Description: The Antarctic Roadmap Challenges (ARC) project identified critical requirements to deliver high priority Antarctic research in the 21st century. The ARC project addressed the challenges of enabling technologies, facilitating access, providing logistics and infrastructure, and capitalizing on international co-operation. Technological requirements include: i) innovative automated in situ observing systems, sensors and interoperable platforms (including power demands), ii) realistic and holistic numerical models, iii) enhanced remote sensing and sensors, iv) expanded sample collection and retrieval technologies, and v) greater cyber-infrastructure to process ‘big data’ collection, transmission and analyses while promoting data accessibility. These technologies must be widely available, performance and reliability must be improved and technologies used elsewhere must be applied to the Antarctic. Considerable Antarctic research is field-based, making access to vital geographical targets essential. Future research will require continent- and ocean-wide environmentally responsible access to coastal and interior Antarctica and the Southern Ocean. Year-round access is indispensable. The cost of future Antarctic science is great but there are opportunities for all to participate commensurate with national resources, expertise and interests. The scope of future Antarctic research will necessitate enhanced and inventive interdisciplinary and international collaborations. The full promise of Antarctic science will only be realized if nations act together.

Description: A bstract Thorogummite has been discredited as a valid mineral species. No type material from the original study was available for analysis. An extensive review of the literature, both recent and historic, reveals the use of the name "thorogummite" for any hydrated, metamict thorite or unidentified alteration product of a Th-bearing mineral. All early studies on "thorogummite" and other alteration products of thorite were performed on heterogeneous mixtures of mostly secondary and metamict materials and must be considered suspect. The validity of Frondel’s (1953) proposed (SiO 4 ) 4– (OH) 4 4– substitution between thorite and thorogummite was examined and shown to be an incomplete solid solution. All compositions in the literature to date are Th- and Si-dominant and must be considered thorite. Furthermore, the majority of the compositions in the literature are outdated and likely do not represent those from crystalline, single-phases. More likely, all so-called "thorogummite" are simply metastable hydrated or metamict thorite with varying volumes of other alteration products. The discreditation has been approved by the IMA Commission on New Minerals, Nomenclature and Classification (Nomenclature Voting proposal 14-B).

Description: Over 10,000 tons of particulate matter (PM) has been emitted over the last 100 years as a result of mining activities in Sudbury, Ontario, Canada. Much of the PM has been deposited in the local soils, causing elevated concentrations of Cu, Ni, Zn, Se, As, and Pb. The goal of this study is to determine the distribution of metals and metalloids in PM in order to draw conclusions about their formation, their weathering, and the mobility of these elements in the local soils. The PM and associated secondary phases have been studied using optical microscopy, SEM, micro-Raman spectroscopy, and laser ablation inductively coupled plasma mass spectrometry. Spherical PM forms during the rapid cooling of hot gasses and is predominantly composed of Cu- and Ni-bearing spinel, silicate, and sulfide mineral inclusions. The collision of precursors of spherical PM with aerosols of residual matte and slag results in the formation of metal- and metalloid-rich outer rims on each sphere. These rims, as well as Fe-silicate and spinel minerals in the silicate-oxide matrix, weather to hematite during a dissolution-precipitation process. Metals and metalloids are released during this process in non-stoichiometric proportions relative to their initial concentration in the spinel, as they have different affinities to sorb on surface sites during their diffusion through the hematite precipitate. Metal-bearing sulfide inclusions alter to sulfate and occasionally into oxide minerals, which are enriched in Ni, Co, and Cu. Particulate matter composed of angular sulfide minerals and NiO particulates is often coated with Fe-Al-hydroxide and aluminosilicate minerals. The coatings contain higher trace-metal and metalloid concentrations than the underlying PM and are thus sinks for metals and metalloids released by other types of PM. The mobility of metals and metalloids in the soils decreases in the sequence Zn 〉 Cu 〉 Ni 〉 Pb and is the result of differences in element adsorption affinities and dissolution rates of phases in the PM.

Description: The crystal structure of the mineral kurilite, a rare silver chalcogenide, was solved using intensity data collected from a twinned crystal of type material from the Prasolovskoe deposit, Kunashir Island, Kuril islands (Russia). The study revealed that the structure is trigonal, space group R 3{macron} , with cell parameters: a 15.8135(18), c 19.618(3) Å, and V 4248.6(9) Å 3 . The refinement had a final R index of 0.0218 for 2513 observed reflections [ I 〉 2( I )] and 0.0265 for all 2776 independent reflections and 193 parameters. Three Te sites, three Se sites, and ten Ag sites occur in the crystal structure of kurilite. The silver cations form various crystal-chemical environments, as is typical of many intermetallic compounds. The Ag positions correspond to the most pronounced probability density function ( pdf ) locations (modes) of diffusion-like paths. The d 10 silver ion distribution was determined by means of a Gram-Charlier development of the atomic displacement factors. Crystal-chemical features are discussed in relation to other copper and silver tellurides and pure metals. The disorder observed for the Ag atoms is compared to that of other natural fast ionic conductors, such as the pearceite-polybasite group minerals. On the basis of information gained from the structural characterization, the Z of the crystal-chemical formula was revised to 18 instead of 15, as previously reported.

Description: Pyrrhotite (Po) from five orebodies (830, 865, 880, 890, and 100 OB) in the Copper Cliff Offset Dike (CCOD) at Sudbury, Ontario was studied using powder X-ray diffraction data and Rietveld analysis, SEM-EDS, magnetic colloid, optical petrographic techniques, and Laser Ablation-ICP-MS in order to: (1) quantify the distribution of NC (non-magnetic, symmetry higher than monoclinic) and 4C (magnetic, monoclinic in symmetry) Po; (2) characterize the major, minor, and trace-element chemistries of both polymorphs; and (3) determine the factors enhancing the stability of NC Po. Results confirm that both NC and 4C Po are present, with ratios varying between 0 to 0.97. In general, 4C Po is the dominant polymorph within the sampled OB, with the exception of the 100 OB, which is dominated by NC Po. Mineral chemistry indicates that there is an almost complete compositional overlap between the major, minor, and trace-element compositions of NC and 4C Po from the CCOD. The data also show that both polymorphs are slightly metal-deficient relative to the ideal chemistry of 4C Po, Fe 7 S 8 . There were no significant differences found in the Ni contents of either polymorph. Data revealed that the main mineralogical difference between the five OB was the presence of ilmenite in the 830, 865, 880, and 890 OB, whereas magnetite dominates in the 100 OB. Mineralization occurs along the eastern margin of the 830–890 OB, in contrast to the 100 OB, where mineralization occurs in the center of the dike. The increased abundance of NC Po in the 100 OB may be explained by this difference in the style of mineralization, specifically, the proximity of ore to the surrounding country rock. Therefore, f O 2 may have directly influenced the distribution and stabilization of NC Po, which would then impact the observed NC:4C Po ratios in the selected OB.

Description: The crystal chemistry of a unique Nb-Ti-rich thorite from Mont Saint-Hilaire (Quebec) has been examined by a combination of single crystal and powder X-ray diffraction, electron microprobe analyses, and Fourier-transform infrared spectroscopy. The average of 9 compositions gave (Th 0.21 Nb 0.20 Ti 0.18 Ca 0.13 Y 0.10 REE 0.09 Fe 0.03 Zr 0.01 Sr 0.01 Mn 0.01 K 0.01 Na 0 . 01 ) 1.00 [(Si 0.49 0.41 Al 0.08 P 0.01 S 0.01 ) 1.00 (O 2.33 F 0.02 )](OH) 1.70 . This is the first example in the literature of a zircon-group mineral containing elevated concentrations of Nb (0.20 apfu , 13.33 wt.% Nb 2 O 5 ) and Ti (0.19 apfu Ti, 7.41 wt.% TiO 2 ), and evidence for the (SiO 4 ) 4– (OH) 4 4– "hydrogarnet" substitution. The crystal structure was solved and refined to R = 3.40% and wR 2 = 9.73% for 68 reflections with F o 〉 4( F o ). The studied thorite is slightly metamict, tetragonal, space group I 4 1 / amd , with a 7.058(1) Å, c 6.2260(12) Å, V 310.15(11) Å 3 , and Z = 4. It is isostructural with other zircon-group minerals and has a unit cell which is 4% smaller than that of thorite sensu stricto , a result of the incorporation of high field-strength elements of smaller radii. The structure consists of one eight-coordinated metal site ( A = Th, Zr, U, REE, Y, Nb, Ti, etc. ), one tetrahedral site ( T ), one O site, and one variably-occupied H site. The A site is coordinated by four axial O atoms [ A –O axial = 2.428(5) Å] and four equatorial O atoms [ A –O eq = 2.322(6) Å], which define a bisdisphenoid with 〈 A –O〉 = 2.374 Å. The T site in MSH thorite is only partially occupied by Si (33% vacant) and coordinated by four O with T –O = 1.641(5) Å. A partially occupied H site (31%) is located 0.980 Å away from the O atom, forming (O 4 H 4 ) 4– groups when the T site is vacant. Removal of the center of symmetry in the structure allows for the possibility of the presence of bimodal T –O and A –O bond lengths, leading to both short Si–O bonds and longer –OH bonds, as well as the shorter A –O bonds required for Nb and Ti. Accommodation of Nb and Ti into the thorite structure may be facilitated by increased distortion of the A O 8 bisdisphenoid, relaxation and shortening of A –O bonds as a result of the (SiO 4 ) 4– (OH) 4 4– substitution, and the likely presence of defects (O vacancies) in regions which have undergone slight metamictization, resulting in short-range ordering of Nb, Ti, and Th. Although it is possible that a metastable, limited solid solution exists between thorite and (OH) 4 4– -dominant "thorogummite" with intermediate compositions defined by Th(SiO 4 ) 1 –x (OH) 4 x , reported compositions indicate otherwise and it is suggested that the name "thorogummite" be abandoned.

Description: Steedeite, ideally NaMn 2 Si 3 BO 9 (OH) 2 , is a new mineral discovered in altered sodalite syenite at the Poudrette quarry, La Vallée-du-Richelieu, Montérégie (formerly Rouville County), Québec, Canada. Crystals of steedeite are colorless to pale pink, and acicular with average dimensions of 0.006 x 0.011 x 0.51 mm. They occur as radiating to loose, randomly oriented groupings within vugs associated with aegirine, nepheline, sodalite, eudialyte-group minerals, analcime, natron, pyrrhotite, catapleiite, and two other unidentified minerals temporarily designated UK78 and UK80. Steedeite is transparent to translucent with a vitreous luster and has a weak pale green to pale yellow fluorescence under medium-wave radiation. No partings or cleavages were observed, although crystals exhibit an uneven fracture. The calculated density is 3.106 g/cm 3 . Steedeite is nonpleochroic, biaxial with n min = 1.636(2) and n max = 1.656(2) and a positive elongation. Chemical analyses (n = 14) from seven crystals gave an average (range, standard deviation) of: Na 2 O 7.51 (6.78–8.32, 0.44), CaO 0.17 (0.08–0.22, 0.03), MnO 31.02 (29.91–32.83, 0.93), FeO 0.86 (0.76–1.01, 0.07), SiO 2 46.34 (40.39–49.29, 2.56), S 0.39 (*b.d.– 2.36, 0.71) (*b.d. = below detection), B 2 O 3 (calc.) 8.73, and H 2 O (calc.) 4.52, total 99.53 wt.%. The empirical formula is: Na 0.97 (Mn 1.75 Fe 0.05 Ca 0.01 ) 1.83 (Si 3.07 S 0.02 ) 3.09 BO 9 (OH) 2 , or ideally NaMn 2 Si 3 BO 9 (OH) 2 . The presence of both B and OH in steedeite were inferred from the refinement of the crystal structure. The Raman spectrum for steedeite show bands at 3250–3500 cm –1 attributed to O–H stretching, strong sharp bands at 575–750 cm –1 and 825–1075 cm –1 attributed to Si–O bonds and possibly B–O bonding, as well as weak to strong bands at 50–500 cm –1 attributed to Na–O/Mn–O bonds. Steedeite crystallizes in space group P $$\overline{1}$$ (#2) with a 6.837(1), b 7.575(2), c 8.841(2) Å, α 99.91(3), β 102.19, 102.78(3)°, V 424.81 Å 3 , and Z = 2. The strongest six lines on the X-ray powder-diffraction pattern [ d in Å (I) ( hkl )] are: 8.454 (100) (00 $$\overline{1}$$ ), 7.234 (39) (00 $$\overline{1}$$ ), 3.331 (83) (1 $$\overline{2}$$ 1, 0 $$\overline{1}$$ $$\overline{2}$$ , 20 $$\overline{1}$$ , 1 $$\overline{1}$$ 2), 3.081 (38) (0 $$\overline{2}$$ $$\overline{1}$$ ), 2.859 (52) (0 $$\overline{1}$$ 3), and 2.823 (80) (21 $$\overline{1}$$ ). The crystal structure of steedeite was refined to R = 1.68% and wR 2 = 4.96% for 2409 reflections ( F o 〉 4 F o ). It is based on silicate chains with a periodicity of three (i.e., dreier chain) consisting of four-membered borosilicate rings of composition [BSi 3 O 9 (OH) 2 ] 5– . The borosilicate chains are classed as single loop-branched dreier chains that are linked together through shared corners to bands of edge-sharing MnO 5 (OH) octahedra. Steedeite is a chain silicate mineral closely related to the sérandite-pectolite series of the pyroxenoid group and is the first mineral found to contain single loop-branched dreier silicate chains.

Description: The major and trace element geochemistry of mafic silicate minerals from alkaline pegmatites within the 10 ring sections of the Larvik plutonic complex, Oslo rift, southern Norway, have been studied to shed light on the complex evolutionary history of the pegmatites. Pyroxene compositions plot within the aegirine-diopside-hedenbergite ternary diagram, trending from the 50-50% Di-Hd tie line towards the 100% Ae endmember. Primary magmatic diopside and hedenbergite with minor aegirine occur primarily within miaskitic to low agpaitic pegmatites, with compositions ranging from Ae 3 Di 45 Hd 51 to Ae 89 Di 5 Hd 6 , whereas aegirine and aegirine-augite are the primary magmatic clinopyroxenes in agpaitic pegmatites, with compositions ranging from Ae 31 Di 27 Hd 42 to Ae 90 Di 6 Hd 4 . Secondary clinopyroxene, after amphibole or as a hydrothermal phase within fractures and vugs, is dominantly aegirine, with compositions ranging from Ae 59 Di 16 Hd 25 to Ae 99 Di 1 Hd 0 . Primary amphibole compositions are dominantly calcic (edenite, ferro-edenite, hastingsite, magnesio-hastingsite, pargasite, and ferro-pargasite), with less common late-stage sodic-calcic amphiboles (katophorite, magnesio-katophorite, ferro-richterite, and taramite); sodic amphiboles (ferro-ferri-nybøite, ferri-nybøite) are only observed in agpaitic pegmatites. All early pegmatite mafic minerals in low agpaitic pegmatites have negative Eu anomalies (Eu/Eu* = 0.16–0.26), positive Ce anomalies, and low Nb/Ta N and Y/Ho N ratios. Sodic mafic silicates in highly agpaitic pegmatites are HREE-enriched, with Ce/Yb N = 0.22–0.58 compared to Ce/Yb N 〉 1 for all other primary mafic phases, are strongly depleted in MREE, and have only slightly negative Eu anomalies (Eu/Eu* = 0.66–0.75). On the basis of major and trace element geochemistry, it can be concluded that miaskitic and alkaline pegmatites in Ring Sections 1–8 within the Larvik complex have been derived from the same parental melt, whereas pegmatites in Ring Sections 9 and 10 have a distinct geochemical signature, suggesting a separate source.

Description: The chemical composition and chemical formula for ferro-ferri-nybøite given by Lussier et al . (2014) are wrong due to incorporation of errors during preparation of the paper. The data given in the original IMA submission are correct and are given here: SiO 2 47.06, TiO 2 0.50, Al 2 O 3 3.16, Fe 2 O 3 12.43, FeO 22.37, (Fe tot = 33.56), MnO 2.18, ZnO 0.06, MgO 0.23, CaO 1.03, Na 2 O 8.15, K 2 O 1.72, F 0.84, H 2 O calc 1.50, O F –0.35 sum 100.88 wt.%. The formula unit, calculated on the basis of 24 (O + OH + F) with (OH + F) = 2 apfu , is (Na 0.67 K 0.35 )(Na 1.83 Ca 0.17 )(Mg 0.05 Fe 2+ 2.96 Mn 0.29 Zn 0.01 Al 0.03 Fe 3+ 1.48 Ti 0.06 )(Si 7.44 Al 0.56 )O 22 (OH 1.58 F 0.42 ).

Description: The relationship between cathodoluminescence (CL) response and chemical composition of scheelite from a variety of ore-deposit settings ( e.g ., orogenic Au, skarn, porphyry-related, greisens, VMS) was investigated using SEM-EDS, CL imaging, and LA-ICP-MS techniques. Our detailed study concentrates on five samples of scheelite from a range of ore-deposit settings, including orogenic Au, skarn, VMS, and greisen deposits, but draws on a yet unpublished data base of more than 39 deposits world-wide. Results indicate that the scheelite zonation patterns observed under CL can be useful in discriminating between scheelite arising from differing mineralized environments. Scheelite from orogenic Au deposits exhibits a homogenous CL response in contrast to that from proximal intrusion-related systems, such as porphyries, skarns, and greisens that show a strong oscillatory zonation, with individual zones ranging from 〈1 μm to 〉300 μm in width. Results from LA-ICP-MS analyses show significant chemical variations in scheelite with respect to Mo, Sr, As, and REE + Y. Maps generated from CL imaging and LA-ICP-MS data reveal a strong negative correlation between the intensity of the CL response in scheelite and Mo content. While enrichments of Sr, As, and REE + Y are noted, none exhibit a correlatable effect with CL response. Furthermore, the qualitative Mo and W X-ray maps produced via SEM-EDS correlate with the corresponding LA-ICP-MS maps of the scheelite grain, successively delineating the zonation patterns observed under CL. This work also demonstrates that the combination of CL and LA-ICP-MS mapping is a powerful tool in the discussion of observed CL textures, elemental relationships, mineral growth history, and paragenesis.