{ "culture": "en-IE", "name": "Rock_Unit_Groups_100K_IE26_ITM", "guid": "EB2978EB-3F3D-4F6D-829F-43BF080A2767", "catalogPath": "", "snippet": "This Hydrostratigraphic Rock Unit Groups map is a reclassification of the 1:100,000 bedrock geology map, created by grouping bedrock formations and members into 27 \u2018Rock Unit Group\u2019 categories based on their hydrogeological properties and other factors.\n\nThe Hydrostratigraphic Rock Unit Groups map is used to determine aquifer classes.\n\nRock Unit Groups are hydrostratigraphic units. Bedrock Formations and Members are grouped within a stratigraphic framework on the basis of what is understand to be important differences between rock units/ rock unit groups in terms of groundwater flow properties. ", "description": "

There are more than 1,200 geological Formations and Members defined within the Republic. Their delineation is based on a variety of factors, many of which are of no relevance to the hydrogeological properties of the aquifer (for example, type of fossil). GSI<\/SPAN><\/SPAN>\u2019<\/SPAN><\/SPAN>s Groundwater Section have, therefore, evaluated these Formations and Members and reduced them to 27 'Rock Unit Groups' that have hydrogeological significance.<\/SPAN><\/SPAN><\/P>

The Rock Unit Groups are defined within a stratigraphic framework on the basis of what is understand to be important differences between rock units/ rock unit groups in terms of groundwater flow properties. For example, <\/SPAN><\/SPAN><\/P>

  • limestone purity and susceptibility to karstification; <\/SPAN><\/SPAN><\/P><\/LI>

  • bedding presence or absence and its influence on the prevalence of jointing;<\/SPAN><\/SPAN><\/P><\/LI>

  • degree of deformation and its impact on flow properties (e.g., older rocks have been deformed many times since their formation, so lack pore spaces and connected fracture networks). <\/SPAN><\/SPAN><\/P><\/LI><\/UL>

    The way in which the aquifer classification has been undertaken is on the basis of <\/SPAN><\/SPAN>\u2018<\/SPAN><\/SPAN>Rock Unit Groups<\/SPAN><\/SPAN>\u2019<\/SPAN><\/SPAN>rather than the individual <\/SPAN><\/SPAN>\u2018<\/SPAN><\/SPAN>rock units<\/SPAN><\/SPAN>\u2019<\/SPAN><\/SPAN>(Formations). Note that a particular Rock Unit Group can, and often does have, a different aquifer classification in different parts of the country (for example, the Dinantian Pure Unbedded Limestones aquifer classification ranges from Ll to Rkc and Rkd, depending upon location).<\/SPAN><\/SPAN><\/P>

    The 27 rock unit groups are as follows:<\/SPAN><\/SPAN><\/P>

    1. Permo-Triassic Sandstones<\/SPAN><\/SPAN><\/P>

    2. Permo-Triassic Mudstones and Gypsum <\/SPAN><\/SPAN><\/P>

    3. Westphalian Sandstones <\/SPAN><\/SPAN><\/P>

    4. Westphalian Shales<\/SPAN><\/SPAN><\/P>

    5. Namurian Shales<\/SPAN><\/SPAN><\/P>

    6. Namurian Sandstones<\/SPAN><\/SPAN><\/P>

    7. Namurian Undifferentiated<\/SPAN><\/SPAN><\/P>

    8. Dinantian Shales and Limestones<\/SPAN><\/SPAN><\/P>

    9. Dinantian Mixed Sandstones, Shales and Limestones<\/SPAN><\/SPAN><\/P>

    10. Dinantian Sandstones<\/SPAN><\/SPAN><\/P>

    11. Dinantian Pure Bedded Limestones<\/SPAN><\/SPAN><\/P>

    12. Dinantian Upper Impure Limestones<\/SPAN><\/SPAN><\/P>

    13. Dinantian Dolomitised Limestones<\/SPAN><\/SPAN><\/P>

    14. Dinantian Pure Unbedded Limestones<\/SPAN><\/SPAN><\/P>

    15. Dinantian Lower Impure Limestones<\/SPAN><\/SPAN><\/P>

    16. Dinantian (early) Sandstones, Shales and Limestones<\/SPAN><\/SPAN><\/P>

    17. Dinantian Mudstones and Sandstones (Cork Group)<\/SPAN><\/SPAN><\/P>

    18. Devonian Kiltorcan-type Sandstones<\/SPAN><\/SPAN><\/P>

    19. Devonian Old Red Sandstones<\/SPAN><\/SPAN><\/P>

    20. Silurian Metasediments and Volcanics<\/SPAN><\/SPAN><\/P>

    21. Ordovician Metasediments<\/SPAN><\/SPAN><\/P>

    22. Ordovician Volcanics<\/SPAN><\/SPAN><\/P>

    23. Cambrian Metasediments<\/SPAN><\/SPAN><\/P>

    24. Precambrian Quartzites, Gneisses & Schists<\/SPAN><\/SPAN><\/P>

    25. Precambrian Marbles<\/SPAN><\/SPAN><\/P>

    26. Granites & other Igneous Intrusive rocks<\/SPAN><\/SPAN><\/P>

    27. Basalts & other Volcanic rocks<\/SPAN><\/SPAN><\/P>

    There is also an <\/SPAN><\/SPAN>\u2018<\/SPAN><\/SPAN>unclassified<\/SPAN><\/SPAN>\u2019<\/SPAN><\/SPAN>class for areas of the map where the geology is undefined. Sands and Gravels are defined separately.<\/SPAN><\/SPAN><\/P>

    Scale: 1:<\/SPAN>10<\/SPAN>0,000<\/SPAN><\/P><\/DIV><\/DIV><\/DIV>", "summary": "This Hydrostratigraphic Rock Unit Groups map is a reclassification of the 1:100,000 bedrock geology map, created by grouping bedrock formations and members into 27 \u2018Rock Unit Group\u2019 categories based on their hydrogeological properties and other factors.\n\nThe Hydrostratigraphic Rock Unit Groups map is used to determine aquifer classes.\n\nRock Unit Groups are hydrostratigraphic units. Bedrock Formations and Members are grouped within a stratigraphic framework on the basis of what is understand to be important differences between rock units/ rock unit groups in terms of groundwater flow properties. ", "title": "Rock_Unit_Groups_100K_IE26_ITM", "tags": [ "Hydrostratigraphic", "Rock", "Unit", "Groups", "hydrogeology", "bedrock", "groundwater", "Ireland" ], "type": "Map Service", "typeKeywords": [ "Data", "Service", "Map Service", "ArcGIS Server" ], "thumbnail": "thumbnail/thumbnail.png", "url": "", "extent": [ [ -10.876065330809, 51.3712109164156 ], [ -5.87574988520851, 55.4519191848688 ] ], "minScale": 0, "maxScale": 1.7976931348623157E308, "spatialReference": "IRENET95_Irish_Transverse_Mercator", "accessInformation": "Contains Irish Public Sector Data (Geological Survey) licensed under a Creative Commons Attribution 4.0 International (CC BY 4.0) licence", "licenseInfo": "

    Data that is produced directly by the Geological Survey Ireland (GSI) is free for use under the conditions of Creative Commons Attribution 4.0 International license. <\/SPAN><\/SPAN><\/P>

    https://creativecommons.org/licenses/by/4.0/legalcode<\/SPAN><\/SPAN><\/P>

    Under the CC-BY Licence, users must acknowledge the source of the Information in their product or application. <\/SPAN><\/SPAN><\/P>

    Please use this specific attribution statement: \"Contains Irish Public Sector Data (Geological Survey) licensed under a Creative Commons Attribution 4.0 International (CC BY 4.0) licence\". <\/SPAN><\/SPAN><\/P>

    <\/P><\/DIV><\/DIV><\/DIV>" }