OR/14/063 Site assessment - ELC 7: Old Markle Quarry, East Linton
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_7: Old Markle Quarry, East Linton | |
Site Information | |
Location and Summary Description: Disused basalt quarry, located ~0.5 km west of the village of East Linton. The site displays the type locality of the ‘Markle Basalt Lava’, which is of widespread occurrence in the lower Carboniferous lavas of the Midland Valley. The basalt forms part of the Garleton Hills Volcanic Formation, part of the Strathclyde Group of the lower Carboniferous. Historically, the quarry was worked at least until 1854, and closed sometime before 1895. | |
National Grid Reference: Mid-point: 358385, 677010 |
Site type:
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Site ownership: Not known | Current use: Disused, agricultural land |
Field surveyors: Sarah Arkley and Rachael Ellen | Current geological designations: None |
Date visited: 16th April 2014 | Other designations: Markle Quarry Pond Local Biodiversity Site |
Site Map |
Site Description |
Background The quarry was active in the early 1800s, for extraction of basalt presumably for aggregate. The plagioclase-macrophyric basalt flow exposed in the quarry is known traditionally as the ‘Markle Basalt Lava’ type, and is of widespread occurrence in the lower Carboniferous lavas of the Midland Valley. This quarry represents the type locality of the Markle Basalt type. The quarry floor is now flooded, but quarry faces remain accessible for examination (Photo ELC_7 P1). Should water levels rise and access be restricted, there are natural exposures to the north of the quarry which could be examined. Volcanic Rocks Structural Geology Access and Additional Information |
Stratigraphy and Rock Types | |
Age: Lower Carboniferous | Formation: Garleton Hills Volcanic Formation |
Rock type: Basalt, plagioclase-macrophyric |
Assessment of Site: Access and Safety | |
Aspect | Description |
Road access and parking | Good access from pavement along the A199, and parking by the roadside either along Haddington Road (B1407), or along the road in the Orchard Field housing estate. Enter through a farmer’s gate from pavement to enter quarry site. |
Safety of access | Pavement is adjacent to a busy and fast road, and is necessary for site access. The path to the quarry is along a rough track. Rough uneven ground on sides and floor of quarry, overgrown and boggy in places. Deep water in front of quarry walls should be avoided. |
Safety of exposure | Care should be taken as in all quarries, and an assessment made of each face before approaching. The quarry faces are high, and potentially loose material may fall, therefore care should be exercised. There is loose material underfoot, overgrown by grass and weeds. |
Access | Accessed via tracks in agricultural land. |
Current condition | The condition is good with rock faces generally well exposed, however moss and lichen cover the basalt in places on the quarry faces. A few trees and vegetation may obscure views in summer, and there are minor amounts of farmer debris, boulders, and wood in places. |
Current conflicting activities | None. |
Restricting conditions | After heavy rainfall the water in front of the quarry face may rise so that access to the lower parts of the quarry faces is not achievable. |
Nature of exposure | Vertical quarry faces. |
Assessment of Site: Culture, Heritage & Economic Value | |
Aspect | Description |
Historic, archaeological & literary associations | No known association. |
Aesthetic landscape | Old quarry on the edge of East Linton, revealing underlying geology. |
History of Earth Sciences | Type locality of Markle basalt. |
Economic geology | Quarried in 1800, activity ceased between 1854 and 1895. Use unknown, probably for road metal. |
Assessment of Site: GeoScientific Merit | ||||
Rarity | Quality | Literature/Collections | Primary Interest | |
Lithostratigraphy | ||||
Sedimentology | ||||
Igneous/Mineral/Metamorphic Geology | Regional | Good | Smith, 1959[1] | X |
Structural Geology | Local | Poor | ||
Palaeontology | ||||
Geomorphology |
Site Geoscientific Value | ||||
This site is the type section for ‘Markle Basalt’ (now a disused term for the plagioclase-macrophyric basalt exposures throughout the Midland Valley of Scotland), and is therefore the most important section through this part of the Carboniferous volcanic sequence in the region. |
Assessment of Site: Current site usage | |
Community | The quarry is on the outskirts of the town of East Linton, and rarely visited by the local community. It is likely to be frequented by the occasional geologist due to its significance as the type locality of Markle Basalt. |
Education | The site is the type locality for the Markle Basalt lava, and is exposed particularly well, with plenty of fresh faces for examination of the large plagioclase phenocrysts. The quarry would act as an excellent reference point to those interested in igneous rocks of the lower Carboniferous of the Midland Valley of Scotland. On-site interpretation boards would be appropriate for this site. |
Assessment of Site: Fragility and potential use of the site | |
Fragility | Natural overgrowth, geohazard. |
Potential use | Research, Higher/Further Education, School Education, On-site interpretation. |
Geodiversity Summary | |
The main value of this site is its geological association of being a type locality for a regionally widespread and common rock type. It contains excellent exposures of the Markle Basalt, a basalt type common and widespread throughout the central belt of Scotland. The site exposes an excellent cross section through a basalt lava flow containing abundant feldspar phenocrysts, vesiculated flow tops and other features typical of a basalt lava flow (e.g. sub-vertical cooling joints). |
Site Photos | |
References
- ↑ SMITH, W W, 1959. Pseudomorphs after olivine in Markle basalt. Mineralogical Magazine, v.32, 247, p.324–331.