The BGS Lexicon of Named Rock Units — Result Details

Deepdale Sandstone Formation

Computer Code: DPD Preferred Map Code: DPD
Status Code: Full
Age range: Caradoc Series (O4) — Caradoc Series (O4)
Lithological Description: Massive bedded units of volcaniclastic sandstone with intercalations of pebbly sandstone, breccia (both also volcaniclastic), tuff and lapilli-tuff. Includes the St Sunday Crag Member - lapilli-tuff.
Definition of Lower Boundary: Base of lowest sandstone, pebbly sandstone or tuff rests unconformably on the Helvellyn Tuff Formation, but locally there is overstep onto the Middle Dudd and Esk Pike Formations.
Definition of Upper Boundary: Overlying strata not preserved.
Thickness: 650m +
Geographical Limits: Grisedale, Deepdale and Dovedale, including Helvellyn and Fairfield, northeast Lake District, Cumbria.
Parent Unit: Borrowdale Volcanic Group (BVG)
Previous Name(s): Deepdale Formation (-4619)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Crags between Mart Crag, where the base of the formation is exposed, to Hart Crag, Deepdale. 
Reference Section  St Sunday Crag, Grisedale. 
Reference(s):
Woodhall, D G, 1998. The geology of the Wythburn, Thirlmere and Fairfield areas of the north-east Lake District. British Geological Survey Technical Report WA/98/07. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E029 E030