Limestone, typically an ooidal and bioclastic grainstone, dolomitic, grey, stylolitic, well-sorted, fossiliferous, with relict cross-bedding, wave ripples and hummocky cross-bedding and rare claystone partings.
The unit is interpreted as a transgressive, high energy, shallow marine facies deposited on a carbonate ramp.
A partial type section occurs in natural foreshore exposures between Derbyhaven and Langness Point (SC 2804 6595 to 2849 6672): specifically 1 km north-east of Langness Point, at a point marked on the 1:50 000 scale Ordnance Survey Map as Creg Inneen Thalleyr (SC 281 659). These represent discontinuous exposures through the entire thickness of the member (see Chadwick et al., 2001).
Lower and upper boundaries
The base of the Turkeyland Member is poorly defined. It rests directly on sandstones of the Langness Conglomerate Formation on the foreshore of the Langness Peninsula (SC 2820 6607), although exposures are discontinuous and poorly exposed. It was formerly exposed at the now infilled Turkeyland Quarry (SC 2950 6940), where Dickson et al. (1987) recorded it resting directly on conglomerates of the Langness Conglomerate Formation.
The top of the Turkeyland Member is poorly exposed on the foreshore at Derbyhaven (SC 2835 6653) where it is overlain by the Sandwick (Isle of Man) Member of the Derbyhaven Formation. The boundary is gradational, taken at the change from limestone to limestone with interbedded claystones.
Between 18 and 25 m.
Distribution and regional correlation
The member occurs in the southern part of the Isle of Man, to the south-east of Castletown, from Derbyhaven (SC 2907 6806) to Creg Inneen Thalleyr (SC 2804 6595). Visean rocks in the northern part of the island are entirely concealed and it is not known whether it is present there.
- 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.
- Lamplugh, G W.1903.The geology of the Isle of Man.Memoir of the Geological Survey of Great Britain.
- 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.