The geological origins of iron oxide-apatite (IOA) rocks, important resources for iron and rare-earth elements, are intensely debated. Using triple oxygen isotope data, we here show that magnetite from IOA deposits near Kiruna, northern Sweden, and related igneous rocks contain high concentrations of oxygen derived from evaporitic sulfate. To explain these observations, we propose that the Kiruna IOA assemblage formed in response to massive assimilation of evaporites by silicate magmas. sulfate from the evaporites would have oxidised ferrous iron in these magmas, facilitating the formation of immiscible ferric iron-rich melts and/or magnetite, which then separated from the magmas to form ore deposits. Ferric iron-bearing fluids with low Δ'17O values, exsolved from the silicate magmas or the ore-forming melts, would have crystallised additional magnetite. An inventory study reveals that Proterozoic and Cambrian IOA deposits have lower Δ'17O values than post-Cambrian IOA deposits. This shows that the Δ'17O values of global IOA deposits reflect the changing isotope composition of atmospheric O2 incorporated by evaporitic sulfate over time, and demonstrates that oxygen released from evaporitic sulfate is a common component in IOA deposits.

Kiruna-type iron oxide-apatite (IOA) deposits contain Fe, P, and REE resources and have formed intermittently over 2 billion years, e.g., the similar to 1880 Ma Kiruna, similar to 2 Ma El Laco, and similar to 0.87 Ma Vetas del Maule IOA mineralizations. However, the cause of their time-space distribution and connection to Earth's evolution remains unclear. Here, we integrate geological and geochemical data to track optimal conditions for IOA formation through time. As previously documented, we find that IOA deposits mainly formed in subduction-related extensional settings with mantle contributions. Additionally, data indicate that peak numbers and tonnages of IOA deposits coincide with extended continental arc activity worldwide, when the likelihood is high for generating chlorinerich magmas likely favorable for IOA mineralization, and high for continental arc-magma reacting with crustal salt sources that either coeval with or predate IOA. Subduction-related silicate melts and associated magmatic fluids may have interacted with crustal salt sources such as magmatic or basinal brines, evaporites, or carbonates, genetically promoting IOA formation by amplifying volatile and metal enrichment. The coincidence of peak times for IOA formation and extensive evaporite formation, together with evidence from natural IOA deposits and petrological experiments, supports the hypothesis that magmatic-hydrothermal system-evaporite reaction promotes IOA formation. Evaporites, either pre-existing or coeval with IOA-forming magmas, could be incorporated into the IOA-forming system at variable depths and magmatic-hydrothermal stages. Marginally earlier/ coeval-IOA evaporite indicates a potential warm climate control. A few IOA deposits in subduction-induced collisional settings expand the potential exploration targets of IOA deposits beyond coevality with the continental magmatic arc. Therefore, IOA deposits captured the interplay between deep processes and surficial reservoirs, reflecting the secular coevolution of Earth's lithosphere and atmosphere, two seemingly unrelated spheres.

The Malmberget and Kiruna iron-oxide-apatite (IOA) deposits in northern Sweden are two of the oldest IOA deposits, but their full ore-forming tale is not yet unambiguously constrained. Apatite from Malmberget IOA deposit was analyzed for U-Pb age, Sr isotopes and trace elements for better understanding its formation and evolution. Limited zoning and relatively homogeneous trace element composition of apatite show no signs of hydrothermal alteration, supporting an ortho-magmatic origin of the Malmberget IOA deposit. Apatite Sr iso-topes (0.7069-0.7078) indicate a mildly enriched (juvenile) source. The apatite U-Pb age is-1809 & PLUSMN; 8 Ma, interpreted as the time of amphibolite-facies recrystallization (& GE;550 degrees C) of the ore, a process that homogenized the dominantly primary igneous apatite composition. Cooling through the closure temperature of apatite U-Pb system occurred shortly after 1.80 Ga preserving the high-T age. Combined with previous studies, the geological history of the Kiruna and Malmberget IOA deposits can be summarized as: i) both were emplaced at-1.88 Ga, ii) they suffered regional metamorphism at-1.80 Ga (low-grade in Kiruna, including hydrothermal overprint), later hydrothermal overprints at iii) c. 1.73 Ga and iv) c. 1.63 Ga, possibly also at v) c. 1.5 Ga and finally clay formation at vi) c. 0.9 Ga.

Sulfide mineralisation types in the Kiirunavaara and Per Geijer iron oxide-apatite deposits in the Kiruna district have been studied by mineralogical means to infer a preliminary potential for future by-products of Co, Cu, and sulfuric acid. Based on the dominance of pyrite over other sulfides, e.g., chalcopyrite and bornite-digenite solid solution series minerals, the main potential can be attributed to pyrite as the source of sulfuric acid. Significant concentrations of cobalt in pyrite types from both deposits may indicate an economic potential if proven processable in the future. Copper minerals have low concentrations of deleterious elements but occur less frequently compared to pyrite, so their potential is not yet tangible. Further studies are planned to evaluate the full potential of sulfides.

The Kiruna area in northern Sweden hosts the classic Kiruna iron-oxide-apatite (IOA) deposit. The area has experienced complex tectonic processes, including basin formation, inversion, and hydraulic fracturing events from -1.9 Ga and possibly down to -1.5 Ga. However, the nature, timing and links of hydrothermal events related to this tectono-thermal evolution are unclear, impairing our full understanding of IOA formation processes. Here, we use multiple analytical methods to study apatite from the Kiirunavaara orebody. Electron microscopy, cathodoluminescence images, and rare earth element contents of the studied apatite indicate alteration by hydrothermal fluids. U-Pb Tera-Wasserburg lower intercept age of the altered apatite is 1800 & PLUSMN; 36 Ma, indicating a contemporaneous hydrothermal event in the central Kiruna area during coeval basin inversion. Sr isotopes obtained in these altered apatites, ranging from 0.709 to 0.713, may represent intermediate Sr isotope values between primary apatite and secondary fluid resetting. The relatively high but scattered 87Sr/86Sr ratios suggest that country rocks of the IOA deposits and other regional intermediate-felsic igneous rocks with old or enriched components are most likely the source of the fluids. Previous studies have revealed two hydrothermal events in the IOA ores at roughly 1.73 Ga and 1.63 Ga. Thus, fluids sourced from the host rocks of the regional IOA deposits and regional granitoids have circulated episodically at 1.80 Ga, 1.73 Ga, 1.63 Ga and possibly 1.5 Ga in the Kiruna area and have partly redistributed rare earth elements formed during the primary 1.88 Ga IOA formation event.

Sulfides are present in various ores and settings in the Kiruna district. Pyrite is most common and often associated with chalcopyrite. Pyrite Co/Ni ratios are mostly high-very high, suggesting magmatic/high-T hydrothermal origins, but stretching to lower values (Ts) in some types, while chalcopyrite is mainly late, interstitial. Depositional episodes probably span several hundred Ma but are not geochronologically confirmed yet.

"Emendment to the term complex in: “Guide for geological nomenclature in Sweden” (Kumpulainen 2016)." GFF, ahead-of-print(ahead-of-print), p. 1 Disclosure statementNo potential conflict of interest was reported by the author(s).

Luossavaara-Kiirunavaara Aktiebolag's Kiirunavaara Mine is an iron ore mine located in Sweden's Lapland.On 18 May 2020, a seismic event of moment magnitude (Mw) 4.2, calculated on the Swedish National Seismic Network (SNSN) and international systems, caused extensive damage to tunnel infrastructure and halted production in Block 22.A study was conducted to investigate the causes and evaluate how to safely restart mining.As discussed in this paper, the study included detailed reviews of existing datasets of core logging, drift mapping, and damage mapping following the event.In addition, new data was collected from drillholes targeting the interpreted area of the seismic source.Geotechnical data interrogation, structural modelling, and rock mass characterisation served to characterise the seismic source area in greater detail, leading to a full description of the crush zone: a zone of weaker rock mass which obliquely cuts the orebody -interpreted as an early extensional fault breccia of probable hydrothermal origin.The crush zone is identified to be susceptible to damage resulting from the seismic event.Associated with the crush zone, strong porphyry intrusions have resulted in complex lithological-structural relationships.This paper highlights the investigation into the source area of the seismic event and demonstrates how geotechnical data integration can give important insights to major mine planning decisions.

ABSTRACT Arrheniusite-(Ce) is a new mineral (IMA 2019-086) from the Östanmossa mine, one of the Bastnäs-type deposits in the Bergslagen ore region, Sweden. It occurs in a metasomatic F-rich skarn, associated with dolomite, tremolite, talc, magnetite, calcite, pyrite, dollaseite-(Ce), parisite-(Ce), bastnäsite-(Ce), fluorbritholite-(Ce), and gadolinite-(Nd). Arrheniusite-(Ce) forms anhedral, greenish-yellow translucent grains, exceptionally up to 0.8 mm in diameter. It is optically uniaxial (–), with ω = 1.750(5), ε = 1.725(5), and non-pleochroic in thin section. The calculated density is 4.78(1) g/cm3. Arrheniusite-(Ce) is trigonal, space group R3m, with unit-cell parameters a = 10.8082(3) Å, c = 27.5196(9) Å, and V = 2784.07(14) Å3 for Z = 3. The crystal structure was refined from X-ray diffraction data to R1 = 3.85% for 2286 observed reflections [Fo > 4σ(Fo)]. The empirical formula for the fragment used for the structural study, based on EPMA data and results from the structure refinement, is: (Ca0.65As3+0.35)Σ1(Mg0.57Fe2+0.30As5+0.10Al0.03)Σ1[(Ce2.24Nd2.13La0.86Gd0.74Sm0.71Pr0.37)Σ7.05(Y2.76Dy0.26Er0.11Tb0.08Tm0.01Ho0.04Yb0.01)Σ3.27Ca4.14]Σ14.46(SiO4)3[(Si3.26B2.74)Σ6O17.31F0.69][(As5+0.65Si0.22P0.13)Σ1O4](B0.77O3)F11; the ideal formula obtained is CaMg[(Ce7Y3)Ca5](SiO4)3(Si3B3O18)(AsO4)(BO3)F11. Arrheniusite-(Ce) belongs to the vicanite group of minerals and is distinct from other isostructural members mainly by having a Mg-dominant, octahedrally coordinated site (M6); it can be considered a Mg-As analog to hundholmenite-(Y). The threefold coordinated T5 site is partly occupied by B, like in laptevite-(Ce) and vicanite-(Ce). The mineral name honors C.A. Arrhenius (1757–1824), a Swedish officer and chemist, who first discovered gadolinite-(Y) from the famous Ytterby pegmatite quarry.

What happens when an organization requires its employees to work from home during a pandemic that needs to be managed? This research in progress article focuses on TELCO-ALPHA and the transition of their emergency operation centre (EOC) to digital and distributed. A qualitative research method approach was applied and liminality has been used as lens to investigate the shift from analog to digital. Focus has been on understanding the transition and how they handled ambiguity within the organization when their crisis management moved online. The transition was successful, and two areas were identified as important to this success: 1. TELCO-ALPHA used IT that the staff in the crisis organization already had experience of working with prior to the Covid-19 pandemic;2. TELCO-ALPHA ran crisis management team meetings as they would run regular business meetings. There was no new "crisis management structure" at the meetings. © 2021 Information Systems for Crisis Response and Management, ISCRAM. All rights reserved.

The northern Norrbotten region in Sweden hosts abundant iron-oxide apatite (IOA) deposits including Kiirunavaara, the type locality for Kiruna-type deposits, and Malmberget. Felsic and intermediate metavolcanic rocks hosting the Malmberget IOA deposit contain oscillatory zoned zircon which yield magmatic U-Pb SIMS ages of 1885 +/- 6 Ma and 1881 +/- 6 Ma, respectively. Metamorphic rims on zircon from these rocks yield 1797 +/- 7 Ma and 1775 +/- 6 Ma, respectively, and record the age of the latest Svecofennian regional metamorphic event in the Gallivare area, tentatively interpreted as regional contact metamorphism. Two granite dikes that cut the ore yield U-Pb zircon emplacement ages of 1790 +/- 6 Ma and 1791 +/- 7 Ma, respectively, overlapping with the metamorphic overgrowths, and set a lower age limit for ore formation in the Malmberget IOA deposit. Rocks hosting the Malmberget IOA deposit have an alkalic to alkali-calcic affinity with a geochemical signature that favors a continental-arc, transitional to extensional setting. These rocks are suggested to have been generated in a back-arc region, in response to subduction beneath the craton margin retreating to the SW or W. The obtained ages and geochemical signatures of these rocks coincide well with the regionally defined Kiirunavaara group rocks, hosting several other IOA deposits in northern Sweden.

Ca-REE fluorocarbonates occur in various geological environments, including A-type granite systems. Here we investigate the character and paragenesis of fluorocarbonates in the A-type Rodo rapakivi complex, central Sweden, and their importance for the late stages of felsic magma evolution. Magma evolution is largely controlled by fractionation of the major phases quartz, plagioclase and K-feldspar, but these do not account for the decrease in LREE in the evolved magmas. Allanite or monazite, the major LREE-fractionating accessory minerals in common silicic igneous rocks, have not been encountered. In the Rodo suite, Ca-REE fluorocarbonates occur in rocks of various evolutionary level, typically as interstitial fibrous masses or filling small vugs. In the more evolved rocks, they are generally associated with fluorite and xenotime. In part, they are rich in Fe, Th, and Y. In composition, they range between synchysite and bastnasite (but not pure bastnasite) and seem to involve a number of less well-known intermediate phases. Ca-REE fluorocarbonate chemistry covaries with whole rock chemistry such that they become depleted in LREE and enriched in Y+HREE with magma evolution. This suggests that fluorocarbonates have crystallized in fluid 'bubbles' from fluids expelled from the evolving high-level, F- and CO2-rich magma system at various stages, which resulted in a progressive depletion in LREE coupled with enrichment in LREE in the residual magmas.

Kiruna-type apatite-iron-oxide ores are key iron sources for modern industry. The origin of the Kiruna-type apatite-iron-oxide ores remains ambiguous, however, despite a long history of study and a concurrently intense scientific debate. Diverse ore-forming processes have been discussed, comprising low-temperature hydrothermal processes versus a high-temperature origin from magma or magmatic fluids. We present an extensive set of new and combined iron and oxygen isotope data from magnetite of Kiruna-type ores from Sweden, Chile and Iran, and compare them with new global reference data from layered intrusions, active volcanic provinces, and established low-temperature and hydrothermal iron ores. We show that approximately 80% of the magnetite from the investigated Kiruna-type ores exhibit δ56Fe and δ18O ratios that overlap with the volcanic and plutonic reference materials (> 800 °C), whereas ~20%, mainly vein-hosted and disseminated magnetite, match the low-temperature reference samples (≤400 °C). Thus, Kiruna-type ores are dominantly magmatic in origin, but may contain late-stage hydrothermal magnetite populations that can locally overprint primary high-temperature magmatic signatures [1] . [1] Troll, V.R., Weis, F.A., Jonsson, E. et al. Global Fe–O isotope correlation reveals magmatic origin of Kiruna-type apatite-iron-oxide ores. Nature Communications 10, 1712 (2019) doi:10.1038/s41467-019-09244-4

Ferriperboeite-(Ce), [CaCe3]a=4[Fe3+Al2Fe2+]a=4[Si2O7][SiO4]3O(OH)2, a new mineral of the gatelite supergroup, from the Nya Bastnas Fe-Cu-REE deposit, Vastmanland, Sweden.

Abstract Zircon ion probe (secondary-ion mass spectrometry or SIMS) data from a set of intrusive rocks emplaced in the vicinity of major ore bodies, as well as from large igneous intrusions in the Gällivare area, gave the following results: (1) the Dundret ultramafic–mafic layered complex (1883±5 Ma), the Aitik granite (1883±5 Ma), the Nautanen diorite (1870±12 Ma), the Vassaravaara ultramafic–mafic layered complex (1798±4 Ma), the Aitik dolerite (1813±9 Ma), the Bergmästergruvan and Sikträsk syenites (1795±4 Ma and 1801±3 Ma, respectively) and the Naalojärvi granite (1782±5 Ma). These data broadly fall within the ranges 1.89–1.87 Ga (early Svecofennian) and 1.80–1.78 Ga (late Svecofennian), but geochronologically allow further subdivision into pulses at 1885–1880, 1875–1870, 1800 and 1780 Ma. During these events, large layered ultramafic–mafic and felsic plutonic rocks were generated with distinct overlap in time suggesting coeval felsic–mafic magmatism. Results also indicate the presence of inherited c. 1.87 Ga zircon crystals in the plutonic rocks at 1.78 Ga, supporting reworking of the previous crust. These data indicate the importance of mantle-derived mafic underplating in the process of crustal magma generation in the region. The c. 1.88 Ga event that generated ultramafic–mafic layered complexes is tentatively suggested to have played an important role in the formation of the Aitik Cu–Au porphyry system. The later event at c. 1.80 Ga, generating voluminous mafic–felsic units, is suggested to be coupled to the regional iron-oxide-copper-gold (IOCG) overprint.

Delhuyarite-(Ce) is a new mineral (IMA no. 2016-091) with ideal formula Ce4Mg(Fe23+W)square(Si2O7)(2)O-6(OH)(2). It is named after Juan and Fausto de Elhuyar (Delhuyar), chemists and metallurgists, who in 1783 isolated tungsten metal for the first time. Associated minerals in the only known sample, from the Nya Bastnas Fe-Cu-REE deposit (Vastmanland, Sweden), include cerite(Ce), tremolite. actinolite, percleveite-(Ce), bastnasite-(Ce), ferriallanite-(Ce), tornebohmite-(Ce), magnetite, chalcopyrite, quartz and scheelite. Delhuyarite-(Ce), which forms subhedral crystals up to 0.3mm long, is brown-black with a dark brown streak and translucent with an adamantine lustre. It is pleochroic in black to rust red and optically biaxial (-). Calculated density and mean refractive index are 5.20 g.cm(-3) and 1.94, respectively. Chemical analyses (electron microprobe) gave (in wt%) La2O3 14.58, Ce2O3 23.29, Pr(2)O(3)1.89, Nd2O3 6.13, Sm2O3 0.74, Gd2O3 0.37, Dy2O3 0.03, Er2O3 0.04, Yb2O3 0.12, Y2O3 0.22, CaO 0.76, Fe2O3 12.86, MgO 2.43, Al2O3 0.73, SiO2 18.16, TiO2 0.09, WO3 15.53, H2Ocalc 1.33, F 0.05, Cl 0.03, O=(F, Cl) -0.03, sum 99.35, corresponding to an empirical formula: (Ce1.89La1.19Nd0.48Pr0.15Sm0.06Gd0.03Y0.03Ca0.18)(Sigma 4.01)(Fe-2(3+).14W0.89Mg0.80Al0.19Ti0.02)(Sigma 4.04)Si4.01O20 (OH1.96F0.04)(Sigma 2), based on 22 O atoms per formula unit (apfu). The presence of H2O is confirmed by IR-spectroscopy, from a strong absorption band at 3495 cm(-1). Delhuyarite-(Ce) is monoclinic, space group C2/m, with unit-cell parameters a = 13.6020(6) angstrom, b = 5.7445(3) angstrom, c = 10.9996(5) angstrom, beta = 100.721(4)degrees, V = 844.47 (6) angstrom(3) and Z = 2 (data for natural crystal). The crystal structure was refined to an R-1 index of 3.9% (natural crystal) and 1.8% (annealed). Delhuyarite-(Ce) has the same structural topology as chevkinitesubgroup minerals, e. g. chevkinite-(Ce). It is the only mineral of the group with a significant content of W6+ = 0.89 apfu. In delhuyarite-(Ce), Mg is dominant at the M1 site as in polyakovite-(Ce); the composition of the M2, M3 and M4 sites is [(Fe23+W square], with M2 being 50% vacant.

The geochemical and isotopic characteristics of metamorphosed Svecofennian mafic dykes from the Dannemora area in the NE part of the Bergslagen region in central Sweden were investigated and compared to mafic intrusive rocks in their vicinity. The dykes, with an inferred age of c. 1860-1870 Ma, are calc-alkaline, sub-alkaline and basaltic in composition and have a mixed subduction and within-plate geochemical affinity. They are the result of mixing of at least three mantle source components with similar basaltic major element composition, but different concentrations of incompatible trace elements. Magma M1 is strongly enriched both in Rare Earth Elements (REE) and High-Field-Strength Elements (HFSE); magma M2 is highly enriched in Large-Ion Lithophile Elements (LILE, except Sr) with only moderate enrichment in HFSE and REE (particularly low in Heavy Rare Earth Elements); and magma M3 is enriched in Sr and has a flat REE profile. Magma M3 also has a somewhat more positive ( depleted) initial epsilon(Nd) value of + 1.8, compared to + 0.4 to + 0.5 for magmas M1 and M2. The magma evolution was controlled by a mixture of fractionation (mainly affecting the compatible elements) and mixing, best seen in the incompatible element concentrations and the Nd isotope data. The basaltic overall composition indicates little or no wholesale contamination by upper continental crust, but the dykes have undergone later metasomatic changes mainly affecting the alkali elements.

The Bastnäs-type deposits, with mineral assemblages of Fe oxides, Ca-Mg silicates, rare earth element (REE) silicates, REE fluorocarbonates, and Cu-Fe-Mo-Bi sulfides, are associated with marble horizons in a strongly Na, K, and/or Mg altered, metavolcanic succession, over a distance of at least 80 km in a SW-NE trending zone in western Bergslagen. Two subtypes occur: (1) enriched (relative to the other type) in light REE (LREE) and Fe, exemplified by the Bastnäs and Rödbergsgruvan deposits, and (2) enriched in heavy REE (HREE), Y, Mg, Ca, and F, represented by deposits in the Norberg district. Bastnäsite hosts primary fluid H2O-CO2 inclusions with salinities of 6–29 eq. wt% CaCl2 and with total homogenization temperatures (Th tot) of ca. 300–400 °C. Subtype 2 has late-stage fluorite with fluid inclusions that show 1–16 eq. wt% NaCl and Th tot of ca. 90–150 °C. Molybdenite Re-Os ages obtained from three deposits are 1,904 ± 6, 1,863 ± 4, and 1,842 ± 4 Ma. Nd isotopic data from five different REE minerals yielded no defined isochron, but a range in εNd (1.88 Ga) of +0.2 to +1.6. The oxygen isotope values (δ18OSMOW) of dolomite and calcite from the associated REE-mineralized skarn and recrystallized carbonate assemblages lie in the range 6.1–8.6 ‰, overlapping with those of the host marbles. Carbon isotope values (δ13CPDB) show typical magmatic signatures of −6.7 to −4.4 ‰, while the host marbles group around ca. −2.4 ‰. The sulfur isotope (δ34SCDT) values of associated sulfides range between −10.8 and +0.2 ‰. The combined evidence suggests REE mineralization, beginning at 1.9 Ga, from mainly Svecofennian, juvenile magmatic (>400 °C) fluids carrying Si, F, Cl, S, CO2, and the REE in addition to other metals; mineralization occurred through reactions with dolomitic layers in the supracrustal units coevally with regional metasomatic alteration associated with fluid circulation through an extensive active volcano–plutonic complex.