1:50,000 maps showing the main geological superficial divisions in Northern Ireland. This series shows the superficial (drift) geology of Northern Ireland at 1:50,000 scale. For each rock unit there is a brief generalised description under the following headings. LEX_D: Description of the selected polygon. LEX_RCS: Map code as it appears on the published 1:250,000 map. RCS_D: Decription of the deposit. VERSION: Version of the data. RELEASED: Date of release/update of the data. Persons interested in the detailed geology of particular sites should consult the latest large-scale maps or the Geological Survey of Northern Ireland at:- Geological Survey of Northern Ireland Colby House Stranmillis Court Belfast BT9 5BF

Superficial Geology (250k) This layer shows the superficial (drift) geology of Northern Ireland at 1:250,000 scale. For each rock unit there is a brief generalised description under the following headings. LEX_D: Description of the selected polygon. LEX_RCS: Map code as it appears on the published 1:250,000 map. RCS_D: Decription of the deposit. VERSION: Version of the data. RELEASED: Date of release/update of the data. Persons interested in the detailed geology of particular sites should consult the latest large-scale maps or the Geological Survey of Northern Ireland at:- Geological Survey of Northern Ireland Colby House Stranmillis Court Belfast BT9 5BF

A 1:250,000 map showing the main geological bedrock divisions in Northern Ireland. The bedrock shown on GeoIndex map comprises the bedrock geology, which represents the outcrops (at surface) and subcrops (at near-surface, beneath superficial deposits) in Northern Ireland. For each rock unit there is a brief generalised description showing the major rock group, rock type and age under the following headings. LEX_D: The name of the selected area. This can be a group, formation or igneous intrusion e.g. dyke. LEX_RCS: Map code as it appears on the published 1:250,000 map. RCS_D: The name of the dominant types of rock (lithologies) in the different areas shown on the map e.g. granite. The names of the rock types given here are often generalisations, appropriate for the large areas of geological coverage at this scale. These areas may include a number of different geological formations whose distribution can only be portrayed on more detailed geological maps. RANK: Identifies formations and groups. Min_Time_D and Max_Tim_D: The age of the rock unit in terms of periods, relatively smaller units of geological time e.g. Carboniferous, Jurassic etc. Some of the map areas include rocks with a range of ages and these are shown as such e.g. Triassic to Cretaceous. The oldest metamorphic rocks are described as Moinian and Dalradian. The rocks range in age from those deposited relatively recently, some 2 million years ago, back to ancient and highly altered Precambrian rocks over 2500 million years old. In broad terms the youngest rocks are found in the south and east of the UK, the oldest in the north and west. VERSION: Version of the data. RELEASED: Date of release/update of the data. CAUTION Because of the generalisation and simplification used in the compilation of this map, it should not be used to determine the detailed geology of any specific sites. It is best used to provide a basic understanding of the geology of the country in general, and for showing the geology of large regions where broad trends are more important than specific details. Persons interested in the detailed geology of particular sites should consult the latest large-scale maps or the Geological Survey of Northern Ireland.

The BGS database of geological maps is an index into BGS holdings of modern and historical published geological maps, geological standards and field slips, and also contains a range of other map series, including geophysical maps, geochemical maps, hydrogeological maps, thematic maps and other small-scale miscellaneous non-series maps. Historical vertical and horizontal sections, as well as indices to colours, are also included. The database comprises map metadata, including the title, theme, survey and revision years, publication years, mapped geological theme, base material, map function, colouration, approval status and the spatial extent of each map sheet. An accompanying file store contains high-resolution JPEG2000 scans for delivery, as well as various digital master and delivery formats. For a small number of maps, no scan exists. In total, the database contains over 240,000 scans of over 130,000 maps and field slips. The majority of the maps in the database cover Great Britain, but other regions are also represented, including a historical series of 1-inch maps of Ireland, 6-inch maps of the Isle of Man, 1:25 000 scale maps of the Channel Islands, and various overseas maps. The database contains a record of all geological maps produced by the British Geological Survey and its predecessors since the commencement of systematic geological mapping in the 1830s. The BGS Maps Database is mostly an archive of previous BGS maps, and is not the same as the latest BGS digital mapping. The maps within the database may differ significantly from BGS digital vector mapping. Further information about BGS digital vector mapping is available on the BGS website, under 'BGS Datasets'. The database has evolved over time, originally being a series of discrete databases. These databases have now been aggregated into a single dataset. BGS published maps, as well as 1:10 560 and 1:10 000 large-scale geological maps of England and Wales, and Scotland, are available through the BGS Maps Portal. Field slips and some thematic maps are not included on the BGS Maps Portal. The information about a map is normally a transcription from the map itself. Sometimes key information such as the title may not be actually printed on the map. Where this is the case the information is supplied in square brackets, e.g. [Kirk Maiden]. Information in square brackets means the information is supplied by the cataloguer and is not transcribed from the item.

[This metadata record has been superseded, see http://data.bgs.ac.uk/id/dataHolding/13608197] Manuscript notebooks, section books and field record cards containing detailed information gathered by the Survey geologists (or other recognised geologists) from various sources as part of the mapping process. Examples include observations linked directly to field slips, borehole logs, sections and drawings. Note: For the basic field mapping work notebooks have now been replaced by field record cards. Covering survey areas in Great Britain from 1840's to date.

[This metadata record has been superseded, see http://data.bgs.ac.uk/id/dataHolding/13608197] An index to the manuscript notebook collection was set up in the 1990's. The notebooks themselves contain detailed information gathered by BGS geologists (or other recognised geologists) from various sources as part of the mapping of Great Britain since the 1840s. Examples include observations linked directly to field slips, borehole logs, sections and drawings. All the notebooks held by National Geological Records Centre (NGRC) are indexed but other notebooks held in the Library may not be included. The index is to the notebooks and is not a detailed index of the information in the notebook. Detailed information from coalfield areas is held in the Happs Hall Index. For the basic field mapping work notebooks have now been replaced by field record sheets.