Arbigland Limestone Member
Arbigland Limestone Member (ARLM), Carboniferous, Northern England Province
Arbigland Limestone Member is part of the Tyne Limestone Formation
Name
Previously known as Arbigland Group (Craig, 1956[1]) and Arbigland Beds (Deegan, 1970[2]). The status was changed from the Arbigland Limestone Formation (Lintern and Floyd, 2000[3]) to a member of the Tyne Limestone Formation.
Lithology
The member comprises interbedded marine limestone, mudstone and subsidiary siltstone, with thick cross-bedded, bioturbated, medium-grained sandstone.
Stratotype
The type section is the Arbigland coast, Kirkcudbrightshire, from Arbigland (NX 9940 5720) to Hogus Point (NX 9970 5880), where mudstones, siltstones, sandstones, and limestones constitute a section probably more than 300.m thick (Craig, 1956[1]; Deegan, 1970[2]; but see Lintern and Floyd, 2000, p. 82[3]).
Lower and upper boundaries
The base of the Arbigland Limestone Member is probably conformable on the Thirlstane Sandstone (Powillimount Sandstone Member, Fell Sandstone Formation) (Figure.10; Column 2). It is stratigraphically the highest unit in the Kirkbean Outlier, and its top is not exposed.
Thickness
More than 300 m.
Distribution and regional correlation
The Kirkbean Outlier of the Kirkcudbright.—.Dalbeattie district.
Age and biostratigraphical characterisation
Asbian. The limestones and mudstones have an abundant and diverse fauna of corals (including Lithostrotion clavicatum, Siphonodendron scotica and Siphonophyllia benburbensis), brachiopods (including Actinopteria persulcata, Linoprotonia cf. ashfellensis, Productus cf. garwoodi, Punctospirifer scabricosta redesdalensis and Stenoscisma cf. isorhyncha), bivalves (including Prothyris cf. oblonga and Pteronites cf. angustatus) and other molluscs, crinoids and bryozoa. Siphonophyllia benburbensis is unknown in strata earlier than the Asbian.
References
- ↑ 1.0 1.1 Craig, G Y, and Nairn, A E M.1956.The Lower Carboniferous outliers of the Colvend and Rerrick shores, Kirkcudbrightshire.Geological Magazine, Vol. 93, 249–256
- ↑ 2.0 2.1 Deegan, C E.1970.The petrology and sedimentology of the Lower Carboniferous rocks between White Port and Kirkbean, Kirkcudbrightshire. Unpublished PhD thesis, University of Wales, Aberystwyth
- ↑ 3.0 3.1 Lintern, B C, and Floyd, J D.2000.Geology of the Kirkcudbright–Dalbeattie district.Memoir of the British Geological Survey, Sheets 5W and 5E, part 6W (Scotland)