The BGS Lexicon of Named Rock Units — Result Details
Froswick Tuff Formation
| Computer Code: | FSW | Preferred Map Code: | Fsw |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Caradoc Series (O4) — Caradoc Series (O4) | ||
| Lithological Description: | Eutaxitic to parataxitic, andesitic to dacitic lapilli-tuff, locally lithic rich with minor tuff-breccia and bedded tuff and lapilli-tuff. | ||
| Definition of Lower Boundary: | Marked by the abrupt change from bedded volcaniclastic rocks of the Mardale Formation to massive pyroclastic rocks. | ||
| Definition of Upper Boundary: | Defined by the base of the overlying Woundale or Seathwaite Fell Sandstone formations. | ||
| Thickness: | To 640m | ||
| Geographical Limits: | Northeastern Lake District, from Kentmere to Place Fell, southeast Ullswater; Hart Fell, Haweswater; Bampton Common, Mardale Common and Wet Sleddale. | ||
| Parent Unit: | Borrowdale Volcanic Group (BVG) | ||
| Previous Name(s): | Froswick Tuffs [Obsolete Name and Code: Use WOU, FSW]
(-264)
Froswick Formation [Obsolete Name and Code: Use FSW] (-2808) |
||
| Alternative Name(s): | none recorded or not applicable | ||
| Stratotypes: | |||
| Reference Section | Eastern slopes of Froswick, west of the River Kent, Kentmere. | ||
| Type Area | Swindale Common, from Fewling Stones to High Wether Howe. | ||
| Reference(s): | |||
| Woodhall, D G. 2000. The geology of the Haweswater and Martindale areas of the north-eastern Lake District. British Geological Survey Technical Report WA/00/55. | |||
| Millward, D. 2004. A stratigraphical framework for the Upper Ordovician and Lower Devonian volcanic and intrusive rocks in the English Lake District and adjacent areas. British Geological Survey, Research Report: RR/01/007. | |||
| Millward, D. 2002. Geology of the area between Haweswater and Shap. British Geological Survey Research Report RR/02/02. | |||
| 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. | |||
| Beddoe-Stephens, B. 2000. The Borrowdale Volcanic Group between Haweswater and eastern Ullswater. British Geological Survey Technical Report WG/00/04. | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| E030 E039 | |||