| Computer Code: |
AF |
Preferred Map Code: |
AF |
| Status Code: |
Full |
| Age range: |
Tournaisian Age (CT)
— Tournaisian Age (CT) |
| Lithological Description: |
Variable thin-bedded sediments: pebbly sandstones, laminated micaceous sandstones, siltstones, shaly mudstones, shales, thin micritic algal stromatolites. |
| Definition of Lower Boundary: |
Unknown but probably conformable with Iniscarn Formation. |
| Definition of Upper Boundary: |
Unknown but probably conformable with Desertmartin Limestone Formation. |
| Thickness: |
Unknown |
| Geographical Limits: |
Desertmartin area, Co.Londonderry, Northern Ireland. |
| Parent Unit: |
Tyrone Group (TYRO)
|
| Previous Name(s): |
Upper Calciferous Sandstones [Obsolete Name and Code: Use AF]
(-3156)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Partial Type Section |
Altagoan River, upstream from Altagoan Bridge. |
| Partial Type Section |
Lower part of formation: Drumard Water, above and below 300ft contour |
| Reference(s): |
| Eagan, F W, 1881. Explanatory memoir to accompany sheet 27 of the maps of the Geological Survey of Ireland |
| Owens, B, Gueinn, K J and Cameron, I B, 1977. A Tournaisian miospore assemblage from the Altagoan Formation (Upper Calciferous Sandstone) Draperstown, Northern Ireland. Pollen et Spores, Vol. XIX, No.2. |
| Geological Survey of Northern Ireland, 1983. Cookstown sheet 27, solid 1:50,000. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
N27
|
