| Computer Code: |
BNH |
Preferred Map Code: |
BnH |
| Status Code: |
Full |
| Age range: |
Caradoc Series (O4)
— Caradoc Series (O4) |
| Lithological Description: |
Parallel-bedded, well sorted, acid andesitic or dacitic coarse-grained tuff and fine-grained lapilli-tuff with locally intercalated thin units of pyroclastic breccia containing large ragged bombs of scoriaceous andesite and intruded by many contemporaneous andesite sills. |
| Definition of Lower Boundary: |
Taken at the abrupt change from masive rhyodacitic tuff and lapilli-tuff of the Whelter Knotts Formtion, to well bedded pyroclastic rocks of intermediate compostion. |
| Definition of Upper Boundary: |
Everywhere overlain by contemporaneous andesite intrusions. |
| Thickness: |
To 135m, but greatly inflated by sills |
| Geographical Limits: |
East of Haweswater Reservoir, northeastern Lake District, Cumbria. |
| Parent Unit: |
Mardale Sandstone Formation (MRL)
|
| Previous Name(s): |
Brown Howe Member [Obsolete Name and Code: Use BNH]
(-1369)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Area |
The fellside at Mardale Banks, south-east of Haweswater Reservoir, 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
|
