Results 41 to 50 of about 64,869 (244)
The Evae transgression: a major event? [PDF]
Estonian Journal of Earth Sciences, 2023 The most extensive sea-level event of the Early Ordovician is known as the Evae transgression. During the highstand of this event, the conodont index species Oepikodus evae reached its acme and often coincided with the peak in conodont generic diversity.
Gisella M. Della Costa +1 more
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Ordovician collections stored at the National Museum of Natural History of the NAS of Ukraine [PDF]
Estonian Journal of Earth Sciences, 2023 We reviewed our departmentâs collections dealing with the Ordovician System, stored at the National Museum of Natural History of the National Academy of Sciences of Ukraine (NMNH NAS).
Galyna Anfimova, Volodymyr Grytsenko
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Ordovician cyclostratigraphy and astrochronology
Geological Society, London, Special Publications, 2023 Abstract Cyclostratigraphy is an important tool for understanding astronomical climate forcing and for reconstructing geological time in sedimentary sequences, provided that an imprint of insolation variations caused by Earth's orbital eccentricity, obliquity and precession is preserved (Milankovitch forcing).
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Evolving Earth, 2023 In this study, we examine how metazoan biodiversity has accumulated from the late Precambrian until the Silurian at various scales of taxonomic organization using compilations of the First Appearance Data (FAD) of global marine Metazoa from the datasets available in the Paleobiology Database (PBDB) and primary literature.
Servais, Thomas +5 more
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Late Ordovician gastropods from the Zhaolaoyu Formation in the southwestern margin of the North China Platform [PDF]
Estonian Journal of Earth Sciences, 2023 The Ordos Basin is located in the western part of the North China Platform and is the second largest sedimentary basin in China; the basin has a huge thickness of the Early Palaeozoic marine deposits, especially the Ordovician ones.
Rao Fu +6 more
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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 +3 more
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Conodont biostratigraphy of the Crawford Group, Southern Uplands, Scotland [PDF]
, 2002 Extensive new conodont collections from the Crawford Group, the oldest succession in the Southern Uplands of Scotland, support the previously documented biostratigraphical ages for the included formations.
Armstrong, Howard A. +3 more
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Metal enrichment in lithologically complex black shales: a case study from the Tremadocian of NE Estonia [PDF]
Estonian Journal of Earth Sciences, 2021 Significantly elevated U, Mo, Zn and Pb contents characterize the Early Ordovician black shales in the Sillamäe area, NE Estonia. The presence of silty interlayers with sulphidic mineralization and authigenic carbonates suggests unique physicochemical ...
Rutt Hints +4 more
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Late Ordovician Palynomorphs [PDF]
Journal of Micropalaeontology, 1985 Abstract. ACRITARCHSOrdovician acritarchs have been recorded in five core samples collected between 2520 ft. and 3000 ft. in Well E1-81, and ten cutting samples taken between 12150 ft. and 13240 ft. in Well J1-81A. All the assemblages recovered are of Late Ordovician age; no Early Ordovician or Middle Ordovician assemblages have been identified ...
Stewart G. Molyneux, Florentin Paris
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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 +3 more
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