| Computer Code: |
OV |
Preferred Map Code: |
OV |
| Status Code: |
Full |
| Age range: |
Caradoc Series (O4)
— Caradoc Series (O4) |
| Lithological Description: |
Grey, laminated siltstones and tuffaceous fine-grained sandstones; channels of sedimentary breccia composed of platy siltstone clasts at base. Formation is intruded by sills of Eycott Volcanic Group age. |
| Definition of Lower Boundary: |
Unconformity with Skiddaw Group rocks below. (Angular discordance seen in places). |
| Definition of Upper Boundary: |
Overlain by conglomerate or by basaltic andesite and andesite lavas and sills forming main part of the Eycott Volcanic Group. |
| Thickness: |
c.8m at type section; up to 10m elsewhere; absent in some areas. |
| Geographical Limits: |
Limited to exposure of the base of the Eycott Volcanic Group. (Entirely within 1:50k Sheet 23, Cockermouth). |
| Parent Unit: |
Eycott Volcanic Group (EVG)
|
| Previous Name(s): |
Overwater Formation [Obsolete Name and Code: Use OV]
(-4239)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Section |
Overwater Spillway, west of Chapelhouse Reservoir; between confluence of River Ellen and southern end of Chapelhouse Reservoir. |
| Reference(s): |
| Millward, D, and Molyneaux, S G. 1992. Field and Biostratigraphic Evidence for an unconformity at the base of Eycott Volcanic Group in the Lake District. Geological Magazine, Vol.129/1, p.77-92. |
| Millward, D, Carruthers, R M, Marriner, G F, Molyneux, S G, and Beddoe-Stephens, B. 1999. The Eycott Volcanic Group. British Geological Survey Technical Report, WA/99/68. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E023
|
