Results 21 to 30 of about 254 (156)
The Depositional Record, Volume 8, Issue 2, Page 502-523, June 2022., 2022 In a study of the Middle–Late Cambrian Port au Port Group, Newfoundland, marine cements precipitated on the lead up to and around the Steptoean Positive Carbon Isotope Excursion (SPICE) have been shown to contain increasing levels of strontium (up to 5500 ppm).
Joyce E. Neilson +4 more
wiley +1 more source
HIRNANTIAN (LATEST ORDOVICIAN) GRAPTOLITES FROM THE UPPER YANGTZE REGION, CHINA [PDF]
Palaeontology, 2005 : The Upper Yangtze region yields a Hirnantian (latest Ordovician) graptolite fauna that includes 41 species assigned to 13 genera. This fauna is particularly important for understanding the Late Ordovician mass extinction event because it is the most diverse known from this interval.
CHEN XU +3 more
openaire +1 more source
Sedimentology, Volume 69, Issue 1, Page 162-198, January 2022., 2022 ABSTRACT Bryozoan–stromatolite associations (bryostromatolites) formed conspicuous reef structures throughout the Sheinwoodian (Wenlock) to Ludfordian (Ludlow) stratigraphy on Gotland but have not been described so far. They are mainly composed of encrusting bryozoans forming a complex intergrowth with porostromate and spongiostromate microbes and are ...
Anna Lene Claussen +3 more
wiley +1 more source
A nutrient control on expanded anoxia and global cooling during the Late Ordovician mass extinction
Communications Earth & Environment, 2022 Phosphorus recycling played a critical role in driving the Late Ordovician mass extinction through ocean euxinia, and in the initiation of the Hirnantian glaciation, according to geochemical analyses of marine rocks from China and global biogeochemical ...
Zhen Qiu +8 more
doaj +1 more source
Changes in shelf phosphorus burial during the Hirnantian glaciation and its implications [PDF]
Estonian Journal of Earth Sciences, 2023 The Late Ordovician mass extinction occurred during an icehouse interval, accompanied by the glaciation of the supercontinent Gondwana, which was located at the South Pole at that time.
Johann Müller +4 more
doaj +1 more source
Lethaia, Volume 54, Issue 5, Page 610-630, December 2021., 2021 The Mora 001 and Solberga 1 drill cores provide the best available overview on the early Silurian (Llandovery, Rhuddanian to Telychian) graptolite succession available for the Siljan Ring impact structure of central Sweden. The Solberga 1 succession includes a nearly complete graptolite succession from the Pernerograptus revolutus Biozone (late ...
Jörg Maletz
wiley +1 more source
Late Ordovician jawed polychaete fauna from the Spiti Valley, northern India [PDF]
Estonian Journal of Earth Sciences, 2023 The final part of the Ordovician Period was characterised by major perturbations in climate, environments and ecosystems, as proved by numerous studies. These changes resulted in one of the biggest extinctions in Earthâs history. Most research in early
Petra Tonarová +3 more
doaj +1 more source
Hirnantian glacial and deglacial record in SW Djado Basin (NE Niger). [PDF]
Geodinamica 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 +3 more sources
The Hirnantian Stage and the Hirnantian Isotope Carbon Excursion (HICE) in the Gotland (Sweden) subsurface [PDF]
, 2022 Summary. We provide a stratigraphic assessment of the Upper Ordovician through lowermost Silurian of theStora Sutarve drillcore from southernmost Gotland. Based on the combined information from lithological characteristics and carbon isotope chemostratigraphy we document a sedimentary succession tentatively ranging fromthe Kinnekulle K-bentonite near ...
Gunnarsson, Niklas +6 more
openaire
More about the Ordovician–Silurian transition beds at Mirny Creek, Omulev Mountains, NE Russia: carbon isotopes and conodonts [PDF]
Estonian Journal of Earth Sciences, 2012 Profound environmental and biodiversity changes take place in the Ordovician–Silurian boundary interval. The Mirny Creek and Neznakomka River bank sections discussed in this paper expose the upper Katian–lower Rhuddanian part of the boundary beds.
Dimitri Kaljo +3 more
doaj +1 more source