Results 81 to 90 of about 1,784 (228)

Late Ordovician ironstone and its relation to ocean redox instability, climate and glaciation

Sedimentology, Volume 72, Issue 2, Page 631-665, February 2025.
Abstract The Upper Ordovician (Katian) Neda Formation, a phosphatic ironstone, records a widespread but short‐lived shift to ferruginous waters across a vast epicontinental area. Lithofacies and stratigraphic reappraisal indicate that Neda ironstone deposition occurred on a storm‐dominated ramp when coastal upwelling emplaced eutrophic ferruginous ...
Edward J. Matheson, Jackson D. Malone, Peir K. Pufahl, Eric E. Hiatt   +3 more
wiley   +1 more source

An Ordovician Assemblage of Cool Water‐Adapted Paleotropical Ostracods Suggests an Early Psychrosphere

Island Arc, Volume 34, Issue 1, January/December 2025.
ABSTRACT An ostracod assemblage from the Late Ordovician (Katian) Phu Ngu Formation of northern Vietnam, South China paleoplate, yields typical Baltic and Laurentian‐affinity genera together with some endemic forms. Detailed paleontological and sedimentary analysis of the Phu Ngu Formation suggests it was deposited in a deeper marine forearc setting ...
Anna McGairy, Phong Duc Nguyen, Mark Williams, Christopher P. Stocker, Thomas H. P. Harvey, Toshifumi Komatsu, Thomas W. Wong Hearing, C. Giles Miller, Chloé M. Marcilly, Alexandre Pohl   +9 more
wiley   +1 more source

Bioturbators as ecosystem engineers in space and time

Palaeontology, Volume 67, Issue 6, November/December 2024.
Abstract Biogenic sedimentary structures offer a unique perspective for understanding the role of the biosphere in the interaction with other Earth subsystems and the building up of our planet. The record of their ancient equivalents provides a wealth of information for reconstructing the role of bioturbators as ecosystem engineers using multiple ...
M. Gabriela Mángano, Luis A. Buatois, Nicholas J. Minter, Romain Gougeon   +3 more
wiley   +1 more source

Reconstructing a Super-Eruption From the Upper Ordovician Period in the Eastern Pyrenees, Spain [PDF]

Lithosphere
The Pyrenean basement rocks, NE of the Iberian Peninsula, southwestern Europe, include evidence of several pre-Variscan magmatic episodes which indicate the complex geodynamic history of this segment of the northern Gondwana margin from late ...
Joan Marti, Josep M. Casas, Josep A. Muñoz   +2 more
doaj   +1 more source

Lower–Middle Ordovician brachiopods from the Eastern Cordillera of Peru: evidence of active faunal dispersal across Rheic and Iapetus oceans

Papers in Palaeontology, Volume 10, Issue 5, September/October 2024.
Abstract New Floian and early middle Darriwilian brachiopod assemblages of the San José Formation of the Eastern Cordillera of Peru are presented. A new genus and species, Apurimella santiagoi, and two new species, Phragmorthis henrylunae and Nocturnellia ashaninka, are described.
Jorge Colmenar, César Augusto Chacaltana, Juan Carlos Gutiérrez‐Marco   +2 more
wiley   +1 more source

Alleged cnidarian Sphenothallus in the Late Ordovician of Baltica, its mineral composition and microstructure [PDF]

Acta Palaeontologica Polonica, 2015
Sphenothallus is a problematic fossil with possible cnidarian affinities. Two species of Sphenothallus, S. aff. longissimus and S. kukersianus, occur in the normal marine sediments of the Late Ordovician of Estonia. S.
Olev Vinn, Kalle Kirsimäe
doaj   +1 more source

Paradox lost: wide gape in the Ordovician brachiopod Rafinesquina explains how unattached filter‐feeding strophomenoids thrived on muddy substrates

Palaeontology, Volume 67, Issue 2, March/April 2024.
Abstract Strophomenoid brachiopods had thin, concavo‐convex shells, were ubiquitous colonizers of Palaeozoic muddy seafloors, and are hypothesized to have filter‐fed in a concave‐upward orientation. This orientation would elevate their line of commissure out of potentially lethal lophophore‐clogging mud.
Benjamin F. Dattilo, Rebecca L. Freeman, Kyle Hartshorn, David Peterman, Aaron Morse, David L. Meyer, Lindsay G. Dougan, James W. Hagadorn   +7 more
wiley   +1 more source

Deep shelf trilobite biofacies from the upper Katian (Upper Ordovician) of the Grangegeeth Terrane, eastern Ireland [PDF]

, 2010
The trilobite fauna of the upper Katian (mid-Ashgill in terms of Anglo-Welsh chronostratigraphy) Oriel Brook Formation in the Grangegeeth Terrane, eastern Ireland comprises 16 species. It is dominated numerically by mesopelagic cyclopygids (Cyclopyge cf.
Romano, M., Owen, A.W., Michael Romano, Alan W. Owen   +3 more
core   +1 more source

Late Ordovician and early Silurian virgianid and stricklandioid brachiopods from North Greenland: implications for a warm‐water faunal province

Papers in Palaeontology, Volume 10, Issue 1, January/February 2024.
Abstract An unusually rich and diverse suite of virgianid brachiopods, hitherto poorly known, is systematically described here for the first time from the Ordovician–Silurian boundary interval (late Katian – Aeronian) of North Greenland. The Late Ordovician virgianids comprise typical taxa of the warm‐water Tcherskidium fauna (e.g.
Jisuo Jin, Christian M. Ø. Rasmussen, Peter M. Sheehan, David A. T. Harper   +3 more
wiley   +1 more source

Orbital and Millennial‐Scale Cycles Through the Hirnantian (Late Ordovician) in Southern China

Geochemistry, Geophysics, Geosystems, Volume 25, Issue 1, January 2024.
Abstract The Hirnantian period, making the end of the Ordovician with significant mass extinctions and large ice‐sheets, is a critical interval for studying paleoclimate variations. This research represents the first cyclostratigraphic study of this period, utilizing high‐resolution (1 mm sampling rate) geochemical data from the ∼7‐m thick SH‐1 drill ...
Siding Jin, Haiyang Cao, Mingcai Hou, Jiawei Wang, Chao Ma, Yu Liu   +5 more
wiley   +1 more source