Pathhead Formation

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Pathhead Formation (PDB), Carboniferous, Midland Valley of Scotland[edit]

The Pathhead Formation is part of the Strathclyde Group in the Fife area.

Name[edit]

From Pathhead, east Fife. The unit was originally described by Forsyth and Chisholm (1977)[1] and given formation status by Browne (1986)[2].

Lithology[edit]

The Pathhead Formation consists predominantly of mudstone and siltstone with beds of limestone and dolostone. Pale coloured, fine- to medium-grained sandstone is subordinate to the argillaceous rocks. Thin beds of coal and ironstone also occur.

Genetic interpretation[edit]

The overall pattern of sedimentation within the formation is of upward-coarsening deltaic cycles, with thinner upward-fining fluvial units erosively capping them, and relatively common marine incursions.

Stratotype[edit]

The type section is on the coast at Pathhead (NO 5419 0226 to NO 5381 0212) between St Monans and Pittenweem.

Lower and upper boundaries[edit]

The conformable base of the formation lies in a transitional sequence, the boundary being drawn at the base of the West Braes Marine Band (WBMB) above the Sandy Craig Formation (Figure 6, Column 4C), stratigraphically a little higher (Browne, 1986, fig. 2)[2] than that originally described by Forsyth and Chisholm (1977)[1].

The top of the formation is at the base of the Hurlet Limestone, present at the base of the Lower Limestone Formation (Clackmannan Group).

Thickness[edit]

The maximum thickness of the formation is about 220 m (Browne, 1986, fig. 2)[2].

Distribution and regional correlation[edit]

Fife.

Age and biostratigraphical characterisation[edit]

Visean (Brigantian). Marine bands are more common than in the underlying formations and their faunas are usually diverse and abundant. Curvirimula dominates the nonmarine faunas.

References[edit]

  1. 1.0 1.1 Forsyth, I H, and Chisholm, J I. 1977. The geology of east Fife. Memoir of the Geological Survey of Great Britain, Sheets 41 part 49 (Scotland)
  2. 2.0 2.1 2.2 Browne, M A E. 1986. The classification of the Lower Carboniferous in Fife and Lothian. Scottish Journal of Geology, Vol. 22, 422-425