| Computer Code: |
RWT |
Preferred Map Code: |
Rwt |
| Status Code: |
Full |
| Age range: |
Caradoc Series (O4)
— Caradoc Series (O4) |
| Lithological Description: |
A well-bedded dacitic tuff and lapilli-tuff, with some pyroclastic breccia and accretionary lapilli-tuff, more thinly-bedded, finer grained and better sorted upwards, with abrupt intra-bed changes in grain size common. |
| Definition of Lower Boundary: |
Taken at the abrupt change from bedded volcaniclastic sandstone to bedded pyroclastic rocks. |
| Definition of Upper Boundary: |
Intruded by andesite sills at the base of the overlying Mardale Formation. |
| Thickness: |
Up to 100 m thick. |
| Geographical Limits: |
Southeast of Haweswater Reservoir, Cumbria, between Rowantreethwaite Beck and Woof Crag. |
| Parent Unit: |
Mardale Sandstone Formation (MRL)
|
| Previous Name(s): |
Rowantreethwaite Member [Obsolete Name and Code: Use RWT]
(-3016)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Section |
Ritchie Crag, 1.7 km SSE of the Haweswater Hotel, Haweswater, 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
|
