Abstract Upper Devonian carbonates deposited through the Frasnian/Famennian (F/F) stage boundary in Xom Nha Formation, Central Vietnam, were studied. The section is mainly composed of fossiliferous, brecciated, and laminated limestone beds, while shale beds occur a subordinate number. Microfacies generally suggests hemipelagic setting on an outer shelf environment with low sedimentation rates. ...

The Frasnian–Famennian biotic crisis (~372 Ma) was one of the “big five” mass extinction events in Phanerozoic. This event associated with dramatic climatic and oceanographic perturbations, including oceanic anoxia, global cooling, sea-level fluctuations. Large-scale volcanic activity is several possible triggers that have been suggested as ultimate cause this crisis, based on Hg enrichment dat...

Abstract The eastern Anti-Atlas of Morocco represents one the most completely exposed and perfectly documented biostratigraphic records entire Devonian worldwide. Paleogeographically it is clearly differentiated into shallow basins, pelagic platforms, land areas which are newly defined illustrated, from top Middle Devonian, other middle Famennian as two characteristic intervals. dominant paleog...

Barnacle borings were found in six heterocoral skeletons. They are present as small (up to 2.9 mm long), slender, pouch-shaped with tapering, slit-like openings. The investigated made by acrothoracican cirripedes, which mostly do not have a shell and bore into hard substrates protect their “naked” bodies. first occurrence of skeletons the Oligophylloides Różkowska, 1969 from Upper Devonian Tafi...

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 ...

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...