The BGS Lexicon of Named Rock Units — Result Details

Skillicore Member

Computer Code: SKIL Preferred Map Code: notEntered
Status Code: Full
Age range: Arundian Substage (CJ) — Arundian Substage (CJ)
Lithological Description: Argillaceous limestone, with common interbedded claystone and siltstone and subordinate sandstone. Limestones are packstone, grey, bioclastic including crinoids and corals, bioturbated, pyritic,with wave ripple cross-lamination. Includes Michelinia megastoma. Claystones and siltstones are grey, forming beds up to 1m thick, generally unfossiliferous, some Chondrites burrows. Sandstones are fine-grained and cross-laminated and wave rippled. Interpreted to represent an upper-ramp, shallow water carbonate facies.
Definition of Lower Boundary: The base of the Skillicore Member is poorly defined. It overlies the Sandwick Member with a gradational contact, taken at the appearance and increasing occurrence of fine-grained sandstone, together with an increase in siltstone and a more tabular bedding style.
Definition of Upper Boundary: The top of the member is poorly defined. It is overlain by the Knockrushen Formation, with the boundary taken as immediately above a byozoan bed which is exposed to the north-east of the airport light gantry at Ronaldway, at Port St Mary and Ballasalla( Dickson et al.1987). No grid references are quoted in the Dickson et al. (1987) paper for these localities.
Thickness: 21 to 46m
Geographical Limits: Southern part of the Isle of Man, in the Castletown area, from Ballasalla [SC 2857 7017] to Derbyhaven[ SC 2798 6754].
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  Lough Skillicore: an embayment of the sea on the foreshore east of Ronaldsway airport exposing the lower part of the Skillicore Member. Dickson et al. (1987) 
Reference(s):
Lewis, H P. 1930. The Avonian succession in the south of the Isle of Man. Quarterly Journal of the Geological Society of London, 86, 234-290. 
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. 
Lamplugh G W. 1903. The geology of the Isle of Man. Memoir Geological Survey of Great Britain 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E400