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This study focuses on analysis of local structural arrangements of ferric and ferrous iron in binary alkali-silicate networks, and the effect of changing Fe2+/Fe3+ ratio on the glass structure, investigated by Raman spectroscopy. Three alkali trisilicate glasses, Li2Si3O7, Na2Si3O7 and K2Si3O7, were synthesized with 4.4–6.0 wt% iron oxide, to form three series with the same nominal composition but changing Fe2+/Fe3+ ratio. Structural analyses of the high-wavenumber envelope in Raman spectra of Fe-free alkali-trisilicate analogues have been useful in identifying structural species in the Fe-bearing glasses. Peak fitting of the high-wavenumber region between ca. 820 and 1200 cm− 1 indicates that the increase in ferric iron content is associated with a considerable increase in the Q2 species while the abundance of Q4- and Q3-decreases. However, the most prominent change with the increase in the ferric content is the rise of the peak centred at ca. 980 cm− 1 that we identify as related to the vibration of Fe3+-O-Si linkage, regardless of the coordination geometry around ferric cation. We have observed a roughly linear trend in the change of the Fe3+-related Raman peak area with the increase in the ferric iron content for all three alkali trisilicate series, with increasing slope from K to Li. Nonetheless, there are discrete differences in the dependence due to composition of the glass. Based on the results of this study, the obtained linear calibration trend can be used only for an approximate determination and not as a routine quantification of ferric content.

Magnetite (Fe3O4) is an iron ore mineral that is globally mined especially for steel production. It is denser (5.15 g/cm3) than Earth’s crust (~2.7 g/cm3) and is expected to accumulate at the bottom of melt-rich magma reservoirs. However, recent studies revealed heterogeneous fluid bubble nucleation on oxide minerals such as magnetite during fluid degassing in volcanic systems. To test if the attachment on fluid bubbles is strong enough to efficiently float magnetite in silicate magma, decompression experiments were conducted at geologically relevant magmatic conditions with subsequent annealing to simulate re-equilibration after decompression. The results demonstrate that magnetite-bubble pairs do ascend in silicate melt, accumulating in an upper layer that grows during re-equilibration. This outcome contradicts the paradigm that magnetite must settle gravitationally in silicate melt.

The viscosity of two series of synthetic alkali silicates, corresponding to Al-bearing pantelleritic and Al-free tri-silicate compositions, has been investigated as a function of temperature, iron redox and Na/(Na + K) ratio. Low temperature (708–1000 K) viscosities were determined by the micropenetration technique in the 10 9.6 to 10 13.6 Pa s range. The effect of Fe 2 + /Fe tot , from 0.15 to 0.86, was explored for [Na/(Na + K)] ratios from 0 to 1. The results demonstrate a strong decrease of viscosity with the replacement of Na for K in both the Al-bearing and Al-free compositions. In the Al-bearing pantelleritic glasses (Ebu) the viscosity as well as the activation energy for viscous flow decrease with an increase of Fe 2 + /Fe tot from 0.15 to 0.76. In contrast, no measurable changes in viscosity occur in the Al-free tri-silicate glasses (NFS and KFS) as Fe 2 + /Fe tot ratio varies from 0.15 to 0.86. The comparison of the pantelleritic glasses with peralkaline compositions from the literature stresses the strong influence of iron redox on the overall viscosity of such melts. This suggests that the contribution of iron species should be accounted for in the calculation of agpaitic index (AI) if magma Fe 3 + contents are known. One peculiarity of peralkaline magmas is the excess of alkali to alumina, which generally results in lower viscosities of pantelleritic liquids compared with more common metaluminous rhyolites and exerts a primary control of the rheological behaviour of these melts. Our new viscosity data, combined with existing literature, allow more accurate constraints on the nature and eruption of the pantelleritic magmas. Moreover, the present experimental study can be used to improve the viscosity models that mostly do not take in consideration parameters as iron redox in the viscosity prediction.

We determined the viscosity and heat capacity of a series of two basaltic liquids containing H 2 O, F, H 2 O + CO 2 , H 2 O + F, and H 2 O + CO 2 + F. One was a natural calc-alkaline basalt from Fuego volcano, Guatemala, and the other was an Fe-free synthetic analog. The viscosity measurements were performed in the low-temperature, high-viscosity range (~ 10 9 –10 12 Pa s) just above the glass transition, where the kinetics of volatile exsolution are slow. Differential scanning calorimetry measurements were performed at atmospheric pressure from room temperature up to ~ 100 K above the glass transition. The water contents ranged from nominally anhydrous to 3 wt.% H 2 O, with F contents up to 2 wt.%, and CO 2 contents up to 0.2 wt.%. Volatiles do not noticeably affect the heat capacity of glasses. The glass transition temperatures obtained from calorimetry and viscometry are in good agreement. Water has a strong viscosity-reducing effect on basaltic melts. F has a measurable viscosity-reducing effect in basaltic melts, but it is significantly smaller than that of water. The combined effects of H 2 O and F on viscosity appear to be additive on a wt.% basis. Both the effects of H 2 O and F on basaltic melts are smaller than those for more polymerized melts. Small quantities of CO 2 do not measurably affect basaltic melt viscosity, at least in the presence of > 1 wt.% water. Future viscosity models incorporating fluorine need to account for the compositional dependence of its effects on dry and hydrous melts.

Magnetite from hydrothermal ore deposits can contain up to tens of thousands of parts per million (ppm) of elements such as Ti, Si, V, Al, Ca, Mg, Na, which tend to either structurally incorporate into growth and sector zones or form mineral micro- to nano-sized particles. Here, we report micro- to nano-structural and chemical data of hydrothermal magnetite from the Los Colorados iron oxide–apatite deposit in Chile, where magnetite displays both types of trace element incorporation. Three generations of magnetites (X–Z) were identified with concentrations of minor and trace elements that vary significantly: SiO2, from below detection limit (bdl) to 3.1 wt%; Al2O3, 0.3–2.3 wt%; CaO, bdl–0.9 wt%; MgO, 0.02–2.5 wt%; TiO2, 0.1–0.4 wt%; MnO, 0.04–0.2 wt%; Na2O, bdl–0.4 wt%; and K2O, bdl–0.4 wt%. An exception is V2O3, which is remarkably constant, ranging from 0.3 to 0.4 wt%. Six types of crystalline nanoparticles (NPs) were identified by means of transmission electron microscopy in the trace element-rich zones, which are each a few micrometres wide: (1) diopside, (2) clinoenstatite; (3) amphibole, (4) mica, (5) ulvospinel, and (6) Ti-rich magnetite. In addition, Al-rich nanodomains, which contain 2–3 wt% of Al, occur within a single crystal of magnetite. The accumulation of NPs in the trace element-rich zones suggest that they form owing to supersaturation from a hydrothermal fluid, followed by entrapment during continuous growth of the magnetite surface. It is also concluded that mineral NPs promote exsolution of new phases from the mineral host, otherwise preserved as structurally bound trace elements. The presence of abundant mineral NPs in magnetite points to a complex incorporation of trace elements during growth, and provides a cautionary note on the interpretation of micron-scale chemical data of magnetite.

Iron oxide copper-gold (IOCG) and Kiruna-type iron oxide-apatite (IOA) deposits are commonly spatially and temporally associated with one another, and with coeval magmatism. Here, we use trace element concentrations in magnetite and pyrite, Fe and O stable isotope abundances of magnetite and hematite, H isotopes of magnetite and actinolite, and Re-Os systematics of magnetite from the Los Colorados Kiruna-type IOA deposit in the Chilean iron belt to develop a new genetic model that explains IOCG and IOA deposits as a continuum produced by a combination of igneous and magmatic-hydrothermal processes. The concentrations of [Al + Mn] and [Ti + V] are highest in magnetite cores and decrease systematically from core to rim, consistent with growth of magnetite cores from a silicate melt, and rims from a cooling magmatic-hydrothermal fluid. Almost all bulk δ 18 O values in magnetite are within the range of 0 to 5‰, and bulk δ 56 Fe for magnetite are within the range 0 to 0.8‰ of Fe isotopes, both of which indicate a magmatic source for O and Fe. The values of δ 18 O and δD for actinolite, which is paragenetically equivalent to magnetite, are, respectively, 6.46 ± 0.56 and-59.3 ± 1.7‰, indicative of a mantle source. Pyrite grains consistently yield Co/Ni ratios that exceed unity, and imply precipitation of pyrite from an ore fluid evolved from an intermediate to mafic magma. The calculated initial 187 Os/ 188 Os ratio (Osi) for magnetite from Los Colorados is 1.2, overlapping Osi values for Chilean porphyry-Cu deposits, and consistent with an origin from juvenile magma. Together, the data are consistent with a geologic model wherein (1) magnetite microlites crystallize as a near-liquidus phase from an intermediate to mafic silicate melt; (2) magnetite microlites serve as nucleation sites for fluid bubbles and promote volatile saturation of the melt; (3) the volatile phase coalesces and encapsulates magnetite microlites to form a magnetite-fluid suspension; (4) the suspension scavenges Fe, Cu, Au, S, Cl, P, and rare earth elements (REE) from the melt; (5) the suspension ascends from the host magma during regional extension; (6) as the suspension ascends, originally igneous mag-netite microlites grow larger by sourcing Fe from the cooling magmatic-hydrothermal fluid; (7) in deep-seated crustal faults, magnetite crystals are deposited to form a Kiruna-type IOA deposit due to decompression of the magnetite-fluid suspension; and (8) the further ascending fluid transports Fe, Cu, Au, and S to shallower levels or lateral distal zones of the system where hematite, magnetite, and sulfides precipitate to form IOCG deposits. The model explains the globally observed temporal and spatial relationship between magmatism and IOA and IOCG deposits, and provides a valuable conceptual framework to define exploration strategies.

In this study the effect of oxygen fugacity (fO2) on the oxidation state and coordination of Fe was investigated in different alkali trisilicate glasses (Rb2Si3O7 = RFS, K2Si3O7 = KFS; Na2Si3O7 = NFS; Li2Si3O7 = LFS) doped with ~ 5 wt.% of Fe2O3 with main focus on K- and Na-bearing compositions. Most of the experiments were conducted at ambient pressure in a gas mixing furnace at 1250 °C with controlled redox conditions (log fO2/bar: − 0.68 to − 16.18). The quenched glasses were analyzed using several methods. Analyses by a colorimetric wet chemistry method revealed a continuous increase in Fe2 +/Fetotal towards more reducing conditions without reaching 100% Fe2 + even at extremely reducing conditions (range of Fe2 +/Fetotal: from 0.08 in air to 0.93 in H2 atmosphere). X-ray absorption near edge structure (XANES) spectroscopy shows an increase of Fe coordination with decreasing ionic radius of the coexisting alkali, while the average coordination number seems to be independent on the oxidation state of iron aside from the largest studied alkali Rb, which seems to support lower coordinated Fe (tetrahedral) at more oxidizing conditions. The Fe2 +/Fetotal ratios inferred by XANES, using an intensity ratio based calibration of Wilke et al. (2004), are systematically higher by 10% compared to the wet chemistry results of this study, which may be due to the different external Fe2 +/Fetotal determination method (Mossbauer spectroscopy) used in their calibration. A new calibration curve based on wet chemistry and centroid positions is proposed for alkali silicate glasses. In optical spectroscopy, the position of the main Fe2 +-related peak shifts to lower wavenumbers with increasing ionic radius of the incorporated alkali and with increasing abundance of ferrous iron. Absorption coefficients eFe(II) and eFe(III) were calculated for the absorbance band at ~ 9000 and ~ 26,000 cm− 1, respectively. A decrease in eFe(II) was detected with decreasing ionic radius of the incorporated alkalis (eFe(II)KFS = 31.8 ± 2.6 L·mol− 1·cm− 1, eFe(II)NFS = 30.7 ± 2.3 L·mol− 1·cm− 1 and eFe(II)LFS = 23.6 ± 1.7 L·mol− 1·cm− 1). Finally, the results of this study are compared with recent models, which predict fO2 based on the knowledge of the Fe2 +/Fetotal ratio. All models overestimate Fe2 +/Fetotal in alkali silicate melts at very reducing conditions probably due to an unanticipated stabilization of Fe3 + by adjacent Fe2 +.

Kiruna-type iron oxide-apatite (IOA) deposits are an important source of Fe ore, and two radically different processes are being actively investigated for their origin. One hypothesis invokes direct crystallization of immiscible Fe-rich melt that separated from a parent silicate magma, while the other hypothesis invokes deposition of Fe-oxides from hydrothermal fluids of either magmatic or crustal origin. Here, we present a new model based on Fe and O stable isotopes and trace and major element geochemistry data of magnetite from the ~350 Mt Fe Los Colorados IOA deposit in the Chilean iron belt that merges these divergent processes into a single sequence of events that explains all characteristic features of these curious deposits. We propose that concentration of magnetite takes place by the preferred wetting of magnetite, followed by buoyant segregation of these earlyformed magmatic magnetite-bubble pairs, which become a rising magnetite suspension that deposits massive magnetite in regionalscale transcurrent faults. Our data demonstrate an unambiguous magmatic origin, consistent with the namesake IOA analogue in the Kiruna district, Sweden. Further, our model explains the observed coexisting purely magmatic and hydrothermal-magmatic features and allows a genetic connection between Kiruna-type IOA and iron oxide-copper-gold deposits, contributing to a global understanding valuable to exploration efforts.

Glasses produced from decompression experiments conducted by Fiege et al. (2014a) were used to investigate the fractionation of sulfur isotopes between fluid and andesitic melt upon magma degassing. Starting materials were synthetic glasses with a composition close to a Krakatau dacitic andesite. The glasses contained 4.55–7.95 wt% H2O, ∼140 to 2700 ppm sulfur (S), and 0–1000 ppm chlorine (Cl). The experiments were carried out in internally heated pressure vessels (IHPV) at 1030 °C and oxygen fugacities (fO2) ranging from QFM+0.8 log units up to QFM+4.2 log units (QFM: quartz–fayalite–magnetite buffer). The decompression experiments were conducted by releasing pressure (P) continuously from ∼400 MPa to final P of 150, 100, 70 and 30 MPa. The decompression rate (r) ranged from 0.01 to 0.17 MPa/s. The samples were annealed for 0–72 h (annealing time, tA) at the final P and quenched rapidly from 1030 °C to room temperature (T). The decompression led to the formation of a S-bearing aqueous fluid phase due to the relatively large fluid–melt partitioning coefficients of S. Secondary ion mass spectrometry (SIMS) was used to determine the isotopic composition of the glasses before and after decompression. Mass balance calculations were applied to estimate the gas–melt S isotope fractionation factor αg-m. No detectable effect of r and tA on αg-m was observed. However, SIMS data revealed a remarkable increase of αg-m from ∼0.9985 ± 0.0007 at >QFM+3 to ∼1.0042 ± 0.0042 at ∼QFM+1. Noteworthy, the isotopic fractionation at reducing conditions was about an order of magnitude larger than predicted by previous works. Based on our experimental results and on previous findings for S speciation in fluid and silicate melt a new model predicting the effect of fO2 on αg-m (or Δ34Sg–m) in andesitic systems at 1030 °C is proposed. Our experimental results as well as our modeling are of high importance for the interpretation of S isotope signatures in natural samples (e.g., melt inclusions or volcanic gases).

The individual influences of F, B and P on viscosity of hydrous pegmatite forming melts have been determined experimentally. A starting glass composition (68.01 wt.% SiO 2 , 20.14 wt.% Al 2 O 3 , 7.73 wt.% Na 2 O and 4.26 wt.% K 2 O, Al / (Na + K) = 1.16) was doped with different amounts of F (up to 4.81 wt.%), B 2 O 3 (0.93 wt.%) and P 2 O 5 (up to 2.98 wt.%). The viscosity of melts containing 0.08 to 6.15 wt.% H 2 O was determined in the high and low viscosity range using the micropenetration technique and the falling sphere method, respectively. Falling sphere experiments were carried out at 200 to 650 MPa and 1173 to 1530 K. Micropenetration measurements were performed in the temperature range of 586 to 1124 K at ambient pressure. For all compositions a large decrease of viscosity upon hydration was observed, consistent with previous findings. The results also confirm that the viscosity decreases with the addition of F at all investigated temperatures. This decrease is more pronounced at low temperature and at low water content. According to our data, P and B do not play a major role on viscous flow in water-rich systems. However, the depolymerizing effect of H 2 O and F is not sufficient to explain very low viscosities of complex highly fractionated melts containing H 2 O, F, B, P and Li (Bartels et al., 2011). Thus, although we confirm that F is clearly a fluxing agent, Li must play a crucial role in lowering the viscosity of natural pegmatite forming melts and combined effects between different constituents need to be taken under consideration.

Iron oxide-apatite (IOA) deposits are an important source of iron and other elements (e.g., REE, P, U, Ag and Co) vital to modern society. However, their formation, including the namesake Kiruna-type IOA deposit (Sweden), remains controversial. Working hypotheses include a purely magmatic origin involving separation of an Fe-, P-rich, volatile-rich oxide melt from a Si-rich silicate melt, and precipitation of magnetite from an aqueous ore fluid, which is either of magmatic-hydrothermal or non-magmatic surface or metamorphic origin. In this study, we focus on the geochemistry of magnetite from the Cretaceous Kiruna-type Los Colorados IOA deposit (~350. Mt Fe) located in the northern Chilean Iron Belt. Los Colorados has experienced minimal hydrothermal alteration that commonly obscures primary features in IOA deposits. Laser ablation-inductively coupled plasma-mass spectroscopy (LA-ICP-MS) transects and electron probe micro-analyzer (EPMA) wavelength-dispersive X-ray (WDX) spectrometry mapping demonstrate distinct chemical zoning in magnetite grains, wherein cores are enriched in Ti, Al, Mn and Mg. The concentrations of these trace elements in magnetite cores are consistent with igneous magnetite crystallized from a silicate melt, whereas magnetite rims show a pronounced depletion in these elements, consistent with magnetite grown from an Fe-rich magmatic-hydrothermal aqueous fluid. Further, magnetite grains contain polycrystalline inclusions that re-homogenize at magmatic temperatures (>850. °C). Smaller inclusions ( 500. ppm) concentrations.

The appropriate treatment of an injury to a single arterial vessel of the calf is still a matter of discussion. Isolated injury of one of the calf arteries is generally not considered to cause severe ischemia of the leg. Other factors such as the degree of concomitant trauma to bones, nerves, veins and soft tissue, which may impair collateral circulation, seem to represent the real threat for the survival of the extremity. On the other hand, high numbers of amputations were reported after the Second World War following ligation of an injured single vessel of the calf. Concomitant injuries are poorly documented in these reports. Consequently a good physical examination as well as arteriography, duplex ultrasound scan and a high index of suspicion are mandatory to evaluate the impaired circulation of the calf and to prevent hasty ligation of a single vessel.

Dynamic cooling-induced solidification experiments were run using six silicate glasses along the basalt–rhyolite join (B100 = 100 wt.% of basalt, R100 = 100 wt.% of rhyolite), i.e. B100, B80R20, B60R40, B40R60, B20R80 and R100; the glasses directly quenched from 1300 °C after a dwell of 120 min (experiment E0) contain 50–400 ppm H2O, ≪ 1 area% μm-sized bubble, and Fe2 +/Fetot between 0.34 and 0.46. Experiments were performed in Pt capsules at room pressure and fO2 of air, between 1300 and 800 °C using three different cooling rates of 0.0167, 3 and 30 °C/min; these cooling rates were run two times: E1–E2 experiments at 0.0167 °C/min, S1–E3 at 3 °C/min, and E4–E5 at 30 °C/min. In experiments E1 to E5, samples were annealed for 120 min at 1300 °C, whereas in the experiment S1 the samples were firstly heated for 30 min at 1400 °C followed by a dwell time of 2400 min at 1300 °C before cooling. In none of the run-products preferential crystallization at the melt/gas interface was observed. B100, B80R20 and B60R40 run-products have a low tendency to preferentially crystallize on Pt walls, while B40R60, B20R80 and R100 are not affected by the presence of Pt substrata. All run-products show homogeneous textures, except for B60R40 and B40R60 at 0.0167 °C/min in the E1 experiment. The duplicates of B40R60 and B60R40 at 0.0167 °C/min and B100 at 30 °C/min show differences in crystal content (> 4 and

Even among the uncommon aneurysms of the visceral arteries the aneurysm of the pancreaticoduodenalis artery is considered a rarity. Etiologically, numerous factors must be taken into account, the most significant one being arteriosclerosis. The clinical presentation is unspecific and ambiguous. CT and, above all, intra-arterial DSA allow for a diagnosis. A generous consideration of indicating operative intervention, even in asymptomatic patients, is especially justified because of the imminent risk of rupture. The preferable therapy consists of elimination of the aneurysm either conventionally by proximal and distal ligature of the pancreaticoduodenalis artery or endovascularly by embolization. In the future a treatment with coated stents (TPEG) would also seem possible. Special attention must be paid to concomitant occlusive disease in other visceral arteries since measures for vessel reconstruction may be required because of intraoperative impairment of the collateral circulation. We report on the rupture of an aneurysm of the pancreaticoduodenal inferior artery in association with celiac axis occlusion.

Traumatische arteriovenose Fisteln sind eine seltene Komplikation nach Gefasverletzungen. Wir berichten uber einen Fall einer traumatischen arteriovenosen Fistel am Hals nach einer Glassplitterverletzung. Die klinische Untersuchung ergab lediglich ein tastbares Schwirren („thrill“) und auskultatorisch ein kontinuierliches Maschinengerausch. Es bestanden keine kardialen Insuffizienzzeichen. Die apparative Diagnostik mit Farbduplexsonographie und Arteriographie zeigte eine Fistel zwischen A. thyreoidea superior und V. thyreoidea superior. Die operative Versorgung gelang problemlos. Die Therapie sollte im Fruhstadium erfolgen, dann ist die Behandlung meist einfach und erfolgreich.

Fibrovascular polyps are extremely rare benign neoplasms of the esophagus. The most prominent clinical symptom is enoral tumor regurgitation, which may lead to asphyxiation by pharyngeal impaction. Usually fibrovascular polyps cause dysphagia and progressive weight loss. Diagnosis by endoscopy and barium swallow may be unexpectedly difficult. The most frequent incorrect diagnoses are achalasia or an intramural or mediastinal tumorous mass compressing the esophagus. CT scan and MR imaging are of little help. Small polyps may be resected endoscopically by means of electrocautery or Nd:YAG laser ablation. In most cases, however, surgical resection is required. Since the basis of the polyp is usually located subcricoidally, tumor exposure and resection are achieved by esophagotomy via a left cervical approach. Thoracotomy is seldom required.

The appropriate treatment of an injury to a single arterial vessel of the calf is still a matter of discussion. Isolated injury of one of the calf arteries is generally not considered to cause severe ischemia of the leg. Other factors such as the degree of concomitant trauma to bones, nerves, veins and soft tissue, which may impair collateral circulation, seem to represent the real threat for the survival of the extremity. On the other hand, high numbers of amputations were reported after the Second World War following ligation of an injured single vessel of the calf. Concomitant injuries are poorly documented in these reports. Consequently a good physical examination as well as arteriography, duplex ultrasound scan and a high index of suspicion are mandatory to evaluate the impaired circulation of the calf and to prevent hasty ligation of a single vessel.

Even among the uncommon aneurysms of the visceral arteries the aneurysm of the pancreaticoduodenalis artery is considered a rarity. Etiologically, numerous factors must be taken into account, the most significant one being arteriosclerosis. The clinical presentation is unspecific and ambiguous. CT and, above all, intra-arterial DSA allow for a diagnosis. A generous consideration of indicating operative intervention, even in asymptomatic patients, is especially justified because of the imminent risk of rupture. The preferable therapy consists of elimination of the aneurysm either conventionally by proximal and distal ligature of the pancreaticoduodenalis artery or endovascularly by embolization. In the future a treatment with coated stents (TPEG) would also seem possible. Special attention must be paid to concomitant occlusive disease in other visceral arteries since measures for vessel reconstruction may be required because of intraoperative impairment of the collateral circulation. We report on the rupture of an aneurysm of the pancreaticoduodenal inferior artery in association with celiac axis occlusion.

Arteriovenous fistula is a rare complication following vascular trauma. We report a case of an arteriovenous fistula of the neck after a penetrating injury. The only presenting symptoms were a thrill and a machinery murmur. There were no signs of cardiac insufficiency. Duplex scan and arteriography detected an arteriovenous fistula between the superior thyroid artery and the superior thyroid vein. Surgical therapy was straight-forward. Treatment should be carried out as soon as possible, and is then usually simple and successful.

There is a high mortality of bacterial aortitis particularly as it is usually not recognized before the stage of rupture. Therefore the disease should early be considered in obscure febrile conditions. Problems of diagnosis and therapy are discussed on two own cases. A 63-year old man had a rupture of a small infrarenal aortic aneurysm in the course of salmonella sepsis, a 79-year old woman had a pyogenic osteomyelitis of a lumbar vertebra that spread to the aorta and caused its rupture. In both cases surgical treatment consisted of bleeding control followed by in-situ reconstruction.

Although studies have proposed that iron oxide-apatite (IOA) deposits may represent the deeper roots of some Andean iron oxide copper-gold (IOCG) systems, their genetic links remain obscure and controversial. A key question when considering an integrated genetic model is whether a magmatic-hydrothermal fluid that precipitates massive magnetite will continue transporting significant amounts of dissolved Fe, Cu, and Au after IOA precipitation. Here we provide new geochemical data for accessory pyrite from the Los Colorados IOA deposit in the Chilean iron belt that confirm the role of this sulfide as a relevant repository for economic metals in IOA deposits. Pyrite occurs at Los Colorados as disseminated grains and as veinlets associated with magnetite and actinolite that postdate the main igneous magnetite stage. Electron probe microanalysis (EPMA) data for pyrite show anomalously high Co and Ni concentrations (up ~3.9 and ~1.5 wt %, respectively) and relatively high As contents (100s of ppm to a maximum of ~2,000 ppm). When combined with results from secondary ion mass spectrometry (SIMS) spot analyses, pyrite data show significant amounts of Cu that range from sub-ppm values (~100 ppb) up to 1,000s of ppm, plus nonnegligible concentrations of Zn, Pb, Cd, Sb, Se, and Te (up to ~100 ppm). The highest contents of Cu measured (wt % level) most likely record the presence of Cu-bearing submicron-sized mineral inclusions. Contents of Au and Ag are up to ~1 and 10 ppm, respectively, with maximum concentrations that can rise up to ~800 ppm Au and ~300 ppm Ag due to the presence of submicron-sized inclusions. The high Co/Ni ratios of pyrite from Los Colorados are consistent with a magmatic-hydrothermal origin associated with a greater mafic affinity, compared to pyrite from porphyry Cu deposits. Furthermore, the geochemical signature of Los Colorados pyrite shares important similarities of composition and microtexture with the few published data for pyrite from IOCG deposits (e.g., Ernest Henry, Australia, and Manto Verde, Chile). These findings, combined with recent geochemical and isotopic studies that support an igneous origin for the dike-shaped magnetite orebodies at Los Colorados, point to a magmatic source of mafic to intermediate composition for the contained metals, and support the hypothesis that IOA systems can source Fe-Cu-Au-rich fluids. Based on experimental studies, these IOA-derived fluids may continue transporting significant amounts of metals to form IOCG mineralization at shallower levels in the crust.