The BGS Lexicon of Named Rock Units — Result Details
Blelham Peat Formation
| Computer Code: | BHPT | Preferred Map Code: | notEntered |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Devensian Stage (QD) — Holocene Epoch (QH) | ||
| Lithological Description: | Peal, organic mud and silt, and fine silty sand infilling lake basins, lowland bogs and mires, kettle holes and alluvial tracts, also blanketing upland areas. It may contain fossilised remains of trees, herbs, grasses, etc, pollen, leaves and insect remains. Two members are recognised: Pow Beck Peat Member, which comprises compressed peat with wood fragments, twigs and seeds, interbedded with grey silt and tufa and some friable peat. It is of Holocene age and underlies alluvial deposits of the flood plain of the Pow Beck at St Bees, Cumbria; it locally underlies beach sand at St Bees beach. It overlies the Lowca Till Member of the Seascale Glacigenic Formation on St Bees beach, and overlies the Fern Bank Silt Member of the Hall Carleton Formation in the Pow Beck valley. The Seacore Peat Member comprises felted peat, thinly interbedded with humic sands in places. It contains insects and pollen of Lateglacial age (typically c.14000-10000 14C years BP) and forms part of the infill of kettle holes (noteably within the St Bees Moraine); it also occurs beneath the Pow Beck Member in the Pow Beck valley. In the kettle holes within the St Bees Moraine it is overlain by solifluction deposits of pebbly silty sand (of Loch Lomond Stadial age) and it overlies the glacitectonised sequence of deposits forming the moraine. | ||
| Definition of Lower Boundary: | Varies from sharply unconformable on bedrock and all Late Devensian or older Quarternary deposits (particularly tills), to disconformable on Lateglacial marine deposits of the Fern Beck Silt Member of the Hall Carleton Formation. | ||
| Definition of Upper Boundary: | The ground surface, or overlain by Holocene blown sand of the Drigg Point Sand Formation or alluvium of the Ehen Alluvium Formation. | ||
| Thickness: | To 5 m thick in the Blelham Bog type area. | ||
| Geographical Limits: | 1.50k Sheets 28 Whitehaven, 37 Gosforth, western Cumbria, 38 (Ambleside) and 39 (Windermere) but can be applied to all Holocene to Lateglacial peat deposits within the Cumbria-Lancashire Catchments Subgroup area. | ||
| Parent Unit: | Britannia Catchments Group (BCAT) | ||
| Previous Name(s): | Submerged forest
(SUF)
Peat And Submerged And Buried Forest (-696) Peat (PEAT) Peat (PEAT) |
||
| Alternative Name(s): | none recorded or not applicable | ||
| Stratotypes: | |||
| Partial Type Section | Dissected kettle hole at top of cliff section (Log NX91SE ME7], 400m north of footbridge at Sea Mill, 300m west of St Bees village, west Cumbria. Nirex Science Report 768 (1995) | ||
| Partial Type Section | 1.2 - 2.8m depth in QBH 19 (BGS Registerd borehole NX19SE 251), sited on the floodplain of the Pow beck, c.300m northnorthwest of St Bees Railway Station, west Cumbria. Nirex Science Report SA/97/045 (Issue 2.0). | ||
| Type Area | Peat core transects from a kettle hole in the eastern, un-wooded, portion of Blelham Bog (c 300m south of Blelham Tarn) c 3km south of Ambleside and 1km west of Lake Windermere, central Cumbria. Huddart (2002a), Thomas (1999). | ||
| Reference(s): | |||
| Merritt, J W and Auton, C A. 1997. Quaternary lithostratigraphy of the Sellafield district. Nirex Science Report SA/97/045 (Issue 2.0). [Report prepared for UK Nirex Ltd. 69pp, 5 tables, 20 figures, 14 enclosures and one appendix.] | |||
| Merritt, J W, Auton, C A, Browne, M A E, Neilson, G and McMillan, A A. 1995. Characterisation of the onshore Quaternary deposits around Sellafield, Cumbria, Phase II. Nirex Science Report 768. | |||
| Thomas, G S P. 1999. Northern England. 91-98 in Bowen, D Q (Editor), A revised correlation of Quaternary and Neogene deposits in the British Isles. Geological Society Special Report No.23. | |||
| Trotter, F M, Hollingworth, S E, Eastwood T and Rose, W C C. 1937. Gosforth District. Geological Survey Memoir, England and Wales, Sheet 37. | |||
| Eastwood T, and others. 1968. Geology of the country around Whitehaven. Memoir of the Geological Survey of Great Britain, Sheet 28 (England and Wales). | |||
| Akhurst, M C, Chadwick, R A, Holliday, D W, McCormac, M, McMillan, A A, Millward, D, Young, B, Ambrose, K, Auton, C A, Barclay, W J, Barnes, R P, Beddoe-Stephens, B, James, J C W, Johnson, H, Jones, N S, Glover, B W, Hawkins, M P, Kimbell, G S, MacPherson, K A T, Merritt, J W, Milodowski, A E, Riley, N J, Robins, N S, Stone, P, and Wingfield, R T R. 1997. The geology of the west Cumbria district. Memoir of the British Geological Survey, Sheets 28, 37 and 47 (England and Wales). 138pp. | |||
| Coope, G R and Joachim, M J. 1980. Lateglacial environmental changes interpreted from fossil coleoptera from St Bees, Cumbria, northwest England. 55-68 in Lowe, J J, Grey, J M and Robinson, J E (editors), Studies in the Lateglacial of northwest Europe. [Oxford: Pergamon Press.] | |||
| Coope, G R. 1994. The Lateglacial coleoptera from St Bees, Cumbria. 86-89 in Boardman, J and Walden, J (editors), The Quaternary of Cumbria: Field Guide. [Cambridge: Quaternary Research Association.] | |||
| Huddart, D. 2002a. Blelham Bog. 179-187 in Huddart, D and Glasser, N F (editors), Quaternary of Northern England. Geological Conservation Review Series, No.25. [Peterborough: Joint Nature Conservation Committee.] 745pp. | |||
| Huddart, D. 2002b. St Bees. 230-241 in Huddart, D and Glasser, N F (editors), Quaternary of Northern England. Geological Conservation Review Series, No.25. [Peterborough: Joint Nature Conservation Committee.] 745pp. | |||
| Kendal, J D. 1881. Interglacial deposits of West Cumberland and North Lancashire. Quarterly Journal of the Geological Society of London, Vol.27, 29-39. | |||
| Pearson, R G. 1962. The coleoptera from a lateglacial deposit at St Bees, West Cumberland. Journal of Animal Ecology, Vol.13, 129-150. | |||
| Pennington, W. 1977. The late-glacial flora and vegetation of Britain. Philosophical Transactions of the Royal Society of London, Vol.280, Series B, 247-271. | |||
| Pickering, R. 1878. Submerged forest at St Bees. Transactions of the Cumberland Association for the Advancement of Literature and Science, Vol.3, 109-114. | |||
| Walker, D. 1956. A Lateglacial deposit at St Bees, Cumberland. Quarterly Journal of the Geological Society of London, Vol.112, 93-101. | |||
| Auton, C A, and Merritt, J W. 2004. Geological summary report: A review of onshore evidence of late glacial and Holocene sea level change in the St Bees-Sellafield area. British Geological Survey Report EE03_0870 for Halcrow H and S Limited. 49pp. | |||
| Pennington, W. 1970. Vegetation history in the North-West of England: a regional synthesis. 41-79 in Walker, D D and West, R G (editors), Studies in the Vegetational History of the British Isles. [Cambridge: Cambridge University.] | |||
| Walker, D. 1966. The Late Quaternary history of the Cumberland Lowland. Transactions of the Royal Society of London, B, 770, Vol 251, 1-210. | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| E028 E037 E038 | |||