Computer Code: |
GGH |
Preferred Map Code: |
GGH |
Status Code: |
Full |
Age range: |
Guadalupian Epoch (PUG)
— Lopingian Epoch (PUL) |
Lithological Description: |
Sandstone, red, fine-to-medium-grained, dolomite cement; thin layers of red siltstone and mudstone, brown mudstone up to 15%. |
Definition of Lower Boundary: |
Sharp contact with white dolomitic limestone of the underlying Magnesian Limestone Formation. |
Definition of Upper Boundary: |
Gradational but rapid decrease in cemented sandstone and increase of red mudstone and siltstones in the overlying Drumderg House Formation [formerly known as Permian Upper Marls]. |
Thickness: |
26.9 - 50.3m [88 - 165ft] |
Geographical Limits: |
Sub-surface on northwest shore of Lough Neagh. |
Parent Unit: |
Belfast Group (BELF)
|
Previous Name(s): |
Permian Upper Sandstone [Obsolete Name and Code: Use GGH]
(-4061)
|
Alternative Name(s): |
none recorded or not applicable
|
Stratotypes: |
Reference Section |
Annaghmore-1 Borehole. GSNI Borehole Database Number 94SE/1 [3177-3265ft--968.3-995.2m] Based on cutting samples at 10ft intervals of which a split sample is stored with the Geological Survey of Northern Ireland. |
Reference(s): |
Naylor, D, Philcox, M E and Clayton, G. 2003. Annaghmore-1 and Ballynamullan-1 wells, Larne-Lough Neagh Basin, Northern Ireland. Irish Journal of Earth Sciences, Vol.21, 47-69. |
1:50K maps on which the lithostratigraphical unit is found, and map code used: |
none recorded or not applicable |