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 9: Craigdhu Burn, Bearsden

Grid reference: [NS 54838 73404]

Site type: Natural exposure

Site ownership: Not known

Current use: Urban

Field surveyor: Sarah Arkley & Luis Albornoz-Parra

Current geological designations: None

Date visited: 6th March 2009

Site map

(Figure 9) Craigdhu Burn Location Map

Summary description

Geological exposures along a tributary of the Craigdhu Burn no longer exist. The burn is now piped underground and exposures have been covered.

The geological map records exposures through the sedimentary strata of the Limestone Coal Formation which contained fossils of the brachiopod 'Lingula' (a marine shell). But no exposures of bedrock are now visible. Where the burn is flowing on the surface to E and W of the recorded exposures, it cuts through glacial till, no bedrock was found.

A second recorded bedrock exposure (on the geological map) describes a 10" coal seam, possibly the Kilsyth Coking Coal, about 60m SE (downstream) of the confluence with the Craigdhu Burn. However, the riverbank where the section is thought to exist is very degraded and vegetated.

Farther west of the recorded exposures, a small burns joins the tributary, the water is very iron-rich and forms deposits on pebbles in the base of the burn - ?mine water.

EDC 9: Stratigraphy and rock types

Age: Upper Carboniferous Formation: Limestone Coal Formation

Rock type: Sedimentary Rock Cycles of the Clackmannan Group Type

Assessment of site value

Access and safety

Aspect/Description

Road access and parking Street parking in the housing estate to the south of the site

Safety of access Public footpath along course of the burn, housing to the south of the burn, farmland to the north. Dense shrubs along course of burn

Safety of exposure Beware of thorny shrubs if looking for any remaining outcrops

Permission to visit No permission sought

Current condition No geology sections exist anymore – burn is now piped underground

Current conflicting activities 'Improved' water course management

Restricting conditions Concrete pipe and soil

Nature of exposure Stream sections were previously recorded

Culture, heritage & economic

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

Aesthetic landscape Located along boundary between housing estate and farmland. Rating: 2.

History of earth sciences None known. Rating: 0.

Economic geology None recorded. Rating: 0.

EDC 9: Geoscientific merit

EDC 9: Craigdhu Burn, Bearsden. Geoscientific merit.

Total Geoscientific merit score. Rating: 0.

Current site value

Community Frequent use by local residents. Rating: 10

Education Site was chosen for it's exposure of fossil shells – these should still exist under there. Rating:2.

Fragility and potential use of the site

Fragility None

Potential use None

Geodiversity value

Unfortunately the exposures displaying Carboniferous fossils for which this site was chosen are no longer visible. But this site has been included as an example of what could happen to a number of other good sites displaying East Dunbartonshire's rich geodiversity if there is not appropriate protection in place. Rating: 0.

Photographs

(Photo 37) Craigdhu Burn channelled underground. Looking SE.

(Photo 38) Craigdhu Burn re-emerging. Looking WSW.

(Photo 39) View W along the course of Craigdhu Burn which is now piped underground. Previous geological maps have recorded exposures of sedimentary rocks belonging to the Limestone Coal Formation containing 'Lingula' shell fossils, but these have now been landscaped and lost.

Bibliography