| Computer Code: |
GRGS |
Preferred Map Code: |
GRGS |
| Status Code: |
Full |
| Age range: |
Neoproterozoic Era (AZ)
— Neoproterozoic Era (AZ) |
| Lithological Description: |
Dominantly siliceous, feldspathic and micaceous psammite with some quartzite. Semipelite developed locally near the base. |
| Definition of Lower Boundary: |
Transition up from graded micaceous psammites of the Corrieyairack Subgroup into clean feldspathic and siliceous psammites. |
| Definition of Upper Boundary: |
First appearance of regionally transgressive semipelites of the overlying Lochaber Subgroup (Appin Group). |
| Thickness: |
To 2km |
| Geographical Limits: |
Glen Spean, Lochaber and the Central Grampian Highlands of Scotland. |
| Parent Unit: |
Grampian Group (GRAM)
|
| Previous Name(s): |
Strath Tummel Succession [Obsolete Name and Code: Use GRGS]
(-4072)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Reference Section |
Glen Spean around Inverlair Falls. |
| Type Section |
A9 road section NW from Calvine to Dalnaspidal. |
| Reference(s): |
| Glover, B W, and Winchester, J A. 1989. The Grampian Group, a major Late Proterozoic clastic sequence in the Central Highlands of Scotland. Journal of the Geological Society, London. Vol. 146, 85-96. |
| Winchester, J A and Glover, BW, 1988. The Grampian Group, in Winchester, J A [ed.]. Late Proterozoic stratigraphy of the northern Atlantic regions. Blackie, Glasgow, 146-161. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
S062
S063
S063
S053
S054
S046
|
