Results 51 to 60 of about 893 (201)

Discovery of trimerellide brachiopod Gasconsia from the Ordovician of Estonia [PDF]

open access: yesEstonian Journal of Earth Sciences
In this study, the first trimerellide brachiopods from Estonia are described. They occur in the uppermost Katian (Upper Ordovician) shallow shelf environments and represent some of the largest Ordovician brachiopods.
Linda Hints, Jiayu Rong
doaj   +1 more source

The youngest representatives of the genus Ribeiria Sharpe, 1853 from the late Katian of the Prague Basin (Bohemia) [PDF]

open access: yesEstonian Journal of Earth Sciences, 2015
Ribeiria apusoides and Ribeiria johni sp. nov. are described from the late Katian of the Prague Basin (Bohemia) as the youngest representatives of the genus Ribeiria.
Marika Polechová
doaj   +1 more source

Carbon isotope chemostratigraphy of the Llandovery in northern peri-Gondwana: new data from the Barrandian area, Czech Republic [PDF]

open access: yesEstonian Journal of Earth Sciences, 2014
The first complete δ13Corg record of the uppermost Hirnantian to lower Telychian strata of the Barrandian area (northern peri-Gondwana) is presented based on 168 new samples.
Jiří Frýda, Petr Štorch
doaj   +1 more source

Late Ordovician (Hirnantian) shelly fossils from New Zealand and their significance [PDF]

open access: yesNew Zealand Journal of Geology and Geophysics, 2004
Abstract A poorly preserved fauna of brachiopods, trilobites, corals, molluscs, bryozoans, echinoderms, and ostracods is described from Wangapeka Valley, northwest South Island. It can be dated to the latest Ordovician Hirnantian Stage, equivalent to Bolindian Bo4‐Bo5, by immediately underlying graptolite faunas ...
L. R. M. Cocks, Roger A. Cooper
openaire   +1 more source

Iron–Phosphorus–Carbon Coupled Cycling in Lacustrine System of Ordos Basin During the Middle Triassic

open access: yesGeochemistry, Geophysics, Geosystems, Volume 27, Issue 2, February 2026.
Abstract Widespread organic‐rich shales are associated with perturbations in productivity or preservation conditions; however, the major controlling factors, especially the phosphorus (P) and iron (Fe) interactions and their impacts on organic carbon burial in the paleolake ecosystem remain poorly understood.
Bo Wang   +7 more
wiley   +1 more source

The uppermost Ordovician (Hirnantian) trilobites of Girvan, SW Scotland with a review of coeval trilobite faunas

open access: yes, 1986
The uppermost Ordovician (Hirnantian) trilobite fauna of the High Mains Formation in the Craighead Inlier near Girvan comprises species of Flexicalymene, Achatella, Hemiarges, Isotelus and an indeterminate proetid. All are illustrated and the first three
Alan W. Owen
core   +1 more source

Hirnantian glacial and deglacial record in SW Djado Basin (NE Niger). [PDF]

open access: yesGeodinamica Acta, 2007
Pluridisciplinary fieldwork highlights features generated by an extended ice-sheet in the Djado Basin during the Hirnantian. Two glacial palaeovalley systems associated with glacial pavements and separated by thin glaciomarine interstadial series are revealed.
Denis, Michaël   +4 more
openaire   +2 more sources

Mercury Deposition in South China Across the Ordovician‐Silurian Transition: Implications for Climate Change

open access: yesGeochemistry, Geophysics, Geosystems, Volume 26, Issue 7, July 2025.
Abstract Most of the global climate changes are closely associated with volcanic activity. However, the link between global cooling during the Ordovician‐Silurian (O‐S) transition and volcanism remains unclear due to limited constraints on large volcanic events before, during, and after the peak of the Hirnantian glaciation (PHG). Here, we present high‐
Weiliang Kong   +4 more
wiley   +1 more source

Mass concentration of Hirnantian cephalopods from the Siljan District, Sweden; taxonomy, palaeoecology and palaeobiogeographic relationships [PDF]

open access: yesFossil Record, 2011
The Hirnantian Glisstjärn Formation (Normalograptus persculptus graptolite Biozone) is a succession of limestones and shales onlapping the Katian Boda Limestone in the Siljan District, Sweden.
B. Kröger   +3 more
doaj   +5 more sources

New evidence for the Hirnantian (Upper Ordovician) in Belgium? An integrated isotopical, biostratigraphic and sedimentologic approach

open access: yesCarnets de Géologie, 2005
The Hirnantian is an important time in Earth history as it includes one of the major episodes of continental glaciation and marine mass extinction (e.g. Brenchley et alii, 1994).
Grassineau Nathalie   +4 more
doaj  

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