| Computer Code: |
PFD |
Preferred Map Code: |
PFD |
| Status Code: |
Full |
| Age range: |
Chadian Substage (CI)
— Holkerian Substage (CQ) |
| Lithological Description: |
The Penny Farm Gill Formation comprises interbedded limestone, dolostone, sandstone and siltstone, commonly rhythmically bedded.
The strata were deposited within a shallow marine, intertidal and supratidal environment, marginal to the more open marine conditions in the Stainmore Trough at the time. |
| Definition of Lower Boundary: |
The formation overlies contiguously the conglomeratic Marsett Formation. |
| Definition of Upper Boundary: |
The top of the Penny Farm Gill Formation is marked locally by a nodular dolostone bed with rhizoliths that is indicative of emergence (Burgess, 1986). The biosparites of the Tom Croft Limestone Formation (Great Scar Limestone Group) disconformably overlie the formation. |
| Thickness: |
According to Dunham and Wilson (1985) the formation is 50.6 m thick in the Penny Farm Gill inlier, and about 56 m thick in the Raydale Borehole (see above). |
| Geographical Limits: |
Askrigg Block. |
| Parent Unit: |
Ravenstonedale Group (RVS)
|
| Previous Name(s): |
Penny Farm Gill Dolomite Formation [Obsolete Name and Code: Use PFD]
(-4837)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Partial Type Section |
The lowest 17 m of the formation is seen in Nor Gill [SD 698 933] in a sequence that comprises mainly sandstones, silty limestones and siltstones. |
| Partial Type Section |
35 m of beds are well seen in the inlier at Penny Farm Gill [SD 698 932], where the sequence comprises sandy and micritic dolostones, siltstone with dolostone beds (not exposed, but suggested by debris), and sandy limestones with interbedded dolostones (Burgess, 1986, pp. 6-7; see also Dunham and Wilson, 1985, p. 26). |
| Partial Type Section |
The formation also occurs in the Raydale Borehole (BGS Registration Number SD98SW/1) [SD 9026 8474] from about 350 to 406 m depth (see Dunham and Wilson, 1985, and references therein). |
| Reference(s): |
| Burgess, I C. 1986. Lower Carboniferous sections in the Sedbergh district, Cumbria. Transactions of the Leeds Geological Association, Vol. 11, 1-23. |
| Dunham, K C, and Wilson, A A. 1985. Geology of the Northern Pennine Orefield. Volume 2 Stainmore to Craven. Economic Memoir of the British Geological Survey, Sheets 40, 41 and 50, and parts of Sheets 31, 32, 51, 60 and 61(England and Wales). |
| Dean, M T, Browne, M A E, Waters, C N and Powell, J H. 2011. A lithostratigraphical framework for the Carboniferous successions of northern Great Britain (onshore). British Geological Survey Research Report, RR/10/007. 165pp. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E040
|
