The BGS Lexicon of Named Rock Units — Result Details
Glen Lethnot Grit Formation
| Computer Code: | GLGT | Preferred Map Code: | litho |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Neoproterozoic Era (AZ) — Neoproterozoic Era (AZ) | ||
| Lithological Description: | Mixed psammite, semipelite and pelite. Psammites typically gritty. Pelites include types rich in staurolite and muscovite, and some are also kyanite-bearing. Schists rich in iron-ore minerals form mappable units in places. Beds of quartzite with specks of green mica occur rarely near the base of the Formation. | ||
| Definition of Lower Boundary: | Gradational transition from Glen Effock Schist Formation marked by incoming of silvery muscovite-rich pelite, increase in proportion of gritty psammite and decrease in proportion of green feldspathic semipelite. | ||
| Definition of Upper Boundary: | Not seen: faulted against Highland Border Complex. | ||
| Thickness: | At least 3000m indicated in Glen Esk; tectonic thickening probably less than in Glen Effock Schist Formation. | ||
| Geographical Limits: | Occurs in the southeast corner of Sheet 65E and the southern border of Sheet 66W from White Hill (NO 402 731) to Bannock Hill (NO 610 760). | ||
| Parent Unit: | Southern Highland Group (SOHI) | ||
| Previous Name(s): | Glen Lethnot Grits [Obsolete Name and Code: Use GLGT]
(-4066)
Glen Lethnot (Grit) Group [Obsolete Name And Code: Use GLGT] (DCGL) |
||
| Alternative Name(s): | none recorded or not applicable | ||
| Stratotypes: | |||
| Type Area | Stream section in West Water (Glen Lethnot) from Waterhead to southern boundary of Sheet 66W south of Stonyford; also adjacent Craigs of Stonyford. | ||
| Reference(s): | |||
| Smith, C G, Goodman, S and Robertson S. 2003. Geology of the Ballater district. Memoir of the British Geological Survey, Sheet 65E (Scotland). | |||
| Harte, B, 1979. The Tarfside succession and the structure and stratigraphy of the eastern Scottish Dalradian rocks. "In" Harris, A L, Holland, C H and Leake, B E. Geological Society of London Special Publication No.8, p.221-228. | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| S065 S066 S067 S066 | |||