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The COVID-19 pandemic has put increased stress on medical systems, infrastructure, and the public in expected and unexpected ways. This case report summarises an unexpected case of methanol poisoning from hand sanitiser ingestion due to changes in industry regulations, increased demand for cleaning products and severe psychosocial stressors brought on by the pandemic. Severe methanol toxicity results in profound metabolic disturbances, damage to the retina and optic nerves, and potentially death.

A case is described of a 29-year-old female who presented with acute hypoxic respiratory failure due to acute eosinophilic pneumonia, associated with the use of electronic cigarettes to vape tetrahydrocannabinol (THC), together with the contemporary clinical understanding of the syndrome of electronic-cigarette associated lung injury (EVALI). Attention is drawn to acute eosinophilic pneumonia as a potential consequence of vaping-associated lung injury to understand the diagnostic evaluations and therapeutic interventions for acute eosinophilic pneumonia associated with vaping THC.

Abstract: The Morrison porphyry Cu-Au-Mo deposit is genetically and spatially related to Eocene plagioclase-hornblende-biotite porphyry intrusions. One porphyry intrusion yielded a U-Pb age of 52.54 ± 1.05 Ma. Mineralization occurs [...]

Newton is an intermediate-sulfidation epithermal gold deposit related to Late Cretaceous continental-arc magmatism in south-central British Columbia. Disseminated gold mineralization occurs in quartz-sericite-altered Late Cretaceous felsic volcanic rocks, and feldspar-quartz-hornblende porphyry and quartz-feldspar porphyry intrusions. The mineralization can be divided into three stages: (1) disseminated pyrite with microscopic gold inclusions, and sparse quartz-pyrite ± molybdenite veins; (2) disseminated marcasite with microscopic gold inclusions and minor base-metal sulfides; and (3) polymetallic veins of pyritechalcopyrite-sphalerite-arsenopyrite. Re-Os dating of molybdenite from a stage 1 vein yielded an age of 72.1 ± 0.3 Ma (published by McClenaghan in 2013). The age of the host rocks has been constrained by U-Pb dating of zircon: Late Cretaceous felsic volcanic rocks, 72.1 ± 0.6 Ma (Amarc Resources Ltd., unpublished data, reported by McClenaghan in 2013); feldspar-quartz- hornblende porphyry, 72.1 ± 0.5 Ma; quartz-feldspar porphyry, 70.9 ± 0.5 Ma (Amarc Resources Ltd., unpublished data, reported by McClenaghan in 2013). The mineralized rocks are intruded by a barren diorite, with an age of 69.3 ± 0.4 Ma. Fluid inclusions in quartz- pyrite ± molybdenite ± gold veins yielded an average homogenization temperature of 313 ± 51°C (number of samples, n = 82) and salinity of 4.8 ± 0.9 wt.% NaCl equiv. (n = 46), suggesting that a relatively hot and saline fluid likely of magmatic origin was responsible for the first stage of mineralization. Some evidence for boiling was also observed in the veins. However, the bulk of the gold mineralization occurs as disseminations in the wall rocks, suggesting that wall-rock reactions were the main control on ore deposition. Le gisement Newton est un gisement epithermal aurifere a sulfuration intermediate relie au magmatisme d'arc continental au Cretace tardif dans le centre-sud de la Colombie-Britannique. La mineralisation aurifere est disseminee dans des roches volcaniques felsiques alterees en quartz-sericite (Cretace tardif) et dans des intrusions de porphyres feldspath-quartzhornblende et de porphyres quartz-feldspath. La mineralisation peut etre divisee en trois stages: (1) de la pyrite disseminee avec des inclusions d'or microscopiques et des filons clairsemes de quartz-pyrite ± molybdenite; (2) de la marcasite disseminee avec des inclusions d'or microscopiques et des quantites mineures de sulfures de metaux de base; et (3) des filons polymetalliques de pyrite-chalcopyrite-sphalerite-arsenopyrite. La datation Re-Os de la molybdenite d'un filon de stage 1 a donne un age de 72.1 ± 0,3 Ma (publie par McClenaghan en 2013). L'age des roches encaissantes a ete contraint par la datation U- Pb du zircon : des roches volcaniques felsiques du Cretace tardif donnant 72,1 ± 0,6 Ma (Amarc Resources Ltd., donnees non publiees, rapportees par McClenaghan en 2013); un porphyre feldspath-quartz-hornblende donnant 72,1 ± 0,5 Ma; un porphyre quartzfeldspath donnant 70,9 ± 0,5 Ma (Amarc Resources Ltd., donnees non publiees, rapportees par McClenaghan en 2013). Une diorite sterile, agee de 69,3 ± 0,4 Ma, penetre les roches mineralisees. Des inclusions de fluides dans les filons quartz-pyrite ± molybdenite ± or ont donne une temperature moyenne d'homogeneisation de 313 ± 51°C (nombre d'echantillons, n = 82) et une salinite de 4,8 [+ or -] 0,9 % (equivalence en poids de NaCl) (n = 46), suggerant qu'un fluide relativement chaud et salin, probablement d'origine magmatique, soit responsable du premier stage de mineralisation. Une certaine evidence d'ebullition a aussi ete observee dans les filons. Toutefois, l'ensemble de la mineralisation aurifere se presente sous forme de disseminations dans les roches encaissantes suggerant que les reactions des roches encaissantes aient constitue le controle principal sur la deposition du minerai. [Traduit par la Redaction], Introduction The Newton gold deposit is a significant new discovery in southern British Columbia. It is located roughly 110 km southwest of Williams Lake at 51°47'N and 123°36'W (Fig. 1). [...]

The plate tectonic revolution, culminating with the formulation of the Wilson Cycle, took place over a period of less than a decade in the 1960s and early 1970s. The model provided a framework for understanding the formation of almost every type of mineral deposit then known on Earth, ranging from base and precious metal deposits associated with rifting, to porphyry Cu-Mo and epithermal Au deposits associated with subduction, and collision-related mesothermal Au deposits. By the end of the 1970s, satisfactory tectonic models for most of these deposit types had been established. Modern geological and economic geology research is largely built on these models, which have been expanded in detail but remain largely unchanged in concept and function. La revolution de la tectonique des plaques a eu lieu au cours d'une periode de moins de dix ans, dans les annees 1960 et le debut des annees 1970; elle a atteint son point culminant avec la formulation du cycle de Wilson. Le modele fournissait un cadre pour comprendre la formation de presque tout type de gisement mineral alors connu sur la Terre, allant des metaux de base et des metaux precieux, associes a la derive, jusqu'aux gisements porphyriques Cu-Mo et Au epithermaux, associes a la subduction, ainsi que les gisements Au mesothermaux associes aux collisions. A la fin des annees 1970, des modeles tectoniques adequats avaient ete etablis pour la plupart de ces types de gisements. La recherche moderne en geologie et en geologie economique est essentiellement fondee sur ces modeles, maintenant beaucoup plus detailles, mais dont les concepts et les fonctions ont peu change. [Traduit par la Redaction], Introduction J. Tuzo Wilson (1908-1993) made seminal contributions to the nascent theory of plate tectonics in the 1960s, for which he won numerous accolades including the American Miscellaneous Society's Albatross [...]

Porphyry Cu [+ or -] Mo [+ or -] All and some epithermal Au deposits are formed from hydrothermal fluids exsolved from cooling, water-rich, calc-alkaline magmas emplaced in volcanoplutonic arcs above subduction zones. These magmas originate by partial melting of the metasomatized asthenospheric mantle wedge. However, there is increasing evidence for the existence of a suite of porphyry Cu-Au and epithermal Au deposits related to magmas generated after subduction beneath the arc has ceased. Associated magmas tend to be mildly alkaline, relatively sulfur poor, and emplaced as isolated complexes rather than in voluminous volcanoplutonic arcs. They are likely formed by remelting of previously subduction-modified arc lithosphere, triggered by postsubduction lithospheric thickening, lithospheric extension, or mantle lithosphere delamination. Metasomatized mantle lithosphere or hydrous lower crustal cumulates residual from first-stage arc magmatism contain small amounts of chalcophile and siderophile element--rich sulfides, and constitute a fertile source for hydrous, Au-rich, but relatively sulfur-poor magmas during later remelting. The recognition that porphyry Cu-Au and related epithermal Au systems can also form in postsubduction and collisional tectonic settings expands the range of geological environments and geographical terranes that are prospective for such deposits.

SUMMARY Humanity is beginning to grapple with the idea that the Earth is quite a small place when shared by over 6 billion people, and that the physical impact of [...]

Arc magmas globally are H2O-Cl-S-rich and moderately oxidized (ΔFMQ = +1 to +2) relative to most other mantle-derived magmas (ΔFMQ = 0). Their relatively high oxidation state limits the extent to which sulfide phases separate from the magma, which would otherwise tend to deplete the melt in chalcophile elements such as Cu (highly siderophile elements such as Au and especially platinum-group elements are depleted by even small amounts of sulfide segregation). As these magmas rise into the crust and begin to crystallize, they will reach volatile saturation, and a hydrous, saline, S-rich, moderately oxidized fluid is released, into which chalcophile and any remaining siderophile metals (as well as many other water-soluble elements) will strongly partition. This magmatichydrothermal fluid phase has the potential to form ore deposits (most commonly porphyry Cu ± Mo ± Au deposits) if its metal load is precipitated in economic concentrations, but there are many steps along the way that must be successfully negotiated before this can occur. This paper seeks to identify the main steps along the path from magma genesis to hydrothermal mineral precipitation that affect the chances of forming an ore deposit (defined as an economically mineable resource) and attempts to estimate the probability of achieving each step. The cumulative probability of forming a large porphyry Cu deposit at any given time in an arc magmatic system (i.e., a single batholith-linked volcanoplutonic complex) is estimated to be ~0.001%, and less than 1/10 of these deposits will be uplifted and exposed at shallow enough depths to mine economically (0.0001%). Continued uplift and erosion in active convergent tectonic regimes rapidly remove these upper-crustal deposits from the geological record, such that the probability of finding them in older arc systems decreases further with age, to the point that porphyry Cu deposits are almost nonexistent in Precambrian rocks. A key finding of this paper is that most volcanoplutonic arcs above subduction zones are prospective for porphyry ore formation, with probabilities only falling to low values at late stages of magmatic-hydrothermal fluid exsolution, focusing, and metal deposition. This is in part because of the high threshold required in terms of grade and tonnage for a deposit to be considered economic. Thus, the probability of forming a porphyry-type system in any given arc segment is relatively high, but the probability that it will be a large economic deposit is low, dictated to a large extent by mineral economics and metal prices. [ABSTRACT FROM AUTHOR]

Most known porphyry Cu ± Au deposits are associated with moderately oxidized and sulfur-rich, calc-alkaline to mildly alkalic arc-related magmas in the Phanerozoic. In contrast, sodium-enriched tonalite–trondhjemite–granodiorite–diorite (TTG) magmas predominant in the Archean are hypothesized to be unoxidized and sulfur-poor, which together preclude porphyry Cu deposit formation. Here, we test this hypothesis by interrogating the causative magmas for the ~2·7 Ga TTG-related Côté Gold, St-Jude, and Clifford porphyry-type Cu ± Au deposit settings in the Neoarchean southern Abitibi subprovince. New and previously published geochronological results constrain the age of emplacement of the causative magmas at ~2·74 Ga, ~2·70 Ga, and ~ 2·69 Ga, respectively. The dioritic and trondhjemitic magmas associated with Côté Gold and St-Jude evolved along a plagioclase-dominated fractionation trend, in contrast to amphibole-dominated fractionation for tonalitic magma at Clifford. Analyses of zircon grains from the Côté Gold, St-Jude, and Clifford igneous rocks yielded ε Hf(t) ± SD values of 4·5 ± 0·3, 4·2 ± 0·6, and 4·3 ± 0·4, and δ18O ± SD values of 5·40 ± 0·11 ‰, 3·91 ± 0·13 ‰, and 4·83 ± 0·12 ‰, respectively. These isotopic signatures indicate that, although these magmas are mantle-sourced with minimal crustal contamination, for the St-Jude and Clifford settings the magmas or their sources may have undergone variable alteration by heated seawater or meteoric fluids. Primary barometric minerals (i.e. zircon, amphibole, apatite, and magnetite–ilmenite) that survived variable alteration and metamorphism (up to greenschist facies) were used for estimating f O2 of the causative magmas. Estimation of magmatic f O2 values, reported relative to the fayalite–magnetite–quartz buffer as ΔFMQ, using zircon geochemistry indicates that the f O2 values of the St-Jude, Côté Gold, and Clifford magmas increase from ΔFMQ –0·3 ± 0·6 to ΔFMQ +0·8 ± 0·4 and to ΔFMQ +1·2 ± 0·4, respectively. In contrast, amphibole chemistry yielded systematically higher f O2 values of ΔFMQ +1·6 ± 0·3 and ΔFMQ +2·6 ± 0·1 for Côté Gold and Clifford, respectively, which are consistent with previous studies that indicate that amphibole may overestimate the f O2 of intrusive rocks by up to 1 log unit. Micro X-ray absorption near edge structure (μ-XANES) spectrometric determination of sulfur (i.e. S6+/ΣS) in primary apatite yielded ≥ΔFMQ −0·3 and ΔFMQ +1·4–1·8 for St-Jude and Clifford, respectively. The magnetite–ilmenite mineral pairs from the Clifford tonalite yielded ΔFMQ +3·3 ± 1·3 at equilibrium temperatures of 634 ± 21 °C, recording the redox state of the late stage of magma crystallization. Electron probe microanalyses revealed that apatite grains from Clifford are enriched in S (up to 0·1 wt%) relative to those of Côté Gold and St-Jude (below the detection limit), which is attributed to either relatively oxidized or sulfur-rich features of the Clifford tonalite. We interpret these results to indicate that the deposits at Côté Gold and Clifford formed from mildly (~ΔFMQ +0·8 ± 0·4) to moderately (~ΔFMQ +1·5) oxidized magmas where voluminous early sulfide saturation was probably limited, whereas the St-Jude deposit represents a rare case whereby the ingress of externally derived hydrothermal fluids facilitated metal fertility in a relatively reduced magma chamber (~ΔFMQ +0). Furthermore, we conclude that variable modes of formation for these deposits and, in addition, the apparent rarity of porphyry-type Cu–Au deposits in the Archean may be attributed to either local restriction of favorable metallogenic conditions, and/or preservation, or an exploration bias. [ABSTRACT FROM AUTHOR]

Cogenetic volatile-rich alkali basalts and gabbros, hawaiites, and mugearites occur in the late Miocene age epizonal Porgera intrusive complex, which is temporally and spatially associated with rich gold-silver mineralization. The least evolved rocks show enrichments in light rare earth elements ([[La/Yb].sub.cn] = 15-19) and other incompatible elements (e.g., Ba/La [is nearly equal] 8-10, La/Nb [is nearly equal] 0.6-0.7, Sr/Nd [is nearly equal] 25) characteristic of intraplate alkalic basalts and have isotopic compositions ([sup.87.Sr/.sup.86.Sr] [is nearly equal] 0.7035, [sup.[epsilon].Nd] [is nearly equal] +6, [sup.206.Pb/.sup.204.Pb] [is nearly equal] 18.66, [sup.207.Pb/.sup.204.Pb] [is nearly equal] 15.56, [sup.298.Pb/.sup.204.Pb] [is nearly equal] 38.55) consistent with derivation from a time-averaged depleted mantle source. The Porgera intrusive complex was emplaced at 6 Ma in Jurassic-Cretaceous shelf-facies sedimentary rocks near the edge of the Australasian plate. Intrusion appears to have occurred in a back-arc environment during subduction of an oceanic microplate segment on two sides, beneath the continental margin and an island arc. We suggest that this unusual tectonic setting promoted partial melting of asthenospheric source materials that were perhaps modified by deep (>150 km) subduction processes to form alkalic magmas with intraplate character.

Baogutu is a large gold deposit (4 Mt @ 5.5 g/t Au) in West Junggar, NW China. We conducted a Re‐Os geochronological study on seven pyrite samples from auriferous quartz‐pyrite veins, which yielded a Re‐Os isochron age of 312 ± 11 Ma (2σ). This age defines the timing of gold mineralization, and overlaps the emplacement age of diorite to granodiorite porphyry stocks (319–310 Ma) in the Baogutu district. The Os initial ratio of 0.46 ± 0.21 (2σ) suggests a mix of components from both mantle and continental crust in the ore‐forming system, which is similar to the proposed magma source of porphyry stocks. The δ34S values of sulphide minerals vary in a narrow range from +0.1 to −3.3‰, indicating that the sulphur is likely of igneous origin. Our data suggest that the Baogutu gold mineralization is probably genetically linked to the regional diorite to granodiorite magmatism. The new data provide important constraints for an evolving genetic model of the Baogutu gold deposit. [ABSTRACT FROM AUTHOR]

The theory that the combined pyrrhotite-arsenopyrite-quartz isochron age represents the age of gold mineralization is faulty because pyrrhotite undergoes re-equilibration at a rapid rate even at low temperatures. Hence, isotopic resetting should be expected in all samples of such minerals, except for the most pristine, of possible Archean age to mimic a Proterozoic mineralization age. Also, gold mineralization may have commenced during the Proterozoic age or that Archean-age mineralization simply underwent isotopic resetting in the Proterozoic era.

Platinum-group element (PGE) geochemistry may be used to constrain the timing of sulfide saturation in magmas, which influences the Cu and Au fertility of evolving magmatic systems. We report new geochronological and geochemical data, with emphasis on PGE geochemistry, for a suite of regional porphyritic hornblende–diorite intrusions and ore-bearing porphyries from the super-giant Escondida and smaller Zaldivar Cu deposits of Northern Chile. The regional dioritic intrusions have zircon U–Pb ages between 39·6 to 37·1 Ma, which overlap with the ages of the ore-bearing Escondida and Zaldivar porphyries (38·1 to 35·0 Ma). Whole-rock major and trace element, and Sr–Nd–Pb and zircon O–Hf isotope geochemistry indicate that the regional diorites and ore-bearing porphyries are co-magmatic and originated from the same mantle-derived magma by fractional crystallization, with minor contamination by Paleozoic crust (∼10%). The low concentrations of PGE in the regional diorites show that they reached sulfide saturation before the MgO content of the melt fell to 4·7 wt %, the MgO content of the most primitive sample analysed. The fraction of sulfide melt which separated from the melts that formed the regional diorites is estimated to be ∼0·12 wt %; this resulted in the partitioning of highly chalcophile elements (Au and PGE) into a sulfide phase that was retained in cumulus rocks at depth. However, the fraction of sulfide melt was too low to have a significant effect on the Cu content of the fractionating melt. As a consequence, when the evolving melt eventually reached volatile saturation, it contained enough Cu (40 ± 10 ppm) to form a super-giant Cu deposit. In contrast, Au was largely stripped from the melt by sulfide precipitation, with the result that the mineralization at Escondida is Cu dominant, with only minor Au. The Zaldivar deposit, on the other hand, contains even less Au, which is attributed to a longer fractionation interval between sulfide and volatile saturation. This study provides evidence to support previously proposed models which suggest that the timing of sulfide saturation, the amount of sulfide melt produced, the water content and oxidation state of the melt, and the magma volume are critical factors in determining the potential to form a porphyry Cu deposit. Plots of Pd/MgO against Y can be used as empirical indicators of magma fertility for porphyry mineralization, and to discriminate between Cu–Au and Cu-dominated systems, but cannot predict the size of the deposit. The super-giant status of the Escondida deposit is attributed to it being underlain by a large batholith with a calculated minimum mass of 1012 tonnes (∼400 km3). [ABSTRACT FROM AUTHOR]

Porphyry Cu deposits form in the shallow crustal parts of arc magmatic systems, which root in the mantle wedge, evolve in lower crustal MASH (melting, assimilation, storage, homogenization) zones and lower to midcrustal hot zones, and accumulate in mid- to upper crustal batholiths at depths of 5 to 10 km. A small proportion of the magma and most of the volatile load rises toward the surface due to buoyancy, and may erupt as volcanic or fumarolic emissions. Low levels of volcanism and fumarolic activity, as well as subsurface hydrothermal flow and alteration, are normal and semicontinuous features of active arc magmatic systems, which may operate for millions of years. Porphyry Cu deposits, on the other hand, form rarely (typically < 1 per batholith) and rapidly (<100,000 years) in the subsurface (2-5 km depth), where hydrous volatiles exsolved from the underlying batholith are channeled into structurally controlled cupola zones and cool before reaching the surface. The explosively brecciated character of early mineralization stages (breccia pipes and stockworks) suggests that the initiation of fluid flow maybe essentially instantaneous and catastrophic, with the longer total duration of hydrothermal activity reflecting slower kinetically controlled fluid exsolution processes, or draining of deeper parts of the system. These fluids generate intense subsurface hydrothermal alteration, and may precipitate economic concentrations of Cu-sulfide minerals in potassic alteration zones as they cool between -400° and 300°C. The suddenness and infrequency of these ore-forming hydrothermal events suggest that they are triggered by an external process acting on otherwise normally evolving magmatic systems. Sudden depressurization or agitation of a large, primed, volatile-saturated or supersaturated mid-upper crustal magma chamber could lead to rapid and voluminous volatile exsolution and fluid discharge. This sudden volatile flux could result in either a large explosive volcanic eruption if the surface is breached, or a large magmatic-hydrothermal system that could form a porphyry Cu deposit if fluid flow is restricted to the subsurface. Candidates for triggers of these destabilizing events are catastrophic mass wasting such as volcanic edifice collapse, or mega-earthquakes, the latter possibly causing the former. The frequency of such catastrophic events occurring in proximity to active arc batholiths may approximate the recurrence rate of formation of large porphyry Cu deposits. [ABSTRACT FROM AUTHOR]

The Red Chris porphyry Cu-Au deposit is located in the Stildnia island-arc terrane in northwest Br itish Columbia. It is hosted by the Red Stock, which has five phases of porphyry intrusions: PI, P2E, P2I, P2L, and P3. New U-Pb dating of zircon shows that these intrusions were emplaced over a ~10 m.y. period, with PI intruded at 211.6 ± 1.3 Ma (MSWD = 0.85), P2I at 206.0 ± 1.2 Ma (MSWD = 1.5), P2L at 203.6 ± 1.8 Ma (MSWD = 1.5), and P3 at 201.7 ± 1.2 Ma (MSWD = 1.05). The ore-forming event at Red Chris was a short-lived event at 206.1 ± 0.5 Ma (MSWD = 0.96; weighted average age of three Re-Os molybdenite analyses), implying a duration of <1 m.y., as defined by the uncertainty range, coincident with the emplacement age of the P2 porphyries. Zircons from PI to P3 porphyry rocks have consistently high E un/E un 0.4), indicating that their associated magmas were moderately oxidized. The magmatic water contents estimated from plagioclase and amphibole compositions suggest ILO contents of ~5 wt %. Taken together, the PI to P3 poiphyries are interpreted to be moderately oxidized and hydrous. The porphyry phases are differentiated by sulfur and chlorine contents. The SCR contents of igneous apatite microphenocrysts from the mineralization-related P2 porphyries are higher (P2E: 0.28 ± 0.10 wt %, n = 19; P2I: 0.32 + 0.17, n = 15; P2L: 0.29 ± 0.18 wt %, n = 100) than those from the premineralization PI (0.11 ± 0.03 wt %, n = 34) and postmineralization P3 porphyries (0.03 ± 0.01 wt %, n = 13). The chlorine contents in apatite grains from the P2E, P2I, and P2L porphyries are 1.47 ± 0.22 (n = 19), 0.82 ± 0.10 (n = 15), and 1.47 ± 0.28 wt % (n = 100), also higher than those from PL (0.51 ± 0.3 wt % Cl, n = 34) and P3 (0.02 ± 0.02 wt % Cl, n = 17). These results imply that the sulfur and chlorine contents of the P2 magmas were higher than in the PI and P3 magmas, suggesting that elevated magmatic S-Cl contents in the P2 poiphvries may have been important for ore formation. Although the process that caused the increase in sulfur and chlorine is not clear, reverse zoning seen in plagioclase phenocrysts from the P2 porphyry, and the occurrence of more mafic compositions in P2L suggest that recharge of the deeper magma chamber by a relatively S-Cl-rich mafic magma may have triggered the ore-forming hydrothermal event. [ABSTRACT FROM AUTHOR]