Upper Ordovician

Upper Ordovician

[′əp·ər ‚ȯr·də′vish·ən]
(geology)
The latest epoch of the Ordovician period of geologic time, beginning approximately 440 million years ago.
References in periodicals archive ?
Elsewhere, the Middle and Upper Ordovician carbonate succession of Baltoscandia almost lacks coastal siliciclastic sand facies and is particularly poor in sand-sized or coarser siliciclastic material throughout the basin (Jaanusson 1973).
By contrast, carbonate rocks of the Upper Ordovician Lianglitag Formation are potential exploration strata, which have received little attention.
Well-drilling exploration has revealed the absence of the Middle Ordovician Yijianfang and Upper Ordovician Tumuxiuke formations in the central Tarim uplift between the Mid-Lower Ordovician Yingshan and the Upper Ordovician Lianglitage formations of the Bachu uplift (Yang et al., 2011).
Slightly lower quality frac sand, referred to as "Brady" or "Brown" sand, is mined from central Texas, The principal sources of "Northern White" or "Ottawa" sand in the upper Midwest are the Middle and Upper Ordovician St.
The Palaeozoic succession of the Punta Negra Anticline should display a stratigraphic gap of Upper Ordovician age, as in other parts of the Central Precordillera (Bracaccini, 1949), interpreted as evidence for a peripheral bulge produced in a foreland basin as the result of the collision of the Cuyania terrane with the Gondwana margin (Astini et al., 1996; Astini, 2003; Ramos, 2004).
The deep shelf black shale samples come from the Upper Ordovician Mossen and Fjacka formations and Lower Silurian Dobele Formation (Fm.) of the Latvian Aizpute-41 core (Fig.
Following the pre-fracture stimulation results announced on 3 rd October 2011, the upper Ordovician interval of the AT-8 well was successfully fracture stimulated.
The Serpent Mound central peak is comprised of Upper Ordovician -Middle Silurian carbonates and shales (Reidel 1975).
Later on, due to the sea transgression, the eroded surface was buried under thin (20-300 m) post-impact, Upper Ordovician carbonate deposits and, possibly, subsequent suites destroyed through erosion (Puura & Suuroja 1992; Ainsaar et al.
Elias, R.J., 1981, Solitary rugose corals of the Selkirk Member, Red River Formation (late Middle or Upper Ordovician), southern Manitoba: Geological Survey of Canada, Bulletin 344, 53 p.
Upper Ordovician mounds in the Alabama Appalachians are dominated by bryozoans and algae, with bachiopods arid sponges important in some mounds.

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