The BGS Lexicon of Named Rock Units — Result Details

Aryleive Limestone Bed

Computer Code: ARYL Preferred Map Code: notEntered
Status Code: Full
Age range: Eifelian Age (DI) — Eifelian Age (DI)
Lithological Description: A thickly-bedded, pale grey, nodular limestone.
Definition of Lower Boundary: Rests unconformably directly on Caledonian igneous or Precambrian Moine [basement] rocks as the basal unit of the Bighouse Formation on the Middle Old Red Sandstone unconformity. Locally interbedded with conglomerates of the Portskerra Conglomerate Member.
Definition of Upper Boundary: Overlain by interbedded, sandstone-dominated rhythmic sequence of sandstones, siltstones and laminated carbonate mudstones (fish beds) of the Baligill Limestone Member of the Bighouse Formation. At the type section site, however, the unit is instead overlain directly by a thin bed of angular pebbly conglomerate.
Thickness: From 3.5m to 4.0m
Geographical Limits: Onshore in the Dounreay area of Caithness, northern Scotland.
Parent Unit: Portskerra Conglomerate Member (PSKA)
Previous Name(s): Gunnscroft Limestone Bed (-1954)
Marginal Limestone At Aryleive (-1955)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Reference Section  Sea cliff exposures at Red Point, 2.5km northwest of Reay village, Caithness. Donovan, 1975. 
Type Section  The western face of a disused limestone quarry at Aryleive, 20m south of a limekiln on the eastern side of the forestry track from Reay village southwards, towards Beinn nam Bad Mor. Located 4km southeast of Reay village, Caithness. Donovan, 1975. 
Reference Section  The eastern face of a disused limestone working at Achvarrasdal, about 500m south of Creag Mor, some 3.5km southsoutheast of Reay village, Caithness. Donovan, 1975. 
Reference(s):
Trewin, N H. 1993 Old Red Sandstone basin margin deposits at Red Point, Port Skerra and Baligill. 157-166 in Trewin, N H and Hurst, A [editors], Excursion guide to the geology of eastern Sutherland and Caithness. [Edinburgh: Scottish Academic Press.] 
British Geological Survey. (In preparation, to be published in 2005). Bedrock geology. Scotland Special Sheet (Dounreay).1:25 000. 
Donovan, R N. 1975. Devonian lacustrine limestones at the margin of the Orcadian Basin, Scotland. Journal of the Geological Society of London, Vol.131, 489-510. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable