| Computer Code: |
MSS |
Preferred Map Code: |
MSS |
| Status Code: |
Full |
| Age range: |
Cisuralian Epoch (PLC)
— Cisuralian Epoch (PLC) |
| Lithological Description: |
Brick red to bright orange sandstone characterised by a predominance of quartz grains of which the larger are wind-rounded and almost free from mica. In the cored Redcraig Borehole (NS42NE/15) thin layers of coarse-grained sandstone alternate with more fine-grained material descibed as "clayey sand". Although dune bedding is characteristic of the Formation this is not seen at the base where it is exposed near Howford Bridge (Weedon and Mykura, 1992; Williamson, 2003, Fig.4.12). |
| Definition of Lower Boundary: |
Sandstone of the Mauchline Sandstone Formation overlies with apparent conformity tuffs of the Mauchline Volcanic Formation. In the Redcraig Borehole the lower boundary is picked at the top of the uppermost occurrence of conglomeratic sandstone with many large pebbles and blocks, up to 25cm [10 inches], of vesicular and non-vesicular basalt in a sandstone matrix and is considered by Mykura [1965] to be diachronous. |
| Definition of Upper Boundary: |
The Mauchline Sandstone Formation is delimited by erosion; the top of the Formation is not seen. There is no evidence for any previous presence of younger overlying strata. |
| Thickness: |
The rocks of the Mauchline Sandstone Formation occupy the centre of the Mauchline Basin and the maximum deposited thickness is not known. However, minimum proven thicknesses are known from boreholes; 229m [700feet] in the Auchinweet Borehole at [NS 4554 2863] and 370m [1130 feet0 in the Middletonhill Borehole two and a half miles east of Tarbolton. A minimum thickness of 311m [948feet] is proven in the Redcraig Borehole. |
| Geographical Limits: |
The Mauchline Sandstone Formation is present only within the Permian Mauchline Basin, in the vicinity of Mauchline, Ochiltree and Tarbolton in Ayrshire, southwest Scotland. |
| Parent Unit: |
Stewartry Group (STEW)
|
| Previous Name(s): |
Mauchline Sandstone [Obsolete Name and Code: Use MSS]
(-408)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Partial Type Section |
Exposure of the lower boundary and upper part of the Mauchline Volcanic Formation in the cliffs of the River Ayr near Howford Bridge immediately west of the old [A76] road. |
| Type Section |
Redcraig Borehole [BGS borehole number NS42NE/15] near Redcraig 2.4km westnorthwest of Mauchline, at depths 1.6m [5 feet] to 313m [953 feet] below start of drilling. A detailed borehole log and selected core samples are held at BGS Edinborough. There are 11 samples, mostly described as sandstone, with one of agglomerate. |
| Reference(s): |
| Wagner, R H. 1983. A lower Rotliegend flora from Ayrshire. Scottish Journal of Geology, Vol.19, 135-155. |
| Williamson, I T. 2003. Howford Bridge, east Ayreshire. 166-169 in Stephenson, D, Loughlin, S C, Millward, D, Waters, C N and Williamson, I T, Carboniferous and Permian rocks of Great Britain north of the Variscan Front. Geological Conservation Review Series, No. 27, Joint Nature Conservation Committee, Peterborough. |
| Mykura, W. 1967. The Upper Carboniferous rocks of south-west Ayrshire. Bulletin of the Geological Survey of Great Britain, Vol.26, 23-98. |
| Jin, Y, Wardlaw, B R, Glenister, B F and Kotlyar, G V. 1997. Permian chronostratigraphic subdivisions. Episodes, Vol.20, 10-15. |
| Mykura, W. 1965. The age of the New Red Sandstone of south-west Scotland. Scottish Journal of Geology, Vol.1, 9-18. |
| Weedon, D S and Mykura, W. 1992. Lugar Sill and Mauchline. In Lawson, J D and Weedon, D S, Geological excursions around Glasgow [The Geological Society of Glasgow]. |
| Eyles, V A, Simpson, J B and Macgregor, M C. 1949. Geology of Central Ayrshire. Memoir of the Geological Survey of Scotland, British Geological Survey, Sheet 14 (Scotland). |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
S014
S023
|
