The BGS Lexicon of Named Rock Units — Result Details

Isle of Man Catchments Subgroup

Computer Code: IMCA Preferred Map Code: notEntered
Status Code: Full
Age range: Devensian Stage (QD) — Holocene Epoch (QH)
Lithological Description: Alluvial gravel, sand, silt and clay forming floodplains, alluvial fans and river terrace deposits. Peat, mud and pebbly sand infilling lowland basins and blanketing upland hillsides and peat, humic clayey silt and calcareous silt infilling kettleholes.
Definition of Lower Boundary: Generally an unconformable boundary with units of the Caledonia Glacigenic Group.
Definition of Upper Boundary: Generally the ground surface, but units of this subgroup interfinger locally with units of the British Coastal Deposits Group.
Thickness: Typically 2.5 m thick, but highly variable and greater than 20 m locally.
Geographical Limits: The Isle of Man (50k sheets 36, 45, 46, 56, 57).
Parent Unit: Britannia Catchments Group (BCAT)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Coastal cliff sections between Glen Balleira and Glen Wyllin, c.0.5km west and northwest of Kirk Michael, Isle of Man. Chadwick, R A et al., 2001. 
Type Area  The Sulby Glen area, c.3km northnorthwest of Snaefell, northwest part of the Isle of Man. Chadwick, R A et al., 2001. 
Reference(s):
McMillan, A A, Hamblin, R J O and Merritt, J W. 2005. An overview of the lithostratigraphical framework for the Quarternary and Neogene deposits of Great Britain (onshore). British Geological Survey Research Report RR/04/04. 
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. 
Chadwick, R A, Jackson, D I, Barnes, R P, Kimbell, G S, Johnson, H, Chiverell, R C, Thomas, G S P, Jones, N S, Riley, N J, Pickett, E A, Young, B, Holliday, D W, Ball, D F, Molyneux, S G, Long, D, Power, G M and Roberts, D H. 2001. Geology of the Isle of Man and its offshore area. British Geological Survey Research Report, RR/01/06. 
Chiverrell, R C, Thomas, G S P and Harvey, A M. 2001. Late Devensian and Holocene landscape change in the uplands of the Isle of Man. Geomorphology, Vol.40, 219-236. 
McMillan, A A, Hamblin, R J O, and Merritt, J W. 2011. A lithostratigraphical framework for onshore Quaternary and Neogene (Tertiary) superficial deposits of Great Britain and the Isle of Man. British Geological Survey Research Report, RR/10/03. 343pp. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable