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 30: Craigen Glen, Balgrochan

Grid reference: [NS 62143 75714]

Site type: Natural section

Site ownership: Not known

Current use: Open country

Field surveyor: Sarah Arkley & Mike Browne

Current geological designations: None

Date visited: 6th April 2009

Site map

(Figure 30) Craigen Glen Location Map

Summary description

Stream section through sedimentary strata belonging to the Lower Limestone Formation and Lawmuir Formation.

Lower part of site displays evidence of former workings; disturbed landscape, burnt mudstone bings, etc. Exposures up the burn are generally on the bank sides, which vary in accessibility and quality. Possible adit was seen approximately half way up the site on the eastern bank beneath a thick sandstone bed.

The Craigenglen Beds, found in the upper part of the Lawmuir Formation, form a marine band within laminated mudstones which are noted for their fossils of brachiopods, molluscs, large productoids and corals (Hall, 1998)

EDC 30: Stratigraphy and rock types

Age: Lower Carboniferous Formation: Lower Limestone Formation

Rock type: Sedimentary Rock Cycles of the Clackmannan Group Type

Age: Lower Carboniferous Formation: Lawmuir Formation

Rock type: Sedimentary Rock Cycles of the Strathclyde Group Type

Assessment of site value

Access and safety

Aspect/Description

Road access and parking Parking for one car at the crossroad of tracks southwest of the site. A footpath is signed from here to the burn and styles exist over fences. At the burn the path disappears and you need to find your way up a wooded stream

Safety of access Access to the lower part of the glen where there is evidence of old workings is good. Access to the upper part is more difficult with lots of new barbed wire fences in the way.

Safety of exposure Care should be taken on slimy rocks in the stream, especially on the smooth rock platform below the waterfall.

Permission to visit No permission sought

Current condition Okay, bit overgrown in places

Current conflicting activities None

Restricting conditions Barbed wire fences

Nature of exposure Stream section, exposures are seen with in the burn and bank sides

Culture, heritage & economic

Historic, archaeological & literary associations None known. Rating: 0.

Aesthetic landscape Pleasant. Rating: 3.

History of earth sciences Members of the Glasgow Geological Society visited here early in the history of the society on their first field excursion.. Rating: 3.

Economic geology Some workings, waste piles remain. Rating: 2.

EDC 30: Geoscientific merit

EDC 30: Craigen Glen, Upper Carlestoun. Geoscientific merit.

Total Geoscientific merit score 27

Current site value

Community. Rating: 9.

Education. Rating: 5.

Fragility and potential use of the site

Fragility Natural overgrowing

Potential use Research, Higher/Further Education, School, Multidisciplinary

Geodiversity value

This site displays a number of sedimentary features and industrial remains and is one of only a few localities where the marine band (Craigenglen Beds) is exposed. Historically the site was first visited by Glasgow Geological Society in 1858 and was famous then for its fossils of marine shells. Rating: 5./p>

Photographs

(Photo 187) Fine-grained, yellowish sandstone unit, approximately 1–1.5 m thick ,in the Lawmuir Formation. Beneath this lies approximately 2 m of mudstone, seen in burn below. Looking SE.

(Photo 188) Close up of the fine-grained, yellowy ochreous weathered sandstone, containing plant fragments and trace fossils.

(Photo 189) View upstream of the lower waterfall in 2–4 m of bedded grey mudstones belonging to the Lawmuir Formation. Looking NW.

(Photo 190) Thin limestone bands (approximately 10 cm thick) and nodules in the bedded grey mudstones of the Lawmuir Formation. Looking NE.

(Photo 191) View looking SW from a bing of burnt mudstone at the mouth of Craigen Glen towards the old workings.

(Photo 192) Close-up of the burnt mudstone on a bing from workings of ?Hurlet Coal etc.

(Photo 193) Possible adit beneath a 1.5 m exposure of yellow fine-grained sandstone belonging to the Lawmuir Formation. Looking ENE.

(Photo 194) New fencing above the lower waterfall in Craigen Glen makes access to the geology difficult.

Bibliography