Results 231 to 240 of about 2,124,047 (278)

Palynostratigraphy of upper Cambrian-upper Ordovician intracratonic clastic sequences, North Africa

1999
Detailed palynological study of subsurface sections in the Algerian Sahara (boreholes Nl-2 and Uc-101) and southern Tunisia (boreholes Sn-1 and St-1) enables precise dating and intrabasinal and extrabasinal stratigraphic correlation. Most of the study samples proved palyniferous, yielding abundant, well preserved acritarchs (148 species) together with ...
VECOLI M., TONGIORGI, MARCO, ABDESSELAM ROUGHI F. F., BENZARTI R., MASSA D.   +4 more
openaire   +3 more sources

Depositional environment and organic matter accumulation of Upper Ordovician–Lower Silurian marine shale in the Upper Yangtze Platform, South China

, 2017
Yangfan Li, Tongwei Zhang, Geoffrey S. Ellis, Deyong Shao   +3 more
semanticscholar   +1 more source

Palynofacies in the Upper Ordovician of the Saxothuringian

Neues Jahrbuch für Geologie und Paläontologie - Monatshefte, 1994
Erhard Reitz, Thomas Heuse
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AULACOPLEURID TRILOBITES FROM THE UPPER ORDOVICIAN OF VIRGINIA

Journal of Paleontology, 2005
Abstract Five species of aulacopleurid trilobites occur in rich, silicified trilobite faunas from the Upper Ordovician of Virginia: Harpidella triloba (Hu, 1975a), Strasburgaspis cona (Hu, 1971), and Strasburgaspis? n. sp. A, all from the Turinian Edinburg Formation, Harpidella whittingtoni new species, from the overlying Turinian Oranda Formation, and
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Mottled Upper Ordovician Carbonates in Northwest Georgia

SEPM Journal of Sedimentary Research, 1975
Mottled red and gray-green, silty limestones and calcareous siltstones occur in the Sequatchie Formation (Upper Ordovician) near Ringgold, Georgia. X-ray diffraction and optical methods show that the red mottles are due to the presence of diagenetic hematite, which was formed by oxidation of iron expelled from detrital chlorite.
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Upper Ordovician Bryozoa from Sardinia.

1990
This paper presents the taxonomical descriptions of Upper Caradocian to Ashgillian bryozoans recovered from different localities from SW Sardinia and from one locality (Mulargia lake) from SE Sardinia. The investigated fauna belongs to 4 bryozoan orders: the Trepostomata, the Cystoporata, the Cryptostomata and the extant order Tubuliporata.
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Upper Ordovician Glaciation in Northwest Africa? Discussion

Geological Society of America Bulletin, 1971
Faunal, paleomagnetic, and sedimentological arguments that claim to show the existence of a continental ice sheet in northwest Africa during the Ordovician and Silurian are questionable. Neither the fauna nor the relevant pole positions necessitate the presence of land ice.
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‘Middle Ordovician’ acritarchs are guide fossils for the Upper Ordovician

Lethaia, 1987
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Characterization of methane adsorption on overmature Lower Silurian-Upper Ordovician shales in Sichuan Basin, southwest China: Experimental results and geological implications

, 2016
H. Tian, Tengfei Li, Tongwei Zhang, X. Xiao   +3 more
semanticscholar   +1 more source

A revision of the Upper Ordovician brachiopod

Geologiska Föreningen i Stockholm Förhandlingar, 1974
openaire   +1 more source