Computer Code: |
CDHP |
Preferred Map Code: |
notEntered |
Status Code: |
Full |
Age range: |
Neoproterozoic Era (AZ)
— Neoproterozoic Era (AZ) |
Lithological Description: |
Grey flaggy quartzo-feldspathic psammite with micaceous psammite interlayers grading into micaceous pelitic tops, including muscovite and biotite. Psammites 10 to 40cm thick are common, thinner near the base; amalgamated psammites up to 6m thick are known. Semipelites/pelites are usually about 1cm thick but locally up to 20cm thick. |
Definition of Lower Boundary: |
Top of the Torr na Truim Semipelite Formation, where predominantly schistose semipelite is overlain by the flaggy bedded, predominantly psammitic succession belonging to the Creag Dhubh Psammite Formation. |
Definition of Upper Boundary: |
Base of the Creag na Sanais Semipelite Formation, where predominantly gneissose semipelite overlies the psammitic succession belonging to the Creag Dhubh Psammite Formation. |
Thickness: |
c.700m + |
Geographical Limits: |
Southwest of Newtonmore, from Glen Banchor southwards to the Ericht-Laidon Fault |
Parent Unit: |
Corrieyairack Subgroup (GRCO)
|
Previous Name(s): |
Part of the Moine Psammites [Obsolete Name and Code: Use ABIP, CDHP]
(-4416)
|
Alternative Name(s): |
none recorded or not applicable
|
Stratotypes: |
Partial Type Section |
Outcrops around Creag Dhubh and eastwards to the base of Creag Ruadh. Leslie, A G et al., BGS Internal Report IR/03/048 |
Partial Type Section |
Outcrops between Cruban Beag and Creag na Sanais (top of the Formation) Leslie, A G et al., BGS Internal Report IR/03/048 |
Reference(s): |
Leslie, A G, Krabbendam, M and Smith, R A, 2003. Progress Report on the Geology of 1:50 k Sheet 64W (Newtonmore) British Geological Survey Internal Report, IR/03/048. 23pp. |
1:50K maps on which the lithostratigraphical unit is found, and map code used: |
none recorded or not applicable |