ALBERT

Description: Ecological succession reveals potential signatures of marine–terrestrial transition in salt marsh fungal communities The ISME Journal 10, 1984 (August 2016). doi:10.1038/ismej.2015.254 Authors: Francisco Dini-Andreote, Victor Satler Pylro, Petr Baldrian, Jan Dirk van Elsas & Joana Falcão Salles

Description: ABSTRACT This work represents a case study concerning the application of reflection seismic imaging methods in the context of geothermal exploration. Our goal is to obtain accurate structural images of a geothermal active area in southern Tuscany. These images will be required in subsequent studies as the input for geological model building and numerical simulation of the heat transport and fluid flow. The target region exhibits great geologic complexity, including strong velocity contrasts, lateral near-surface inhomogeneities, fracture zones, and significant topography. Those features are typical for a volcanic hard-rock environment and pose significant challenges to conventional seismic imaging methodology. Therefore, we apply a sophisticated and robust depth imaging workflow to previously acquired surface seismic data. Within our workflow, we focus on estimating the seismic velocities of the predominant rock units and subsequently carry out Kirchhoff pre-stack depth migration and Fresnel volume migration to obtain high-resolution images of the subsurface. Our results demonstrate that the applied methodology provides a valueable tool for imaging in a complex environment such as a volcano-geothermal area. In detail, the resulting reflector images show the main horizons that delineate the Tuscan sedimentary rocks in the target region. The images from standard Kirchhoff migration can be significantly enhanced by utilizing Fresnel volume migration, which eliminates migration artefacts and provides a better result. Moreover, we obtain the migration velocities and depths for an important regional reflector, known as the K-horizon, which is of major interest for geothermal characterization.

Description: Abstract Understanding the mechanisms by which earthquake cycles produce folding and accommodate shortening is essential to quantify the seismic potential of active faults and integrate aseismic slip within our understanding of the physical mechanisms of the long‐term deformation. However, measuring such small deformation signals in mountainous areas is challenging with current space‐geodesy techniques, due to the low rates of motion relative to the amplitude of the noise. Here we successfully carry out a multitemporal Interferometric Synthetic Aperture Radar analysis over the North Qaidam fold‐thrust system in NE Tibet, where eight Mw〉 5.2 earthquakes occurred between 2003 and 2009. We report various cases of aseismic slip uplifting the thickened crust at short wavelengths. We provide a rare example of a steep, shallow, 13‐km‐long and 6‐km‐wide afterslip signal that coincides spatially with an anticline and that continues into 2011 in response to a Mw 6.3 event in 2003. We suggest that a buried seismic slip during the 2003 earthquake has triggered both plastic an‐elastic folding and aseismic slip on the shallow thrusts. We produce a first‐order two‐dimensional model of the postseismic surface displacements due to the 2003 earthquake and highlight a segmented slip on three fault patches that steepen approaching the surface. This study emphasizes the fundamental role of shallow aseismic slip in the long‐term and permanent deformation of thrusts and folds and the potential of Interferometric Synthetic Aperture Radar for detecting and characterizing the spatiotemporal behavior of aseismic slip over large mountainous regions.

Description: Tapiaite (IMA2014-024), Ca 5 Al 2 (AsO 4 ) 4 (OH) 4 ·12H 2 O, is a new mineral from the Jote mine, Tierra Amarilla, Copiapó Province, Atacama, Chile. The mineral is a late-stage, low-temperature, secondary mineral occurring with conichalcite, joteite, mansfieldite, pharmacoalumite, pharmacosiderite and scorodite in narrow seams and vughs in the oxidized upper portion of a hydrothermal sulfide vein hosted by volcanoclastic rocks. Crystals occur as colourless blades, flattened on {101I} and elongated and striated along [010], up to ~0.5 mm long, and exhibiting the forms {101I}, {101} and {111}. The blades are commonly intergrown in subparallel bundles and less commonly in sprays. The mineral is transparent and has a white streak and vitreous lustre. The Mohs hardness is estimated to be between 2 and 3, the tenacity is brittle, and the fracture is splintery. It has two perfect cleavages on {101} and {101I}. The calculated density based on the empirical formula is 2.681 g cm –3 . It is optically biaxial (+) with α = 1.579(1), β = 1.588(1), = 1.610(1) (white light), 2V meas = 66(2)° and 2V calc = 66°. The mineral exhibits no dispersion. The optical orientation is X [101I]; Y = b, Z [101]. The electron-microprobe analyses (average of five) provided: Na 2 O 0.09, CaO 24.96, CuO 0.73, Al 2 O 3 10.08, Fe 2 O 3 0.19, As 2 O 5 40.98, Sb 2 O 5 0.09, H 2 O 23.46 (structure), total 100.58 wt.%. In terms of the structure, the empirical formula (based on 32 O a.p.f.u.) is (Ca 4.83 $${\mathrm{Cu}}_{0.10}^{2+}$$ Na 0.03 ) 4.96 (Al 2.14 $${\mathrm{Fe}}_{0.03}^{3+}$$ ) 2.17 [( $${\mathrm{As}}_{3.87}^{5+}$$ $${\mathrm{Sb}}_{0.01}^{5+}$$ ) 3.88 O 16 ][(OH) 3.76 (H 2 O) 0.24 ] 4 (H 2 O) 10 ·2H 2 O. The mineral is easily soluble in RT dilute HCl. Tapiaite is monoclinic, P 2 1 / n , with unit-cell parameters a = 16.016(1), b = 5.7781(3), c = 16.341(1) Å, β = 116.704(8)°, V = 1350.9(2) Å 3 and Z = 2. The eight strongest lines in the powder X-ray diffraction pattern are [ d obs Å ( I )( hkl )]: 13.91(100)(1I01), 7.23(17)(200,002), 5.39(22)(110,011), 4.64(33)(1I12,2I11,3I03), 3.952(42)(1I13,3I11,2I13), 3.290(35)(2I14,4I12,1I14,4I11), 2.823(39)(303,3I15) and 2.753(15)(5I13,1I15,121,5I11). The structure of tapiaite ( R 1 = 5.37% for 1733 F o 〉 4 F ) contains Al(AsO 4 )(OH) 2 chains of octahedra and tetrahedra that are topologically identical to the chain in the structure of linarite. CaO 8 polyhedra condense to the chains, forming columns, which are decorated with additional peripheral AsO 4 tetrahedra. The CaO 8 polyhedra in adjacent columns link to one another by corner-sharing to form thick layers parallel to {101I} and the peripheral AsO 4 tetrahedra link to CaO 6 octahedra in the interlayer region, resulting in a framework structure.

Description: Bariopharmacoalumite, ideally Ba0.5Al4(AsO4)3(OH)4{middle dot}4H2O, is a new mineral from Cap Garonne, France. It occurs in several places within the mine as colourless to pale yellow interpenetrating cubes up to 0.5 mm across. Bariopharmacoalumite is transparent to translucent, with a white streak, has an adamantine lustre and imperfect cleavage on {001}. The Vickers hardness is 234.35 and the Mohs harness is 3.5. Bariopharmacoalumite is isotropic, with n = 1.573 (upper estimate) [calculated from reflectance values at 589 nm using Fresnel Equations]. The empirical formula, based on 20 oxygen atoms, is: (Ba0.54Cu0.03K0.01){Sigma}0.58(Al3.99Fe0.02){Sigma}4.01(AsO4)3.00(OH)3.85O0.15{middle dot}4H2O and the calculated density (on the basis of the empirical formula and single-crystal unit cell) is 2.580 g/cm3. The four strongest lines in the X-ray powder diffraction pattern are [dobs(A), Iobs,(hkl)]: 7.759, 100, (001); 5.485, 27, (011); 3.878, 27, (002); 4.454, 18, (011). Bariopharmacoalumite from Cap Garonne is cubic, space group P[IMG]f1.gif" ALT="Formula" BORDER="0"〉3m with a = 7.742(4) A, V = 464.2(4) A3 and Z = 1. The crystal structure was solved by direct methods and refined to R1 = 0.0705 for 215 reflections with I 〉 4{sigma}(I) and is consistent with members of the pharmacosiderite supergroup. Data are also presented from zoned bariopharmacoalumite-bariopharmacosiderite crystals found at the Mina Grande mine, Chile.

Description: Climate change affects key nitrogen-fixing bacterial populations on coral reefs The ISME Journal 8, 2272 (November 2014). doi:10.1038/ismej.2014.70 Authors: Henrique F Santos, Flávia L Carmo, Gustavo Duarte, Francisco Dini-Andreote, Clovis B Castro, Alexandre S Rosado, Jan Dirk van Elsas & Raquel S Peixoto

Description: The new mineral canutite (IMA2013-070), NaMn 3 [AsO 4 ][AsO 3 (OH)] 2 , was found at two different locations at the Torrecillas mine, Salar Grande, Iquique Province, Chile, where it occurs as a secondary alteration phase in association with anhydrite, halite, lavendulan, magnesiokoritnigite, pyrite, quartz and scorodite. Canutite is reddish brown in colour. It forms as prisms elongated on [201I] and exhibiting the forms {010}, {100}, {102}, {201} and {102I}, or as tablets flattened on {102} and exhibiting the forms {102} and {110}. Crystals are transparent with a vitreous lustre. The mineral has a pale tan streak, Mohs hardness of 21/2, brittle tenacity, splintery fracture and two perfect cleavages, on {010} and {101}. The calculated density is 4.112 g cm –3 . Optically, canutite is biaxial (+) with α = 1.712(3), β = 1.725(3) and = 1.756(3) (measured in white light). The measured 2V is 65.6(4)°, the dispersion is r 〈 v (slight), the optical orientation is Z = b ; X ^ a = 18° in obtuse β and pleochroism is imperceptible. The mineral is slowly soluble in cold, dilute HCl. The empirical formula (for tabular crystals from near the mine shaft), determined from electron-microprobe analyses, is (Na 1.05 Mn 2.64 Mg 0.34 Cu 0.14 Co 0.03 ) 4.20 As 3 O 12 H 1.62 . Canutite is monoclinic, C 2/ c , a = 12.3282(4), b = 12.6039(5), c = 6.8814(5) Å, β = 113.480(8)°, V = 980.72(10) Å 3 and Z = 4. The eight strongest X-ray powder diffraction lines are [ d obs Å( I )( hkl )]: 6.33(34)(020), 4.12(26)(2I21), 3.608(29)(310,1I31), 3.296(57)(1I12), 3.150(28)(002,131), 2.819(42)(400,041,330), 2.740(100)(240,4I02,112) and 1.5364(31)(multiple). The structure, refined to R 1 = 2.33% for 1089 F o 〉 4 F reflections, shows canutite to be isostructural with protonated members of the alluaudite group.

Description: Type specimens of the molybdoarsenates betpakdalite, natrobetpakdalite and obradovicite and the molybdophosphates mendozavilite, paramendozavilite and melkovite, and similar material from other sources, have been examined in an effort to elucidate the relations among these phases, which we designate as the heteropolymolybdate family of minerals. Using electron microprobe analysis, X-ray powder diffraction and single-crystal X-ray diffraction with crystal structure determination where possible, it was found that natrobetpakdalite, mendozavilite and melkovite are isostructural with betpakdalite and that obradovicite has a closely related structure.The betpakdalite and obradovicite structure types are based on frameworks containing four-member clusters of edge-sharing MoO6 octahedra that link by sharing corners with other clusters, with Fe3+O6 octahedra and with PO4 or AsO4 tetrahedra (T). The structures differ in the linkages through the Fe3+O6 octahedra, which produce different but closely related framework configurations. The structures contain two types of non-framework cation sites, which are designated A and B. In general, there are two or more A sites partially occupied by disordered, generally larger cations that are coordinated to O atoms in the framework and to H2O molecules. The B site is occupied by a smaller cation that is octahedrally coordinated to H2O molecules. The general formula for minerals with either the betpakdalite or the obradovicite structure is: [A2(H2O)nB(H2O)6][Mo8T2 O30+7(OH)7–x], where x is the total charge of the cations in the A and B sites (+3 to +7) and n is variable, ideally 17 for arsenates and 15 for phosphates. The ideal total number of A cations is defined as 2 in the general formula, but varies from 1 to 3.8 in analysed samples. Dominant cations at the A site include K, Na and Ca and at the B site Na, Ca, Mg, Cu and Fe. The combinations that have been identified in this study define six new heteropolymolybdate species.A suffix-based nomenclature scheme is established for minerals of the betpakdalite, mendozavilite and obradovicite groups, with the following root names based on the structure types and the T-site cations: betpakdalite (T = As), mendozavilite (T = P) and obradovicite (T = As). Two suffixes of the form -AB, corresponding to the dominant cations in the two different types of non-framework cation sites complete the species name. The historical name melkovite is retained rather than introducing mendozavilite-CaCa.Our investigation of the paramendozavilite type specimen revealed no paramendozavilite, but an apparently closely related new mineral; however, another sample of paramendozavilite analysed had K 〉 Na.

Description: Dynamics of bacterial community succession in a salt marsh chronosequence: evidences for temporal niche partitioning The ISME Journal 8, 1989 (October 2014). doi:10.1038/ismej.2014.54 Authors: Francisco Dini-Andreote, Michele de Cássia Pereira e Silva, Xavier Triadó-Margarit, Emilio O Casamayor, Jan Dirk van Elsas & Joana Falcão Salles