| Computer Code: |
DPT |
Preferred Map Code: |
DpT |
| Status Code: |
Full |
| Age range: |
Caradoc Series (O4)
— Caradoc Series (O4) |
| Lithological Description: |
Andesitic lapilli-tuff, interbedded with some units of pyroclastic breccia and sparse beds of tuff; bedded and cross-bedded. Interpreted as a mixture of pyroclastic surge and fallout deposits |
| Definition of Lower Boundary: |
Taken at the abrupt change from massive tuff/lapilli-tuff of the main part of the Woundale Tuff Formation, to bedded and cross-bedded tuff or pyroclastic breccia; the boundary is an erosion surface |
| Definition of Upper Boundary: |
An erosion surface that is either overlapped by fluviolacustrine sedimentary rocks of the Seathwaite Fell Sandstone Formation or overlain by dacite tuff and lapilli-tuff of the Glaramara Tuff |
| Thickness: |
Up to 200m |
| Geographical Limits: |
Cumbria, on the west side of Woundale (NY405 056), via Doup Crag (NY419 092) and Park Head Fell (NY428 097] at the head of the Troutbeck valley to Threshtwaite Mouth [NY428 102] |
| Parent Unit: |
Woundale Tuff Formation (WOU)
|
| Previous Name(s): |
"Bedded Tuff" [Obsolete Name and Code: Use DPT]
(-2764)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Area |
Doup Crag to Hart Crag on the west side of the Troutbeck valley, Windermere, Cumbria |
| Reference(s): |
| Mitchell, G H, 1929. The succession and structure of the Borrowdale Volcanic Series in Troutbeck, Kentmere and the western part of Long Sleddale (Westmorland). Quarterly Journal of the Geological Society of London, Vol. 85, 9-44. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E039
|
