Dbk: 1 revision imported

2021-07-26T14:53:59Z

1 revision imported

← Older revision	Revision as of 15:53, 26 July 2021
(No difference)

Geosource>Volunteer 01: Created page with "==Potts Beck Limestone Formation [http://www.bgs.ac.uk/lexicon/lexicon.cfm?pub=PBK (PBK)], Carboniferous, Midland Valley of Scotland == Potts Beck Limestone Formation is part ..."

2015-07-30T10:45:54Z

Created page with "==Potts Beck Limestone Formation [http://www.bgs.ac.uk/lexicon/lexicon.cfm?pub=PBK (PBK)], Carboniferous, Midland Valley of Scotland == Potts Beck Limestone Formation is part ..."

New page

==Potts Beck Limestone Formation [http://www.bgs.ac.uk/lexicon/lexicon.cfm?pub=PBK (PBK)], Carboniferous, Midland Valley of Scotland ==
Potts Beck Limestone Formation is part of the [[Great Scar Limestone Group]]
=== Name ===
The name is derived from Potts Beck near Ravenstonedale, Cumbria (see George et al., 1976<ref name="George76">George, T N, Johnson, G A L, Mitchell, M, Prentice, J E, Ramsbottom, W H C, Sevastopulo, G D, and Wilson, R B.1976.A correlation of Dinantian rocks in the British Isles.''Geological Society of London Special Report'', No.7</ref>).

=== Lithology ===
See Mitchell (1978)<ref name="Mitchell78">Mitchell, M.1978.Dinantian.168–177 in The geology of the Lake District. Moseley, F (editor).''Occasional Publication of the Yorkshire Geological Society'', No. 3</ref>; Dunham and Wilson (1985)<ref name="DandW">Dunham, K C, and Wilson, A A.1985.Geology of the Northern Pennine Orefield: Volume 2, Stainmore to Craven.''Economic Memoir of the British Geological Survey'', Sheets 40, 41 and 50, parts 31, 32, 51, 60 and 61(England and Wales)</ref>; Millward et al., (2003)<ref name="Millward">Millward, D, McCormac, M, Hughes, R A, Entwistle, D C, Butcher, A, and Raines, M G.2003.Geology of the Appleby district.''Sheet explantion of the British Geological Survey'',Sheet 30 (England and Wales)</ref>. The Potts Beck Limestone Formation is composed largely of pale grey, thick-bedded, strongly jointed, sparry packstone. Rubbly weathered calcrete horizons are present, as are subordinate sandstones and mudstones.

=== Genetic interpretation ===
Marine.

=== Stratotype ===
The type section is at Great Kinmond (NY 6728 0892 to 6728 0927) where some 39 m of mostly fossiliferous limestone is exposed. The type area is at Little Asby Scar (NY 6988 0827) on the north side of Potts Valley, near Newbiggin-on-Lune, Cumbria where the base of the formation is exposed.

=== Lower and upper boundaries ===
The base of the formation is conformable, and taken at the change from dark grey, cross-bedded, coarse-grained, crinoidal grainstone with mudstone interbeds (the ‘Bryozoa Band’ of Garwood, 1913) at the top of the underlying Ashfell Limestone Formation (Figure 9, Column 16), to grey, coralline packstone.

The upper boundary of the formation is overlain by the grey, scar-forming, rhythmically bedded, limestone (mainly wackestone and packstone) of the Knipe Scar Limestone Formation.

=== Thickness ===
The formation is up to 45 m thick in the Stainmore Trough, but thins rapidly towards the surrounding block areas. It is, for example, absent north of Shap village.

=== Distribution and regional correlation ===
Stainmore Trough.

=== Age and biostratigraphical characterisation ===
Latest Holkerian to early Asbian. Fossils, which can be abundant, include the corals ''Axophyllum'' sp., ''Dibunophyllum bourtonense'', ''Palaeosmilia murchisoni'', ''Siphonodendron junceum'' and ''S. martini'', and the brachiopods ''Daviesiella llangollensis'' and ''Gigantoproductus'' sp. The Stainmore Trough includes the basal Asbian Stratotype at Little Asby Scar (NY 6988 0827) (George et al., 1976<ref name="George76"></ref>). Faunal analysis of this section places the Holkerian/Asbian boundary above the base of the formation (Ramsbottom, 1981<ref>Ramsbottom, W H C.1981.Fieldguide to the boundary stratotypes of the Carboniferous stages in Britain. Biennial Meeting of the Subcommisson of Carboniferous Stratigraphy, Leeds</ref>).

== References ==
<references/>
[[Category:Carboniferous lithostratigraphical nomenclature]]

Potts Beck Limestone Formation - Revision history

Dbk: 1 revision imported

Geosource>Volunteer 01: Created page with "==Potts Beck Limestone Formation [http://www.bgs.ac.uk/lexicon/lexicon.cfm?pub=PBK (PBK)], Carboniferous, Midland Valley of Scotland == Potts Beck Limestone Formation is part ..."