scholarly journals A Study of Cathodoluminescence and Trace Element Compositional Zoning in Natural Quartz from Volcanic Rocks: Mapping Titanium Content in Quartz

2012 ◽  
Vol 18 (6) ◽  
pp. 1322-1341 ◽  
Author(s):  
William P. Leeman ◽  
Colin M. MacRae ◽  
Nick C. Wilson ◽  
Aaron Torpy ◽  
Cin-Ty A. Lee ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Volcanic Rocks ◽  
Quantitative Information ◽  
Titanium Content ◽  
Natural Quartz ◽  
Compositional Zoning ◽  
Quartz Crystals ◽  
Element Abundances ◽  
Inductively Coupled ◽  
Plasma Mass Spectrometry

AbstractThis article concerns application of cathodoluminescence (CL) spectroscopy to volcanic quartz and its utility in assessing variation in trace quantities of Ti within individual crystals. CL spectroscopy provides useful details of intragrain compositional variability and structure but generally limited quantitative information on element abundances. Microbeam analysis can provide such information but is time-consuming and costly, particularly if large numbers of analyses are required. To maximize advantages of both approaches, natural and synthetic quartz crystals were studied using high-resolution hyperspectral CL imaging (1.2–5.0 eV range) combined with analysis via laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS). Spectral intensities can be deconvolved into three principal contributions (1.93, 2.19, and 2.72 eV), for which intensity of the latter peak was found to correlate directly with Ti concentration. Quantitative maps of Ti variation can be produced by calibration of the CL spectral data against relatively few analytical points. Such maps provide useful information concerning intragrain zoning or heterogeneity of Ti contents with the sensitivity of LA-ICPMS analysis and spatial resolution of electron microprobe analysis.

scholarly journals Feathery and network-like filamentous textures as indicators for the re-crystallization of quartz from a metastable silica precursor at the Rusey Fault Zone, Cornwall, UK

Solid Earth ◽  
2016 ◽  
Vol 7 (6) ◽  
pp. 1509-1519 ◽  
Author(s):  
Tim I. Yilmaz ◽  
Florian Duschl ◽  
Danilo Di Genova
Keyword(s):  
Fault Zone ◽  
Inductively Coupled Plasma ◽  
Quartz Crystals ◽  
Inductively Coupled ◽  
Hydrothermal Quartz ◽  
Violet Luminescence ◽  
Icp Ms ◽  
Plasma Mass Spectrometry ◽  
Silica Precursor ◽  
Weak Peak

Abstract. Hydrothermal quartz crystals, which occur in the Rusey Fault Zone (Cornwall, UK), show feathery textures and network-like filamentous textures. Optical hot-cathodoluminescence (CL) analysis and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) investigations on quartz samples revealed that positions exhibiting feathery textures (violet luminescence) contain higher amounts of Al and Li than quartz positions without feathery textures (blue luminescence), while concentrations of Al and Li are significantly lower in feathery textures. Both Al and Li correlate negatively with Si. Raman spectroscopy investigations revealed the presence of a weak peak at 507–509 cm−1 in quartz affected by feathery textures, which we attribute to the presence of  ≤  5 % moganite, a microcrystalline silica polymorph, intergrown with chalcedony. The combined occurrence of feathery textures and network-like filamentous textures in quartz samples from the Rusey Fault Zone points to the presence of a metastable silica precursor (i.e., amorphous silica or silica gel) before or during the crystallization.

Distribution of gallium between phenocrysts and melt in peralkaline salic volcanic rocks, Kenya Rift Valley

2010 ◽  
Vol 74 (2) ◽  
pp. 351-363 ◽  
Author(s):  
R. Macdonald ◽  
N. W. Rogers ◽  
B. Bagiński ◽  
P. Dzierżanowski
Keyword(s):  
Rift Valley ◽  
Inductively Coupled Plasma ◽  
Magma Mixing ◽  
Volcanic Rocks ◽  
Alkali Feldspar ◽  
Volcanic Complex ◽  
Kenya Rift ◽  
Inductively Coupled ◽  
Plasma Mass Spectrometry ◽  
Kenya Rift Valley

AbstractGallium abundances, determined by laser ablation-inductively coupled plasma-mass spectrometry, are presented for phenocrysts and glassy matrices from a metaluminous trachyte and five peralkaline rhyolites from the Greater Olkaria Volcanic Complex, Kenya Rift Valley. Abundances in the glasses range from 28.9 to 33.3 ppm, comparable with peralkaline rhyolites elsewhere. Phenocryst Ga abundances (in ppm) are: sanidine 31.5–45.3; fayalite 0.02–0.22; hedenbergite 3.3–6.3; amphibole 12; biotite 72; ilmenite 0.56–0.72; titanomagnetite 32; chevkinite-(Ce) 364. The mafic phases and chevkinite-(Ce) are enriched in Ga relative to Al, whereas Ga/Al ratios in sanidine are smaller than in coexisting glass. Apparent partition coefficients range from <0.01 in fayalite to 12 in chevkinite-(Ce). Coefficients for hedenbergite, ilmenite and titanomagnetite decrease as melts become peralkaline. The sharp increase in Ga/Al in the more fractionated members of alkaline magmatic suites probably results from alkali feldspar-dominated fractionation. Case studies are presented to show that the Ga/Al ratio may be a sensitive indicator of such petrogenetic processes as magma mixing, interaction of melts with F-rich volatile phases, mineral accumulation and volatile-induced crustal anatexis.

scholarly journals Hydrogeochemistry and lead contamination of groundwater in the north part of Esfahan province, Iran

2018 ◽  
Vol 16 (4) ◽  
pp. 622-634 ◽  
Author(s):  
Kaveh Pazand ◽  
Davoud Khosravi ◽  
Mohammad Reza Ghaderi ◽  
Mohammad Reza Rezvanianzadeh
Keyword(s):  
Inductively Coupled Plasma ◽  
Arid Regions ◽  
Volcanic Rocks ◽  
Primary Source ◽  
Lead Contamination ◽  
Inductively Coupled ◽  
The North ◽  
Icp Ms ◽  
North Part ◽  
Plasma Mass Spectrometry

Abstract Geochemical and hydrogeochemical studies were conducted to assess the origin and geochemical mechanisms driving lead enrichment in groundwaters of semi-arid regions in Central Iran. In this study, 149 water samples were analyzed using inductively coupled plasma mass spectrometry (ICP-MS). Concentrations of Pb and As in about 68% and 27% of the samples, respectively, exceeded WHO guidelines. Analyzing the results of ICP-MS of parental rocks and aquifer sediments shows that unweathered volcanic rocks were the primary source for lead mobilizing to groundwaters.

scholarly journals Geoquímica de lantánidos de los yacimientos de fluorita de los distritos mineros de Taxco y Zacualpan, sur de México: implicaciones sobre el origen y la evolución de los fluidos

2017 ◽  
Vol 34 (3) ◽  
pp. 199 ◽  
Author(s):  
Teresa Pi ◽  
Jesús Solé ◽  
Ofelia Morton-Bermea ◽  
Yuri Taran ◽  
Elizabeth Hernández-Álvarez
Keyword(s):  
Inductively Coupled Plasma ◽  
Early Stage ◽  
Volcanic Rocks ◽  
Wall Rock ◽  
Mining District ◽  
Strontium Content ◽  
Inductively Coupled ◽  
Eu Anomaly ◽  
Plasma Mass Spectrometry ◽  
Ree Patterns

We present and evaluate lanthanide contents measured by inductively coupled plasma mass spectrometry (ICP-MS) in fluorite samples from the fluorite deposits in Zacualpan and Taxco mining districts in the south of Mexico. The information is used to distinguish different generations of fluorite, to establish a correlation between mineralization episodes and the wall rock nature, and to identify postdepositional processes.The total lanthanide content of the fluorites are variable, and early- stage fluorite samples are usually enriched in LREE. The concentration of REE in fluorite is low in comparison with the volcanic and metamorphic rocks (∑REE > 100 ppm) and is generally high respect the carbonates (∑REE < 30 ppm). There is host rock influence. The higher REE concentra- tions are in fluorites hosted by volcanic rocks. The fluorite that replaced carbonate is characterized by low REE to very low concentrations. Fluorite samples associated with sulfurs are typically enriched in HREE. Nearly all fluorites show a negative Eu anomaly similar to the REE anomaly observed in the volcanic rock. Only some early stage dark, uranium rich fluorites, from la Azul deposit, have a strong positive Eu anomaly. Direct correlation between color and REE patterns is observed in some samples.In the Zacualpan mining district, only an episode of mineralization has been discriminated, where fluorite presents flat to HREE- enriched chondrite-normalized REE patterns.In the Taxco mining district and particularly in the “Mina la Azul”, multiple hydrothermal events of mineralization have been determined. The first generation of fluorite is formed by replacement of carbonates and is characterized by very low contents of lanthanides, chondrite- normalized REE patterns similar to the limestone, high strontium content and primary textures (e.g. massive fluorite and rhythmites). The second generation of fluorite is related to the entry of new fluid to the system and has higher REE concentrations, chondrite-normalized REE patterns similar to volcanic rocks, low strontium content and secondary textures (i.e. breccias, nodules). Most of the samples show a genetic relationship between fluorite and fluids of magmatic origin.

scholarly journals Early Paleozoic Adakitic Granitoids from the Xingshuping Gold Deposit of East Qinling, China: Petrogenesis and Tectonic Significance

Minerals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1032
Author(s):  
Pei Zan ◽  
Shouyu Chen ◽  
Jinduo Chen ◽  
Shengli Li
Keyword(s):  
Gold Deposit ◽  
Inductively Coupled Plasma ◽  
Volcanic Rocks ◽  
Major And Trace Elements ◽  
Biotite Granite ◽  
Early Paleozoic ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Monzonitic Granite ◽  
Plasma Mass Spectrometry

This study discussed the pertrological classification, geochronology, petrogenesis and tectonic evolution of early Paleozoic granites from the Xingshuping gold deposit in the East Qinling orogenic belt. In order to achieve this target, we carried out an integrated study of zircon U–Pb age, whole-rock major and trace elements, as well as Sr–Nd–Hf isotope compositions for the Xingshuping granites (part of the Wuduoshan pluton) from the Erlangping unit. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) zircon U–Pb dating constrains the emplacement age of the Xingshuping granites at 446.2 ± 1.2 Ma. The rocks at Xingshuping can be divided into two types: mainly biotite granite and monzonitic granite. The biotite granites are typical adakitic rocks, while the monzonitic granites show characteristics similar to normal arc volcanic rocks. The geochemical compositions reveal that they were derived from a clay-rich, plagioclase-rich and biotite-rich psammitic lower continental crust source, with contributions of mantle-derived magmas. The distinction is that the biotite granites were primarily derived from partial melting in a syn-collision extension setting, whereas the monzonitic granite went through a fractional crystallization process in an intraplate anorogenic setting.

scholarly journals Chronostratigraphic framework and provenance of the Ossa-Morena Zone Carboniferous basins (southwest Iberia)

Solid Earth ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 1291-1312
Author(s):  
Manuel Francisco Pereira ◽  
Cristina Gama ◽  
Ícaro Dias da Silva ◽  
José Brandão Silva ◽  
Mandy Hofmann ◽  
...  
Keyword(s):  
Detrital Zircon ◽  
Inductively Coupled Plasma ◽  
Volcanic Rocks ◽  
Early Carboniferous ◽  
Inductively Coupled ◽  
Minimum Age ◽  
Plasma Mass Spectrometry ◽  
Depositional Age ◽  
Siliciclastic Rocks ◽  
Detrital Zircon Ages

Abstract. Carboniferous siliciclastic and silicic magmatic rocks from the Santa Susana–São Cristovão and Cabrela regions contain valuable information regarding the timing of synorogenic processes in SW Iberia. In this region of the Ossa-Morena Zone (OMZ), late Carboniferous terrigenous strata (i.e., the Santa Susana Formation) unconformably overlie early Carboniferous marine siliciclastic deposits alternating with volcanic rocks (i.e., the Toca da Moura volcano-sedimentary complex). Lying below this intra-Carboniferous unconformity, the Toca da Moura volcano-sedimentary complex is intruded and overlain by the Baleizão porphyry. Original sensitive high-resolution ion microprobe (SHRIMP) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) U–Pb zircon are presented in this paper, providing chronostratigraphic and provenance constraints since available geochronological information is scarce and only biostratigraphic ages are currently available for the Santa Susana–São Cristovão region. Our findings and the currently available detrital zircon ages from Paleozoic terranes of SW Iberia (Pulo do Lobo Zone – PLZ – South Portuguese Zone – SPZ – and OMZ) were jointly analyzed using the K–S test and multidimensional scaling (MDS) diagrams to investigate provenance. The marine deposition is constrained to the age range of ca. 335–331 Ma (Visean) by new U–Pb data for silicic tuffs from the Toca da Moura and Cabrela volcano-sedimentary complexes. The Baleizão porphyry, intrusive in the Toca da Moura volcano-sedimentary complex, yielded a crystallization age of ca. 318 Ma (Bashkirian), providing the minimum age for the overlying intra-Carboniferous unconformity. A comparison of detrital zircon populations from siliciclastic rocks of the Cabrela and Toca de Moura volcano-sedimentary complexes of the OMZ suggests that they are derived from distinct sources more closely associated with the SPZ and PLZ than the OMZ. Above the intra-Carboniferous unconformity, the Santa Susana Formation is the result of the recycling of distinct sources located either on the Laurussian side (SPZ and PLZ) or Gondwanan side (OMZ) of the Rheic suture zone. The best estimate of the crystallization age of a granite cobble which was found in a conglomerate from the Santa Susana Formation yielded ca. 303 Ma (Kasimovian–Gzhelian), representing the maximum depositional age for the terrestrial strata. The intra-Carboniferous unconformity seems to represent a stratigraphic gap of approximately 12–14 Myr, providing evidence of the rapid post-accretion and collision uplift of the Variscan orogenic belt in SW Iberia (i.e., the OMZ, PLZ, and SPZ).

U–Pb Neoproterozoic–Ordovician protolith age constraints for high- to medium-pressure rocks thrust over low-grade metamorphic rocks in theIxcamilpa area, Acatlán Complex, southern Mexico

2011 ◽  
Vol 48 (1) ◽  
pp. 45-61 ◽  
Author(s):  
M. A. Ramos-Arias ◽  
J. D. Keppie
Keyword(s):  
High Pressure ◽  
Inductively Coupled Plasma ◽  
Volcanic Rocks ◽  
Low Grade ◽  
Southern Mexico ◽  
Western Margin ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Plasma Mass Spectrometry ◽  
Acatlan Complex

High-grade and high-pressure rocks in Acatlán Complex (southern Mexico) are inferred to have been emplaced either during the convergence and collision between Laurentia and Gondwana or during subduction on the western margin of Pangea. In the Ixcamilpa area, such rocks occur in a synformal nappe and are subdivided into (1) the Neoproterozoic–Ordovician Piaxtla Suite (metapsammite, meta-pelite, and amphibolite) that passes structurally upwards from blueschist through eclogite to amphibolite facies; intruded by (2) Cambro-Ordovician megacrystic granitoids; both of which were thrust westwards over (3) the Carboniferous Zumpango Unit consisting of clastic and meta-volcanic rocks. Laser ablation – inductively coupled plasma – mass spectrometry (LA–ICP–MS) U–Pb zircon geochronology yielded age population peaks at (i) 435–490 Ma, probably derived from Acatlán granitoids; (ii) 500–700 Ma, likely derived from the Yucatan Peninsula and Brasiliano orogens; (iii) 800–900 Ma, with provenance in the Goiás arc of eastern Amazonia; and (iv) 950–1300 Ma, sourced either from Oaxaquia, Amazonia, or Laurentia: the younger ca. 310–360 Ma ages are limited to the Zumpango Unit and likely have a local provenance. The overall similarity of the Piaxtla rocks in the Ixcamilpa area and those in the Piaxtla-Mimilulco median belt suggests that Ixcamilpa nappe roots in the median belt, which is interpreted as an extrusion zone within the Acatlán Complex. Since neither high-pressure belt represents a closed ocean, deposition of the Neoproterozoic–Ordovician rocks is inferred to have taken place on the southern margin of Rheic Ocean adjacent to Oaxaquia–Amazonia, whereas the Carboniferous rocks were deposited on the western margin of Pangea synchronous with extrusion of the high-pressure rocks.

LA-MC-ICP-MS U-Pb dating of low-U garnets reveals multiple episodes of skarn formation in the volcanic-hosted iron mineralization system, Awulale belt, Central Asia

2019 ◽  
Vol 132 (5-6) ◽  
pp. 1031-1045
Author(s):  
Shuang Yan ◽  
Renjie Zhou ◽  
He-Cai Niu ◽  
Yue-xing Feng ◽  
Ai Duc Nguyen ◽  
...  
Keyword(s):  
Central Asia ◽  
Inductively Coupled Plasma ◽  
Large Scale ◽  
Volcanic Rocks ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Two Samples ◽  
Plasma Mass Spectrometry ◽  
Iron Deposits ◽  
Multiple Episodes

Abstract Volcanic-hosted iron deposits of the eastern Awulale metallogenetic belt in Central Asia possess a reserve of over 1.2 billion tons of iron ores and constitute one of the most important basements for high-grade iron resources in China. Skarns are widespread in these deposits and closely associated with iron mineralization. The ages of these skarns are unclear, and their genesis remains debated, preventing further investigation into their metallogenic processes. We focused on garnets in nine ore-bearing skarns from three large-scale iron deposits (Chagangnuoer, Dunde, and Beizhan) in the eastern Awulale belt. U-Pb dating was conducted on these garnets using our in-house reference material, the Taochong garnet (TC-13, Pb-Pb isochron age: 126.2 ± 2.3 Ma, initial 207Pb/206Pb ratio: 0.845 ± 0.022). Laser-ablation–multicollector–inductively coupled plasma–mass spectrometry (LA-MC-ICP-MS) was employed in the garnet U-Pb dating, and high-precision U-Pb ages (0.3%–1.6%) were obtained, highlighting the advantages of LA-MC-ICP-MS in dating low-U minerals. The garnet U-Pb ages of the nine skarn samples fall into three groups, i.e., 329.0 ± 5.1–326 ± 3.3 Ma (two samples), 316.3 ± 2.9–311.2 ± 2.4 Ma (six samples), and 295.6 ± 1.0 Ma (one sample), implying three episodes of skarn alteration in the volcanic-hosted iron mineralization system. The first and second episodes of skarns formed as a result of contact metasomatism between coeval volcanic rocks and limestone, and they have economically important iron mineralization. The third was likely caused by a local postcollision granitic intrusion, but its metallogenic potential deserves further assessment.

scholarly journals The individual analysis of fluid inclusions in minerals using Laser Ablation Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS): an evaluation

2001 ◽  
Vol 3 (3-4) ◽  
pp. 215-230
Author(s):  
Wouter HEIJLEN ◽  
Philippe MUCHEZ
Keyword(s):  
Mass Spectrometry ◽  
Laser Ablation ◽  
Fluid Inclusions ◽  
Inductively Coupled Plasma ◽  
Internal Standard ◽  
Natural Quartz ◽  
Inductively Coupled ◽  
Ms Analysis ◽  
Icp Ms ◽  
Plasma Mass Spectrometry

During the last decade, the possible application of laser ablation inductively coupled plasma - mass spectrometry (LA-ICP-MS) as a quantitative technique for the analysis of individual fluid inclusions has been intensely studied. The quantitative ability of this technique is, however, complicated by several fractionation processes that operate during ablation, transport and analysis in the ICP-MS. In the present study, a number of these fractionation effects were studied and the quantitative ability of LA-ICP-MS analysis of fluid inclusions in natural quartz is evaluated. Using NIST SRM 612 and 614 as reference materials, it is shown that the fractionation during transport is minimised when the sample cell is flushed with He, in contrast with the set-up where Ar is used. Calcium has been successfully applied as an internal standard to calibrate the REE in NIST-glasses. The use of Ca to calibrate other lithophile and chalcophile elements, such as K, Zn, Cu and Pb, can however be questioned. It is shown that the technique is capable of semi-quantitatively characterising different fluid inclusion populations in natural quartz, which demonstrates its importance as a tool for palaeofluidflow modelling. However, during LA-ICP-MS analysis of fluid inclusions in natural quartz, elements are reprecipitated in a glassy phase, as shown by SEM-EDX analysis of the sample surface after ablation. This process could result in a fractionation and may account for the poor precision of the analysis.

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