The BGS Lexicon of Named Rock Units — Result Details
Tullochroisk Semipelite Formation
| Computer Code: | TULS | Preferred Map Code: | TulS |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Neoproterozoic Era (AZ) — Neoproterozoic Era (AZ) | ||
| Lithological Description: | Lower part - rusty weathering pyritic semipelite with psammitic beds, non-graphitic; Upper part - semipelite, moderately graphitic, with biotite porphyroblasts. | ||
| Definition of Lower Boundary: | Sharp contact with pale limestone of Strath Fionan Pale Limestone Formation. | ||
| Definition of Upper Boundary: | Sharp boundary with graphitic limestone at base of Blair Atholl Dark Limestone and Dark Schist Formation. | ||
| Thickness: | 0 - 200m in Sheet 55W; probably some tectonic thinning. | ||
| Geographical Limits: | Intermittently from closure of Errochty Synform [NN 713 670] to the south bank of Allt Kynachan [NN 7778 5722]. Not present east of the Loch Tay Fault, where its place is taken by the upper part of the Monzie Limestone and Schist Formation. | ||
| Parent Unit: | Ballachulish Subgroup (DABH) | ||
| Previous Name(s): | Monzie Limestone and Schist Formation [Obsolete Name and Code: Use SFBS, SFPL, TULS]
(-4323)
Strath Fionan Dark Schist and Limestone Formation [Obsolete Name and Code: Use TULS] (-1242) |
||
| Alternative Name(s): | none recorded or not applicable | ||
| Stratotypes: | |||
| Partial Type Section | Upper part of formation - 700m southeast of south end of Lochan an Daim; along line of traverse C-C' (Fig.4 of Treagus, in press). | ||
| Partial Type Section | Lower part of formation - Section in the stream, 700m southeast of south end of Lochan an Daim; close to C-C' (Fig.4 of Treagus, J E. 2001). | ||
| Reference(s): | |||
| Treagus, J E. 2001. Solid geology of the Schiehallion district. Memoir of the British Geological Survey, Sheet 55W (Scotland). | |||
| Bailey, E B. 1925. Perthshire tectonics: Loch Tummel, Blair Atholl and Glen Shee. Transactions of the Royal Society of Edinburgh, Vol. 53, 671-698. | |||
| Bailey, E B, and McCallien, W J. 1937. Perthshire tectonics: Schiehallion to Glen Lyon. Transactions of the Royal Society of Edinburgh, Vol. 59, 79-117. | |||
| Harris, A L, Haselock, P J, Kennedy, M J and Mendum, J R, 1994. The Dalradian Supergroup in Scotland, Shetland and Ireland. 33-53 in Gibbons, W E and Harris, A L (editors). A revised correlation of Precambrian rocks in the British Isles. Special Report of the Geological Society, London, No.22. | |||
| Smith, R A and Harris, A L, 1976. The Ballachulish rocks of the Blair Atholl district. Scottish Journal of Geology, Vol.12, 153-157. | |||
| Stephenson, D and Gould, D. 1995. British Regional Geology: the Grampian Highlands (4th edition). (London: HMSO for the British Geological Survey), 67-68. | |||
| Treagus, J E and King, G, 1978. A complete Lower Dalradian succession in the Schiehallion district, central Perthshire. Scottish Journal of Geology, Vol.14, 157-166. | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| S055 | |||