Results 51 to 60 of about 92,675 (274)

Cascading trend of Early Paleozoic marine radiations paused by Late Ordovician extinctions

Proceedings of the National Academy of Sciences of the United States of America, 2019
Significance The first 120 million years of Phanerozoic life witnessed significant changes in biodiversity levels. Attempts to correlate these changes to potential short-term environmental drivers have been hampered by the crude temporal resolution of ...
C. Rasmussen, B. Kröger, M. L. Nielsen, J. Colmenar   +3 more
semanticscholar   +1 more source

The Irish Ordovician brachiopod fauna: A taxonomic renaissance [PDF]

Estonian Journal of Earth Sciences, 2023
Despite its small areal extent, the island of Ireland exposes eight Caledonian tectonic terranes; six of them contain Ordovician brachiopod assemblages. These terranes record the early phases and destruction of the Iapetus Ocean through the occurrence of
David A. T. Harper
doaj   +1 more source

The first hirnantian (Uppermost Ordovician) Odontopleurid trilobite from western Gondwana (Argentina) [PDF]

, 2014
An odontopleurid trilobite remain is described for the fi rst time from Hirnantian (uppermost Ordovician) rocks of Western Gondwana. Very rare material, represented by a single left librigena, comes from a new fossil locality of the Don Braulio Formation
Halpern, Karen, Meroi Arcerito, Facundo René, Rustán, Juan José   +2 more
core   +1 more source

Oil and gas sources in Shunbei Oilfield, Tarim Basin

Shiyou shiyan dizhi, 2020
The hydrocarbon sources in the Middle and Lower Ordovician in the Shunbei area of the Tarim Basin were studied based on the geochemical characteristics of oil and gas samples.
Rong GU, Lu YUN, Xiuxiang ZHU, Meng ZHU
doaj   +1 more source

Detrital-zircon geochronology and provenance of the Ocloyic synorogenic clastic wedge, and Ordovician accretion of the Argentine Precordillera terrane [PDF]

, 2015
The Precordillera terrane in northwestern Argentina is interpreted to be anexotic (Laurentian) continental fragment that was accreted to western Gondwanaduring the Ordovician. One prominent manifestation of the subductionand collision process is a Middle?
Astini, Ricardo Alfredo, McClelland, William C., Mueller, Paul A., Thomas, William A.   +3 more
core   +1 more source

High resolution carbon isotope stratigraphy of the basal Silurian stratotype (Dob's Linn, Scotland) and its global correlation [PDF]

, 1997
Since its designation as the Global Stratotype Section and Point (GSSP) for the base of the Silurian System, the choice of Dob's Linn, Southern Scotland, has received criticism due to the difficulties of relating its well constrained graptolite ...
Brenchley, P.J., Crowley, S.F., Marshall, J.D., Underwood, Charlie J.   +3 more
core   +1 more source

First plants cooled the Ordovician [PDF]

Nature Geoscience, 2012
The Late Ordovician period, ending 444 million years ago, was marked by the onset of glaciations. The expansion of non-vascular land plants accelerated chemical weathering and may have drawn down enough atmospheric carbon dioxide to trigger the growth of ice sheets.
Lenton, T, Lenton, T, Crouch, M, Crouch, M, Johnson, M, Pires, N, Pires, N, Dolan, L, Dolan, L   +8 more
openaire   +4 more sources

Rifting and arc-related early Paleozoic volcanism along the North Gondwana margin: geochemical and geological evidence from Sardinia (Italy) [PDF]

, 2012
Three series of volcanic rocks accumulated during the Cambrian to Silurian in the metasediment-dominated Variscan basement of Sardinia. They provide a record of the changing geodynamic setting of the North Gondwana margin between Upper Cambrian and ...
BUZZI L, FUNEDDA A., GAGGERO L, OGGIANO G   +3 more
core   +1 more source

An extraterrestrial trigger for the mid-Ordovician ice age: Dust from the breakup of the L-chondrite parent body

Science Advances, 2019
The disruption of a 150-km large asteroid filled the inner solar system with dust that cooled Earth and caused faunal turnovers. The breakup of the L-chondrite parent body in the asteroid belt 466 million years (Ma) ago still delivers almost a third of ...
B. Schmitz, K. Farley, S. Goderis, P. Heck, S. M. Bergström, S. Boschi, P. Claeys, V. Debaille, A. Dronov, M. van Ginneken, D. Harper, F. Iqbal, J. Friberg, S. Liao, E. Martin, M. Meier, B. Peucker‐Ehrenbrink, B. Soens, R. Wieler, F. Terfelt   +19 more
semanticscholar   +1 more source

The only known cyclopygid–‘atheloptic’ trilobite fauna from North America: the upper Ordovician fauna of the Pyle Mountain Argillite and its palaeoenvironmental significance [PDF]

, 2012
The trilobite fauna of the upper Ordovician (middle Katian) Pyle Mountain Argillite comprises a mixture of abundant mesopelagic cyclopygids and other pelagic taxa and a benthic fauna dominated by trilobites lacking eyes.
Adrain, ALAN W. OWEN, Angelin, Apollonov, Barrande, Bartholomew, Bergström, Beyrich, Boucot, Bruton, Brøgger, Budil, Cocks, Cocks, Cooper, Dalman, DAVID L. BRUTON, Dean, Dean, Dean, Fortey, Fortey, Fortey, Fortey, Fortey, Fortey, Gürich, Hammann, Hammann, Hammann, Hansen, Hawle, Horný, Hörbinger, Ingham, Ingham, Ingham, Jaekel, Jell, Ji, Kaesler, Kielan, Kielan, Kobaysahi, Kolobova, Kozák, Krueger, Kutorga, Lane, Lespérance, Lespérance, Linnarsson, Lu, Lu, M'Coy, Marek, Marek, McCormick, Morris, Nicholson, Nicholson, Nielsen, Nielsen, Owen, Owen, Owen, Owen, Owen, Owen, Parkes, Pek, Pek, Prantl, Price, Přibyl, Raymond, Reed, Reed, Reed, Reed, Repina, Rong, Ross, Roy, Salter, Schrank, Shaw, Shaw, Sheehan, Shergold, Shergold, Thomas, Volborth, Warburg, Weir, Whittard, Whittard, Whittington, Whittington, Whittington, Whittington, Whittington, Whittington, Whittington, Zhou, Zhou, Zhou, Zhou, Zhou, Zhou, Zhou, Zhou, Šnajdr   +112 more
core   +1 more source