| Computer Code: |
YSPS |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Tonian Period (AT)
— Tonian Period (AT) |
| Lithological Description: |
Psammite, variably gneissose; with subsidiary layers or lenses of amphibolite, pelite, quartzite and gneissose semipelite. |
| Definition of Lower Boundary: |
Likely overlying Lewisian Gneiss (L), with sheared unconformity. |
| Definition of Upper Boundary: |
Overlain by the Mid Yell Psammite Formation. |
| Thickness: |
Unknown: strongly deformed. |
| Geographical Limits: |
Shetland: Yell, Mainland; east of the Walls Boundary Fault. |
| Parent Unit: |
Yell Sound Group (ME)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| none recorded or not applicable |
| Reference(s): |
| Krabbendam, M. 2021. A stratigraphic framework for the early Neoproterozoic successions of the Northern Highlands of Scotland. UK Stratigraphic Framework Series. British Geological Survey Open Report, OR/21/072. 86pp. |
| Flinn, D, 1994. Geology of Yell and some neighbouring islands in Shetland. Memoir of the British Geological Survey, Sheet 130 (Scotland). |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
S127
S128
S129
|
