Results 191 to 200 of about 7,297 (224)

The Late Ordovician Wufengian Sediments and the Ordovician‐Silurian Boundary in Western Zhejiang Province

Acta Geologica Sinica-English, 1987
Abstract The Late Ordovician Wufengian sediments in western Zhejiang include three facies: 1) graptolite shale facies, composed of two parts— the upper part the Yankou Formation, with the Diplograptus bohemicus (graptolite) zone and Dalmanitina sp. (trilobite), and the lower part the yuqian Formation with four graptolite zones: (4) the Paraorthograptus
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A Late Ordovician high‐energy temperate‐water carbonate ramp, southern Quebec, Canada: implications for Late Ordovician oceanography*

Sedimentology, 1995
ABSTRACTThe Trenton Group (Late Ordovician), the youngest carbonate unit in the Taconic foreland basin of southern Quebec, is a tripartite unit with a distinctive coarse‐grained middle part, the Deschambault Formation.Lithofacies of the Deschambault Formation are dominated by coarse‐grained bioclastic/intraclastic limestones; finer‐grained lithofacies ...
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Ordovician-Late Silurian geodynamics of north Queensland

2016
Palaeozoic continental growth and accretionary tectonism along the eastern margin of Gondwana is characterised by the inversion of back-arc basins and accretion of the magmatic arc terranes and micro-continental ribbons.
Armit, Robin, Betts, Peter, STEWART, JOHN   +2 more
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Morphometry of Late Ordovician Microbial Borings: ABSTRACT

AAPG Bulletin, 1980
Microborings within Late Ordovician shells of the brachiopod Raphinesquina alternata from the Tanner Creek Formation, Richmond Group, of southeastern Indiana, were studied by scanning electron microscopy of their resin casts. The shells have been exposed to microbial boring in quiet and illuminated waters below the wave base and then buried with ...
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Possible Late Ordovician Glaciation of Nova Scotia

Canadian Journal of Earth Sciences, 1972
A thin, poorly stratified, polymictic diamictite at the the base of the White Rock Formation (perhaps Caradocian or younger) contains unsorted, clustered, faceted, and grooved clasts apparently dropped into a shaly or sandy lithotope. Ice probably transported these stones from a distant source.
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The late Ordovician—Early Silurian glacial period

Palaeogeography, Palaeoclimatology, Palaeoecology, 1985
Abstract Late Ordovician to Early Silurian tillites and evidence of extensive glacial erosion were first discovered in the western Sahara in the late 1950's, although the concept of a glacial period at this time had been around since the late 19th century.
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Late Ordovician Extinctions

2021
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Paleoenvironmental changes during the Middle-Late Ordovician transition, Northwestern Tarim Basin, NW China and implications for the great Ordovician Biodiversification Event

Journal of Asian Earth Sciences, 2023
Jingchun Tian
exaly  

Late Ordovician Mass Extinction: Earth, fire and ice

National Science Review, 2023
David A T Harper
exaly  

Biotic crisis in the late Ordovician

2007
Q Wang, D Yan, D Chen
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