The BGS Lexicon of Named Rock Units — Result Details
Schiehallion Quartzite Formation
| Computer Code: | DBSQ | Preferred Map Code: | SchQ |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Neoproterozoic Era (AZ) — Neoproterozoic Era (AZ) | ||
| Lithological Description: | Quartzite, white to grey, fine-grained. The upper half of the formation is especially pure and glassy, with little feldspar or mica. Includes Tempar Dolomitic Member and some beds of conglomerate. | ||
| Definition of Lower Boundary: | Sharp change from diamictite of Boulder Bed to fine-grained well-bedded quartzite. However, a 10-20m bed of reworked granite diamictite occurs near the base of the Schiehallion Quartzite Formation on Cnocnan Aighean [NN 7292 5551]. | ||
| Definition of Upper Boundary: | Sharp (<10m) change from fine-grained quartzite of Shiehallion Quartzite Formation to dark, layered semipelite and thin-bedded psammite containing 8cm layers of fine-grained garnet-amphibolite. | ||
| Thickness: | 0 - 800m in Sheet 55W (most thinning is tectonic). | ||
| Geographical Limits: | From 1km north-east of Forest Lodge, where it pinches out in a tight fold core, southwards to the north shore of Loch Tummel and Loch Kinardochy via Schiehallion to the north-west side of Beinn a Chuallaich. West of this it is cut off by Schiehallion Slide. | ||
| Parent Unit: | Islay Subgroup (DBIS) | ||
| Previous Name(s): | Schichallion Quartzite
(-849)
Schiehallion Quartzite [Obsolete Name and Code: Use DBSQ] (*870) |
||
| Alternative Name(s): | none recorded or not applicable | ||
| Stratotypes: | |||
| Type Section | From Meall nan Aighhean at top of Boulder Bed section via Tempar Dolomitic Member section [NN 725 548] to south side of Schiehallion. | ||
| Reference(s): | |||
| Treagus, J E. 2001. Solid geology of the Schiehallion district. Memoir of the British Geological Survey, Sheet 55W (Scotland). | |||
| 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. | |||
| Barrow, G, Grant Wilson, J S, and Cunningham Craig, E H. 1905. The geology of the country around Blair Atholl, Pitlochry and Aberfeldy. Memoir of the British Geological Survey, Scotland (Sheet 55). | |||
| 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. | |||
| Bailey, E B. 1925. Perthshire tectonics: Loch Tummel, Blair Atholl and Glen Shee. Transactions of the Royal Society of Edinburgh, Vol. 53, 671-698. | |||
| Stephenson, D and Gould, D. 1995. British Regional Geology: the Grampian Highlands (4th edition). (London: HMSO for the British Geological Survey), 67-68. | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| S055 S055 S064 | |||