Arkley, S. L. B., Browne, M. A. E., Albornoz-Parra, L. J. and Barron, H. F. 2011. East Dumbartonshire Geodiversity Audit. British Geological Survey Open Report, OR/09/19. 265pp.
EDC 23: Douglas Muir Quarry, Milngavie
Grid reference:
Site type: Artificial quarry works
Site ownership: Mains Estate. Tarmac lease the site from Mains Estate
Current use: In current use
Field surveyor: Mike Browne & Hugh Barron
Current geological designations: None
Date visited: 19th March 2009
Site map
Summary description
The Douglas Muir Quartz-Conglomerate Member (DMQ) of the Lawmuir Formation (Strathclyde Group) consists mainly of hard, white conglomerates with subordinate pebbly sandstones with a few lenses of (purplish-grey)/grey mudstone up to 30 cm thick. Trough cross-bedding is present in sets from 0.2 m to 1.0 m thick. Many of the units are upward fining in grain size. The clasts and pebbles are almost exclusively of white and pink vein quartz and well-rounded, averaging 2 cm but up to 10 cm in diameter (, but some blocks of sandstone up to 15 cm across are also present). Palaeocurrent directions indicate transport of the original sediments towards the south-south-west. Channel bases of at least 20 m lateral extent are currently visible. Note the older working faces are weathered to a strong darkish yellow brown colour. The fresh conglomerate has a slightly yellow tinge. The sandstones are pale grey (i.e. off-white).
The base of the Douglas Muir Quartz Conglomerate is not seen on the site but elsewhere it rests apparently unconformably on volcaniclastic sediments of the Kirkwood Formation. The top boundary is transitional, by upward passage by interbedding from conglomerate to white and pale grey sandstones of the Craigmaddie Muir Sandstones of the Lawmuir Formation. Note this transition seems to be happening laterally southwards (and with thinning?) within the current quarry with less conglomerate and more mudstone lenses preserved.
Thickness is said to be 15 m at the type locality at Douglas Muir Quarry, and up to 70 m maximum elsewhere. Good examples of petrified fossil trees seen (not in situ). Possible glacial striae seen.
EDC 23: Stratigraphy and rock types
Age: Lower Carboniferous Formation: Douglas Muir Quartz-Conglomerate Member, Lawmuir Formation
Rock type: Conglomerate
Assessment of site value
Access and safety
Aspect/Description
Road access and parking On entry call into the site office
Safety of access As this is a working quarry, prior requests for a visit (to the quarry manager) would be essential and all visitors should follow the required site health and safety regulations. For safety, visitors may need to be accompanied by quarry personnel during visits. Plenty of parking is available next to the site office. Be aware of quarry vehicles at all times and wear all appropriate PPE.
Safety of exposure Working faces should not be approached as they are generally unstable
Permission to visit Permission given from the site office (Tarmac) Current condition Good clean quarry faces
Current conflicting activities Working quarry
Restricting conditions As these are working faces it is currently not known what exposures will remain when quarrying ceases.
Nature of exposure Sub vertical quarry faces
Culture, heritage & economic
Historic, archaeological & literary associations None known. Rating: 0.
Aesthetic landscape Quarry reveals good sections through the underlying geology. Rating: 2.
History of earth sciences None known. Rating: 0.
Economic geology Active crushed rock quarry – high specification material. Rating: 5.
EDC 23: Geoscientific merit
Total Geoscientific merit score 37
Current site value
Community. Rating: 2.
Education. Rating: 6.
Fragility and potential use of the site
Fragility Development. Value of the site depends on the development of conservation sections once working has finished. Restoration mixes wetlands/lakes with partly heather covered bare bedrock and false screes against remaining quarry faces. Paths will cross the area so interpretation with a leaflet and info board is possible.
Potential use Higher/Further Education, School, On-site Interpretation, Geotrail, Multidisciplinary
Geodiversity value
This site provides the best exposures and is the type locality for the Douglas Muir Conglomerate Member. The current operators (Tarmac Ltd) are additionally willing to discuss leaving key areas of some quarry faces accessible following extraction for the purpose of geoconservation, so future visitors may access and learn from the site. One such face would be the one facing south–west above the silt lagoon in the eastern part of the quarry. This face displays excellent channel features. This site's geodiversity value would be enhanced if the current or any other operator leaves conservation sections after cessation of working.