The Canadian Journal of Mineralogy and Petrology最新文献

{"title":"Mineral Chemistry of the Eagle Lake Granite Porphyry, Southwestern New Brunswick, Canada: Implications for Cu-Mo-Au Mineralization","authors":"Fazilat Yousefi, D. Lentz, K. Thorne","doi":"10.3749/2200060","DOIUrl":"https://doi.org/10.3749/2200060","url":null,"abstract":"\u0000 The oxidized I-type Eagle Lake Granite stock in southwestern New Brunswick, Canada, is texturally divided into porphyritic and equigranular phases. The porphyritic granite consists of phenocrysts (i.e., plagioclase, K-feldspar, quartz, and biotite) and microcrystalline groundmass with minor magnetite–ilmenite, titanite, apatite, and zircon. The equigranular phase has a similar primary mineral assemblage to the porphyritic phase. Their common magnetite-ilmenite-titanite assemblage reflects co-crystallization (magnetite series) from a magma imparting some redox control. However, these granite phases show minor potassic to propylitic alteration mineral assemblages with very minor sulfides, suggesting localized fluid–rock reaction.\u0000 The composition of plagioclase varies between albite and oligoclase, and K-feldspar is orthoclase commonly displaying considerable turbidity. The An% versus Al/(Ca+Na+K) data indicate that these feldspars are slightly aluminous, reflecting cryptic alteration. Biotite is rich in Fe, plotting near the boundary of primary and re-equilibrated biotite; these biotites formed at temperatures ranging from 670 to 725 °C, based on Ti-in-biotite thermometry. Secondary biotite grains are also locally evident, formed from magmatic-hydrothermal fluids. Secondary fine-grained biotite associated with fine-grained magnetite-pyrite indicates potassic alteration and related Cu±Mo±Au mineralization. Some of these various biotites are partially altered to chlorite at ∼301–361 °C. Like biotite, apatite occurs as both igneous and hydrothermal phases. Based on the concentration of F (4.21–2.90 wt.%), all these apatites are fluorapatites with content of light rare earth elements about 7000 ppm and Eu/Eu* = 0.16.","PeriodicalId":218967,"journal":{"name":"The Canadian Journal of Mineralogy and Petrology","volume":"8 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121015296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Alkali Sulfates with Aphthitalite-Like Structures from Fumaroles of the Tolbachik Volcano, Kamchatka, Russia. IV. Aphthitalite–Palmierite Regular Intergrowths: Crystallography, Chemistry, and Genesis","authors":"N. V. Shchipalkina, N. Koshlyakova, I. Pekov, A. Agakhanov, S. Britvin, M. Nazarova","doi":"10.3749/2200062","DOIUrl":"https://doi.org/10.3749/2200062","url":null,"abstract":"\u0000 The first discovery of regular intergrowths of aphthitalite K3Na(SO4)2 and palmierite K2Pb(SO4)2 are reported. Crystals of aphthitalite, intergrown with lamellae of palmierite (up to 15 μm thick), along with grains of arcanite, occur in encrustations recovered from the active Arsenatnaya fumarole (Tolbachik volcano, Kamchatka, Russia). These were studied using a combination of scanning electron microscopy, electron probe microanalysis, powder X-ray diffraction, and electron backscatter diffraction techniques. Three types of grain boundaries involving intergrowths of aphthitalite and palmierite were observed: (1) those with a misorientation angle of 60° relative to [001] (twinning), (2) those parallel to the (001) plane, and (3) those with a misorientation angle of 60° relative to [001]. The twinned aphthitalite domains are related by a two-fold rotation about [001] (Dauphiné twin law). The heating of aphthitalite crystals containing palmierite lamellae at 400, 600, and 750 °C shows a nearly complete redistribution and gradual dissolution of palmierite in the aphthitalite matrix. The character of solid-state transformations in the K2SO4–Na2SO4–PbSO4 system during cooling is controlled by the structural similarity of aphthitalite-type sulfates and palmierite, which contain topologically identical 2[M(SO4)2] (M = Na, Pb) layers.","PeriodicalId":218967,"journal":{"name":"The Canadian Journal of Mineralogy and Petrology","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130852996","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nanoscale Distribution of Elements in Gold: Examples from Contrasting Deposit Types","authors":"K. Tait, L. White, E. Hastie, D. Crabtree, H. Gibson, R. Sherlock, J. Petrus, B. Langelier","doi":"10.3749/2200024","DOIUrl":"https://doi.org/10.3749/2200024","url":null,"abstract":"\u0000 Quantifying the distribution and nature of trace elements in native gold is a novel approach to understanding the genesis of gold deposits and has implications for metallogenic processes, mineral exploration, and metallurgical processing. Most previous research on the formation of gold deposits has utilized proxies for gold, rather than gold itself, to infer its source, transport, and depositional mechanisms, despite the difficulty in establishing unequivocal relationships among the proxies and gold. This approach has left many questions regarding the formation of high-grade coarse gold. This contribution presents results on the composition and distribution of trace elements in native gold using electron probe microanalysis and, for the first time, atom probe tomography. Gold grains selected are from a deformed and metamorphosed Archean orogenic gold deposit (Preston Mine) and a young, undisturbed epithermal gold deposit (McLaughlin mine) which are endmembers in terms of deposit type and geologic time. Results show that Cu, Ag, and Hg are homogenously distributed in gold while Sb is not, which raises questions regarding the substitution mechanisms of large radii metallic elements in gold. These data provide new insights into the incorporation of trace elements in gold, as well as primary and secondary processes related to the formation of high-grade gold deposits through time.","PeriodicalId":218967,"journal":{"name":"The Canadian Journal of Mineralogy and Petrology","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117235107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Driekopite, Ideally PtBi, a New Mineral Species from the Driekop Platinum Pipe, Republic of South Africa","authors":"A. McDonald, L. Cabri, Nobumichi Tamura, F. Melcher, A. Vymazalová","doi":"10.3749/2300005","DOIUrl":"https://doi.org/10.3749/2300005","url":null,"abstract":"\u0000 The new mineral driekopite, ideally PtBi, was found in a concentrate from the Driekop mine, one of three zoned Pt pipes (mined from 1925 to 1930) that crosscut the layered mafic and ultramafic sequences of the eastern Bushveld Complex, Republic of South Africa. The holotype grain of driekopite (∼ 22 × 13 μm) occurs in a complex, rounded aggregate ∼120 μm in diameter, in association with isoferroplatinum (Pt3Fe), hollingworthite (RhAsS), geversite (PtSb2), insizwaite (PtBi2), andrieslombaardite (RhSbS), stibiopalladinite (Pd5Sb2), sobolevskite (PdBi), possible tatyanaite (Pt9Cu3Sn4), osmium-bearing tulameenite (Pt2FeCu), and Pt-Fe alloy (∼Pt2Fe). Driekopite appears slightly orange under reflected light compared to Pt-Fe alloys. It shows moderate to strong bireflectance, varying from light yellow to brownish yellow, no pleochroism or internal reflections, and moderate to strong anisotropism. The empirical formula, calculated from the average of six wavelength-dispersive spectrometry analyses made on five grains, on the basis of two atoms, is (Pt0.68Pd0.31Fe0.01)Σ1.00(Bi0.53Sb0.43As0.02Sn0.02S0.01)Σ1.01. The mineral is hexagonal, space group P63/mmc (#194) with the refined unit-cell dimensions a = 4.1993(5), c = 5.6194(6) Å, V = 85.82 Å3, Z = 2, and Dcalc = 12.91 g/cm3. Driekopite is isostructural with NiAs, with mixed compositions of Pt and Pd at the 2a site (0.55:0.45, respectively) and Bi and Sb at the 2c site (0.63:0.37, respectively). Its crystal structure was refined to wR = 6.3% using 13 unique Laue reflections obtained using synchrotron radiation. The six strongest lines for the powder X-ray diffraction pattern calculated from the crystal structure refined from synchrotron data is [d in Å (I) (hkl)]: 3.0531 (92) (101), 2.2234 (100) (102), 2.0997 (77) , 1.5266 (28) (202), 1.2347 (24) , 1.1676 (18) . The holotype grain of driekopite is observed to be paragenetically later than isoferroplatinum and hollingworthite and is considered to be synformational with Bi-bearing geversite, insizwaite, andrieslombaardite, and sobolevskite. The entire aggregate containing these platinum-group minerals is overgrown by a rim of tulameenite and Pt-Fe alloy (∼Pt2Fe), indicating they are paragenetically the last minerals to form. Experiments designed to synthesize PtBi over the range of 200 to 500 °C were all successful. Synthetic PtBi melts congruently at 765 °C, suggesting that driekopite likely crystallized at sub-magmatic temperatures.","PeriodicalId":218967,"journal":{"name":"The Canadian Journal of Mineralogy and Petrology","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130220104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Saponite as a New Generation Engineered Buffer Material for High Level Nuclear Waste Disposal: Its Chemical Stability in High-pH and High-Temperature Environments","authors":"Y. Xiong, Yifeng Wang","doi":"10.3749/2200053","DOIUrl":"https://doi.org/10.3749/2200053","url":null,"abstract":"\u0000 Saponite, a tri-octahedral smectite with an ideal formula of Mg3(Si,Al)4O10(OH)2·4H2O for an Mg-endmember (saponite-15Å), has similar swelling properties as montmorillonite and therefore can be considered as a potential buffer material for nuclear waste disposal. In this experimental study, we investigated the chemical stability of this material under alkaline conditions (pH ∼ 12) at high temperatures (up to 150 °C) and saturated vapor pressures over an experimental duration of about three weeks. Alkaline conditions in a geologic repository can be induced by the interaction of groundwater with borosilicate waste forms or by the leaching of alkaline porewaters from cementitious materials introduced as structural components, such as seals, liners, and plugs. The interactions of saponite with portlandite [Ca(OH)2]-saturated solutions at 60, 125, and 150 °C were experimentally simulated. The results indicated that saponite is chemically more stable in these environments than montmorillonite and remained unchanged after the interactions. The stability is attributed to its low solubility, with dissolved-magnesium concentrations in the portlandite-saturated solutions estimated to be less than 4×10−7 mol/kg or 2×10−7 mol/kg at 60 or 150 °C, respectively. For comparison, we also investigated the interactions of montmorillonite (SWy-2) with a portlandite-saturated solution at 150 °C. Our results indicate that montmorillonite is not stable, leading to the formation of zeolite (phillipsite) after 9 days of reaction. This study thus demonstrates the feasibility of using saponite as a potential buffer material (as an alternative to montmorillonite currently being considered in many disposal concepts) in an alkaline and elevated-temperature disposal environment.","PeriodicalId":218967,"journal":{"name":"The Canadian Journal of Mineralogy and Petrology","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121801759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Method for Detrital Corundum Characterization in Sediments: Case Study of the Gem Mountain Mine Placer Sapphire Deposit (Rock Creek, Montana, USA)","authors":"P. Belley","doi":"10.3749/2200033","DOIUrl":"https://doi.org/10.3749/2200033","url":null,"abstract":"\u0000 A new, comprehensive approach to characterizing detrital corundum in sediments and placer deposits is outlined and applied to a sample of poorly sorted, mud-supported colluvium rich in rhyolite tuff clasts from the sapphire-producing layer at Gem Mountain Mine, Rock Creek, Montana. High angularity and the predominance of inherited surface features indicate that corundum was not abraded during transport, consistent with deposition by mass wasting. Corundum grain abundances per 10 kg of sediment (rounded to nearest whole number) are as follows: 4–8 mm (1 grain), 2–4 mm (12 grains), 1.0–2.0 mm (10 grains), 0.5–1.0 mm (43 grains), 0.25–0.50 mm (90 grains), 0.125–0.250 mm (480 grains), and <0.125 mm (55 grains; underrepresentation due to poor recovery). The ∼ 50× abundance of corundum in <2 mm size fractions relative to the >2 mm size fraction of potential economic interest suggests that fine-grained corundum may have potential as a pathfinder for gem corundum deposits in heavy mineral surveys. Corundum grains are transparent and divided into four types by surface texture and extent of crystal face development: (1) rounded with frosted surface, anhedral/subhedral; (2) angular with hillocky/irregular surface, anhedral/subhedral; (3) angular subhedral grains with glassy curved faces; and (4) angular, idiomorphic blue grains (all <1 mm). Surface texture Types 1–3 occur in pastel-colored corundum (green, yellowish-green, yellow, colorless) and are the result of dissolution subsequent to euhedral crystal growth. Mineral inclusions in corundum include: pastel corundum – biotite (variable Fe, Mg, Ti, F contents), plagioclase feldspar (andesine-labradorite), rutile, hercynite; blue corundum – alkali feldspar, rutile, zircon, ilmenite, apatite, spinel. Corundum uncommonly occurs in composite grains with biotite, plagioclase, and K-feldspar. Rhyolite occurs as a partial encrustation on one corundum grain. Rock Creek corundum may have originated from partially melted metapelite in a metamorphic basement, and incorporated and transported to the surface by rhyolitic magmas. Due to scant geologic context and an absence of radiometric age data, the proposed genetic model remains highly speculative.","PeriodicalId":218967,"journal":{"name":"The Canadian Journal of Mineralogy and Petrology","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127480446","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chinleite-(Nd), NaNd(SO4)2(H2O), the Nd Analogue of Chinleite-(Y) from the Markey Mine, Red Canyon, San Juan County, Utah, USA","authors":"A. R. Kampf, Chiu‐Shun Ma, J. Marty","doi":"10.3749/2200065","DOIUrl":"https://doi.org/10.3749/2200065","url":null,"abstract":"Chinleite-(Nd) (IMA2022-051), NaNd(SO4)2(H2O), is a new mineral discovered in efflorescence on tunnel walls in the Markey mine, Red Canyon, White Canyon district, San Juan County, Utah, USA. It occurs as colorless prisms with pyramidal terminations in association with gypsum and natrozippeite on asphaltite. Crystals are transparent with vitreous luster. The mineral has a white streak, Mohs hardness 2½–3, one good cleavage (probably on {100}), brittle tenacity, and a splintery fracture. The calculated density is 3.436 g/cm3. Electron probe microanalysis provided the empirical formula (Ca0.538Na0.395Nd0.244Sm0.150Ce0.130Y0.117Gd0.113Dy0.061Pr0.043Sr0.032Eu0.039La0.008Ho0.006)Σ1.876(SO4)2[(H2O)0.73(OH)0.27]. Chinleite-(Nd) is trigonal, P3221, a = 6.9540(7), c = 12.8590(9) Å, V = 538.52(11) Å3, and Z = 3. The structure of chinleite-(Nd) (R1 = 0.0258 for 791 I > 2σI reflections), a three-dimensional framework consisting of SO4 groups, irregular NaO8 polyhedra, and NdO9 distorted tri-capped trigonal prisms, is the same as that of chinleite-(Y) and similar to the structure of bassanite.","PeriodicalId":218967,"journal":{"name":"The Canadian Journal of Mineralogy and Petrology","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129855337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Apatite and Biotite in Syenitic Intrusions, Archean Karari Gold Deposit: Evidence for an Oxidized Magma and Oxidized Subsolidus Potassic (Biotite) Alteration","authors":"W. Witt, M. Roberts, S. Hagemann, C. Fisher","doi":"10.3749/2200043","DOIUrl":"https://doi.org/10.3749/2200043","url":null,"abstract":"\u0000 Apatite and biotite from syenitic intrusions at the Karari gold deposit, Kurnalpi Terrane, Archean Yilgarn Craton, Western Australia, were targeted for microprobe and LA-ICP-MS analyses in order to determine some parameters (e.g., temperature, oxygen fugacity) during magmatic crystallization and potassic (biotite) hydrothermal alteration. The understanding of magmatic conditions is limited by the almost complete hydrothermal modification of magmatic minerals but made possible by the analysis of refractory magmatic apatite and rare relics of Ba-rich biotite. The SO3 contents of apatite cores (up to 1 wt.%) indicate that the syenitic magmas were strongly oxidized (fO2 > NNO +1) and contained approximately 1360 ppm S. The Cl contents of apatite are very low, suggesting crystallization from a low-Cl magma resulting from early separation of a volatile phase that sequestered Cl from the magma. Trends defined by wt.% SO3, at constant XF/XCl, are consistent with partitioning of oxidized S into the volatile phase during apatite crystallization.\u0000 Early potassic alteration of the syenitic intrusions produced fine-grained seams of hydrothermal biotite and compositional modifications of igneous biotite phenocrysts. The magnesian composition of the hydrothermal biotite (mg# > 0.5) suggests that oxidized magmatic conditions persisted during potassic alteration. Provinciality of compositional data for different intrusion samples suggests that potassic alteration took place at low fluid:rock ratios. The potassic hydrothermal fluid modified the rims of igneous apatite crystals, depleting them in F, light rare earth elements, Mn, and S. The rare earth elements were rapidly redeposited, as monazite, in the apatite rims or surrounding groundmass. The depletion of S in apatite rims indicates that the potassic (biotite) alteration fluid was under-saturated in S. Application of the biotite-apatite geothermometer suggests potassic (biotite) alteration took place at temperatures of about 660 °C. The results of this study suggest the syenitic magmas at Karari were strongly oxidized, similar to Canadian examples of syenite-associated gold deposits, and therefore potentially fertile for hydrothermal gold.","PeriodicalId":218967,"journal":{"name":"The Canadian Journal of Mineralogy and Petrology","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116758588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Helvine Mineralization in Devonian-Carboniferous Skarns of the Oriental Pampean Ranges, Córdoba, Argentina: Mineralogy and Nature of Ore-Forming Fluids","authors":"R. Lira, M. J. Espeche, Natalia A. Bonadeo, M. Dorais","doi":"10.3749/2200047","DOIUrl":"https://doi.org/10.3749/2200047","url":null,"abstract":"\u0000 Helvine [Be3Mn2+4(SiO4)3S] occurs in less than one meter-sized spotty concentrations in some calcic skarns of Córdoba province, Argentina. The local geology, mineral chemistry, paragenetic mineral associations, and the evolution of helvine mineralizing fluids were studied from two selected localities (i.e., the Chingolo scheelite mine and Casa la Plata). Helvine from the Chingolo scheelite mine occurs in idiomorphic crystals up to 15 cm long, partially intergrown with spessartine-rich garnet, and in part or totally included in vug-filling spar calcite in the prograde garnet-vesuvianite skarn zone developed between replaced aplite-pegmatite dikes and calcic phlogopite-bearing marbles. Helvine from Casa la Plata occurs abundantly in vein-like, fluorite-rich garnet-vesuvianite skarn associations, where tetrahedrons up to 2 cm long occur preferentially included in fluorite in an illite-sericite-chlorite strongly replaced schist. The composition of helvine from both localities does not differ from other worldwide known compositions. Associated garnet from both localities is enriched in molar subcalcic garnet, largely as spessartine. Clinochlore is a conspicuous phase that occurs both as late infills and/or replacing phases in both the Chingolo scheelite mine and Casa la Plata. Primary fluid inclusions from helvine of both localities suggest that helvine deposited from moderate to high temperature and salinity aqueous fluids of likely magmatic origin. In both localities a late influx of gas-rich, CO2-bearing, moderate temperature, and moderate to low salinity fluid was trapped as secondary fluid inclusions. At the Chingolo scheelite mine, CO2-bearing fluids likely originated from decarbonation along the skarnification reaction front distanced from the prograde zone at lower temperature. In both studied areas, the latest trapped secondary fluids were of lower temperature and lower salinity. Pressure-corrected homogenization temperatures between 1.8 and 2.0 kbar sustain trapping temperatures for primary fluid inclusions within the 510–610 °C range for both localities. In the Chingolo scheelite mine, helvine formed at the contact zone between Ordovician aplite-pegmatites and Cambrian marbles that differentially reacted with infiltrated distal metasomatic-hydrothermal Be-bearing fluids fractionated from evolved granitic facies and/or pegmatites of the neighboring Devonian to Carboniferous Achala Batholith. Calculated δ18OH2O in equilibrium with garnet at ∼575 °C yielded δ18OH2O = 11.1 or 12.2‰. These heavy δ18OH2O values may derive from a magmatic fluid source possibly enriched in 18O from marbles or any other metasedimentary country rock during skarnification. This interpretation is supported by δ18OH2O values (8.3 to 10.1‰) and heavy δD values (−21.6 to −20.6‰) from retrograde epidote of other neighboring scheelite mines related to the Chingolo scheelite mine. The presence of beryl partially replaced by bertrandite + K-feldspar, non-paragenetically ass","PeriodicalId":218967,"journal":{"name":"The Canadian Journal of Mineralogy and Petrology","volume":"108 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124141400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of Hydrothermal Alteration in Palagonitized Deposits Using Short-Wave Infrared Spectroscopy and X-Ray Diffraction Methods","authors":"Lindsey Abdale, S. Leiter, Sasha Wilson, K. Russell, L. Groat","doi":"10.3749/2200056","DOIUrl":"https://doi.org/10.3749/2200056","url":null,"abstract":"\u0000 In this contribution, we evaluate the applicability of short-wave infrared spectroscopy to characterizing mineral assemblages in palagonitized glaciovolcanic edifices at Cracked Mountain, a basaltic volcano within the Garibaldi Volcanic Belt, and Kima Kho, a basaltic tuya within the Northern Cordilleran Volcanic Province. Second-order evaluation of the approach was established through comparison with data obtained by semi-empirical X-ray diffraction methods. Reflectance spectra show an increase in the depth of water and hydroxyl bands in samples with increasing amounts of hydrated minerals and decreasing amounts of amorphous materials (as determined through X-ray diffraction), indicating that the relative strengths of H2O- and OH-related absorption features may be used as a proxy for the degree of palagonite alteration (hydrated minerals crystallized from basaltic glass). In addition, the full width at half maximum of the OH- and H2O-related absorption bands decreased with the formation of zeolites, indicating that the full width at half maximum of OH- and H2O-related features may be used to estimate the degree of crystallinity across the progressive palagonitization process. Finally, short-wave infrared spectroscopy revealed a decrease in band depth of water-related absorption features with no change in the full width at half maximum along the devitrification or alteration process that converts analcime to chabazite to wairakite, indicating that spectroscopy may be used to identify the final dehydration and cementation stages of palagonitization. Results show that the short-wave infrared spectroscopy method is more robust in identifying poorly crystalline hydrated samples, while X-ray diffraction methods are better suited to understanding the crystalline components of palagonite. Short-wave infrared spectroscopy is a remote sensing technique that has proven to successfully characterize the state of H2O in hydrated clay-rich material and thus may serve as an invaluable tool in identifying stages of palagonitization not only on subglacial edifices on Earth but also on off-planet environs, including the Martian surface.","PeriodicalId":218967,"journal":{"name":"The Canadian Journal of Mineralogy and Petrology","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115770361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}