The BGS Lexicon of Named Rock Units — Result Details

Ackworth Member

Computer Code: ACKW Preferred Map Code: notEntered
Status Code: Full
Age range: Bolsovian Substage (CC) — Bolsovian Substage (CC)
Lithological Description: Grey mudstones, siltstones and sandstones with thin coals.
Definition of Lower Boundary: Top of Cambriense Marine Band (or where absent through washout: base of Ackworth Rock).
Definition of Upper Boundary: Base of Brierley Coal.
Thickness: c.100m
Geographical Limits: Yorkshire Coalfield.
Parent Unit: Pennine Upper Coal Measures Formation (PUCM)
Previous Name(s): ACKWORTH DIVISION
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Cherry Tree Borehole (near South Elmsall, Yorkshire). SE41SE/9. Depths of member 154.91-241.25m. (Samples RG 4241-4455 from 50' to 1946'). 
Reference(s):
Goossens, R F and Smith, E G, 1973. The stratigraphy and structure of the Upper Coal Measures in the exposed Yorkshire Coalfield between Pontefract and South Kirkby. Proceedings of the Yorkshire Geological Society, Vol.39, 487-514. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable