The Holkerian is a sub-stage of the Viséan stage of the International Commission on Stratigraphy (ICS) geological timescale.[1] It is one of five sub-stages commonly used in the Viséan stage within stratigraphy by British, Irish and other geologists outside the US and Asia.[2][3][4]
As part of the Viséan, Holkerian rocks were formed about 339 to 335 million years ago,[5][6][7] in the Early Carboniferous subperiod. Rock formations laid down in this time were frequently different types of fossiliferous limestone. The material for all these rocks was laid down in warm, sub-tropical marine conditions of the time when north-western Europe was close to the equator.[8]
^International Commission on Stratigraphy. "ICS Chronostratigraphic Chart". www.stratigraphy.org. Retrieved 4 November 2017.
^Holliday, D.W.; Molyneux, S.G. (2006). "Editorial statement: new official names for the subsystems, series and stages of the Carboniferous System - some guidance for contributors to the Proceedings". Proceedings of the Yorkshire Geological Society. 56 (1): 57–58. doi:10.1144/pygs.56.1.57. Retrieved 21 October 2017.
^Waters, Colin, ed. (2011). "A revised correlation of Carboniferous rocks in the British Isles: South Wales" (PDF). Geological Society of London: 29–36. Archived from the original on 4 July 2012. Retrieved 21 October 2017.
^Heckel, Phil; Clayton, Geoffrey (2006). "The Carboniferous System. Use of the new official names for the subsystems, series, and stages". Geologica Acta: 403–407. Retrieved 21 October 2017.
^"Holkerian Age". A BGS Geochronostratigraphy division of time. British Geological Survey. Retrieved 12 November 2017.
^"Base Holkerian". A boundary between geological divisions of time. British Geological Survey. Retrieved 12 November 2017.
^"Base Asbian". A boundary between geological divisions of time. British Geological Survey. Retrieved 12 November 2017.
^British Geological Survey (1997). "Hunts Bay Oolite Subgroup". www.bgs.ac.uk. Retrieved 22 October 2017.
The Holkerian is a sub-stage of the Viséan stage of the International Commission on Stratigraphy (ICS) geological timescale. It is one of five sub-stages...
chronostratigraphy, the British sub-stage of the Carboniferous period, the "Holkerian" derives its name from Holker Hall. The land on which the house stands...
area: Knockcrushen Formation (wackestones, packstones and mudstones; of Holkerian age) Derbyhaven Formation (packstones and mudstones with some mudstones...
magnesium). This subgroup was deposited in equatorial seas largely during the Holkerian (British regional) substage of the Viséan stage of the Carboniferous,...
Ravenstonedale Group Stratigraphic range: Courceyan to Holkerian substages of Carboniferous Type Group Sub-units Raydale Dolomite, Marsett and Penny Farm...
Cowside. The underlying stone of the valley floor is Cove Limestone (Holkerian), but at the valley sides and tops, it consists of Gordale Limestone,...
(Mississippian). Lethiscus is known from only a single specimen from the Holkerian Stage (Middle Viséan) of the Early Carboniferous (Middle Mississippian)...
doctoral research investigated the foraminiferal stratigraphy of the Holkerian, Asbian and Brigantian stages of the British lower carboniferous and was...
Border Group Stratigraphic range: Chadian to Holkerian substages of Carboniferous Type Group Sub-units Lyne and Fell Sandstone formations, Kershopefoot...
only. The basal beds of the Carboniferous succession on Anglesey are of Holkerian to Asbian age and are termed the Lligwy Sandstone Formation. These sandstones...
chronostratigraphy, the British sub-stage of the Carboniferous period, the 'Holkerian' derives its name from Holker Hall. Cumbria portal Listed buildings in...
The limestone at Scaleber Force is either Late Arundian stage, or the Holkerian stage of the Viséan age limestone. The waterfall is located on Stockdale...
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