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Earth Science Conservation Review
| Leckpatrick Point | Antrim |
| Site number: | 159 | ||
| ESCC: | EC | ||
| Locality Type: | Coastal section | Status: | ESCR |
| Grid Reference: | D225397 Centroid | ||
| Google maps: | 55.18965,-6.07659 | ||
| County: | Antrim | Council area: | Causeway Coast & Glens Borough Council |
| Period: | Precambrian | ||
| Stages: | Dalradian | ||
| Lithostrat: | Altmore Formation, Leckpatrick Green Beds, Runabay Head Formation, Southern Highlands Group | ||
| Site Description | |
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| Highlights: | |
Leckpatrick Point contains unsurpassed coastal exposure of the stratotype (type section) of the Leckpatrick Green Bed Member which defines the stratigraphic base of the Runabay Formation (Southern Highland Group) in north-east Antrim. | |
| Introduction: | |
Leckpatrick Point is a prominent headland situated at the southern end of Port-aleen Bay approximately 750m south of Torr Head. Access to the site can be gained either by walking southwards along the shoreline from Torr Head Port [D232 404] or overland from the Torr Road via farm tracks and through fields in Ballyloughan Townland. On the first edition of the one inch to one mile geological map of the area (Ballycastle, Sheet 8) (Geological Survey of Ireland, 1887), rocks at Leckpatrick Point were classified simply as "gneiss, mica & hornblende schist" and referred to jointly as "crystalline schists". McCallien (1931) produced the first detailed lithostratigraphic map of the Dalradian in north-east Antrim adopting the lithostratigraphic nomenclature that was already in use in Scotland. McCallien's stratigraphy was predicated on a structural interpretation which viewed the North-east Antrim area as the south-westerly continuation into Ireland of recumbent fold structures already identified on the Cowal Peninsula, SW Scotland (Gunn et al., 1897). The second edition of the Ballycastle Sheet, (Geological Survey of Northern Ireland, 1963; Wilson et al., 1966) included a revised lithostratigraphy based on detail mapping of the Dalradian. The rocks at Leckpatrick Point were shown as green beds within the "Quartzose Grit and quartz schist". This work also led to an alternative to Bailey and McCallien's interpretation of the structure of north-east Antrim. A more formal approach to lithostratigraphic terminology was introduced on the first edition of the Solid Geology Map of Northern Ireland (Geological Survey of Northern Ireland, 1977) on which the non-green bed rocks at Leckpatrick Point were included within the "Altmore Schists". Arthurs (1976) produced a major revision of the Dalradian stratigraphy and most notably defined a new lithostratigraphic framework for north-east Antrim based on new formations with local names. Although this work was based largely on reconnaissance mapping and further detailed work remains to be done in the area, Arthurs' linework and lithostratigraphy were incorporated in the second edition of the Solid Geology Map of Northern Ireland (Geological Survey of Northern Ireland, 1997), see table below. TABLE TO BE ADDED Dalradian stratigraphy and ESCR sites in North-east Co. Antrim. | |
| Description: | |
In the sea-cliffs at Leckpatrick Point, a lithologically complex series of hornblende and biotite schists (Leckpatrick Green Bed Member) overlies quartzo-feldspathic schistose psammite and grit (Altmore Formation). The entire succession is flat-lying with a broadly bedding-parallel regional schistosity. The coarse-grained siliciclastic rocks on the foreshore and at the base of the cliff at Leckpatrick Point are predominantly pinkish brown and grey quartz-feldspar grits, psammites and quartz schists containing distinctive grey and blue quartz grains. Lithology and structure is broadly similar to rocks exposed further north at Port-aleen Bay. These rocks have a flaggy appearance and a well developed, bedding-parallel schistosity (S2?) which dips at about 15° E.  Green beds form the uppermost 60m of the cliff at Leckpatrick Point. They comprise a lithologically diverse sequence of light to dark green biotite-albite schists and phyllites containing variable amounts of hornblende which, in some cases is the only mafic phase. The more hornblendic varieties form hard more massive units which in part resemble metabasite. Albite (or sometimes more calcic plagioclase) and biotite occur as porphyroblastic phases in these rocks. Thin sections of these rocks contain various accessory minerals including epidote, apatite, magnetite with occasional rounded zircon. Details of the mineralogy and textures have been discussed by Bailey et al. (1934 and by Wilson et al., 1966). | |
| Importance: | |
This site has national and potentially international stratigraphic importance. The detailed interpretation of the structure and stratigraphy of North-east Antrim has not yet been completed. However, it is anticipated that the Leckpatrick Green Beds, which are so well exposed at this site, will continue to be a key marker horizon for establishing stratigraphic correlations within Antrim and possibly between Antrim, the Sperrin Mountains and Scotland. | |
| Interpretation: | |
During late-Proterozoic (Upper Dalradian) times, sedimentation took place mainly in marine basins which developed along the unstable margin of the Laurentian continent. These basins were filled with turbidite facies siliciclastic sediments derived from the nearby continental landmass. The presence of green beds is a common feature of the Upper Dalradian stratigraphy in Northern Britain. Towards the end of Middle Dalradian times (Tayvallich Subgroup, Argyll Group), the break up and extension of the Laurentian continental margin led to crustal thinning and was accompanied by a major upsurge of volcanic activity. This activity persisted well into Upper Dalradian times and is represented in the stratigraphic record occasionally by basaltic lavas but more commonly by green beds. The latter are predominantly chloritic and amphibolitic rocks which formed either as water-lain volcanic tuffs or as volcaniclastic sediments derived primarily by erosion of volcanic terranes. The rocks at Leckpatrick Point, are a contrasting mixture of coarse siliciclastic and finer grained volcanogenically derived sediments typical of Southern Highland Group successions throughout Scotland and Ireland. Stratigraphically the siliciclastic lithologies belong to the uppermost part of the Altmore Formation while the green beds belong to the lowermost part of the Leckpatrick Green Bed Member which lies at the base of the younger Runabay Head Formation. The Altmore Formation occurs in a structural setting and stratigraphic position comparable to the Dart Formation in the Sperrin Mountains and the Ben Bheula Schists in the Cowal Peninsula, Scotland. The Caledonian Orogeny resulted in the deformation and regional metamorphism of Dalradian rocks across Northern Britain. In north-east Antrim, as in Scotland and the Sperrin Mountains deformation was complex and polyphase and resulted in folding and the formation of up to four separate cleavages (Arthurs, 1976; Goldring, 1961). Structurally, the rocks at this site (Altmore Formation and the Leckpatrick Green Beds) now lie on the downward-facing inverted limb and close to the core, of the Altmore Anticline. This structure is regarded as the south-westerly continuation into Ireland of the Cowal Anticline in SW Scotland (Gunn et al., 1892; Arthurs, 1976). The metamorphic mineral assemblages in rocks at this site indicate that regional metamorphism took place within the quartz-albite- muscovite-chlorite sub-facies of the Greenschist Facies. | |
| Conclusions: | |
Leckpatrick Point is a site of national and potentially international significance. It is the unofficial stratotype (type section) for the Leckpatrick Green Bed Member, which marks the stratigraphic base of the Runabay Head Formation and is an important marker horizon in the Dalradian of north-east Antrim. | |
| Notes: | |
For site specific information and references on other Dalradian sites in North-east Antrim see the following sites: Key Site 155 - Benvan Key Site 156 - Escort Port Key Site 157 - Torr Head Key Site 158 - Altmore Burn Key Site 160 - Carnaneigh Key Site 161 - Loughan Bay Key Site 162 - Loughareema Channel Key Site 163 - Knocknacarry Bridge Key Site 164 - Cushendun Bay and Rock Port For site specific information and references on other Dalradian sites in the Sperrin Mountains, Londonderry and Tyrone see the following sites: For Central and Southern Sperrin Mountains: Key Site 130 - Butterlope Glen Key Site 131 - Craig Key Site 132 - Mullaghcarbatagh Key Site 133 - Henry's Bridge, Glensass Burn Key Site 134 - Oughtboy Burn Key Site 135 - Garvagh Burn Key Site 136 - Barnes Gap Key Site 137 - Barnes Burn Key Site 138 - Golan Burn Key Site 139 - Glendarragh Burn, Glenlark Key Site 140 - Mountfield Old Quarry Key Site 141 - McNally's Burn, Broughderg For North Sperrin Mountains and Londonderry: Key Site 142 - Letterbrat Quarry Key Site 143 - Banagher Glen Quarry Key Site 144 - Strabane Quarry Key Site 145 - Glenmornan River, Artigarvan Key Site 146 - Balix Hill Key Site 147 - Drain Quarry Key Site 148 - Kildoag Quarry Key Site 149 - Loughermore Mountain Key Site 150 - Burntollet and Tamnymore Wood Key Site 151 - Dog Leap, Limavady Key Site 152 - Kittybane Quarry Key Site 153 - Prehen Quarry Key Site 154 - Creevagh Hill Old Quarry For general information on the Dalradian rocks of Northern Ireland see the following site: Key Site 124 - The Dalradian Rocks of Northern Ireland For general and site specific information on the Pre-Dalradian rocks of Northern Ireland see the following site: Key Site 123 - The Pre-Dalradian Rocks of Northern Ireland For general information and an extensive reference list on the Precambrian of Northern Ireland see the following site: Key Site 122 - An Introduction to the Precambrian of Northern Ireland | |
| Keywords | |
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| Rocks: | Green beds, Grit, Psammite |
| Access | |
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| Approach: | Access to the site can be gained either by walking southwards along the shoreline from Torr Head Port [D232 404] or overland from the Torr Road via farm tracks and through fields in Ballyloughan Townland. |
| Management: | |
Because most of the site lies within an area currently under the stewardship of the National Trust this may have implications for access to the site or parts of the site and for sampling policy . Notwithstanding any recommendations or restrictions that the National Trust may make regarding these matters, it is worth highlighting some safety considerations relating to access to Leckpatrick Point. This site, in particular the cliffs where the best exposures of the green beds can be seen, lies on an exposed stretch of the Co. Antrim coastline. This area is prone to high winds and waves. Sea spray wets much of the outcrop even during relatively calm weather making some surfaces treacherous. Extreme care must be exercised at all times when visiting the site. | |
| Threats: | At present there do not appear to be any specific threats to the integrity of this site. |
| References (6) | |||
|---|---|---|---|
| Arthurs, J.W., 1976a. The geology and metalliferous mineral potential of the Sperrin Mountains area Geological Survey of Northern Ireland Special Report. | |||
| Bailey, E.B. & McCallien, W.J., 1934. The metamorphic rocks of North-east Antrim Transactions of the Royal Society of Edinburgh: Earth Sciences, vol. 58, pp.163-177. | |||
| Golding, D.C., 1961. The relationship of the micro-fabric to the small-scale structures of the Dalradian of north-eastern Antrim Proceedings of the Royal Irish Academy, vol. 61 pt. B, pp.345-367. | |||
| Gunn, W., Clough, C.T. & Hill, J.B., 1897. The Geology of Cowal Memoir of the Geological Survey of Scotland. | |||
| McCallien, W.J., 1931. A contribution to the correlation of the Dalradian rocks of Scotland Geological Magazine, vol. 68, pp.153-175. | |||
| Wilson, H.E. & Robbie, J.A., 1966. Geology of the country around Ballycastle. Memoirs of the Geological Survey Northern Ireland. | |||
| Map(s): | GSI (1887). 1:63,360 Geological Sheet 8 (Ballycastle), Dublin, OS for GSI GSNI (1963). 1:63,360 Ballycastle, Northern Ireland Sheet 8, Drift, Southampton, OS for GSNI GSNI (1977). 1:250,000 Northern Ireland, Solid Geology (1st edition), Southampton, OS for IGS GSNI (1997). 1:250,000 Northern Ireland, Solid Geology (2nd edition), BGS, Keyworth, Nottingham | ||
| Record type: | ESCR report | ||
| Entered by: | E M Porter | ||
| Enlander, I., Dempster, M. & Doughty, P., 2026. Leckpatrick Point, County Antrim, site details. [In] Earth Science Conservation Review. https://www.habitas.org.uk/escr/site.php?item=159. Accessed on 2026-11-06. |
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