| Computer Code: |
STFA |
Preferred Map Code: |
StF |
| Status Code: |
Full |
| Age range: |
Tournaisian Age (CT)
— Chadian Substage (CI) |
| Lithological Description: |
A lower member comprises thinly interbedded laminated dolostones, dolomitic-siliciclastic siltstone, mudstone and laminated anhydrite. This is overlain by interbedded sandstone, siltstone, mudstone and thin limestone. The sandstones are arkosic, pale grey, fine-grained, micaceous and carbonaceous. Limestones are dark grey micrites with subordinate packstones and wackestones.The upper member comprises interbedded limestone, siltstone and mudstone, lithologically similar to the middle member, but lacking sandstones. |
| Definition of Lower Boundary: |
Not seen, but possibly an angular unconformity above Lower Palaeozoic sandstone, siltstone and mudstone. |
| Definition of Upper Boundary: |
A deeply fissured top surface marking a significant non-sequence, overlain by conglomerates of the Chapel House Limestone Formation and underlain by limestone, siltstone and mudstone of the Stockdale Farm Formation. |
| Thickness: |
At least 165m |
| Geographical Limits: |
The southern margin of the Askrigg Block, in the transition zone to the Craven sub-basin. |
| Parent Unit: |
Not Applicable (-)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Reference Section |
Stockdale Farm (SD86SE/6, Cominco Borehole S7) from 170.00 to 309.4m, proves the upper and middle part of the formation. |
| Type Section |
Halsteads (SD86SW/6, Cominco Borehole S2), shows the basal 37m of the lower part of the formation. |
| Reference(s): |
| Arthurton, R S, Johnson, E W, and Mundy, D J C. 1988. Geology of the country around Settle. Memoir of the British Geological Survey, Sheet 60 (England and Wales). |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E060
|
