Ordovician period

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Ordovician period

a period of the PALAEOZOIC ERA which occurred between 515 and 445 million years ago. Algae, particularly calcareous, reef-building forms, were common as were graptolites, corals and brachiopods. The first armoured fish evolved in the Ordovician.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005
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Because of the flat relief of the surrounding land areas and tectonic stability of the interior of the Baltica craton, the erosion rate in the surrounding land areas and sediment input into the basin were very low during the Ordovician (Jaanusson 1973).
The oxygen increase during the Ordovician radiation could have made more locations on Earth habitable and "supported more predators in the food chain."
Despite their low regional metamorphic grade, the Late Ordovician to Early Devonian cover strata record multi-phase deformation including episodes of recumbent and upright folding, and thrust, strike-slip and high-angle dip-slip faulting.
(1) What are the petrological and geochemical characteristics of diagenetic calcites in the Late Ordovician Lianglitag Formation?
Thus far, the Bashituopu oil/gas field with the Carboniferous system as the production layer in the west of the Maigaiti slope and the Hetianhe gas field with the Ordovician carbonatite rock-containing buried hill and Carboniferous system as the production layer in the Mazhatage tectonic belt on the northern border of the eastern Maigaiti slope have been identified.
The Lower/Middle Ordovician in the Aldeaquemada area comprises two lithostratigraphic units: the Armorican Quartzite Formation and the Pochico Formation (Fig.
While the Carboniferous and Ordovician plays identified at Beehive have not yet been drilled in the Petrel sub-basin, there are giant oil field analogues in similar aged rocks elsewhere in the world.
The epicontinental Ordovician Baltic Basin was opened to the Iapetus Ocean in its western, and to the Tornquist Ocean in the southern side.
But in the case of the Late Ordovician, the researchers found that the duration of the gap did not matter, indicating that a mass extinction very likely did occur.
We are also evaluating a multi-stage horizontal application in the main Ordovician reservoir."
The Ordovician period is one of the most significant chapters in the Earth's history, encompassing 44 million years of great geologic and climate changes, as well as an explosion of biodiversity.
This is the first evidence that a decrease in carbon from volcanic degassing--combined with continued weathering of the Appalachians--caused the long-enigmatic glaciation and extinction in the Ordovician period, explains Lee Kump, professor of geosciences.

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