| 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
|
