The BGS Lexicon of Named Rock Units — Result Details
Hafotty Formation
| Computer Code: | HF | Preferred Map Code: | Hf |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Comley Series (EC) — St David's Series (ED) | ||
| Lithological Description: | Grey, thinly-bedded turbiditic sandstones and mudstones interbedded with manganiferous mudstones. | ||
| Definition of Lower Boundary: | Sharp conformable contact on coarse-grained, thick bedded turbiditic sandstones of the Rhinog Formation. | ||
| Definition of Upper Boundary: | Conformably overlain by coarse-grained turbiditic sandstones of the Barmouth Formation. | ||
| Thickness: | 170 to 300m | ||
| Geographical Limits: | Harlech Dome, North Wales. | ||
| Parent Unit: | Harlech Grits Group (HGG) | ||
| Previous Name(s): | Hafotty Group [Obsolete Name and Code: Use HF]
(-312)
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| Alternative Name(s): | Trwyn Y Fulfran Formation Manganese Group |
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| Stratotypes: | |||
| Partial Type Section | Haffoty mines. On hillside above Llanaber. Basal contact and up to 30m of overlying beds are exposed. | ||
| Reference(s): | |||
| Andrew, A R. 1910. The geology of the Dolgelly gold belt, North Wales. Geological Magazine, Vol. 7, 159-171, 201-211, 261-271. | |||
| Woodland, A W. 1938. Petrological studies in the Harlech Grit Series of Merionethshire. Geological Magazine, Vol.75, 366-382 and 440-454. | |||
| Allen, P M, and Jackson, A A. 1985. Geology of the country around Harlech. Memoir of the British Geological Survey, Sheet 135 with part of Sheet 149 (England and Wales). (London: HMSO.) 112 pp. | |||
| Woodland, A W. 1939. The petrography and petrology of the Lower Cambrian manganese ore of West Merionethshire. Quarterly Journal of the Geological Society of London, Vol.95, 1-35. | |||
| Cowie, J W, Rushton, A W A and Stubblefield, C J, 1972. A correlation of Cambrian rocks in the British Isles. Special Report of the Geological Society of London, No.2, p.26. | |||
| Matley, C A and Wilson, T S. 1946. The Harlech Dome, North of the Barmouth Estuary. Quarterly Journal of the Geological Society of London, Vol.102, 1-40. | |||
| Waters, C N, Smith, K, Hopson, P M, Wilson, D, Bridge, D M, Carney, J N, Cooper, A H, Crofts, R G, Ellison, R A, Mathers, S J, Moorlock, B S P, Scrivener, R C, McMillan, A A, Ambrose, K, Barclay, W J, and Barron, A J M. 2007. Stratigraphical Chart of the United Kingdom: Southern Britain. British Geological Survey, 1 poster. | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| E119 E135 E149 | |||