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Earth Science Conservation Review
| Mourne Plain Complex - Moore Lodge Moraine | Down |
| Site number: | 444 | ||
| ESCC: | IS | ||
| Locality Type: | Inland exposure | Status: | TBC |
| Grid Reference: | J32873150 Approximate | ||
| Google maps: | 54.21567,-5.96424 | ||
| County: | Down | Council area: | Newry, Mourne & Down District Council |
| Period: | Quaternary | ||
| Stages: | Late Midlandian | ||
| Site Description | |
|---|---|
| Description: | |
This dissected, subdued ridge trends south to north from 0.5 km east of Derryvogue Harbour to the vicinity of the Giant's Grave (328700 315000) where it turns northwestwards across the plain. Ridge remnants rise to ~ 20m above the intermorainal lows and are up to 150m wide. Higher and more continuous moraine ridges trend in a similar direction both to the east and the west of the ridge. A pit excavated at (329000 313000) in the southernmost fragment of the moraine contains a section 30m long by up to 8m deep. Three facies are present within the pit. Facies description F1 Laminated medium and fine sand Stratified sand consists of undulating to contorted beds (<15cm thick) of laminated sand. Internal contacts are conformable, and beds are laterally extensive (>10m). Beds show both fining up and coarsening up trends. Often subhorizontal beds become contorted laterally. Folds verge to the northeast, and are frequently recumbent along the strike, with an amplitude of >1m. High angle normal and reverse faults are frequent. Discontinuous granule stringers occasionally occur along bed boundaries and dispersed granules frequently penetrate laminae surfaces. F2 Stratified gravel There is a conformable, undulating contact with a <1m thick unit of stratified pebble gravel (F2). Beds are deformed though less so than F1. A single bed of gravel (<30cm thick) penetrates the laminated sand of F1 at an angle of 45°. Clasts are rounded to subrounded. Cobbles occasional occur at the top of the facies sequence. F3 Stratified Diamict F2 is overlain by stacked beds of stratified diamict (F3). The contact between the gravel and diamict is undulating and conformable, and is marked by a discontinuous cobble line. Beds (<20cm thick) are clast-to-matrix supported and folded. Internal contacts are conformable. Clasts are up to cobble size. INTERPRETATION The high degree of sorting and lateral extent of the beds exposed in the Moore Lodge moraine suggest deposition by sheet flow. The penetration of the laminae by granules and graded beds, indicates that the lamination is the result of sedimentary rather than tectonic processes. This indicates that the sands were deposited as a flat outwash surface before being pushed into their present ridge morphology by glaciotectonics. The ice push must have been deep-seated as no sole-thrust is recorded. A superficial thrust would have probably homogenised the sediments. Extensional reverse and normal faulting record the removal of support as ice retreated westward. Conformable contacts between the three facies indicate that they were all deposited in a subaqueous setting prior to glaciotectonic deformation. A vertical increase in the cobble content of the gravel beds indicates an increasing proximity to the ice margin or a switch in the efflux position. Textural changes between gravel and diamict, with an increased cobble content in the diamict may also indicate an advancing ice front. Stacked beds, sharp bed boundaries and dominance of matrix support are all characteristic of pulsed debris flows. Ridges on the Mourne Plain represent ice limits of a glacier which retreated westwards across the Mourne Plain towards Carlingford Lough (Charlesworth, 1939; McCabe et al., 1984). Two major phases of ice activity are recognised. Ridges between Ballymartin and the Cranfield moraine record a minimum of fourteen major standstills or oscillations during the main withdrawal of the Late Midlandian ice. The kettle-holes around Ballykeel represent deposition of fluvioglacial sediment across the detached remnants of an ice mass which retreated at least to the position of the Kilkeel valley. The successive ridge positions record phased retreat and extensive kettleholes record rapid ice mass removal and stagnation of residual ice (Mulholland, 1982). A later readvance of ice eastwards out of Carlingford Lough reached Cranfield Point. Decay westward into the Carlingford trough formed four major lines of moraine within 1km behind the outer limit at Cranfield. | |
| Interpretation: | |
The high degree of sorting and lateral extent of the beds exposed in the Moore Lodge moraine suggest deposition by sheet flow. The penetration of the laminae by granules and graded beds, indicates that the lamination is the result of sedimentary rather than tectonic processes. This indicates that the sands were deposited as a flat outwash surface before being pushed into their present ridge morphology by glaciotectonics. The ice push must have been deep-seated as no sole-thrust is recorded. A superficial thrust would have probably homogenised the sediments. Extensional reverse and normal faulting record the removal of support as ice retreated westward. Conformable contacts between the three facies indicate that they were all deposited in a subaqueous setting prior to glaciotectonic deformation. A vertical increase in the cobble content of the gravel beds indicates an increasing proximity to the ice margin or a switch in the efflux position. Textural changes between gravel and diamict, with an increased cobble content in the diamict may also indicate an advancing ice front. Stacked beds, sharp bed boundaries and dominance of matrix support are all characteristic of pulsed debris flows. Ridges on the Mourne Plain represent ice limits of a glacier which retreated westwards across the Mourne Plain towards Carlingford Lough (Charlesworth, 1939; McCabe et al., 1984). Two major phases of ice activity are recognised. Ridges between Ballymartin and the Cranfield moraine record a minimum of fourteen major standstills or oscillations during the main withdrawal of the Late Midlandian ice. The kettle-holes around Ballykeel represent deposition of fluvioglacial sediment across the detached remnants of an ice mass which retreated at least to the position of the Kilkeel valley. The successive ridge positions record phased retreat and extensive kettleholes record rapid ice mass removal and stagnation of residual ice (Mulholland, 1982). A later readvance of ice eastwards out of Carlingford Lough reached Cranfield Point. Decay westward into the Carlingford trough formed four major lines of moraine within 1km behind the outer limit at Cranfield. | |
| Notes: | |
For site specific information on other sand and gravel sites within the Mourne Plain Complex see the following sites: Key Site 441 - Cranfield Moraine Key Site 442 - Glenloughan Pit Key Site 443 - Tullyframe Pit Key Site 445 - Sandpiper Pit Key Site 446 - Kilkeel Cliff For overview information and references on the Mourne Plain Complex see the following site: Key Site 440 - Mourne Plain Complex - Overview For overview and site specific information on other sand and gravel sites within the Mourne Mountains area see the following sites: Key Site 447 - Attical Complex, Mourne Mountains - Overview Key Site 448 - Bloody Bridge River Valley Complex, Mourne Mountains - Overview Key Site 449 - Northeast Mournes Complex - Overview Key Site 450 - Western Mournes - Overview Key Site 451 - Annalong Valley For general information and references on the sand and gravel landscapes of N. Ireland, and for directions to sand and gravel sites other than those within the Mourne Mountains area, see the following site: Key Site 439 - Introduction to the Sand and Gravel Landscapes of N. Ireland This site is also a Site of Local Nature Conservation Importance. See Key Site 742 - Moore Lodge Moraine. | |
| Keywords | |
|---|---|
| Relations: | Glacial deposit, Glaciomarine deposit, Glaciotectonic |
| Geomorph: | ice lobe, moraine ridge, outwash |
| Record type: | ESCR report | ||
| Entered by: | E M Porter | ||
| Enlander, I., Dempster, M. & Doughty, P., 2026. Mourne Plain Complex - Moore Lodge Moraine, County Down, site details. [In] Earth Science Conservation Review. https://www.habitas.org.uk/escr/site.php?item=444. Accessed on 2026-11-06. |
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