OR/14/063 Site assessment - ELC 22: Garleton Hills

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Whitbread, K, Ellen, R, Callaghan, E, Gordon, J E, and Arkley, S. 2014. East Lothian geodiversity audit. British Geological Survey Internal Report, OR/14/063.
ELC_22: Garleton Hills
Site Information
Location and Summary Description:

The Garleton Hills form a distinctive area of ice-moulded volcanic hills located 2.5 km north of Haddington.

National Grid Reference:

Mid-point: 351017, 676294

Site type:
  • Natural landform
  • Natural view
Site ownership: not known Current use: Agricultural land (mainly)
Field surveyors: John Gordon Current geological designations: SSSI (Igneous petrology: Carboniferous — Permian Igneous); GCR ID 1155
Date visited: 26th September 2014 Other designations: None known
Site Map
Figure 27    Garleton Hills Location Map. The site boundary covers an area of erosional glacial landforms. The area contains numerous exposures of volcanic bedrock, but these have not been marked as they are already covered by SSSI designation.
Site Description
Background

The Garleton Hills form a prominent area of higher ground to the north of Haddington that has been streamlined and moulded by glacial erosion. The site boundary includes the core area of glacial landforms, and largely coincides with the boundaries of the SSSI.

Quaternary Deposits and Landforms
The Garleton Hills form an area of low hills, comprising the more resistant remnants of an area of trachyte and basaltic lavas, belonging to the Garleton Hills Volcanic Formation of Carboniferous age.

The hills have the form of an escarpment, the lavas dipping southwards (ELC_22 P1) with a series of rock ridges and scarps facing north (ELC_22 P2). The lavas are more areally extensive than the present area of higher ground, suggesting scarp retreat from the north by erosion during pre-glacial times and latterly by ice sheets during the course of repeated Quaternary glaciations. Glacial erosion has streamlined the hills in a direction slightly north of east, in alignment with other indicators of ice movement in the area, producing a smooth, ice-moulded outline when viewed from the south (ELC_22 P1). At a more detailed level, differential glacial erosion of the scarps has formed several fine examples of crag and tail landforms, with steeper slopes facing westwards and streamlined tails extending eastwards (e.g. Byres Hill and Craigy Hill, ELC_22 P3, P4). Skid Hill also has the form of a roche moutonnée when viewed from the north. Several deep channels run between the scarps. These were probably formed by glacial erosion but also occupied by glacial meltwaters (ELC_22 P2). Clough et al. (1910)[1] described a series of ice-marginal meltwater benches along the northern slopes.

The Hopetoun Monument on Byres hill provides an excellent viewpoint to appreciate the geology and landscape of East Lothian.

Stratigraphy and Rock Types
Age: Carboniferous Formation: Garleton Hills Volcanic Formation
Rock type: Trachyte, plagioclase-macrophyric basalt
Age: Carboniferous Formation: Southern Scotland Dinantian Plugs and Vents Suite
Rock type: Tuff and breccia
Age: Carboniferous Formation: Central Scotland Late Carboniferous Tholeiitic Dyke Swarm
Rock type: Quartz-microgabbro
Assessment of Site: Access and Safety
Aspect Description
Road access and parking There is good access from Haddington via the A6137 and B1343 with parking near Hopetoun Monument, an East Lothian Council Countryside Site. A minor road with limited roadside parking runs across the hills between Haddington and Drem.
Safety of access There is a footpath to the summit of Hopetoun Hill and other footpaths and tracks allow the main landforms to be viewed.
Safety of exposure Not applicable.
Access Access possible by footpaths, the site can also be viewed from roads.
Current condition Generally good, the area is largely agricultural land.
Current conflicting activities None known.
Restricting conditions None known.
Nature of exposure Landscape feature, glacial landforms.
Assessment of Site: Culture, Heritage & Economic Value
Aspect Description
Historic, archaeological & literary associations There is a prehistoric fort at Kae Heughs, near Barney Mains.
Aesthetic landscape The Garleton Hills provide excellent viewpoints to appreciate the geology and landscape of East Lothian.
History of Earth Sciences Not applicable.
Economic geology Former quarry on Skid Hill.
Assessment of Site: GeoScientific Merit
Rarity Quality Literature/Collections Primary Interest
Lithostratigraphy
Sedimentology
Igneous/Mineral/Metamorphic Geology
Structural Geology
Palaeontology
Geomorphology Regional Excellent Clough et al., 1910[1]; Jackes, 1973[2]; Sissons, 1975[3], Hall, 2012[4] X
Site Geoscientific Value

The Garleton Hills are part of a suite of ice-moulded bedrock features characteristic of East Lothian. They form a fine example of ice-moulded lowland hills, with several crag and tail landforms and streamlined bedrock forms produced by glacial erosion.
The site is an excellent example of a glaciated escarpment and lowland forms of glacial erosion with regional significance.

Assessment of Site: Current site usage
Community Hopetoun Hill is a popular walk and there is a footpath from Athelstaneford to the minor road near Yellow Craigs.
Education It is unknown to what extent the site is used for education. It has potential to be used for school visits and local interest groups for education and interpretation of glacial landforms.
Assessment of Site: Fragility and potential use of the site
Fragility The landforms are potentially sensitive to any large-scale quarrying, afforestation or tipping.
Potential use School education and interpretation linking geology and landscape. Educational visits could be combined with visits to Whitekirk and North Berwick Law.
Geodiversity Summary
The site is a good example of an ice-moulded escarpment. There is significant potential for developing the geodiversity value of the site through the provision of geological information on-site as part of the existing countryside site interpretation and through engagement with local schools.
Site Photos
Photo ELC_22 P1:    Dip slope of the Garleton Hills viewed from the south-east. © John Gordon.
Photo ELC_22 P2:     View east along the Garleton Hills from Hopetoun Hill, showing a series of escarpments and channels between them. © John Gordon.
Photo ELC_22 P3:    Garleton Hills. View north-west from Barney Hill showing streamlined bedrock forms. © John Gordon.
Photo ELC_22 P4:    Craigy Hill crag and tail (centre). © John Gordon.

References[edit]

  1. 1.0 1.1 CLOUGH, C T, BARROW, G, CRAMPTON, C B, MAUFE, H B, BAILEY, E B, and ANDERSON, E M. 1910. The Geology of East Lothian (second edition). Memoir of the British Geological Survey, Explanation of Sheet 33, with parts of 34 & 41 (Scotland).
  2. JACKES, M. 1973. Sites of geomorphological interest in East Lothian. Unpublished report to the Nature Conservancy Council, Edinburgh.
  3. SISSONS, J B. 1975. The geomorphology of East Lothian. In Craig, G Y, and Duff, P McL D. (eds), The Geology of the Lothians and South-east Scotland: an Excursion Guide. Scottish Academic Press, Edinburgh, 131–143.
  4. HALL, A. 2012. East Lothian Landscapes [online: http://www.landforms.eu/Lothian/]