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 [Obsolete Name and Code: Use GTLA]
(-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
|