Whitbread, K., Ellen, R., Callaghan, E., Gordon, J. E. and Arkley, S. 2015. East Lothian Geodiversity Audit. British Geological Survey Open Report, OR/14/063. 192pp.
ELC_8: Blaikie Heugh – Balfour Monument
Site information
Location and summary description:
The Balfour Monument sited on the 15m high lava escarpment of Blaikie Heugh offers stunning views of Traprain Law, Berwick Law and the Garleton Hills
National Grid reference:
Mid-point:
West end:
East end:
Site type: Natural section; Natural exposure; Natural view
Site ownership: Unknown
Current use: Agricultural Land
Field surveyors: Rachael Ellen and Eileen Callaghan
Current geological designations: None known
Date visited: 10th June 2014
Other designations: The Balfour Monument is listed
Site map
Site description
Background
The Balfour Monument is located by the roadside on an escarpment overlooking Traprain Law. The Monument is a red sandstone obelisk, dedicated to James Balfour (1820–56), a Major Commandant of the East Lothian Yeomanry Cavalry. The Blaikie Heugh escarpment is formed of an olivine- clinopyroxene-macrophyric basalt traditionally known as the ‘Craiglockhart Basalt’ type, which is of widespread occurrence in the lower Carboniferous lavas of the Midland Valley. A nearby escarpment to the east is also of geological interest, being composed of a hornblende-bearing trachybasalt.
Volcanic rocks
The escarpment below the Balfour Monument
The minor escarpment just to the east of the Balfour Monument (moulded and streamlined by glacial erosion) is composed of a westward dipping hornblende-bearing trachybasaltic flow (an alacime- bearing hornblende-phyric trachybasalt), which stratigraphically underlies the olivine-clinopyroxene macrophyric basaltic lava found at Blaikie Heugh. The minor escarpment is approximately 3 metres in height
The volcanic rocks described above form part of the Garleton Hills Volcanic Formation, part of the Strathclyde Group of the lower Carboniferous.
Access and additional information
Access to the site is at the Balfour Monument off a minor road
Stratigraphy and rock types
Age: Carboniferous Garleton Hills Volcanic Formation
Rock type: Olivine-clinopyroxene-macrophyric basalt (Craiglockhart Basalt)
Age: Carboniferous
Formation: Garleton Hills Volcanic Formation
Rock type: Trachybasalt
Assessment of site: access and safety
Road access and parking Parking in the lay by at the Balfour Monument.
Safety of access Care has to be taken as the monument is at the top of the escarpment looking down onto the fields. The ground is steep and traversing the field either east or west gives access to the base of the escarpment. There is also a boulder field at the foot of the escarpment, and loose rock is covered by grass. The minor escarpment to the north-east is accessed through fenced pastures.
Safety of exposure Care should be taken and an assessment made of the escarpment face before approaching as loose material may fall.
Access Access via agricultural land.
Current condition Lichen covers the basalt but generally well exposed.
Current conflicting activities None
Restricting conditions Livestock in fields.
Nature of exposure Escarpment
Assessment of site: culture, heritage & economic value
Historic, archaeological & literary associations Balfour Monument erected in 1858 in memory of James Maitland Balfour of Whittinghame, father of Prime Minister Arthur James Balfour.
Aesthetic landscape Panoramic views from the monument of the Pentland Hills, Edinburgh, Fife, and in East Lothian, the Garleton Hills, Berwick Law, Traprain Law and the Bass Rock.
History of earth sciences No known association
Economic geology No known association
Assessment of site: geoscientific merit
| Rarity | Quality | Literature/collections | Primary interest | |
| Lithostratigraphy | ||||
| Sedimentology | ||||
| Igneous/mineral/metamorphic geology | Regional/National | Moderately good | X | |
| Structural geology | ||||
| Palaeontology | ||||
| Geomorphology |
Site geoscientific value
The site comprises exposures of two different kinds of basalt, relevant to the interpretation of the volcanic environment during the Carboniferous. There are few examples of hornblende-bearing trachybasalts across East Lothian, whereas the ‘Craiglockhart’ basalt is found across the Midland Valley of Scotland.
Blaikie Heugh provides a moderately good example of Carboniferous basalt lava flows, with national to regional significance.
Assessment of site: current site usage
Community The Balfour Monument at the site is of historical interest, and is likely to attract some visitors. The views from the monument are also impressive.
Education The site presents moderately good exposures of ‘Craiglockhart’ type basalt and hornblende-bearing trachybasalt, and affords excellent views across much of East Lothian. This site may be a good locality for educational fieldwork relating to the volcanic environment of the Carboniferous in Scotland, and on-site interpretation board explaining the geology of the view from the monument may also be appropriate.
Assessment of site: fragility and potential use of the site
Fragility Natural overgrowth and erosion and weathering of feature.
Potential use Higher/further education, school education, on-site interpretation
Geodiversity summary
Blaikie Heugh contains natural exposures of two types of basalt lava flows belonging to the Garleton Hills Volcanic Formation: anolivine-clinopyroxene-macrophyric basalt traditionally known as the ‘Craiglockhart Basalt’ type, and a hornblende-bearing trachybasalt. Both of these lava types are not well distributed throughout East Lothian, and this site represents an opportunity to study both of the lava types at the same time. A trachybasalt is also exposed at North Berwick Shore, but exposure is limited in the intertidal zone. The site also affords historical links (Balfour Monuments) and panoramic views across East Lothian.