Difference between revisions of "Langness Conglomerate Formation"

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Langness Conglomerate Formation (LNCO), Carboniferous, Isle of Man[edit]

Langness Conglomerate Formation is part of the Ravenstonedale Group

Name[edit]

The name is derived from Langness, south Isle of Man, and was given by Dickson et al. (1987)[1].

Lithology[edit]

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)[2].

Genetic interpretation[edit]

The formation is an alluvial fan deposit, transported by debris flow and streamflow processes.

Stratotype[edit]

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[1]).

Lower and upper boundaries[edit]

The formation is unconformable on the underlying, steeper-dipping, Ordovician Lonan Formation (see Chadwick et al., 2001[2]).

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.

Thickness[edit]

The formation is about 30 m thick.

Distribution and regional correlation[edit]

The formation occurs in the south Isle of Man.

Age[edit]

Devonian to Courceyan (Chadwick et al., 2001, p. 59[2])

References[edit]

  1. 1.0 1.1 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
  2. 2.0 2.1 2.2 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