Results 21 to 30 of about 893 (201)

Miospore assemblages from Late Ordovician (Katian-Hirnantian), Ghelli Formation, Alborz Mountain Range North-eastern Iran: Palaeophytogeographic and palaeoclimatic implications [PDF]

open access: yesJournal of Sciences, Islamic Republic of Iran, 2016
Well-preserved miospore assemblages are recorded from the Late Ordovician (Katian-Hirnantian), Ghelli Formation in Pelmis-gorge at the north-eastern Alborz Mountain The palynomorphs were extracted from siliciclastic deposits which are well-dated by using
M. Ghavidel-syooki
doaj   +1 more source

Early land plant remains from the uppermost Ordovician–?lowermost Silurian Cedarberg Formation of South Africa [PDF]

open access: yesEstonian 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]

open access: yesEstonian Journal of Earth Sciences, 2023
The study of the Ordovician of Paraná Basin culminated on the three-fold lithostratigraphic subdivision of the Rio Ivaí Group as follows: Alto Garças, Iapó and Vila Maria formations.
Carolina Zabini   +11 more
doaj   +1 more source

The Late Ordovician extinction conundrum [PDF]

open access: yesEstonian 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]

open access: yesEstonian 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

Ostracods of the Ordovician–Silurian boundary beds: Jūrmala core (Latvia) and its implications for Baltic stratigraphy [PDF]

open access: yesEstonian Journal of Earth Sciences, 2020
Ostracods of the Ordovician and Silurian transition interval in the Jūrmala 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

An integrative biostratigraphic, chemostratigraphic, and sequence stratigraphic perspective of the Ordovician–Silurian boundary on Anticosti Island (Canada) [PDF]

open access: yesEstonian Journal of Earth Sciences, 2023
Anticosti Island, Canada, has long been recognized as an exceptional Ordovician–Silurian 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

Latest Ordovician age of the Spinachitina fragilis Chitinozoan Biozone in Baltoscandia [PDF]

open access: yesEstonian Journal of Earth Sciences, 2023
The global Spinachitina fragilis Chitinozoan Biozone has been considered the lowermost Silurian zone in most publications. S. fragilis was first described from the Ohesaare drill core, Estonia, and utilised as a Baltic regional zonal taxon together with ...
Jaak Nõlvak, Yan Liang, Olle Hints
doaj   +1 more source

The supercontinent cycle and Earth's long‐term climate

open access: yesAnnals of the New York Academy of Sciences, Volume 1515, Issue 1, Page 33-49, September 2022., 2022
The supercontinent cycle, by which Earth history is viewed as having been punctuated by the episodic assembly and breakup of supercontinents, has, through its management of plate motion, planetary geography, sea level and mantle circulation, profoundly influenced Earth's long‐term climatic history.
R. Damian Nance
wiley   +1 more source

The Steptoean Positive Carbon Isotope Excursion (SPICE), inorganic aragonite precipitation and sea water chemistry: Insights from the Middle–Late Cambrian Port au Port Group, Newfoundland

open access: yesThe 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

Home - About - Disclaimer - Privacy