Founded in 1845, Geological Survey Ireland (GSI) is Ireland’s public earth science knowledge center. An early adopter of free data principles, it provides free, open, and accurate data and maps on Ireland’s subsurface to landowners, the public, industry, and all other domestic and international stakeholders. The Survey also acts as a project partner in interpreting data and developing models and viewers to allow people to understand the underground.
GSI is a section of the Department of Climate, Energy and the Environment. As such, it has a strong focus on sustainability and supporting the green transition through its work on critical raw materials, groundwater, and geothermal energy, and is a key contributor to Ireland’s leading position as a mineral exploration destination in Europe.
Ireland as a mining jurisdiction
Ireland is an internationally significant mining district, with a record of repeated discoveries, established mining and exploration expertise, extensive and open geological data, and infrastructure capable of supporting mineral exploration. In combination with its resource potential, these inform Ireland’s strategic role in securing the sustainable supply of critical raw materials (CRMs) needed for the EU’s 2030 climate and digital objectives.
World-class Zn–Pb
A a world-class zinc–lead province, the Irish Midlands Orefield covers approximately 22 000 km² (8494 mi²) hosting Irish-type deposits. It is commonly ranked in the top five globally for zinc and lead metal discovered per unit area. While the Navan deposit is currently the most internationally significant, the Orefield has demonstrated repeated discoveries such as Tynagh, Silvermines, Galmoy, and Lisheen.
Critical Raw Material potential
Historically, Ireland was a copper province, with the Gortdrum and Avoca deposits producing significant volumes of copper. Gortdrum is related to the metallogenic system of the Irish-type province, suggesting an undiscovered endowment of Cu in a mature orefield. The Avoca deposit is entirely external to the Irish Midlands Orefield, as a VMS deposit hosted in the Lower Palaeozoic of southwest Ireland.
Germanium, gallium, and indium are EU critical raw materials that can be recovered as co- or by-products. Sphalerite can incorporate all three, indicating Ireland may become productive in them. Recent drilling at the Ballywire Zn–Pb discovery by Group Eleven Resources has demonstrated elevated germanium in Irish-type mineralization.
Ireland also contains a recognized lithium pegmatite system along the eastern margin of the Leinster granite. Spodumene has been recognized in this area since the 1960s and active exploration is ongoing.
GSI’s exploration capacity
GSI supports exploration activities in a variety of ways, including regional mapping campaigns and the provision of national-scale datasets, mineral prospectivity research projects, and close collaborations with industry.
As part of its National Archive responsibilities, the Survey maintains two drill core libraries and has accepted significant volumes of core from industry partners to preserve this valuable resource. The archive now contains more than 500 km (310.7 mi) of core, all available for examination and analysis free of charge to industry and academia.
A key issue identified on multiple occasions by GSI’s industry partners has been the volume of legacy data and the logistical difficulty in accessing drill core. GSI responded by acquiring a hyperspectral core scanner and commencing a scanning program to make the entire archive available online and free of charge. The Survey has taken on a significant global leadership role in hyperspectral scanning over the past few years, founding the International Working Group on Hyperspectral Core Scanning and developing free, open-source software packages to reduce the barriers to entry surrounding hyperspectral imaging. Hyperspectral core scanning datasets are information dense and are often provided as sequences of images or in niche, specialized file types. Too frequently, exploration geologists are unfamiliar with the specialized skills or software required to fully interrogate hyperspectral data; GSI efforts have focused on demystifying the technology, providing easy entry points, and facilitating its use.
The Survey is also one of the few remaining surveys across Europe that still operates an in-house drilling program, with three rigs available for deployment across the country. The primary diamond coring rig has capacity to core to depths over 1 km (3280.8 ft). It is a mainstay of Ireland’s response to the Critical Raw Materials Act and will be a key component of the forthcoming National Exploration Program.
Recent work has focused on a deeper understanding of the stratigraphy of the Irish Midlands Orefield, with targets often selected following industry workshops and discussions. Without the demands of an economic imperative, GSI is able to drill deep stratigraphic holes that provide invaluable data for the exploration industry but are highly unlikely to be sanctioned by active exploration projects where mineralized targets are paramount and drilling budgets are tightly controlled.
Supporting European drilling
Ireland is known internationally as a drilling export jurisdiction, with Irish drilling companies in huge demand across the globe. GSI has been a significant supporter of the importance of drilling as the best source of subsurface geological knowledge and was involved in a recent drilling apprenticeship program to train drillers in Ireland. It is also currently examining options to assist other European surveys in redeveloping their drilling capacities to ensure that European companies can address the relevant challenges in supporting the exploration industry.
GSI Tellus project
The Tellus program is GSI’s national scale geochemical and geophysical data acquisition program, and 2026 saw the final acquisition flights of the geophysical component. The entire island has now been overflown with a magnetic, EM, and radiometric survey at 200 m (656.2 ft) line spacing. This has been a concerted effort over the past two decades and a key project in National Development Programs across numerous governments.
Alongside it, a large-scale national soil geochemistry component has just completed its final field sampling phase, with samples now entering the processing and analytical workstreams. Early geophysical full coverage maps will be available in early 2027, with additional data arriving over the following period. As a key GSI product, the Tellus data has been one of the largest drivers of Ireland’s inward investment into the exploration industry, along with a highly rated jurisdiction for permitting and licensing.
The Tellus program also took advantage of several rounds of industry co-funding where areas were prioritized ahead of schedule in return for industry investment. This public–private approach maintained the data as free and open while reducing the burden on public spending. It also allowed the Survey to build close relationships with industry and to understand where it could best add value to the sector.
As a national public body, GSI has a mandate to look at significantly larger scales than individual exploration companies and so has been able to add regional data and interpretations which have been invaluable in mapping out mineralizing structures and broader trends across geological terranes that span license areas. The Survey has also entered partnerships with industry to acquire seismic reflection data and in relation to archiving drill core.
National Exploration Program
Within the Critical Raw Materials Act, each member state is mandated to design and implement a National Exploration Program for CRMs to stimulate European exploration activities and underpin a more diverse and secure raw materials supply chain. It is clear across Europe that geological surveys will have to increase their operational activities to ensure that new national-scale data is acquired, published, and that feedback is taken on board to improve workflows.
GSI is positioned to be a key leader in ensuring that exploration expertise is shared and made available to all stakeholders. The Survey is currently chairing a National Exploration expert sub-group of all European surveys and will be providing drilling expertise across future pan-European activities and in support of large-scale research programs. Within Ireland, the focus will be on the most prospective commodities found across its diverse geology, including copper, and CRMs hosted in Irish-style deposits such as gallium and germanium. The program will bring together legacy datasets and newly acquired and planned geochemical, geophysical, and geological data to develop Ireland as a preferred jurisdiction for exploration expenditure.
Existing work has seen the Survey commence drilling operations on mine waste stockpiles in support of circularity targets, and a clear vision of Ireland as one of Europe’s leading mining jurisdictions is emerging in response to the Critical Raw Materials Act. The future of Irish exploration is bright, and the already significant investment in exploration is expected to grow over the coming years.
For more information: Visit gsi.ie
