Lindsayston Burn Member
Lindsayston Burn Member is part of the Ballagan Formation.
After Lindsayston Burn, south-east of Dailly. The member was defined by Monaghan (2004), having previously been referred to as ‘cornstone-bearing beds’ of the Cementstone Group of the Calciferous Sandstone Measures by Eyles et al. (1949). See also Floyd (1999).
Between (NS 2821 0082 and NS 2272 0089), the strata are characterised by buff-white-grey, hard, flaggy sandstone, interbedded with soft red-green sandstone with pedogenic carbonate nodules and pipes, and rarer red-green siltstone and mudstone with pedogenic carbonate nodules. Thick channelised sandstone and conglomerate, a few metres thick and tens of metres wide, is observed at several localities. In the north-western part of the Lindsayston Burn section (NS 2272 0089 to NS 2749 0097) the upper part of the member records a gradational change. Medium- to coarse-grained sandstone interbedded with red-grey siltstone with pedogenic carbonate is still common, but intercalations of grey calcareous siltstone and mudstone and thinly bedded fine-grained sandstone in packages up to about 0.7.m thick are also observed.
The type section occurs along the Lindsayston Burn (NS 2824 0080 to 2735 0112), south-east of Dailly on 1:10 000 scale Geological Sheet NS20SE (see Eyles et al., 1949; Monaghan, 2004).
Lower and upper boundaries
The lower boundary is defined as the lithological change from the underlying Drumwhirn Member of yellow sandstone with grey silty mudstone, to red-purple sandstone with conglomerate and pedogenic carbonate (Figure.6, Column 4B). It is mapped as a conformable contact on 1:10 000 scale Geological Sheet NS20SE in the type stream section at (NS 2824 0080) but it is not actually exposed.
The upper boundary is defined as the lithological change from red-purple sandstone with conglomerate and pedogenic carbonate, to the grey-green mudstone with thin nonmarine limestones and sandstone that is typical of the Ballagan Formation in the Midland Valley of Scotland. It is mapped as a conformable contact on 1:10.000 scale Geological Sheet NS20SE in the type stream section at (NS 2735 0112) but it is not actually exposed.
About 200.m at the type section (see above) with 134.m proved by logging where exposed. Interpreted to be laterally variable and up to 285 m thick in other parts of 1:10 000 scale Geological Sheet NS20SE.
Distribution and regional correlation
The member occurs on 1:10 000 scale Geological sheets NS20SE, NS20SW, and NS30SW near Dailly, South Ayrshire. The lateral extent of the unit is not yet known.