Bedrock Geology of the UK and Ireland (scale 1:1,250,000)

The Geological Mapping programme collaborated with the British Geological Survey and the Geological Survey of Northern Ireland to publish a summary map for Britain and Ireland, derived from our respective national maps.  The map is intended primarily as a teaching resource and geological summary for international projects.

Bedrock Geology 1 Million (scale 1:1,000,000)

Coordinate System: Irish Transverse Mercator / ITM

Bedrock 500k (scale 1:500,000)

Coordinate System: Irish Transverse Mercator / ITM

The 1:500k bedrock maps provide a simplified, smaller scale view of the bedrock geology of Ireland. The map was created in 2013 using the detailed 1:100k geology linework and polygons, which was adjusted and scaled to provide the best representation of the geology at this overview level.

The data represents a seamless bedrock geological dataset encompassing Rep of Ireland and parts of Northern Ireland at the 500,000 scale. This dataset is part of the ‘Bedrock Geology 500K Series’ (seamless bedrock geological dataset encompassing Rep of Ireland and parts of Northern Ireland) that comprises 3 parts – Bedrock Lithology 500K, Bedrock Faults 500K and Bedrock Dykes 500K.

Bedrock 100k (scale 1:100,000)

Coordinate System: Irish Transverse Mercator / ITM

Bedrock is the solid rock at or below the land surface. Over much of Ireland, the bedrock is covered by materials such as soil and gravel.  The Bedrock map shows what the land surface of Ireland would be made up of if these materials were removed. As the bedrock is commonly covered, bedrock maps are an interpretation of the available data.

Geologists map and record information on the composition and structure of rock outcrops (rock which can be seen on the land surface) and boreholes (a deep narrow round hole drilled in the ground). Areas are drawn on a map to show the distribution of rocks.

To produce this dataset, the twenty one 1:100,000 paper maps covering Ireland were digitised and borders and overlaps between map sheets were removed. We collect new data to update our map and also use data made available from other sources.

Bedrock 50k (scale 1:50,000)

Coordinate System: Irish Transverse Mercator / ITM

Bedrock is the solid rock at or below the land surface. Over much of Ireland, the bedrock is covered by materials such as soil and gravel. The Bedrock maps shows what the land surface would be made up of if these materials were removed. As the bedrock is commonly covered, bedrock maps are an interpretation of the available data.

To produce these datasets, the bedrock geology 1:100,000 map was used as a base. Historical information was compiled from mineral exploration reports and old geology maps. This new information was used to re-interpret the geology.

Bedrock Outcrops

Coordinate System: Irish Transverse Mercator / ITM

Rock outcrops are rocks which can be seen on the land surface.

Geologists map and record information on the composition and structure of rock outcrops. Areas are drawn on a map to show the location and extent of these outcrops.

Verified Boreholes With Logs

Coordinate System: Irish Transverse Mercator / ITM

The verified drill holes dataset is a cartographic representation of the collar coordinates of Geological Survey Ireland drill holes combined with a new compilation of historical mineral exploration holes from the Open File system for 2019. 

This dataset was generated as part of the Geological Mapping programme's 1:50k re-mapping compilation. This dataset is built on the existing Bedrock Borehole Locations dataset with numerous corrections of the entries and a compilation of previously uncaptured drill holes. Exploration drill holes were captured from the mandatory reporting requirements of exploration in Ireland. Recent holes had coordinates provided in the reports, usually in Irish Grid, allowing transposition into the database. For many holes coordinates were not provided, or were provided in a local or mining grid format. Holes of this type were accompanied by a location map, which could be georeferenced allowing coordinates to be derived. As this was developed during 1:50k mapping it only covers those areas of Ireland where this mapping and compilation were undertaken. As such, it does not yet replace the Bedrock Borehole Locations dataset. This dataset is included in the viewer with the purpose of making the pdf logs of these holes available by direct link. The pdfs will be hosted by GSI.

Bedrock Boreholes (unverified)

Coordinate System: Irish Transverse Mercator / ITM

We are currently working on upgrading our borehole and core store databases.  In the meantime, this database may provide useful information.  If you have any remaining queries, please contact Brian McConnell at brian.mcconnell[AT]gsi.ie.  For core store queries and to request access, please see the core store page.

Rosguill Peninsula bedrock special sheet (scale 1:12,000)

The Land Mapping Unit teamed up with Prof. Bernard Anderson to produce a special sheet (1:12,000 scale) of his previously unpublished detailed bedrock mapping of Rosguill Peninsula, Co. Donegal.