Pinskey Gill Formation
Pinskey Gill Formation (PNKG), Carboniferous, Northern England Province
Pinskey Gill Formation is part of the Ravenstonedale Group
Name
Derived from Pinskey Gill, by Newbiggin on Lune, Cumbria. The formation was originally named the Pinskey Gill Beds by Garwood (1913, p. 496)[1].
Lithology
The Pinskey Gill Formation comprises grey, vuggy, dolomitic limestone and dolostone interbedded with grey to dark grey calcareous mudstone and thin-bedded, calcareous, silty sandstone.
Genetic interpretation
The strata were deposited in a peritidal marine and fluvial environment.
Stratotype
The type section is in Pinskey Gill (NY 698 040) where the formation is about 20 m thick and comprises beds of sandstone, calcareous mudstone with sporadic pebbles, sandy shale, interbedded mudstone and shale, and dolomite, (see Garwood, 1913, pp. 496– 499[1]).
Lower and upper boundaries
The formation rests unconformably upon a smooth planation surface cut into Lower Palaeozoic strata. Conglomerate beds of the Marsett Formation overlie it unconformably (Figure 9, Column 16).
Thickness
Up to 50 m.
Distribution and regional correlation
The formation is found only at Ravenstonedale in the Stainmore Trough.
Age and biostratigraphical characterisation
Miospores including Schopfites claviger and S. delicatus of the CM and possibly PC zones (Johnson and Marshall, 1971[2]; Holliday et al., 1979[3]) and conodonts dominated by Bispathodus aculeatus aculeatus, B. stabilis and Clydagnathus unicornis of the Pseudopolygnathus multistriatus Zone (Varker and Higgins, 1979[4]; Varker and Sevastopulo, 1985[5]) indicate a Tournaisian (mid Courceyan) age for the formation (Table 2).
References
- ↑ Jump up to: 1.0 1.1 Garwood, E J.1913.The Lower Carboniferous succession in the north-west of England.Quarterly Journal of the Geological Society, Vol. 68, 449–596.
- ↑ Johnson, G A L, and Marshall, A E.1971.Tournaisian beds in Ravenstonedale, Westmorland.Proceedings of the Yorkshire Geological Society, Vol. 38, 261–280
- ↑ Holliday, D W, Neves, R, and Owens, B.1979.Stratigraphy and palynology of early Dinantian (Carboniferous) strata in shallow boreholes near Ravenstonedale, Cumbria.Proceedings of the Yorkshire Geological Society, Vol. 42, 343–356.
- ↑ Varker, W J, and Higgins, A C.1979.Conodont evidence for the age of the Pinskey Gill Beds of Ravenstonedale, north-west England.Proceedings of the Yorkshire Geological Society,Vol. 42, 357–369
- ↑ Varker, W J, and Sevastopulo, G D.1985.The Carboniferous System: Part 1.—.conodonts of the Dinantian Subsystem from Great Britain and Ireland.167–209 in A Stratigraphical Index of Conodonts. Higgins, A C, and Austin, R L (editors). (Chichester: Ellis Horwood Limited for the British Micropalaeontological Society)