available online at http://meteoritics.org 591 © The Meteoritical Society, 2005. Printed in USA. Laser argon dating of melt breccias from the Siljan impact structure, Sweden: Implications for a possible relationship to Late Devonian extinction events Wolf U. REIMOLD1*, Simon P. KELLEY2, Sarah C. SHERLOCK2, Herbert HENKEL3, and Christian KOEBERL4 1Impact Cratering Research Group, School of Geosc...

Abstract The famous Martenberg section of the eastern Rhenish Massif, Germany, type-section classical Frasnian goniatite and conodont zonations, has been restudied in order to document microfacies development refine stratigraphy around global semichatovae Event/Transgression, proposed level define a future upper substage. More than 8.000 platform elements were identified include new taxa. Palma...

Purpose. Studying the geological features of large industrial Atasu type ore objects. Methodology. Critical analysis literature and stock materials, comparative factors characteristic stratiform ores, stages peculiarities formation depending on processes volcanism, results isotope dating rocks. Findings. Participation volcanism (magmatism) in forming deposits ferromanganese barite-polymetallic ...

Details of the Early-Middle Frasnian boundary interval Pymvashor River section (Timan-Pechora Basin, Cis-Urals, in far north European Russia) are revealed by biostratigraphically constrained carbonate (δ13Ccarb) and organic carbon (δ13Corg) stable data. The studied corresponds to lower part Domanik Formation, which consists interbedded limestone shale beds. Organic-rich black that lacks bioturb...

Most of the Frasnian regional stages Ukhta region, South Timan, Russia, are composed basinal deposits, however, hassi and jamieae zones Standard Conodont Zonation cannot be easily recognised in this region. A revision previously elaborated succession Timan-Pechora associations revealed that correlation problems connected with taxonomic interpretation zonal species Palmatolepis . Analysis conodo...

The diversification of the tetrapod stem group occurred during the late Middle through the Late Devonian, that is from the Givetian to Famennian stages about 385-365 million years ago. The relationships between the known taxa representing this radiation have currently reached a reasonable consensus so that interpretations of the order of appearance of tetrapod characters is possible. The immedi...