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
Type Area  Great Ladstones, Ralfland Forest near Shap, Cumbria 
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