IGH Themes
The geological heritage of Ireland is considered and evaluated within an overall framework of 16 themes. Each theme considers specific aspects, such as stratigraphy, sedimentology, structural geology, volcanic rocks, etc and addresses all aspects of the particular geology involved, but some sites may be considered within two or more themes.

Under the IGH Programme, expert panels were set up for each theme, resulting in an indicative list of sites worthy of more detailed assessment within the relevant themes. This is a response to the present urgent demands for information for development projects, Environmental Impact Statements and planning.

The site lists are now undergoing a final assessment, with individual Site Reports being written by various panel experts, currently for the IGH6 Minerals and IGH7 Quaternary themes. The site reports will then be followed up by fieldwork to assign boundaries.

Of the majority of geological sites not eventually selected for NHA designation, some are being promoted as County Geological Sites (CGS), which have no statutory protection, but may be included within County Development Plans. Many counties have now adopted County Geological Sites into their development plans, promoting their interest through Heritage Plans, having comissioned and completed their audit of geological heritage.

IGH15 - Economic Geology Theme
Geology is not just an academic study of the earth, but principally a practical subject, whereby theoretical understanding of processes and events in the record of the rocks are translated into discovery, exploitation and use of geological resources. This geological foundation of resources to suppor...
IGH 1 - Karst Theme
Karst is the name given to areas of limestone bedrock which have a high degree of weathering caused by solution together with a characteristic underground drainage system. The Burren is the best known classical karst landscape in Ireland, yet the majority of limestone throughout Ireland shows karsti...
IGH 2 - Precambrian to Devonian Palaeontology Them...
The sites selected for NHA designation in this theme cover a significant range of palaeontological interest and importance. No genuine Precambrian fossils are yet known from Ireland, and only a small handful of sites are known with significant Cambrian fossils. These include Bray Head with its disti...
IGH 3 - Carboniferous to Pliocene Palaeontology Th...
under construction
IGH 4 - Cambrian-Silurian Theme
under construction
IGH 7 - Quaternary Theme
The Ice Ages over the past couple of million years have had a profound effect on our landscape. Over most of the country, the geology of the bedrock is either strongly sculpted by frost shattering and ice movements or else partially obscured by a blanket of glacial deposits. This geological heritage...
IGH 6 - Mineralogy Theme
Minerals are individual combinations of elements that are found as distinct forms in their own right. Several thousand individual minerals are known. Igneous rocks and metamorphic rocks are usually formed from particular associations of minerals and their classification can be based on the mineral s...
IGH 8 - Lower Caboniferous Theme
under construction
IGH 9 - Upper Carboniferous and Permian Theme
under construction
IGH11 - Igneous Intrusions Theme
Most volcanic rocks in Ireland are considered under the relevant stratigraphical theme in which they occur, so for example, the Ordovician volcanic rocks of Wexford and Waterford are assessed in the Cambrian to Silurian Theme, IGH4. However, some igneous rocks are intrusive, that is they penetrated ...
IGH12 - Mesozoic and Cenozoic Theme
This theme is a limited one for the simple reason that rocks of this age are rare in the Republic of Ireland. Much of Antrim has rocks of Jurassic and Cretaceous age as well as the Tertiary basalts best displayed at the Giants Causeway, but the panels for this theme will mainly consider only very ra...
IGH13 - Coastal Geomorphology Theme
Coastal geomorphology is the theme that includes all the landforms around the coast of Ireland, which have been created by the power of the sea. This theme will be trying to find the best examples of particular landforms. The panel will also try to identify locations where processes are actively hap...
IGH14 - Fluvial and Lacustrine Geomorphology Theme
under construction
IGH16 - Hydrogeology Theme
This geological theme is a very specialised one which will eventually select only a handful of sites which are important for their exceptional characteristics. The kinds of sites to be examined include warm springs, other non-karstic springs, or sites which demonstrate particular hydrogeological pro...