The BGS Lexicon of Named Rock Units — Result Details

Great Ladstones Breccia Member

Computer Code: GTLA Preferred Map Code: GtLa
Status Code: Full
Age range: Caradoc Series (O4) — Caradoc Series (O4)
Lithological Description: A massive to weakly bedded, volcaniclastic breccia and pebbly coarse-grained, clast- to matrix-supported and very poorly sorted sandstone with dominantly silicic or andesitic fragments.
Definition of Lower Boundary: Taken at the change from generally well bedded volcaniclastic sandstone to significantly coarser and weaker bedded volcaniclastic rocks.
Definition of Upper Boundary: The member is the uppermost unit of the Mardale Formation, and is overlain, along a sharp contact, by the Froswick Tuff Formation.
Thickness: To 250m
Geographical Limits: Northeastern Lake District, east of Swindale.
Parent Unit: Mardale Sandstone Formation (MRL)
Previous Name(s): Great Ladstones Member (-297)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Great Ladstones, Ralfland Forest near Shap, Cumbria 
Reference(s):
Millward, D, 2002. Geology of the area between Haweswater and Shap. British Geological Survey Research Report RR/02/02 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E030 E039