A new ammonoid fauna from theGattendorfia-Eocanites Genozone of the Anti-Atlas (Early Carboniferous; Morocco)

From the eastern part of the Tafilalt (Anti-Atlas, Morocco), rich assemblages of ammonoids of the Gattendorfia-Eocanites Genozone are described. The detailed investigation of an outcrop near Mfis in the south-eastern Tafilalt yielded a diverse fauna with 24 species, of which 13 are new. The genus Weyerella n. gen. is newly erected with Weyerella protecta n. sp. as type species. Furthermore, the following new species are described: Paragattendorfia aboussalamae n. sp., Acutimitoceras hollardi n. sp., Acutimitoceras posterum n. sp., Acutimitoceras mfisense n. sp., Acutimitoceras occidentale n. sp., Imitoceras oxydentale n. sp., Kazakhstania nitida n. sp., Zadelsdorfia debouaaensis n. sp., Weyerella minor n. sp., Eocanites simplex n. sp., Eocanites rtbeckeri n. sp., and Eocanites dkorni n. sp. The state of preservation of the ammonoids as limonitic steinkern specimens permits a detailed study of sutures and conch ontogeny.Aus dem östlichen Tafilalt (Anti-Atlas, Marokko) wird eine Ammonoideen-reiche Abfolge aus der Gattendorfia-Eocanites Genus-Zone beschrieben. Ein im Detail untersuchtes Profil bei Mfis hat eine individuenreiche und diverse pelagische Fauna mit 24 Arten geliefert, von denen 13 neu sind. Die Gattung Weyerella n. gen. wird mit Weyerellaprotecta n. sp. als Typusart aufgestellt. Weitere neue Arten sind: Paragattendorfiaaboussalamae n. sp., Acutimitocerashollardi n. sp., Acutimitocerasposterum n. sp., Acutimitocerasmfisense n. sp., Acutimitocerasoccidentale n. sp., Imitocerasoxydentale n. sp., Kazakhstanianitida n. sp., Zadelsdorfiadebouaaensis n. sp., Weyerellaminor n. sp., Eocanitessimplex n. sp., Eocanitesrtbeckeri n. sp. und Eocanitesdkorni n. sp. Die in Limonit erhaltenen Steinkerne erlauben eine Detailuntersuchung der Lobenlinien und der Gehäuse-Ontogenie.doi:10.1002/mmng.20060000

Late Givetian ammonoids from Hassi Nebech (Tafilalt Basin, Anti-Atlas, southern Morocco)

The Hassi Nebech area of the SE Tafilalt (Tafilalt Basin, Anti-Atlas, Morocco) yielded the richest and most diverse late Givetian ammonoid fauna on a global scale. Above the distinctive regional "Lower Marker Bed" (<i>Synpharciceras clavilobum</i> Zone), abundant loosely collected limonitic specimens derive from hypoxic shales of the <i>Taouzites taouzensis</i> to <i>Petteroceras errans</i> zones. The ontogenetic morphometry and intraspecific variability of a total of 30 species representing five families, the Acanthoclymeniidae, Taouzitidae, Pharciceratidae, Petteroceratidae, and Tornoceratidae, are documented. New taxa are: <i>Pseudoprobeloceras praecox</i> n. sp., <i>Scaturites minutus</i> n. gen. n. sp., <i>Darkaoceras velox</i> n. sp., <i>Pharciceras decoratum</i> n. sp., <i>Ph. fornix</i> n. sp., <i>Ph. subconstans</i> n. sp., <i>Ph. involutum</i> n. sp., <i>Lunupharciceras incisum</i> n. sp., <i>Transpharciceras procedens</i> n. gen. n. sp., <i>Stenopharciceras progressum</i> n. sp., <i>Pluripharciceras</i> n. gen. (type species: <i>Synpharciceras plurilobatum</i> Petter, 1959), <i>Plu. orbis</i> n. sp., <i>Synpharciceras frequens</i> n. sp., <i>Lobotornoceras bensaidi</i> n. sp., <i>Nebechoceras eccentricum</i> n. gen. n. sp., and <i>Phoenixites lenticulus</i> n. sp. The documentation of conch and particularly suture ontogeny and intraspecific variability necessitates a revised diagnosis for ten taxa. <i>Manticoceras pontiformis</i> Termier & Termier, 1950, <i>Probeloceras costulatum</i> Petter, 1959, and <i>Pseudoprobeloceras nebechense</i> Bensaïd, 1974 are regarded as subjective junior synonyms of <i>Ps. pernai</i> (Wedekind, 1918). <i>Sandbergeroceras acutum</i> Termier & Termier, 1950 is a subjective synonym of <i>Taouzites taouzensis</i> (Termier & Termier, 1950). <i>Pharciceras applanatum</i> Bensaïd, 1974 is transferred to <i>Extropharciceras</i>. Other forms (<i>Ph</i>. aff. <i>tridens</i>, <i>Ph</i>. cf. <i>subconstans</i> n. sp., <i>Extropharciceras</i> n. sp. 2, <i>Ex</i>. cf. <i>arenicum</i>, <i>Ex</i>. cf. <i>applanatum</i>, <i>Synpharciceras</i> sp., <i>Plu</i>. cf. <i>plurilobatum</i>) are described in open nomenclature. <br><br> doi:<a href="http://dx.doi.org/10.1002/mmng.201300001" target="_blank">10.1002/mmng.201300001</a

The ammonoids from the Dalle à <i>Merocanites</i> of Timimoun (Late Tournaisian–Early Viséan; Gourara, Algeria)

The ammonoids from the Early Carboniferous (Mississippian) Dalle à Merocanites of Timimoun (Gourara, Algeria) are described. The following new ammonoid taxa are introduced: subfamily Hammatocyclinae n. subfam., Hammatocyclus pollex n. sp., Hammatocyclus corrugatus n. sp., Neopericyclus arenosus n. sp., Ammonellipsites pareyni n. sp., Ammonellipsites menchikoffi n. sp., Ammonellipsites conradae n. sp., Muensteroceras fabrei n. sp., Eurites commutatus n. sp., Eurites pondus n. sp., subfamily Trimorphoceratinae n. subfam., Trimorphoceras n. gen., Trimorphoceras crassilens n. sp., Trimorphoceras absolutum n. sp., Trimorphoceras molestum n. sp., Obturgites n. gen., Obturgites polysarcus n. sp., Obturgites oligosarcus n. sp., Dzhaprakoceras dzhazairense n. sp., and Merocanites merocanites n. sp. These species occur in one very prolific horizon and can be attributed to the North African Ammonellipsites-Merocanites Assemblage (Fascipericyclus -Ammonellipsites Genus Zone; Late Tournaisian to Early Viséan). They represent one of the most diverse ammonoid faunas known from this time interval. doi:10.1002/mmng.200900011</a

High voltage performance degradation of the 14ud tandem accelerator

The 14UD at the Australian National University's Heavy Ion Accelerator Facility (HIAF) operated at a maximum voltage of 15.5 MV after the installation of tubes with a compressed geometry in the 1990s. In recent years, the performance of the accelerator has shown a gradual decline to a maximum operation voltage of ~14.5 MV. There are some fundamental factors that limit the high voltage performance, such as SF6 gas pressure, field enhancement due to triple junctions and total voltage effect. In addition, there are nonfundamental factors causing high voltage degradation. These are: operation with faulty ceramic gaps; operation at inappropriate voltage and SF6 pressure combinations; SF6 leaks into the vacuum space; use of SF6 and O2 as a stripper gases; poor electron suppression in the high energy stripper and frequent use of highly reactive ions such as sulphur and fluorine. In this paper we will discuss factors that limit the high voltage performance. The main outcomes of a preliminary investigation of titanium (Ti) electrodes removed from the accelerator after a few decades of operation will be reported. The investigation confirmed contamination of Ti electrodes with unstable films containing traces of oxides, sulphur and fluorine. The rehabilitation strategies for the accelerator will be discussed.This work is supported by Australian Federal Government Superscience/EIF funding under the NCRIS mechanis