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Earth Science Conservation Review

Summary Full report
Hill's Port, The Gobbins, Island Magee - MineralogyAntrim
Site number:527
ESCC:EC
Locality Type:Coastal section, Roadside section Status: ASSI
Grid Reference: J485971 Approximate
Google maps: 54.80019,-5.69078
County: AntrimCouncil area:Mid & East Antrim Borough Council
Period:Tertiary
Lithostrat:Antrim Lava Group, Lower Basalt Formation
Site Description
image: 0527a.jpg Hill’s Port, The Gobbins, Islandmagee, Co.Antrim, June 1997.
Hill’s Port, The Gobbins, Islandmagee, Co.Antrim, June 1997.
Highlights:
Roadcut and sea-cliff exposures of amygdaloidal basalt containing unusual zeolite minerals.
Introduction:
Zeolite-bearing basalts are prone to weathering and consequently useful sites are mostly confined to coastal exposures and active quarries, where erosion and extraction expose fresh material. Hill’s Port at the south end of The Gobbins cliffs on Island Magee, is of particular interest as it is the type locality for the zeolite mineral gobbinsite.
Description:
image: 0527b.jpg Hill’s Port, The Gobbins, Islandmagee, Co.Antrim, June 1997: layby on Gobbins Road.
Hill’s Port, The Gobbins, Islandmagee, Co.Antrim, June 1997: layby on Gobbins Road.
The lay-by on the Gobbins Road due east of Hill’s Port, opposite the lane descending to the shore, is a convenient place to park and is also of mineralogical interest. The 6m high roadcut exposes the uppermost part of a basaltic flow, which is increasingly amygdaloidal upwards and is overlain by the basal massive part (1m thick) of another flow. Natrolite and analcite are the dominant zeolite species, and samples can be obtained from loose boulders and cobbles at the base of the cliffs.

The shore at Hill’s Port is accessible on foot. The Gobbins cliff and waterfall form impressive features north of Hill’s Port.
image: 0527c.jpg Hill’s Port, The Gobbins, Islandmagee, Co.Antrim, June 1997: tunnel entrance to Gobbins Path.
Hill’s Port, The Gobbins, Islandmagee, Co.Antrim, June 1997: tunnel entrance to Gobbins Path.
By going through the short tunnel next to the carving of ‘Gobbins Path’ and following the path around a small headland, a rocky bay is reached where the path has been destroyed by erosion and landslips.
image: 0527d.jpg Hill’s Port, The Gobbins, Islandmagee, Co.Antrim, June 1997: Gobbins Path.
Hill’s Port, The Gobbins, Islandmagee, Co.Antrim, June 1997: Gobbins Path.
Boulders in this area (some 10m2 in extent) are of amygdaloidal basalt containing a wide variety of zeolite minerals: analcime, chabazite, cowlesite, gonnardite, gobbinsite, heulandite, levyne and mesolite have been observed.
image: 0527e.jpg Hill’s Port, The Gobbins, Islandmagee, Co.Antrim, June 1997: zeolitic boulders.
Hill’s Port, The Gobbins, Islandmagee, Co.Antrim, June 1997: zeolitic boulders.
Some vesicles also contain calcite and travertine.
Importance:
Although analcime-zone zeolite-bearing basalts are widely distributed in County Antrim, Hill’s Port provides a reasonably accessible site where specimen material is abundant. The zeolite minerals gobbinsite (named after The Gobbins cliffs) and gonnardite are of restricted occurrence elsewhere.
Interpretation:
Zeolite minerals are alkali-bearing aluminosilicates that contain chemically-bound water molecules (Tschernich, 1992). Their occurrence in amygdales is characteristic of flood basalt lava piles such as the British Tertiary Province and Iceland. Walker (1960 and earlier papers) studied the distribution of zeolite mineral species in the lava piles of Ireland and Iceland, and was the first to demonstrate that zeolite mineralogy related to (a) rock type i.e. whether the host basalt is olivine-bearing or tholeiitic, and (b) depth in the lava pile, i.e. the temperature attained during hydrothermal alteration. The zeolite mineral assemblage at Hill’s Port is characteristic of olivine basalt alteration within the scolecite-mesolite zone (Walker, 1960), whereas the roadcut exposures are probably within the topographically higher (lower temperature) analcime zone.
Conclusions:
This area is strongly recommended for site designation as it is of mineralogical and historical interest, is reasonably accessible, and is an area of spectacular coastal scenery.
Notes:
See also SLNCI Key Site 755 - Hill's Port, The Gobbins.
Keywords
Minerals:Analcime, Analcite, Calcite, Chabazite, Gobbinsite, Natrolite, Zeolites, Heulandite, Levyne, Cowlesite, Mesolite, Gonnardite, Travertine
Rocks:Amydaloidal Basalt, Olivine Basalt
Structures:amygdales
Access
Approach:Hill's Port is accessed via the path from the private untarred road to Gobbins Cottage.
Management:
Natural processes of erosion and landslip will ensure a supply of fresh zeolite-bearing basalt. The main threats are over-zealous collectors, and modification of the shoreline if the Gobbins Path is reconstructed. Although the path is accessible for c.250m beyond the entrance tunnel, in several sections it is hazardous and unsafe in all but the calmest conditions. For this reason it would be undesirable to encourage visitors to the area, unless warning signs and perhaps a barrier were erected beyond the area of mineralogical interest and before the hazardous sections of the Gobbins path.
Threats:The main threats are over-zealous collectors and modification of the shoreline if the Gobbins Path is reconstructed.
Uses
Uses:Intertidal zone accessed via path from the private untarred road to Gobbins Cottage.
Map(s): OSNI 1:50,000 sheet 9.
Record type: ESCR report Recorded by: R. Nawaz and N.R. Moles
Entered by: E M Porter
Last updated:07 MAY 68
 Enlander, I., Dempster, M. & Doughty, P., 2026. Hill's Port, The Gobbins, Island Magee - Mineralogy, County Antrim, site details. [In] Earth Science Conservation Review.
https://www.habitas.org.uk/escr/site.php?item=527. Accessed on 2026-11-06.

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