geology, the Arenig group is the name applied to the lowest stage of the OrdovicianSystem.
The term was first used by
Adam Sedgwickin 1847 with reference to the "Arenig Ashes and Porphyries" in the neighborhood of Arenig Fawr, in Merioneth, North Wales. The rock-succession in the Arenig district has been recognized by W. G. Fearnsides(“On the Geology of Arenig Fawr and Moel Llanfnant", Q.J.G.S. vol. lxi., 1905, pp. 608–640, with maps). The above succession is divisible into:
# A lower series of gritty and calcareous sediments, the “Arenig Series" as it is now understood;
# A middle series, mainly volcanic, with shale, the "
# The shale and limestones of the Bala or
It was to the middle series (2) that Sedgwick first applied the term "Arenig". In the typical region and in North Wales generally the Arenig series appears to be unconformable upon the
Cambrianrocks; this is not the case in South Wales.
North American Deposits
The Arenig series is represented in North Wales by the Garth grit and
Ty Obrybeds, by the Shelve series of the Corndondistrict, the Skiddawslates of the Lake District, the Ballantraegroup of Ayrshire, and by the Ribbandseries of slates and shale in Wicklowand Wexford. It may be mentioned here that the " Llanvirn" Series of H. Hickswas equivalent to the bifidus shale and the Lower Llandeilo Series.
geologic timescale, the Arenig is the age of the Lower Ordovicianepoch of the Ordovicianperiod of the Paleozoicera of the Phanerozoiceon that is comprehended between 478.6 ± 1.7 Ma and 471.8 ± 1.6 Ma (million years ago), approximately. The Arenig age succeeds the Tremadocianage and precedes the Stage IIIage.
The Arenig age began with a worldwide sudden rise in sea level rise in sea level (
marine transgression). The early ordivician surge in marine diversity also began around the beginning of the Arenig age. [http://www.palaeos.com/Paleozoic/Ordovician/Arenig.htm] .
* [http://www.palaeos.com/Paleozoic/Ordovician/Arenig.htm palaeos]
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ARÉNIG — ou SKIDDAW L’Ordovicien X correspond en gros à la majeure partie de l’Arénig ou du Skiddaw anglais. La localité type de Skiddaw est située dans le Cumberland (district des Lacs), celle de l’Arénig est située dans les Galles du Nord. L’extension… … Encyclopédie Universelle
Arenig — [englisch ærɪnɪg; nach einem Berg in Wales] das, s, Arenigien [arəniʒj jɛ̃, französisch], Arenigium, Geologie: Stufe des Ordoviziums … Universal-Lexikon
Arenig — Are|nig [ ærinig] das; [s] <aus gleichbed. engl. arenig, nach dem Bergzug Arenig in Wales> erdgeschichtlicher Zeitraum; Stufe des ↑Ordoviziums (Geol.) … Das große Fremdwörterbuch
arenig — əˈrānig adjective Usage: usually capitalized Etymology: from Arenig mountains, Wales : of or relating to a subdivision of the European Ordovician see geologic time table … Useful english dictionary
arenig — are·nig … English syllables
Arenig (disambiguation) — Arenig can mean: *The Arenig geological period *Arenig Fawr, a mountain in Wales *The Arenigs, mountains in Wales *Arenig railway station in Wales: it closed down in 1960 and 1961 … Wikipedia
Arenig Fawr — Infobox Mountain Name = Arenig Fawr Photo = Arenig Fawr w.jpg Caption = Arenig Fawr from the Ffestiniog road Elevation = 854 m (2802 ft) Location = Gwynedd, WAL Range = Snowdonia Prominence = 479 m Parent peak = Moel Siabod Coordinates =… … Wikipedia
Arenig railway station — Infobox UK disused station name = Arenig caption = original = Festiniog and Blaenau Railway pregroup = Great Western Railway locale = Bala borough = Gwynedd platforms = ? years = 19 June 1865 events = Station opened years1 = 4 January 1960… … Wikipedia
Llyn Arenig Fawr — Infobox lake lake name = Llyn Arenig Fawr image lake = caption lake = image bathymetry = caption bathymetry = location = Gwynedd, North Wales coords = coord|52|55|39|N|3|43|0|W|type:waterbody region:GB|display=inline,title type = reservoir inflow … Wikipedia
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