Computer Code: |
CLAG |
Preferred Map Code: |
CG |
Status Code: |
Full |
Age range: |
Neoproterozoic Era (AZ)
— Neoproterozoic Era (AZ) |
Lithological Description: |
Schistose to locally gneissose semipelite with interbeds of micaceous psammite and feldspathic psammite. Locally interbanded psammite and semipelite in places on a few centimetres scale. |
Definition of Lower Boundary: |
Change from graded beds of feldspathic and micaceous psammite of the Creag Meagaidh Formation up into semipelite-dominated succession. |
Definition of Upper Boundary: |
Transitional contact into psammites and quartzites of the overlying Inverlair Psammite Formation. |
Thickness: |
0 to 580m generally. Locally up to 820m although this may be tectonically thickened. |
Geographical Limits: |
Southern Monadhliath Mountains. On sheet 63W and 63E in an arc extending from west of Creag Meagaidh around [NN 385 875] through Meall Cos Charnan [NN 432 774] to Creag Pitridh [NN 485 810] with another occurrence in Coire Sgoir [NN 493 740], NNEfor 6km. |
Parent Unit: |
Glen Spean Subgroup (GRGS)
|
Previous Name(s): |
none recorded or not applicable
|
Alternative Name(s): |
none recorded or not applicable
|
Stratotypes: |
Type Area |
Coire Clachaig area on south flank of Beinn a Chaorainn. |
Reference Section |
Coire mor A'Chlachair on Beinn A'Chlachair. |
Reference(s): |
Key, R M, Clark, G C, May, F, Phillips, E R, Chacksfield, B C and Peacock, J D, 1997. Geology of the Glen Roy district. Memoir of the British Geological Survey, Sheet 63W [Scotland]. |
British Geological Survey. 1995. Glen Roy, Scotland sheet 63W. Solid Geology 1:50 000 (Keyworth, Nottingham: British Geological Survey.) |
1:50K maps on which the lithostratigraphical unit is found, and map code used: |
S063
S063
|