ESCR - Western Mournes Complex - Western lowlands, drumlins and moraines

Earth Science Conservation Review

Summary Full report
Western Mournes Complex - Western lowlands, drumlins and moraines	Down

Site number:	458
ESCC:	IS
Locality Type:	Inland exposure	Status:	TBC
Grid Reference:	J129222,J145192 End(s) of linear site, Not Entered
Google maps:	54.13693,-6.27261
County:	Down	Council area:	Newry, Mourne & Down District Council
Period:	Quaternary
Stages:	Late Midlandian

Site Description
Description:
The lowlands are characterised by drumlins with numerous poorly-aligned hummocks and enclosed depressions on their lower slopes and in intervening lows. Drumlins have a consistent long axis orientation towards the southeast. Long axes are 500-800m, and short axes are 300-500m in length. Morphology is generally of the classic type (Hanvey, 1988), although long profiles are frequently slightly undulating. A drumlin at Ballyrussell (J151215) is slightly arcuate. An exposure in the lower central slopes of a drumlin at Drumesk (J167193) contains vaguely stratified sandy gravel and massive diamict. Facies description Vaguely stratified, poorly-sorted gravel (<1m thick) is characterised by undulating beds (<15cm) of mainly matrix supported pebbles. Bed boundaries are conformable and are marked by discontinuous pebble lines and minor textural changes. Sandy beds grade laterally into clast supported pebbles, there are sandy lenses, and cobbles are frequent. Clasts are generally rounded to subrounded, and clast ab planes are mainly horizontal. The undulating contact with overlying massive diamict (<1m thick) is mainly gradational or interdigitated, and occasionally erosional. The unit consists mainly of pebbly sand, with occasional pebbly lenses. Facies interpretation Textural variability, non-erosional contacts and bimodality of the sandy gravel are typical of debris flow deposits (Postma, 1986). The location on the flank of the drumlin suggests that deposition was in a subglacial channel which drained meltwater around the landform. Interdigitation of massive diamict may record opening of a cavity and subsequent downslope debris flows (Hanvey, 1989). Undulating beds probably record deformation of saturated sediments. Inter-drumlin hummocks are low (<5m high), rounded to oval in plan, closely spaced, occasionally connected and are generally non-aligned. They are frequently separated by small enclosed depressions. These are kettleholes, and vary from 0.2ha to 2.5ha (J141203). An exposure in a hummock on the flank of a drumlin (J143216) consists of chaotic, poorly-sorted, and mainly angular to subangular, pebbles to small boulders in a coarse sand matrix. The spatial organisation and internal structure of hummocks is consistent with inverted disintegration topography at a stagnant ice margin (Paul and Eyles, 1990).
Notes:
For site specific information on other sites within the Western Mournes Complex see the following sites: Key Site 455 - Kilbroney River Valley Moraines Key Site 456 - Ghann River Moraines Key Site 457 - Moygannon River Valley Moraines For overview information and references on the Western Mournes Complex see the following site: Key Site 450 - Western Mournes 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 440 - Mourne Plain Complex - Overview 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 451 - Annalong Valley For general information and references on the sand and gravel landscapes of N. Ireland, and directions to 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 757 - Western Mournes Lowlands, Drumlins and Moraines.

Keywords
Geomorph:	drumlin, recessional moraine


Record type:	ESCR report
Entered by:	E M Porter
Last updated:	4 Aug 2004

Enlander, I., Dempster, M. & Doughty, P., 2026. Western Mournes Complex - Western lowlands, drumlins and moraines, County Down, site details. [In] Earth Science Conservation Review.
https://www.habitas.org.uk/escr/site.php?item=458. Accessed on 2026-11-07.