Use of micro-XRF chemical analysis for mapping volcanogenic massive sulfide related hydrothermal alteration: Application to the subaqueous felsic dome-flow complex of the Cap d'Ours section, Glenwood rhyolite, Rouyn-Noranda, Québec, Canada

Genna, Dominique; Gaboury, Damien; Moore, Lyndsay; Mueller, W.U.

doi:10.1016/j.gexplo.2010.12.001

Cited by 30 publications

(10 citation statements)

References 29 publications

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“…The 2.7 Ga Blake River Group mainly consists of volcanic units of basaltic to rhyolitic composition 26 , 29 . All associated lava flows are interpreted to have been emplaced in a submarine environment, based in part on the widespread occurrence of pillow lavas and pillow breccias (including hyaloclastites) and the presence of turbidite and argillite interbeds 26 , 30 . Volcanic units of the Blake River Group were intruded by several generations of plutons, dikes, and sills 26 , with the most prominent intrusions including the Flavrian and Powell tonalites and the Lac Dufault granodiorite 29 , 31 (Fig.…”

Section: The Rouyn-noranda Study Areamentioning

confidence: 99%

Delineating Areas of Past Environmental Degradation near Smelters using Rock Coatings: A Case Study at Rouyn-Noranda, Quebec

Leverington

Schindler

2018

Sci Rep

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Emissions of SO2 from smelters can promote formation of acid rain, which can dissolve siliceous minerals on exposed rock surfaces and promote the formation of silica gel layers within which detrital and smelter-derived particulates can become trapped. These processes of dissolution and entrapment can result in the formation of rock coatings that contain elevated levels of heavy metals. Between 1927 and 1976, the Horne smelter processed sulfide ore derived from the Rouyn-Noranda region and became one of the largest emitters of particulates and sulfur dioxide in North America, promoting the formation of coatings on nearby rock surfaces. The reflectance spectra of these coatings are relatively flat, with typical reflectance values ranging between ~5% at visible wavelengths and ~16% in the shortwave infrared. Absorption troughs in coating spectra are consistent with the presence of materials including opaline silica, olivine, pyroxene, hydrous phyllosilicates, and sulfates. Classification of Landsat 8 Operational Land Imager data indicates that rock coatings near Rouyn-Noranda comprise a total surface area of ~1.5 km2, nearly all of which is located within ~6 km of the Horne smelter. Remote sensing techniques can used to delineate the geographic extents of coatings near smelters, highlighting areas previously subjected to severe environmental degradation.

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Section: The Rouyn-noranda Study Areamentioning

confidence: 99%

Delineating Areas of Past Environmental Degradation near Smelters using Rock Coatings: A Case Study at Rouyn-Noranda, Quebec

Leverington

Schindler

2018

Sci Rep

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“…Understanding mineral distributions in rocks is of particular value to the mineral industry, where ascertaining the distribution of mineral species in a deposit could be beneficial to defining mineral resources, or more efficiently processing ore. Micro-X-ray fluorescence (µXRF) scanning is a relatively new analytical tool that allows chemical mapping of rock samples at a very fine scale (<100 µm), yet on sample sizes that lie between traditional SEM thin-section observations (< ~1 mm) and the corescale observations made during logging and assay chemistry (~1 mm to m). Examples of applications of geochemical analyses using µXRF include studies of volcanogenic massive sulfides (Genna et al, 2011), shale-hosted uranium (Xu et al, 2015), greenstone-hosted Cu-Co-Au (Fox et al, 2019), and environmental sciences (Croudace and Rothwell, 2015;Flude et al, 2017). In each of these studies, µXRF is used to visualize and, in some cases, quantify (Flude et al, 2017) the distribution of elements over the surface of mineral and rock samples, which in turn reveals textures and patterns that cannot be observed in hand samples.…”

Section: Introductionmentioning

confidence: 99%

Quantitative Mineral Mapping of Drill Core Surfaces I: A Method for µXRF Mineral Calculation and Mapping of Hydrothermally Altered, Fine-Grained Sedimentary Rocks from a Carlin-Type Gold Deposit

Barker

Wilson

et al. 2021

Economic Geology

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Mineral distributions can be determined in drill core samples from a Carlin-type gold deposit, using micro-X-ray fluorescence (µXRF) raster data. Micro-XRF data were collected using a Bruker Tornado µXRF scanner on split drill core samples (~25 × 8 cm) with data collected at a spatial resolution of ~100 µm. Bruker AMICS software was used to identify mineral species from µXRF raster data, which revealed that many individual sample spots were mineral mixtures due to the fine-grained nature of the samples. In order to estimate the mineral abundances in each pixel, we used a linear programming (LP) approach on quantified µXRF data. Quantification of µXRF spectra was completed using a fundamental parameters (FP) standardless approach. Results of the FP method compared to standardized wavelength dispersive spectrometry (WDS)-XRF of the same samples showed that the FP method for quantification of µXRF spectra was precise (R2 values of 0.98–0.97) although the FP method gave a slight overestimate of Fe and K and an underestimate of Mg abundance. Accuracy of the quantified µXRF chemistry results was further improved by using the WDS-XRF data as a calibration correction before calculating mineralogy using LP. The LP mineral abundance predictions were compared to Rietveld refinement results using X-ray diffraction (XRD) patterns collected from powders of the same drill core samples. The root mean square error (RMSE) for LP-predicted mineralogy compared to quantitative XRD results ranges from 0.91 to 7.15% for quartz, potassium feldspar, pyrite, kaolinite, calcite, dolomite, and illite. The approaches outlined here demonstrates that µXRF maps can be used to determine mineralogy, mineral abundances, and mineralogical textures not visible with the naked eye from fine-grained sedimentary rocks associated with Carlin-type Au deposits. This approach is transferrable to any ore deposit, but particularly useful in sedimentary-hosted ore deposits where ore and gangue minerals are often fine grained and difficult to distinguish in hand specimen.

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“…Compositional mapping obtained by electron microprobe, scanning electron microscopy ( SEM ), X‐ray fluorescence (XRF) or laser ablation coupled with inductively coupled plasma and mass spectroscopy, is used to characterize altered mineralization (e.g. Augustin & Gaboury, ; Genna, Gaboury, Moore, & Mueller, ), metamorphic (Lanari, Vho, Bovay, Airaghi, & Centrella, ) and igneous rocks (Jenner & Arevalo, ). However, two‐dimensional (2D) images of rocks are sections of a complex three‐dimensional (3D) arrangements of minerals and extrapolating the geometry beneath the surface requires assumptions and interpretations may not be valid.…”

Section: Introductionmentioning

confidence: 99%

Compositional tomography of a gold‐bearing sample by Laser‐induced breakdown spectroscopy

Gervais

Rifaï²,

Plamondon

et al. 2019

Terra Nova

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This contribution presents the first results of compositional tomography of a geological sample. The volume render of 6 × 8 × 1 mm 3 was constructed by assembling 63 compositional maps acquired in 21 min (19.5 s/layer) by laser-induced breakdown spectroscopy (LIBS), which determines the chemical composition of the analysed spot from the light emitted by a plasma produced by the laser. This technique is, therefore, able to directly reveal the 3D distribution of chemical elements in a sample. As an example, the spatial distribution and 3D geometry of visible gold in an ultramafic schist are presented. Inasmuch as this newly developed portable LIBS instrument is able to the rapidly characterize the 3D geometry of any geological materials, it has a high potential to be useful for the mining industry and for a wide range of geosciences, such as structural geology, petrology, sedimentology and economic geology.

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Use of micro-XRF chemical analysis for mapping volcanogenic massive sulfide related hydrothermal alteration: Application to the subaqueous felsic dome-flow complex of the Cap d'Ours section, Glenwood rhyolite, Rouyn-Noranda, Québec, Canada

Cited by 30 publications

References 29 publications

Delineating Areas of Past Environmental Degradation near Smelters using Rock Coatings: A Case Study at Rouyn-Noranda, Quebec

Delineating Areas of Past Environmental Degradation near Smelters using Rock Coatings: A Case Study at Rouyn-Noranda, Quebec

Quantitative Mineral Mapping of Drill Core Surfaces I: A Method for µXRF Mineral Calculation and Mapping of Hydrothermally Altered, Fine-Grained Sedimentary Rocks from a Carlin-Type Gold Deposit

Compositional tomography of a gold‐bearing sample by Laser‐induced breakdown spectroscopy

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