Waterloo Bay
Waterloo - geograph.org.uk - 454845.jpg
Tilted mudstones at Waterloo Bay, Larne
Map showing the location of Waterloo Bay
Map showing the location of Waterloo Bay
Location in Northern Ireland
LocationCounty Antrim, Northern Ireland
OSI/OSNI gridD408037
Coordinates54°51′07″N 5°49′48″W / 54.852°N 5.83°W / 54.852; -5.83Coordinates: 54°51′07″N 5°49′48″W / 54.852°N 5.83°W / 54.852; -5.83
Elevation0 m
GeologyMercia Mudstone Group, Lias Group
AgeJurassic, Triassic
Topo mapOSNI Discoverer 9

Waterloo Bay is an area of foreshore in Larne on the east coast of County Antrim, Northern Ireland. It is of particular interest to geologists because it provides a clear, complete and accessible example of the sequences from Upper Triassic to Lower Jurassic, when the rock types changed from land to marine.


Early investigation

Joseph Ellison Portlock studied the Triassic and Jurassic rocks of Ireland in 1843 as part of his engagement by Ordnance Survey Ireland.[1]

In 1864 Ralph Tate made an investigation of the Triassic rocks of County Antrim, which he reported to the Geological Society of London.[1]

Status and significance

Because the location provides an unusually clear, complete and accessible example of the sequences from Upper Triassic to Lower Jurassic, when the rock types changed from land to marine, Waterloo Bay was designated an Area of Special Scientific Interest for its geological importance in 1995.[2][3]

In 2007, it was a candidate for Global Boundary Stratotype Section and Point (also known as a GSSP, or 'golden spike') to mark the base of the Jurassic system and Hettangian stage.[4][1][5] although the Kujoch in Austria was chosen instead.

The "Larne Sea Dragon"

In 1999, an ichthyosaur, also popularly known as the 'Larne Sea Dragon' or 'Minnis Monster'[6] was found in the Langport Member strata by Brian McGee. Remains were found of the backbone and rib cage, scattered pieces of the front limbs, the lower jaw, and several teeth. These were uncovered by fossil preparator Andy Cowap and put on display in the Ulster Museum.[7]

From 2007-9, while the Ulster Museum was undergoing refurbishment, the ichthyosaur was exhibited in Larne Tourist Information Centre.[8]

Public right of way

The promenade, a footpath between the foreshore and the low cliffs at Waterloo, is a public right of way.[9]


See also


  1. ^ a b c Simms; M J; Jeram, A J (January 2007). "Waterloo Bay, Larne, Northern Ireland: A potential Global Stratotype Section and Point (GSSP) for the base of the Jurassic System, National Museums Northern Ireland". Retrieved 28 May 2019.
  2. ^ Department of the Environment NI, Waterloo ASSI
  3. ^ "Rocks Of Ages: Waterloo Bay". Geocaching. Retrieved 28 May 2019.
  4. ^ International Commission on Stratigraphy
  5. ^ "Marina Plan Could Be 'Golden-Spiked'". Larne Times. 15 May 2007.
  6. ^ BBC Attic
  7. ^ Unearthing the Larne Sea Dragon (2007) National Museums Northern Ireland
  8. ^ McIlwaine Biggins, Fiona (15 Nov 2007) 200m year old resident returns home to Larne, Belfast Telegraph
  9. ^ Council Papers Confirm Members Labelled Marina Minute Erroneous (1 Dec 2005) Larne Times