The BGS Lexicon of Named Rock Units — Result Details

Turkeyland Member

Computer Code: TURK Preferred Map Code: notEntered
Status Code: Full
Age range: Arundian Substage (CJ) — Arundian Substage (CJ)
Lithological Description: Limestone, typically an ooidal and bioclastic grainstone, with rare claystone partings, dolomitic, grey, stylolitic, well-sorted, fossiliferous, relict cross-bedding, wave ripples and hummocky cross-bedding. Interpreted as a transgressive, high energy, shallow marine facies deposited on a carbonate ramp.
Definition of Lower Boundary: The base of the Turkeyland Member is poorly defined. It rests directly on conglomerates 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 it was recorded by Dickson et al. (1987) as resting directly on conglomerates of the Langness Conglomerate Formation.
Definition of Upper Boundary: In the field the top of the Turkeyland Member is poorly exposed on the foreshore at Derbyhaven [SC 2835 6653] where it is overlain by the Sandwick Member. The boundary is gradational, taken at the change from limestone(Turkeyland Member) to limestone with interbedded claystones (Sandwick Member).
Thickness: 18 to 25m.
Geographical Limits: 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].
Parent Unit: Derbyhaven Formation (DBH)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Partial Type Section  Natural foreshore exposures between Derbyhaven and Langness Point: specifically 1km north-west of Langness Point, at a point marked on the 50K OS map as Creg Inneen Thalleyr. These represent discontinuous exposures through the entire thickness of the member. Chadwick et al.(2001) 
Reference(s):
Lamplugh G W. 1903. The geology of the Isle of Man. Memoir Geological Survey of Great Britain 
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. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E400