Merelaniite, Mo4Pb4VSbS15, a New Molybdenum-Essential Member of the Cylindrite Group, from the Merelani Tanzanite Deposit, Lelatema Mountains, Manyara Region, Tanzania

This is an open access publicationThis is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0). The attached file is the published version of the article.© 2016 The Author(s). Published by Taylor & Francis. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/Licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The attached file is the published version of the article

Micron- to nano-scale intergrowths among members of the cuprobismutite series and paderaite: HRTEM and microanalytical evidence

Copyright © 2004 The Mineralogical SocietyCoherent intergrowths, at the lattice scale, between cuprobismutite (N = 2) and structurally related padraite along both major axes (15 Åand 17 Årepeats) of the two minerals are reported within skarn from Ocna de Fier, Romania. The structural subunit, DTD, 3 layers of padraite, is involved at interfaces of the two minerals along the 15 Årepeat, as well as in transposition of 1 padraite unit to 2 cuprobismutite units along the 17 Årepeat in slip defects. Lattice images obtained by HRTEM across intervals of 200 -400 nm show short- to long-range stacking sequences of cuprobismutite and padraite ribbons. Such nanoscale slabs mimic µm-scale intergrowths observed in back-scattered electron images at three orders of magnitude greater. These slabs are compositionally equivalent to intermediaries in the cuprobismutite-padraite range encountered during microanalysis. Hodrushite (N = 1.5) is identified in the µm-scale intergrowths, but its absence in the lattice images indicates that, in this case, formation of polysomes between structurally related phases is favoured instead of stacking disorder among cuprobismutite homologues. The tendency for short-range ordering and semi-periodic occurrence of polysomes suggests they are the result of an oscillatory chemical signal with periodicity varying from one to three repeats of 15 Å, rather than simple 'accidents' or irregular structural defects. Lead distribution along the polysomes is modelled as an output signal modulated by the periodicity of stacking sequences, with Pb carried within the D units of padraite. This type of modulator acts as a patterning operator activated by chemical waves with amplitudes that encompass the chemical difference between the minerals. Conversion of the padraite structural subunit DTD to the C unit of cuprobismutite, conserving interval width, emphasizes that polysomatic modularity also assists interference of chemical signals with opposite amplitudes. Observed coarsening of lattice-scale intergrowths up to the µm-scale implies coupling between diffusion-controlled structural modulation, and rhythmic precipitation at the skarn front during crystallization.C.L. Ciobanu, A. Pring and N.J. Coo

Oscarkempffite, Ag10Pb4(Sb17Bi9)∑ 26S48, a new Sb-Bi member of the lillianite homologous series

Published by the Mineralogical Society. This is a 'preproof' accepted article for Mineralogical Magazine. This version may be subject to change during the production process.10.1180/minmag.2016.080.024. You are advised to consult the publisher's version if you wish to cite from it

An unusual new theropod with a didactyl manus from the upper cretaceous of patagonia, Argentina

Background Late Cretaceous terrestrial strata of the Neuquén Basin, northern Patagonia, Argentina have yielded a rich fauna of dinosaurs and other vertebrates. The diversity of saurischian dinosaurs is particularly high, especially in the late Cenomanian-early Turonian Huincul Formation, which has yielded specimens of rebacchisaurid and titanosaurian sauropods, and abelisaurid and carcharodontosaurid theropods. Continued sampling is adding to the known vertebrate diversity of this unit. Methodology/ Principal Findings A new, partially articulated mid-sized theropod was found in rocks from the Huincul Formation. It exhibits a unique combination of traits that distinguish it from other known theropods justifying erection of a new taxon, Gualicho shinyae gen. et sp. nov. Gualicho possesses a didactyl manus with the third digit reduced to a metacarpal splint reminiscent of tyrannosaurids, but both phylogenetic and multivariate analyses indicate that didactyly is convergent in these groups. Derived characters of the scapula, femur, and fibula supports the new theropod as the sister taxon of the nearly coeval African theropod Deltadromeus and as a neovenatorid carcharodontosaurian. A number of these features are independently present in ceratosaurs, and Gualicho exhibits an unusual mosaic of ceratosaurian and tetanuran synapomorphies distributed throughout the skeleton. Conclusions/ Significance Gualicho shinyae gen. et sp. nov. increases the known theropod diversity of the Huincul Formation and also represents the first likely neovenatorid from this unit. It is the most basal tetatanuran to exhibit common patterns of digit III reduction that evolved independently in a number of other tetanuran lineages. A close relationship with Deltadromaeus from the Kem Kem beds of Niger adds to the already considerable biogeographic similarity between the Huincul Formation and coeval rock units in North Africa.Fil: Apesteguía, Sebastián. Universidad Maimónides. Área de Investigaciones Biomédicas y Biotecnológicas. Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y de Diagnóstico; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Smith, Nathan D.. Natural History Museum Of Los Angeles County; Estados UnidosFil: Valieri, Rubén Juárez. Provincia de Rio Negro; ArgentinaFil: Makovicky, Peter J.. Field Museum Of Natural History; Estados Unido

The crystal structure of uytenbogaardtite, Ag3AuS2, and its relationships with gold and silver sulfides-selenides

The file attached is the Accepted/final draft post-refereeing version of the article

Mineralogy of sulfides

Metal sulphides are the most important group of ore minerals. As shown in this brief introduction, much is known about their compositions, crystal structures, phase relations and paragenesis. Much less is known about their surface chemistry and, in particular, about their biogeochemistry, and about the formation and behaviour of ‘nanoparticle’ sulphides, whether formed abiotically or biogenically. These are large and complex topics which can only be touched upon in this article which also serves to direct readers to more comprehensive accounts