AGU Advances, 2022 The Ordovician (Hirnantian; 445 Ma) hosts the second most severe mass extinction in Earth history, coinciding with Gondwanan glaciation and increased geochemical evidence for marine anoxia.
Nevin P. Kozik +4 more
doaj +2 more sources
Chitinozoan biozonation in the upper Katian and Hirnantian of the Welsh Basin, UK
Review of Palaeobotany and Palynology, 2014 AbstractHere we present a chitinozoan biostratigraphical framework for the South Wales upper Katian and Hirnantian (Ashgill) succession. The current study indicates that three of the six Avalonian Ashgill chitinozoan biozones are recognised in the Welsh Basin; the bergstroemi, fossensis and umbilicata biozones.
Thijs R A Vandenbroucke
exaly +2 more sources
Geophysical Monograph Series, Page 169-190., 2021 Exploring the links between Large Igneous Provinces and dramatic environmental impact
An emerging consensus suggests that Large Igneous Provinces (LIPs) and Silicic LIPs (SLIPs) are a significant driver of dramatic global environmental and biological changes, including mass extinctions.
Nasrrddine Youbi +9 more
wiley +3 more sources
Early land plant remains from the uppermost Ordovician–?lowermost Silurian Cedarberg Formation of South Africa [PDF]
Estonian Journal of Earth Sciences, 2023 The Cape Supergroup forms a regionally extensive and extremely thick Ordovician to Carboniferous succession of sedimentary rocks in southwestern South Africa.
Charles H. Wellman +2 more
doaj +1 more source
A summary of the Brazilian Paraná Basin Ordovician [PDF]
Estonian Journal of Earth Sciences, 2023 The study of the Ordovician of Paraná Basin culminated on the three-fold lithostratigraphic subdivision of the Rio Ivaà Group as follows: Alto Garças, Iapó and Vila Maria formations.
Carolina Zabini +11 more
doaj +1 more source
A diverse Hirnantian scolecodont assemblage from northern Estonia and resilience of polychaetes to the end-Ordovician mass extinction [PDF]
Estonian Journal of Earth Sciences, 2023 We report the discovery of a rich assemblage of latest Katian and Hirnantian scolecodonts (polychaete jaws) from a new OrdovicianâSilurian boundary outcrop in the Reinu quarry, northern Estonia.
Olle Hints, Petra Tonarová
doaj +1 more source
The Late Ordovician extinction conundrum [PDF]
Estonian Journal of Earth Sciences, 2023 The Late Ordovician mass extinction (LOME) has long been known for its association with the Hirnantian glaciations. Two extinction pulses seem to reflect global cooling and warming, respectively. The effects climate change had on Ordovician life are well
Christian M. Ø. Rasmussen
doaj +1 more source
Latest Ordovician–early Silurian palaeoenvironmental changes and palaeotemperature trends indicated by stable carbon and oxygen isotopes from northern Estonia [PDF]
Estonian Journal of Earth Sciences, 2021 Brachiopods are the biological constituents most often used for the delineation of stable C and O isotopic compositions in Palaeozoic sediments. We present C and O isotope data for the Late Ordovician and early Silurian to evaluate the palaeotemperatures
Bilal Gul, Leho Ainsaar, Tõnu Meidla
doaj +1 more source
An integrative biostratigraphic, chemostratigraphic, and sequence stratigraphic perspective of the Ordovician–Silurian boundary on Anticosti Island (Canada) [PDF]
Estonian Journal of Earth Sciences, 2023 Anticosti Island, Canada, has long been recognized as an exceptional OrdovicianâSilurian boundary succession with the potential to serve as one of the best records of climatic, oceanographic, and biological events associated with the Late Ordovician ...
Joshua B. Zimmt +10 more
doaj +1 more source
Ostracods of the Ordovician–Silurian boundary beds: Jūrmala core (Latvia) and its implications for Baltic stratigraphy [PDF]
Estonian Journal of Earth Sciences, 2020 Ostracods of the Ordovician and Silurian transition interval in the JÅ«rmala section, Latvia, were studied. The diverse pre-Hirnantian ostracod assemblage is replaced by the Harpabollia harparum association that has been recorded across the Baltoscandian
Tõnu Meidla +3 more
doaj +1 more source