Geociencias, UNAM), while one sample was also dated by ID–TIMS (at Laboratorio Universitario de Geoquímica Isotópica, UNAM). These samples have igneous emplacement or metamorphic ages broadly ranging from the Neoproterozoic to the Paleocene. The obtained apatite U-Pb ages agree well with other radioisotopic data (U-Pb on zircon and K-Ar or Ar-Ar on micas and hornblende) available for the same rock samples tested, or for the same geological units studied. These apatite U-Pb results, obtained for the first time at two main Mexican geochronology laboratories, are precise enough to be geologically meaningful and usually represent the cooling ages; though, in some cases they may also indicate the crystallization or the metamorphic age. Some advantages and disadvantages of LA–ICP-MS- and ID–TIMS-based methodologies were observed and outlined. Our results validate the analytical procedures used and will serve as an important trigger towards the development or improvement of medium-temperature thermochronology techniques in Mexico.

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Stable lead isotope characteristics of lead ore deposits of environmental significance

Environmental Reviews ◽

10.1139/a00-008 ◽

2000 ◽

Vol 8 (2) ◽

pp. 115-147 ◽

Cited By ~ 143

Author(s):

D F Sangster ◽

P M Outridge ◽

W J Davis

Keyword(s):

Inductively Coupled Plasma ◽

Environmental Science ◽

Ore Deposits ◽

Pb Isotopes ◽

Discrimination Power ◽

Source Discrimination ◽

Icp Ms ◽

Unequivocal Identification ◽

Isotopic Characterization ◽

Industrial Sources

Stable Pb isotopes are increasingly used in environmental science as tracers of natural and anthropogenic Pb sources. This review provides a summary of the recent geological literature concerning Pb isotopes in global Pb ore deposits. The isotopic characteristics of 151 Pb deposits, including 78 20th-century producing mines, have been summarized using the 204Pb-based ratios common to geological science and the 206Pb- and 207Pb-based ratios (i.e., excluding 204Pb) more often employed in environmental studies. A number of current mines, including those exploiting several Australian, Scandinavian, and U.S.A. deposits, have extreme isotopic compositions that provide unique signatures. However, a majority of mines (and unproductive deposits) fall within a relatively narrow range:206Pb/207Pb of 1.15-1.22 and 208Pb/207Pb of 2.42-2.50. In some contexts, unequivocal identification of a source exhibiting one of these common signatures would be difficult, especially with the relatively low precision (ca. 0.2-0.5% RSD) of quadrupole inductively coupled plasma - mass spectrometry (ICP-MS) which has been the most common instrument for environmental Pb isotope measurements. In settings with disparate industrial and natural Pb signatures (i.e., sources withisotopic ratios differing by about 2% or more), ICP-MS precision is adequate for source discrimination. Statistical analyses suggested that while 204Pb is critical for identifying a small proportion of environmental Pb sources, about 86% of the source discrimination power is due to the 206Pb, 207Pb, and 208Pb isotopes. Thus, the requisite analytical precision, rather than a lack of 204Pb data, is the most critical issue with respect to unequivocal identification of Pb sources in most cases. Several factors, especially the increasing dominance of recycling in global Pb production and the international transportation of ore concentrate and refined Pb, may cause unpredictable changes in the isotopic signatures of industrial sources,with a long-term trend towards homogenization. More frequent,comprehensive, and high-precision isotopic characterization of possible point and non-point Pb emitters such as gasoline, smelters, and battery-recycling plants, together with increased efforts to document the origin of constituent leads in industrial sources, would help to address these concerns.Key words: lead isotopes; lead pollution; source identification; lead ore deposits.

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