Langness Conglomerate Formation
Langness Conglomerate Formation is part of the Ravenstonedale Group
The name is derived from Langness, south Isle of Man, and was given by Dickson et al. (1987).
The formation comprises reddish brown, generally poorly sorted, typically clast-supported conglomerate with subordinate interbedded sandstone. Sedimentary structures include crude stratification and rare cross-bedding. See Chadwick et al. (2001).
The formation is an alluvial fan deposit, transported by debris flow and streamflow processes.
A partial type section includes foreshore exposures along the Langness Peninsula (SC 2819 6604 to 2854 6661) where an estimated 30 m of coarse clastic sedimentary rocks are present (see Dickson et al., 1987, p. 205).
Lower and upper boundaries
The formation is unconformable on the underlying, steeper-dipping, Ordovician Lonan Formation (see Chadwick et al., 2001).
The limestones of the Turkeyland Member, Derbyhaven Formation, Great Scar Limestone Group (Figure.8, Column.8) overlie the apparently partly reworked sandstone top to the Langness Conglomerate Formation.
The formation is about 30 m thick.
Distribution and regional correlation
The formation occurs in the south Isle of Man.
Devonian to Courceyan (Chadwick et al., 2001, p. 59)
- Dickson, J A D, Ford, T D, and Swift, A.1987.The strati-graphy of the Carboniferous rocks around Castletown, Isle of Man.Proceedings of the Yorkshire Geological Society, Vol. 46, 203–229
- Chadwick, R A, Jackson, D I, Barnes, R P, Kimbell, G S, Johnson, H, Chiverrell, 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.The geology of the Isle of Man and its offshore area.British Geological Survey Research Report, RR/01/06