IE GSI Aggregate Potential Mapping Sand and Gravel Scores 50k Ireland (ROI) ITM

ISO-19139 Metadata

Resource Identification Information:

Citation:
Title:  IE GSI Aggregate Potential Mapping Sand and Gravel Scores 50k Ireland (ROI) ITM

Reference date - creation:  2004-12-31
Reference date - publication:  2013-10-31

Presentation format:  mapDigital

Unique resource identifier:
Value: MR_MineralOccurrence_IE_GeologicalSurveyIreland_AggregatePotentialMappingSandGravelScores_50k_Ireland_ITM
Authority that defines the value:
Title:  geodata.gov.ie

Reference date - creation:  2004-12-31
Reference date - publication:  2013-10-31

Edition: 2018


Party responsible for the resource - pointOfContact: 
Individual's name: Minerals
Organization's name: Geological Survey Ireland
Contact's position: Head of Minerals

Contact information:
Phone:
Voice: +353-1-6782896
Address:
Delivery point: Block 1, Booterstown Hall, Booterstown Avenue, Booterstown, Blackrock
City: Dublin
Postal code: A94 N2R6
Country:  IE
e-mail address: support@geodata.gov.ie
Online resource:
Name of resource: GSI Website
Online location:https://www.gsi.ie
Connection protocol: text/html
Function performed:  information
Description: GSI Website
Themes or categories of the resource:  environment, geoscientificInformation, location

Place keywords:
Keywords:  Ireland

Thesaurus name:
Title:  Metadata Registry of the Publications Office of the EU Named Authority Lists - Country
Alternate titles:  MDR-COUNTRIES

Reference date - publication:  2015-03-18

Edition: 20200624-0

Theme keywords:
Keywords:  Mineral resources

Thesaurus name:
Title:  GEMET - INSPIRE themes, version 1.0
Alternate titles:  GEMET INSPIRE

Reference date - publication:  2008-06-01

Descriptive keywords:
Keywords:  IE/GSI

Thesaurus name:
Title:  Global Change Master Directory (GCMD) Data Center Keywords 9.1.5
Alternate titles:  GCMD Data Center Keywords

Reference date - publication:  2016-08-04

Edition: 9.1.5

Descriptive keywords:
Keywords:  National

Thesaurus name:
Title:  Spatial scope

Reference date - publication:  2019-05-22

Descriptive keywords:
Keywords:  Downloadable Data

Thesaurus name: ArcGIS Content Type
Abstract:  “Aggregates” is the term geologists use to describe rocks used for building and construction purposes. Aggregate Potential Mapping aims to identify areas where aggregate is most likely to be found.This map shows the sand and gravels across Ireland used in the Aggregate Potential Mapping process.Unlike the crushed rock potential map there are large areas uncoloured because sand or gravel has not been mapped in these areas.This map is to the scale 1:50,000. This means it should be viewed at that scale. When printed at that scale 1cm on the map relates to a distance of 500m.It is a vector dataset. Vector data portray the world using points, lines, and polygons (areas). The data is shown as polygons. Each polygon holds information on the county it is located in, Subsoil Label (Teagasc, 2006), Quaternary Sediment Type (GSI), Note on Sources, Geological Characteristics, Evaluation, Sediment, sediment description and the area in m2.Please read the metadata lineage for further information.

Purpose: “Aggregates” is the term geologists use to describe rocks used for building and construction purposes. They are used in today’s world for building our roads, schools, hospitals and houses. Hard rocks can be crushed to make material for foundations and to fill in spaces. Naturally occurring sands and gravels are used for making concrete and concrete products such as building blocks. It is very important that we know where these rocks occur so that they can be used for any new projects. The aggregate potential maps show where it might be possible to find suitable rocks for building purposes. The map should be of interest to the building and road construction sectors, and planning authorities at local and regional level.

Dataset language:  eng
Dataset character set:  utf8

Status:  onGoing
Maintenance:
Update frequency:  notPlanned


Resource constraints:
Constraints:
Limitations of use: 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.https://creativecommons.org/licenses/by/4.0/https://creativecommons.org/licenses/by/4.0/legalcodeUnder the CC-BY Licence, users must acknowledge the source of the Information in their product or application.Please use this specific attribution statement: "Contains Irish Public Sector Data (Geological Survey Ireland) licensed under a Creative Commons Attribution 4.0 International (CC BY 4.0) licence".In cases where it is not practical to use the statement users may include a URI or hyperlink to a resource that contains the required attribution statement.

Resource constraints:
Legal constraints:
Resource constraints:
Legal constraints:
Resource constraints:
Security constraints:
Classification:  unclassified

Spatial representation type:  vector

Processing environment: Esri ArcGIS 13.2.0.49743

Spatial resolution:
Dataset's scale:
Scale denominator: 50000
Spatial resolution:
Ground sample distance: 500 m
Extent:
2004-12-31T00:00:00 2013-10-31T00:00:00
Extent:
Geographic element - Bounding rectangle:
Extent contains the resource: true
West longitude: -10.658847
East longitude: -5.903942
North latitude: 55.38287
South latitude: 51.4486
Credits: Geological Survey Ireland

Point of contact - pointOfContact: 
Individual's name: Minerals
Organization's name: Geological Survey Ireland
Contact's position: Head of Minerals

Contact information:
Phone:
Voice: +353-1-6782896
Address:
Delivery point: Block 1, Booterstown Hall, Booterstown Avenue, Booterstown, Blackrock
City: Dublin
Postal code: A94 N2R6
Country:  IE
e-mail address: support@geodata.gov.ie
Online resource:
Name of resource: GSI Website
Online location:https://www.gsi.ie
Connection protocol: text/html
Function performed:  information
Description: GSI Website

Spatial Representation - Vector:

Level of topology for this dataset:  geometryOnly
Geometric objects:
Object type:  composite
Object count: 36859

Reference System Information:

Reference system identifier:
Value: 2157
Authority that defines the value:
Title:  European Petroleum Survey Group (EPSG) Geodetic Parameter Dataset
Alternate titles:  EPSG

Reference date - publication:  2004-04-07

Edition: 9.8.12

Code space: EPSG
Version: 6.5.3(8.1.2)

Data Quality Information:

Scope of quality information:
Level of the data:dataset

Lineage:
Lineage statement: The Geological Survey Ireland (GSI) started a programme of aggregate potential mapping (APM) for both sand and gravel, and crushed rock resources in Ireland in 2007. The six-year project ran from Nov. 1st, 2007 to Oct. 31st, 2013. The project followed on from three county APM surveys which were completed successfully earlier in the decade: County Donegal (McCarron, 2002), County Meath (Lally, 2004) and County Wicklow (Gallagher, 2004). The scoring parameters, and their integration, used in Irish Granular APM are: [Genesis-Petrology x 2] + [Number of pits x 1.2] + [Area x 2] + [Thickness x 2] + [Elevation x 0.5] + [Markets x 1.2] Those used in Crushed Rock APM are: [Rock Type Suitability x 2.8] + [Deleterious Substances x 0.7] + [Number of quarries x 1.2] + [Area x 0.5] + [Overburden thickness x 2] + [Elevation x 0.8] + [Markets x 1.2] The treatment of individual parameters is elaborated on in each datasets metadata. The above formulae show that the Irish method uses a scoring system of Weighted Sums. In both algorithms, a Phase 1 subtotal is arrived at after the addition of Area; this represents scoring of original Quaternary deposits or Bedrock blocks in the form in which they have been mapped. Thereafter, Phase 2 parameters are introduced which have a different geography; they are scored and then added successively, in combination with the geoprocessing operation Union. Thus, with the possible exception of very small initial units, Phase 2 evaluation is carried out on subsets of the original geological bodies. The Markets parameter is partitioned between a Construction sector (house building, and social and business infrastructure) whose proxy for scoring purposes in this project is Population Density, and a Road Building sector. Partitioning of the weight of 1.2 associated with this parameter is calculated separately for each county after a review of the product range of the more recent pits and quarries within the confines of the county. Parameters are scored from 1 to 10 or from 0 to 10. Those in the former group are Genesis-Petrology, Area, Elevation, and the Population Market in Granular APM; and Rock Type Suitability, Area, Elevation and the Population Market in Crushed Rock APM. Those in the latter group are Number of Pits, Thickness, and the Roads Market in Granular APM; and Deleterious Substances, Number of Quarries, Overburden Thickness, and the Roads Market in Crushed Rock APM. Parameters which include a score of 0 can register an amount of zero of the factor in question, based on data to hand e.g. no recorded pits/quarries. A score of zero in other cases is used to differentiate between the lowest value and an outside designation, such as “Lake” in DTB maps from which deposit thickness is derived. Parameters whose lowest score is 1 may always offer some possibility, however small, of attaining an influence on the aggregate potential of the host e.g. a very poor quality rock type/lithology. Individual scoring scales are explained fully in relevant sections later in the report. In order that higher scores will always represent higher potential, and lower scores lower potential, some parameters of a negative character are scored inversely i.e. a high score means little of the parameter, and a low score means much of it. The factors which are scored thus are Deleterious Substances, Overburden Thickness, Elevation, and Roads Market. A large amount of Deleterious Substances lowers the potential of a rock; its score will therefore be low for this factor. A shallow thickness of overburden will increase the potential of a bedrock rock source; therefore the rock will attract a high score for this parameter. A deposit or bedrock aggregate source which is found at a high elevation will attract a low score. And finally, a deposit or rock type located a short distance from a proposed road will be given a high market potential score. The sum of weights shown in the algorithms was, at the conception of the project, designed to be 10. When multiplied by scores for each factor, the total score range would emerge as 10-100. However, with the impracticality of including several parameters which require a large time input for data research and perhaps field checks, and due to the consideration of scores of 0 in several of the factors, revised total score ranges have come about: 4.5 – 89 in the case of Granular AP estimation, and 4.1 - 92 in the case of Crushed Rock AP estimation. Parameters which have not been included in the NDP six-year project for reasons of time are: Granular APM • Grading curve of S&G, using two scores from particle size analysis - % Stone (> 5mm), and % Fines (< 65μm, equivalent to the silt and clay fractions) • Deleterious content in S&G, including peaty zones, clay and organic matter, calcrete, iron pans, flaky clasts etc. Crushed Rock APM • Rock Test Data from individual formations Granular Aggregate Potential Mapping EVALUATION PARAMETERS and SCORING ALGORITHM The scoring parameters, and their integration, used in Irish Granular APM are: [Genesis-Petrology x 2] + [Number of pits x 1.2] + [Area x 2] + [Thickness x 2] + [Elevation x 0.5] + [Markets x 1.2] The treatment of individual parameters is elaborated on in later sections. The above formula show that the Irish method uses a scoring system of Weighted Sums. A Phase 1 subtotal is arrived at after the addition of Area; this represents scoring of original Quaternary deposits in the form in which they have been mapped. Thereafter, Phase 2 parameters are introduced which have a different geography; they are scored and then added successively, in combination with the geoprocessing operation Union. Thus, with the possible exception of very small initial units, Phase 2 evaluation is carried out on subsets of the original geological bodies. The Markets parameter is partitioned between a Construction sector (house building, and social and business infrastructure) whose proxy for scoring purposes in this project is Population Density, and a Road Building sector. Partitioning of the weight of 1.2 associated with this parameter is calculated separately for each county after a review of the product range of the more recent pits and quarries within the confines of the county. Parameters are scored from 1 to 10 or from 0 to 10. Those in the former group are Genesis-Petrology, Area, Elevation, and the Population Market. Those in the latter group are Number of Pits, Thickness, and the Roads Market. Parameters which include a score of 0 can register an amount of zero of the factor in question, based on data to hand e.g. no recorded pits/quarries. A score of zero in other cases is used to differentiate between the lowest value and an outside designation, such as “Lake” in DTB maps from which deposit thickness is derived. Parameters whose lowest score is 1 may always offer some possibility, however small, of attaining an influence on the aggregate potential of the host e.g. a very poor quality rock type/lithology. Individual scoring scales are explained fully later on. In order that higher scores will always represent higher potential, and lower scores lower potential, some parameters of a negative character are scored inversely i.e. a high score means little of the parameter, and a low score means much of it. The factors which are scored thus Overburden Thickness, Elevation, and Roads Market. A shallow thickness of overburden will increase the potential of a bedrock rock source; therefore the rock will attract a high score for this parameter. A deposit or bedrock aggregate source which is found at a high elevation will attract a low score. And finally, a deposit or rock type located a short distance from a proposed road will be given a high market potential score. The sum of weights shown in the algorithms was, at the conception of the project, designed to be 10. When multiplied by scores for each factor, the total score range would emerge as 10-100. However, with the impracticality of including several parameters which require a large time input for data research and perhaps field checks, and due to the consideration of scores of 0 in several of the factors, revised total score ranges have come about: 4.5 – 89 in the case of Granular AP estimation. Parameters which have not been included in the NDP six-year project for reasons of time are: Granular APM • Grading curve of S&G, using two scores from particle size analysis - % Stone (> 5mm), and % Fines (< 65μm, equivalent to the silt and clay fractions) • Deleterious content in S&G, including peaty zones, clay and organic matter, calcrete, iron pans, flaky clasts etc. The parameter Genesis-Petrology has been inserted to score composition of granular sediment in the absence of grading curve analysis, although they are somewhat distinct in what they measure. The weights assigned to the various parameters were postulated at the initiation of the Meath and Wicklow APM projects in 2002, and implemented in final form in 2003 after discussions between Minerals Programme staff and external consultant R. Fox. The experience of work within the aggregates industry was thus brought to bear. A key point for the user of APMs is to appreciate that not all initial materials of the same type, be they similar S&G deposits or similar bedrock lithologies, are ultimately of similar value as aggregates. The application of the project’s scoring algorithm models both inherent potential of a resource, and also how its value changes due to the influence of size, location and saleability. MAPS COMMON TO BOTH GRANULAR AND CRUSHED ROCK AP ESTIMATION These maps display geographic data which are contributary layers to both final AP maps: • Map of Pits and Quarries for each county. In this project, “pits” are excavations into Quaternary sediments, and the gravel pit inventory is used to score Granular AP; “quarries” are excavations into bedrock, and the quarry inventory is used to score Crushed Rock AP • Map of Topographic Elevation Bands for each county. Height interval classes are introduced to reflect difficulty of access of a deposit. • Map of Population Density of the Irish State (2006). From this one map are clipped county parcels, each for use as a Demand for Construction Aggregate market layer • Map of Current and Future Road Construction in Ireland (2010). Roads on this map are subsequently buffered to produce a template for scoring haulage distance from aggregate source to road scheme • Map of Current and Future Demand for Road Aggregate (2010). From this one map are clipped county parcels, each for use as a Demand for Road Aggregate market layer. GRANULAR AGGREGATE POTENTIAL MAPS These maps display geographic phenomena which are contributory layers to the final Granular AP Map. Each county has the following: • Map of Quaternary Deposits, with emphasis on Sand and Gravel • Granular AP process maps (Phase 1), consisting of four panels placed together on an AO-sized sheet, and showing the results of scoring of original S&G deposits, prior to geoprocessing • Quaternary Thickness Map. This is, for the present, equivalent to the DTB Map of each county which either the Groundwater or Quaternary Sections of GSI have produced as part of the work in their own programmes. As revisions of some DTB maps have taken place after APMs were carried out, no Quaternary Thickness maps are published at this time. (For latest versions of DTB, please consult “Groundwater” on the GSI website). Future Quaternary Thickness maps for S&G, incorporating variation within the subsoil profile are expected to depart from DTB maps of most counties • The final Granular AP Map (Preliminary). COMPILATION OF MAPS COMMON TO BOTH GRANULAR and CRUSHED ROCK AGGREGATE POTENTIAL ESTIMATION MAP OF PITS AND QUARRIES Evidence of extraction over time is a key indicator of aggregate potential. While older pits and quarries are important to include, the generally larger operations of recent times receive the highest scores in the APM process. These latter are also of more relevance in that they reflect the demands of modern aggregates production, both in market type and in material standards. Gravel pits and bedrock quarries are displayed on an AO-sized map for each county. Assembly of the data is time-consuming, as there are numerous sources from which to draw, both within and outside GSI. It can be stated that these maps represent the most complete documentation of the excavation history of counties to date, and further that the pits and quarries included most probably represent between 95% and 100% of all excavations that have taken place. Source and type of Pit and Quarry data used by the project Source Age Size Feature type Local Authority planning applications 2005-present Many large Polygon Local Authority Section 261* applications 2004-5 Variable Polygon GSI Quaternary mapping, recent phase 1992-present Variable Point GSI Quarry Directories, three editions** 1988-2001 Many large Point GSI Mineral Localities (MinLocs) database Up to 1995 Variable Point GSI Industrial Minerals database, updates 1930’s-1990’s Medium size Polygon GSI Bedrock mapping projects 1960’s-1970’s Mostly small Polygon GSI Quaternary mapping: “Drift Series” 1900-1930’s Small Point GSI 6”: 1 mile geological mapping 1850’s-1880’s Mostly small Polygons, points OSI 6”: 1 mile mapping, up to four editions 1833-1946 Mostly small Polygon; some points, some multipoint clusters * Section 261 of the Planning and Development Act 2000: Control of Quarries. This piece of legislation took effect on 28th April 2004; it required all pit/quarry owners, except those who had been granted planning permission within the previous five years, to register with their local authority. Details of extraction and processing were to be provided within one year of that date. The APM project gathered information from these applications at local authority Planning Offices in the first months of 2008. ** Lists of pits and quarries, and their locational and production details, finalised in 1988 (Howes et al., 1988), 1994 (Claringbold et al., 1994), and 2001 (Doyle et al., 2001). All the information gathered was volunteered by producers; in the event, a percentage of operations were not recorded in these surveys. Many pits and quarries are documented in more than one of the above sources. On the county maps, due to limitations of time, no elimination of overlapping or duplicated records has been carried out. These are however noted at the time of counting of pits and quarries for scoring purposes as the method is being implemented, and what appear to be multiples of the same operation are only scored one time. The Map of Pits and Quarries is presented against a background of the edited Quaternary geology of the county. This is meant to put the extractive environment into context, directly in the case of pits, and in the case of quarries, at least in relation to areas of Rck (Bedrock within 1m of surface). A fuller contextual display of quarries is available in the “Map of Bedrock Formations, with (overlay of) Quarries”. MAP OF TOPOGRAPHIC ELEVATION BANDS High elevations represent a challenge to the extractive industry. Costs of transport increase, with longer and often sinuous access trajectories, and wear and tear on trucks rises. Modelling of the effect of this parameter in the Irish context was carried out in 2004, using a Weights of Evidence survey (Gallagher, 2004). The routine was carried out separately for pits and for quarries. The datasets used were pits and crushed rock quarries recorded in GSI’s Quarry Directory (QD) 2001, together with a 10m digital elevation model (DEM) – i.e. topographic contouring with intervals of 10m – by OSI. The procedure sought to assess the probability of finding pits and quarries at various elevations. (a) Analysis of the QD2001’s 242 listed pits shows a positive statistical correlation between pits and heights of 100m or less. In Co. Wicklow, one of Ireland’s counties with highest relief, all recorded pits, whether active or disused, occur at heights below 400m. Accordingly, a unified scoring scale to assess Granular AP across the State is adopted; classes are shown on the left of the Table below. (b) Analysis of the QD2001’s 244 listed crushed rock quarries shows a strong positive correlation between quarries and heights of 200m or less, a lesser one for quarries between 200m and 500m, and a negative correlation for heights exceeding 500m. On this basis, a unified scoring scale is similarly adopted in the APM model to assess Crushed Rock AP; classes are shown on the right of the table below. Scoring of aggregate based on Topographic Elevation Elevation interval, Granular AP assessment Score Elevation interval, Crushed Rock AP assessment Score < 100m 10 ≤ 200m 10 100 – 200m 7 200 – 500m 5 200 – 300m 4 > 500m 1 > 300m 1 An A2-sized display is produced for each county showing the above elevation intervals in separate panels. Colour coding is distinct for Granular AP and Crushed Rock AP, though colouring for each of the two is uniform across all counties. In developing an elevation layer compatible with the data format and methodology of the project i.e. polygon geoprocessing, a number of procedures were necessary: • Using the Clip tool, export a contour set of each county from the OSI 10m DEM • select contours enumerated in the two scoring scales above, and export to separate polyline shapefiles • repair gaps in linework where needed • convert line to polygon geometry using ArcToolboxTM • add Elevation band and Elevation score fields to the two attribute tables generated. The two elevation files are now ready for layer processing. MAP OF POPULATION DENSITY Population density is used in the project as a proxy for demand for general construction aggregate. The greater proportion of uptake may be in pre-cast and readymix concrete, and in concrete blocks. In rural areas where farming families are concentrated, significant demand arises for unbound aggregate to construct farmyards and line drainage ditches. The Map of Population Density classifies returns of the 2006 Census of the Irish Republic, published by the Central Statistics Office (CSO). Ten categories of approximately equal area are established in the scoring scheme (1-10), made up of combinations of parcels known as District Electoral Divisions (DEDs). There are a total of 3409 of these administrative units across the State. Population density among these units varies from a minimum of 0.01 persons per hectare (p/ha) to a maximum of 98.4 p/ha. While other more direct reflections of demand in this area could have been used, the census returns provide a speedy if summary estimation tool. In the 2004 Co. Wicklow APM project, for example, buffering around (projected) urban growth centres listed in the County Development Plan (CDP) of the time was carried out; census parcels with population densities above 10 p/ha were also buffered. Buffer rings were then scored in decreasing value away from the nuclei. In the current NDP project, however, time does not allow for an adequate consultation of CDPs. Nor have projected growth centres in these plans been immune to the downturn in the Irish economy since 2008: it is highly likely that many planned expansions will now stagnate, as Ireland once again in its history has become a country of net emigration. MAP OF CURRENT AND FUTURE ROAD CONSTRUCTION This map was compiled in order to establish where demand for road metal will occur. Road building and repair represents the second major market for aggregates, and in addition to crushed rock for the road pavement layers themselves, a significant volume of granular and crushed rock is also consumed in concrete bridges and in embankment fill. Indeed, in a survey of the product ranges, where stated, of pits and quarries listed in GSI’s three Quarry Directories and in the Section 261 era inventory (2004-present), the breakdown as regards destination is in favour of road building: 57% as compared to 43% for general construction. This result is tentative because of the considerable number of operations who do not state their products; of those who do, many are ambiguous or less than explicit with details and in whom they supply to. In producing this map, data relating to all important road schemes were assembled. Works on Third Class and unpaved roads are not included, as they are deemed to be roughly of equal input in terms of manpower and materials across all counties. The chief sources of information regarding road location, delivery time scale, and magnitude are websites: that of Ireland’s National Roads Authority (NRA), where motorway and National Primary Route schemes are described; those of most of the thirty County Councils in the State, where planned National Secondary and Regional Road realignments, upgrades and town bypasses are described; that of the Roads Service of Northern Ireland; and finally the websites of the government’s development projects – the NDP itself, and Transport 21. In the case of Northern Ireland (NI), those road schemes within 20 km of the border with the APM study area are included: a factor of 3/2 can be applied to this in order to approximate real trucking trajectories. Thus a band of 30 kms is thought to be a realistic market zone for Twenty-Six County producers. (For further discussion, see “Notes” in the separate spreadsheet “Road Buffer Scoring”). The Government’s development projects consist of transport infrastructure targets which stretch into the second decade of the 21stC, and include funding of regionally strategic road development to be carried out within NI. The Regional Transportation Strategy (RTS) for Northern Ireland 2002-2012, and the Regional Strategic Transport Network Transport Plan (RSTN TP), 2005-2015, both programmes of the Department of Regional Development of the NI Assembly, were also consulted. Digital plotting of road works consisted either of a staightforward incorporation of an existing piece of linework, or the digitising of a new route design based on website information. Existing linework is obtained from OSI datasets (under licence agreement to GSI); most Secondary and Regional realignments and upgrades were plotted in this way. Many new/planned roads, on the other hand, were digitised based on sketch maps on their web pages, or at least in accordance with textual indicators of the route. Where a route is digitised based on text, or where a credible trajectory is digitised avoiding hamlets, abrupt hills etc. on the basis of a most favoured “route corridor” on a webpage, the phrase “Preliminary Design (Author)” is entered in the attribute table. In a small number of cases where total uncertainty was felt as to a route, contact by phone was made to the Roads Section of county councils to clarify designers’ intentions. After all road schemes have been digitised, grouping is carried out as displayed in the legend of the map. This classification then becomes the basis for buffering and scoring of the roads market. MAP OF CURRENT AND FUTURE DEMAND FOR ROAD AGGREGATE Road schemes are classified into fourteen groups, each of which is buffered separately. Buffer distances of 1.5 km are employed, equivalent to 2.25 km real distance with a “road curving” factor of 3/2. Major road schemes are expected to warrant trucking journeys of up to 50 km by suppliers of aggregate, while lesser volume upgrades to National Secondary and Regional Roads are constrained to 30 km. These maximum haulage distances equate to buffer outer limits of 33 km and 19.5 km respectively. The full distribution of scores through all buffer distances, in the fourteen road classes, is explained in tabular form in the separate spreadsheet “Road Buffer Scoring”. Score ranges vary according to the category of road: that for major new roads planned is from 4 to 30, with the buffer closest to the road project i.e. 0-1.5 km scoring 30 points. This score implies that an aggregate source at a distance of <1.5 km from a new road project has the highest potential; the economics of haulage, and consequently the potential of deposits, then decrease proportionately with distance from the new scheme. Scores for planned Secondary Road schemes, and for future schemes within government longer-term strategies range from 2 to 24; scores for NI schemes range from 2 to 15; and Roads under construction in 2009, for completion by 2011 range from 1 to 12. The fourteen buffer shapefiles are brought together with the Union tool, producing a mosaic of 118,658 polygons. Many of these have multiple scores, where the influence of geographically close road projects overlap. Scores are added across the new table for each record, giving a total road aggregate demand figure. These totals are divided into 20 classes, to which a rank out of ten is applied (0.5, 1, 1.5, 2, etc.). Upon clipping the mosaic to the APM area extent, it was found that three coastal headland areas in Donegal, Mayo and Cork were outside the influence of road building according to the haulage maxima set. To these three additional polygons was given a score of 0. A final geoprocessing step in the preparation of this market map is the disssolution of boundaries between like ranks to produce a shapefile of 21 multipart records. Colour coding is then applied to the display. COMPILATION OF GRANULAR AGGREGATE POTENTIAL MAPS MAP OF QUATERNARY DEPOSITS, WITH EMPHASIS ON SAND AND GRAVEL NATURE OF THE SEDIMENTS Granular aggregate is also referred to as natural aggregate, in that Nature itself – notably through the agency of glaciofluvial processes of the last Ice Age, or through later depositional processes – has fragmented, shaped and sized the rock. Except for washing and screening, most of this material is ready-made for use in aggregate applications. All the material is either unconsolidated or in rippable sequences which do not require blasting. Geologically, the material belongs to the current Period, called the Quaternary, and may date from the Pleistocene Epoch (2.6 million years to 11,700 years before present), or the Holocene/Recent Epoch (11,700 years ago to present). Granular aggregate comprises however only one category among Quaternary deposits as a whole. There are other categories – aerially and volumetrically by far the largest – which are of no use as aggregate. A breakdown in percentage terms of the broad Quaternary deposit types is given in the Table below. The data are derived from the Teagasc Subsoils Map, 2006 (Spatial Analysis Group, Teagasc, Kinsealy Research Centre, Co. Dublin). Relative areal extent of main subsoil types in the Irish Republic (derived from Teagasc) MATERIAL EXTENT, Km2 % Till 38,797.9 55.5 Bedrock within 1m of surface 9,791.6 14.0 Peat (raised, blanket and fen) 7,776.4 11.1 Cutover/cutaway Peat 5,686.5 8.1 UNDIFFERENTIATED SORTED SEDIMENTS (S&G possible): Alluvium, Lacustrine/Glaciolacustrine deposits 2,700.3 3.9 SAND AND GRAVEL, of glaciofluvial (and minor marine) origin 2,345.8 3.4 Water 1,317.6 1.9 Made ground 870.6 1.3 Silts and Clays, of alluvial/lacustrine/marine/estuarine origin 199.2 0.3 SAND, of marine/aeolian origin 167.6 0.2 SCREE 163.4 0.2 MARL (shell) 43.1 0.1 Marsh and Tidal marsh 4.2 0.006 SANDY-GRAVELLY SEDIMENT in alluvial/lacustrine deposits 2.2 0.003 The total area occupied by subsoils which are considered to be potential sources of construction materials in this project (in capitals in the above table) is therefore approximately 8%. In relative terms, such materials should be considered a precious resource. It is also evident from a glance at the distribution of such sediments when seen in isolation on a map of Ireland that the key category of glaciofluvial S&G is subject to a concentration in the province of Leinster, with only pockets elsewhere. Of the sediments which are not used as aggregate (till, peat, silts and clays), till may on occasions become gravelly and where mapping has been able to isolate such areas, they are included in the APM process. In the case of silts and clays, of whatever origin, their grain size is too fine for aggregate use; they are not considered “granular” as such in the present context. These sediments, together with areas of Bedrock within 1m of surface, water, Made ground, and marsh are subject to prior elimination in the current project. Areas of Bedrock within 1m of surface have little or no Quaternary sediment to estimate potential for. All eliminated areas appear in white on county Granular APMs. It is important to clarify that these eliminations are based on (sub)surface Quaternary geology; it is an objective of the project in the future, time permitting, to study entire Quaternary profiles, and where granular sediments exist at depth beneath unusable upper types, to reintroduce them - probably as a distinct layer of evidence - into the APM analysis. The following are more explanatory descriptions of Quaternary sediments or subsoils which are evaluated after the elimination of unusable types; the order in which they are presented is an approximation of their importance or value as aggregate sources based on findings of the project so far: • glaciofluvial S&G, including the morphologically distinct eskers, of the Pleistocene (or Ice Age) • mixed till with gravel (TwG), also referred to as sandy-gravelly till (Pleistocene). This category is not mapped by Teagasc. It is added to the granular sediments during integration of Quaternary mapping by GSI (and to a minor extent some other sources). Bodies of TwG are added to the database either as original GSI designations, or as a result of compromise labelling between GSI gravels and Teagasc till • undifferentiated sorted sediments of Recent age: Alluvium, making up by far the greater area, and Lacustrine, of more localised extent. There is possible inclusion of unidentified glaciolacustrine material in the latter. These undifferentiated sediments may contain clay, silt, sand, or gravel • S&G of alluvial, lacustrine, or marine origin. These are of Recent (post-glacial) formation, though some may be reworked glacial sediments, particularly in the marine sphere. S&G bodies in alluvium and lacustrine sediments are small in number as they are difficult to isolate from general sequences in the field. They may also be noted as sandy-gravelly alluvium or lacustrine sediment. Marine S&G is found in raised beach and beach deposits, and there is undoubtedly much of this material offshore and as yet unmapped. Onshore marine S&G is not accessible for aggregates use in Ireland due to the amenity and protected status of beaches and the coastal zone generally • glaciolacustrine S&G, in the few locations where it is identified positively as being of glacial/periglacial origin (Pleistocene) • marl (shell) of Pleistocene age usually associated with former glacial lakes. This sediment, while not “granular”, is of a type which could have potential in the quarry products or construction trade: production of agricultural lime, lime mortar, and possibly chemical lime • scree (Recent), which is broken rock usually at the base of mountain slopes. It is a product of weathering and limited transport caused by gravity. As an aggregate source, bodies of scree are probably limited in Ireland more because of their isolated and elevated location than because of inherent material defects • sand, of marine/aeolian origin, in beach sand and sand dunes. No commercial extraction has taken place in these deposits in the modern era, despite periods of pressure in the market to respond to scarcity of sand There are two further sediments which are included by Irish Quaternary geologists in subsoil type lists, but which to date have not been marked on maps: colluvium and residuum. Both are potential sources of aggregate and will be included in the AP estimation process should they occur. The former is also known as head; it results from downslope collapse of existing Quaternary and soil cover and is of periglacial or post-glacial origin. The latter consists of in-situ broken, weathered bedrock produced due to exposure over time; it may be of Holocene, Pleistocene or even older Tertiary Period age. QUATERNARY MAP SOURCES Two main sources were drawn from in compiling the S&G dataset used by the project: • Subsoils mapping by Teagasc, the Agriculture and Food Development Authority of the Irish Republic • Quaternary mapping by GSI Subsoils mapping across the State was carried out by Teagasc between 1998 and 2005, initially to answer the urgent requirements of the Forestry Service, Department of the Marine and Natural Resources. Subsoils mapping was one element of a model developed by Teagasc as part of a dual project to provide an updated inventory of soils, and enable planning of forest resources. The project went under the hyphenated title of FIPS-IFS, the Forest Inventory and Planning System and the Irish Forest Soils project (Bulfin et al.). The endeavour came against the backdrop of an incomplete soil survey dating from the 1950’s (An Foras Talúntais), and the absence of a Quaternary Geology map for the country by the Geological Survey of Ireland from which to model topsoil. The term “Subsoils” is preferred to “Quaternary” by Teagasc because the work is seen as a basis for Soils mapping. The leader of the subsoils mapping element was R. Meehan. As this mapwork developed, it became clear that it could be of benefit not only to the Forestry Service, but also to the Groundwater Programme of GSI, the Irish Environmental Protection Agency (EPA), and others.. The mapping method consisted of approximately 70% desk and research work and 30% field checks. GSI acquired a copy of the finished map in early 2006 through the offices of the EPA, who had by then assumed sponsorship of the venture. To the knowledge of this project, the Teagasc Subsoils Map has never been published as such, even though several diverse agencies avail of its results in their work. The GSI’s Quaternary Programme has mapped a number of counties or parts of counties to a modern “reconnaissance” standard; these in truth constitute very thorough surveys. A larger number of counties or parts of counties are mapped to a less rigorous standard, consisting of compilations of older data from the 19th and 20th Centuries, combined with desk work such as stereophotographic interpretation, and a degree of field checking in some cases. Some counties have a mosaic of surveys by different geologists, carried out at different times and to a different mapping standard. Finally, four of the twenty-six counties have no mapping, or compilation of older data by GSI at all. The Subsoils Map of Teagasc has advantages over the Quaternary maps of GSI because of complete coverage, and consistency of mapping standard. The scientists who developed it used novel techniques including remote sensing and oblique light photointerpretation, and generated 3-D images from black and white stereophoto pairs to assist in the drawing of sediment boundaries. In addition, reports to hand were consulted. The work is also influenced by an appreciation of glacial history models and of a glacial event chronology; these lead to convincing map patterns suggestive of transport direction and regional deposit genesis in not a few counties. As to advantages of GSI’s mapping, the benefit of fieldwork, where carried out to the maximum level of detail is doubtless unequalled in Teagasc’s more cursory survey. However, as mentioned earlier, detailed Quaternary surveying by GSI covers only a reduced area of the country as a whole. A third source of Quaternary information was consulted in Co. Kildare. It is described in more detail in the account of APM for that county. This additional mapwork consists of the results of landform interpretation referred to in the Preamble. CHOICE OF PRIMARY QUATERNARY MAP SOURCE Due to the departure from original or published Quaternary maps resulting from the focus on depicting the maximum possible extent of granular sediments, and the use of more than one source in most cases, the project’s Quaternary Deposits maps bear the title “Sand and Gravel Deposits of Co. X”. In compiling the maps, a choice was made as to the primary source (Teagasc or GSI). Sands and gravels are taken from this source, and further deposits may be added from the secondary source(s). The remaining non-granular “background” geology will then be that of the primary source. This procedure obviously does not obtain for counties with no GSI coverage. Where choice is possible, selection criteria divide into four groupings: 1) Cartographic 2) Study level / study category 3) Precision and detail 4) Glacial history model CARTOGRAPHIC CONSIDERATIONS • Whether mapwork is available in GIS file format, or only as CAD coverages. The Teagasc Subsoils Map is available as a shapefile; many of GSI’s surveys date from the period 1992-2004, effectively before the general use of ArcGIS within GSI, and AutoCAD® was the software of the time. While many of these CAD projects have been converted to GIS format, some have not. It is understood that there are currently no plans within the Quaternary Section of GSI to make further conversions. It is necessary to have time to carry out edits and seal topology, but more importantly, it is the owners of the data i.e. the Quaternary geologists themselves who know which line and polygon CAD features to combine in order to make the deposit polygons of the GIS shapefile. Therefore, due to circumstances, a number of counties are denied the opportunity of having GSI data as a primary map source in this project. • Whether mapping of a county is cartographically seamless or not. Teagasc’s map is a unified whole, whereas in GSI’s case several counties have been mapped piecemeal, as referred to earlier. The result of this is the presence of hard linear edges in the GSI displays (reflecting map project boundaries), and of discontinuous polygons and abutting polygons with distinct petrologies and even deposit types. In nearly all these cases, Teagasc’s map has had to be chosen over that of GSI. • Not strictly of a cartographic nature, but important to include, is the fact of one or other map is already in use within the Industry. Such is the case in a portion of Co. Westmeath, and in Co. Louth, where a major company entered into cooperative partnership with GSI to have those areas mapped. In these instances, GSI’s work must be fully represented to avoid contradictions between APMs and the corresponding Quaternary or resource maps being used by stakeholders. STUDY LEVEL / STUDY CATEGORY CONSIDERATIONS • There was a reticence to use GSI’s work in cases where the survey had been carried out to “Draft” quality. This designation has been applied to one or two published maps carried out by students completing a doctorate, under the supervision of the Head of Quaternary; clearly the intention is to revisit the county at some future date • In counties where GSI’s mapping is uniform but of an inferior study category e.g. a desk compilation based on very old, chiefly spot, data, the inclination is to use Teagasc’s map instead • Where GSI map tiles within a given county are of a different study level or mapping standard, the alternative option of Teagasc’s map is chosen in most cases • There was a reticence to use as a primary source GSI Quaternary maps showing vast swathes of undifferentiated sand and gravel, when this project’s own evidence e.g. gravel pit history, sand and gravel output figures for the region, comments regarding scarcity of resource in planning applications, suggest otherwise. There is often a stark contrast with Teagasc’s mapping also • Some of GSI’s work, as alluded to previously, has entailed very detailed fieldwork of high quality, with a large investment of time. Moreover, this project is cogniscent of the academic mettle of the various authors of the work, and has chosen such surveys as primary sources in several counties • A difference arises due to the two methodologies employed by GSI and Teagasc in the case of built-up areas. GSI’s maps show original geology here, based on a combination of historic surveys and recent site inspections, whereas Teagasc’s largely remote methodology has mapped these for what they are now, at surface i.e. Made ground. In some counties, the combined area of Made ground is a significant proportion of the whole; this is a factor which has inclined the project towards the use of the GSI map as primary source. In some cases at least, Made ground can be thought of more as areas of unavailable resource than fixed geological units. For example parcels may not extend to a great depth, or may form areas used lightly for urban use e.g. parkland or outlying industrial estate yards; in these cases the Made ground may at some future date be deemed suitable for recovery, and underlying gravels could be utilised. CONSIDERATIONS OF PRECISION AND DETAIL • Teagasc’s linework is in many cases more detailed, reflecting the resolution of as much as 1m achieved in its stereophotogrammetric analysis. Conversely, some GSI sediment boundaries, where based on restricted fieldwork or indeed a low degree of exposure, are straight or otherwise generalised • The total number of Quaternary or subsoil polygons in a county is a factor in decision, as is the number of sand and gravel polygons, and indeed the percentage of total area which sand and gravel represents. A judgement is made in each case with the objective of having the greatest area of resource possible for APM assessment, while at the same time achieving a high degree of mapping detail • In a similar way, the number of subsoil categories and the number of sand and gravel types is considered. These indicate the level of geological discrimination attained in the mapping • The Teagasc Subsoils Map is consistent in having a full complement of alluvial deposits. In some counties, GSI’s maps overlook many of these thin, meandering, linear bodies; perhaps they were not of interest, or took up too much time in cases where the survey was being carried out by Ph.D. students focussing primarily on till. These Ph.D. projects have tended to comprise studies of till fabric, deformation, porosity and sedimentology in general, the aim of which is to elucidate the history and patterns of glaciation and deglaciation. An all-encompassing mapping of the Quaternary geology in these cases is not the primary objective. CONSIDERATIONS regarding A GLACIAL HISTORY MODEL • Choices in this regard have considered whether the Quaternary geology reflects process, or a sequence of glacial events, whether there seems to be a consistent interpretation of geomorphology, whether mapping is patterned, etc. These tend to be features of Teagasc’s map, whereas the results of the GSI survey in a few cases look rather amorphous and undirected by comparison. The county in which this difference has appeared most marked to date is Co. Longford. • Sometimes, in contrast, topography is so muted that the limitations of Teagasc’s remote method become relevant. It has been suggested to the project that Co. Kildare is such a case • The project has been made aware of procedures of Teagasc geologists in counties such as Offaly, in which existing GSI coverages and drawings in CAD format were heavily drawn upon. The resulting Teagasc mapping reflects that of GSI quite closely, and gives assurance in the use of Teagasc’s data • One of the interesting findings of Teagasc’s survey has been the identification of erratic or “carryover” till. This is where surface petrology does not reflect the underlying bedrock. In many cases it was found that there is a lodgement till underlying the top till, and this does indeed have detritus of the immediate bedrock. In the course of scanning the historic GSI 6” geological maps of each county in search of gravel pits and quarries, it has been possible to note how correct this finding is in some areas. In north and southernmost Co. Monaghan, for instance, the dichotomy between surface till petrology, and underlying bedrock geology, is clear. The norm in GSI map compilations from older sources with sparse information is the assignation of petrology based on the local bedrock. ADDITION OF SECONDARY SOURCE MATERIAL After one of the sources has been chosen as the basis for the AP map, and non-granular sediments have been eliminated, an exercise of appending sands and gravels from the other map(s) is carried out. The full procedure is as follows: 1. The deposits of interest in the primary source are selected and exported as a stand-alone shapefile 2. Granular sediments are similarly selected in the second source map, and the two are added by means of a Union operation in ArcGIS 3. Those bodies, many truncated, of the second set which coincide with the extent of the first, are deleted 4. A scrutiny of the remaining polygons i.e. truncated or whole units of the second source lying outside the extent of the first source, is carried out. Depending on the quality of mapping of the second source, either all the new polygons are retained en masse, or individual polygons are deleted and others retained. Polygons are examined with a view to corroborating their Quaternary composition based on all evidence to hand: presence of gravel pits active and disused; Quaternary logs; sediment-at-outcrop records and symbols on GSI’s Quaternary maps and in CAD coverages; and annotations of various sorts, including morphological observations 5. Added polygons may have the sediment denomination of their authors retained, if evidence warrants, or a compromise between it and the primary source sediment at that location may be made. Thus “Till with Gravel” is found quite frequently in cases where the added polygon proclaims gravel, there are sparse confirmatory data, and the primary map has assigned till 6. In cases where a decision has been taken at the outset to add secondary source units en masse (for example in East Co. Westmeath), many unresolvable contradictions can occur. The secondary map may assign “Alluvium”, for instance, and the primary “Peat”. In a case such as this, if there are no confirmatory data in the polygon, “Alluvium” is the type retained. In some parts of the midlands of Ireland, where there are large tracts of cutaway bog, the secondary source may in fact be reporting the underlying sediment which can be noted in ditches beneath the remnant peat 7. In all events, fields entitled Source and Reasoning are added in the attribute table of the new shapefile of coalesced S&G bodies. Here the secondary (or further) source map titles are entered, and some text is supplied explaining the reason for the final denomination chosen for the polygon. As a footnote, it is worth emphasising that the addition of areas of granular sediment outside those of the primary map is not meant as a revision of GSI or Teagasc’s work. GRANULAR AGGREGATE POTENTIAL PROCESS MAPS (PHASE 1) Four panels are presented on an AO-sized sheet, showing colour-coded scoring of sand and gravel deposits for: 1) Genesis-Petrology 2) Density of gravel pits 3) Area 4) The weighted sum of the above three SCORING OF GRANULAR AGGREGATE FOR GENESIS and PETROLOGY BACKGROUND It was intended at the conception of the project to apply values to granular aggregate bodies on the basis of their grading curve and also if possible on the basis of their morpho-genetic type. The latter would take deposit morphology and genesis into account in a way exemplified in several of the Canadian APM programmes (see for example Proudfoot, 1993): a hierarchy of value is established from glaciofluvial braided stream through glaciofluvial outwash plain, glacial delta, alluvial fan, talus, to rogen, hummocky and other moraine types. Many other morphologies are mapped which are not in that list. Through a combination of the sedimentological and textural characteristics of the different types, and their history of extraction, a valuable reference scale is set up for the estimation of aggregate potential. Quaternary mapping, whether by GSI or Teagasc, does not unfortunately allow for this level of discrimination; there is a broad genetic categorization of granular sediments into glaciofluvial, (glacio)lacustrine, alluvial, marine, aeolian and miscellaneous (e.g. scree). There are no morphological distinctions, with the exception of Esker, and of lesser relevance those of Raised beach and Dune. While Teagasc’s mapping did not plan to record morphology - a perfectly understandable premise given the extent of the survey and the urgency with which the basic subsoil cartography was required - GSI in its maps does attempt to do so. Erosive features such as striae and glacial channels tend to dominate numerically over depositional ones such as hummocks or ice-marginal ridges. In any event, morphologies are recorded unevenly, and certainly are not applied to the majority of S&G bodies on any map. This indicates, presumably, the difficulty in recognising morpho-genetic characteristics in Irish Quaternary sediments. For one thing Ice Age activity is considerably older than in parts of Canada, and landforms have been eroded, denuded and covered with bog and soil; glacial sediment topography is no longer stark. Having said that, inferences as to genesis are made in the neighbouring jurisdiction, where the Geological Survey of Northern Ireland (GSNI) have provided S&G Resource Maps with quite a different classification to GSI’s (e.g. Cooper, 2004). GENETIC-PETROLOGICAL SCORING SYSTEM Given the limitations described above, the project had to decide how to rank composition – the keystone of aggregate potential estimation - in granular sediments. It was decided to induce a ranking of the genetic types available (glaciofluvial, alluvial, lacustrine, marine, aeolian) from the level of extraction in each county, and combine that with the distinctions of petrology given in GSI and Teagasc’s classification. (As staff members have overlapped between the two organisations, a unitary coding has evolved). This classification is applied to tills and glaciofluvial sands and gravels, and derives from stone counts: thus, there are Greywacke Sands and Gravels (Lower Palaeozoic), Sandstone Sands and Gravels (Devonian), Granite Sands and Gravels, Limestone Sands and Gravels (Carboniferous), and a host of others. While these categories are of great use to the Quaternary geologist, S&G petrology is not usually of critical importance to the aggregates producer. The application of scores based on levels of extraction is carried out in each county after the pit and quarry dataset has been compiled. Then, the number of pits in each separate polygon is recorded, polygons of like sediment type are grouped, and the sum of pits is divided by the combined area of the type. This gives a pit density figure for each Quaternary sediment in that county, and is a rough reflection of its level of utilization. To this Utilization Value indicator is added the Intrinsic Value or Rock Type rank from the Rock Type Suitability scoring scale and the Rock Type Suitability scale with Derived scores. The proportion in which the two factors are brought together is 2:1, Utilization Value: Intrinsic Value. Aggregate deposits in which petrology is not stated retain only the Utilization Value as their total score. This is the case with alluvium, (glacio)lacustrine, marine/beach, and aeolian sediments, whether sandy, gravelly or undifferentiated. SCORING OF GRANULAR AGGREGATE BASED ON DENSITY OF PITS The purpose of this layer of evidence is to evaluate the productivity of individual polygons as opposed to sediment types. It had been planned to use pit density only once for scoring purposes; future inclusion of grading curve data should diminish the influence of this metric in the Genesis-Petrology evidence layer (previous Section), where it has been used in a more generalised way out of necessity. Gravel pits are counted in each sand and gravel unit. As many sources of data as possible are used with a view to establishing categories of pits, varying in age and size. The data sources drawn from are shown in the table below. The categories of pit arising out of these sources are displayed in the Table below, each category being assigned a weight reflecting its importance: Classification and scoring of gravel pits Category Name Content Weight S261 large Applications with Local Authorities since 2004, of area >4.5 ha* 12 S261 small Applications with Local Authorities since 2004, of area <4.5 ha* 10 Quat Map Active Pits noted as active during GSI Quaternary mapping 1992-present 10 Three QDs Pits recorded in GSI Quarry Directories, 1988/1994/2001 10 Rec MinLocs Recent pits, dating from the 1970’s-1995 in GSI MinLocs database 10 Ind Mins DB Pits recorded in GSI Industrial Minerals database; activity dates variable 5/(10) Newer MinLocs Pits dating from the 1930’s-1970 in GSI MinLocs database 5 Quat Map Disused Pits noted as disused on GSI Quaternary maps 1992-present; activity dates variable 5/(3) Quat Map Ann/Comments/Ind Annotations/comments indicating pits on GSI Quaternary maps 1992-present; activity dates variable 5/(3) Bedrock Map Disused Pits noted as disused during GSI Bedrock mapping projects 3 Drift Series Pits recorded during “Drift Series” Quaternary mapping 1900-1930’s 3 Brickfields Recorded in GSI MinLocs database; 19thC-1930’s 3 Old MinLocs 19th-early 20thC pits in GSI MinLocs database 3 Six Inch Pits noted during OSI/GSI 6”: 1 mile mapping 1 * The division of Section 261 pit size at 4.5ha was made so as to assign approximately half of the pits digitised so far to the larger, and the other half to the smaller category. “Applications” includes both submissions for registration as pits during the year April 2004-April 2005, as required by law, and also planning applications in respect of new or existing pits since 2004. Note: minor adjustments in weight to the table above will be found in individual counties to accommodate local age/size situations and at the same time keep scoring charts reasonably compact. Pits are assigned to one or other category in the scoring table. The computation of the total pit score of a polygon is done by weighted sum across all categories, followed by division of that figure by the area of the polygon. Density figures thus produced are split into ten ranges and colour-coded to produce the display shown in the second panel of the Granular AP Process Map sheet. SCORING OF GRANULAR AGGREGATE FOR AREA Sand and gravel bodies need to be of a reasonable size to allow for the development of a modern extractive operation. Deposits that are of small area may benefit from a good thickness of sediment, and be amenable to deep excavation; in general, however, due to the unconsolidated nature of the raw material, lateral expansion is the most notable spatial feature of gravel pits. Area is used in this project as a layer of evidence for aggregate potential estimation, without modification for depth extension of the sediment, nor indeed for high length:breadth ratios which produce constraining elongate shapes. These would both be useful to include, but have not been modelled due to limitations of time. Scoring is designed to reflect potential yield of a deposit: how many gravel pits and of what size could an individual deposit provide space for? Estimation and classification is based on the size of Irish sand and gravel pits; the largest recorded during digitising of recent and operating pits (2010) measures 59 ha in its entirety, including space required for ancillary works, decanting lagoons, berms etc. This operation is Cemex Ltd.’s pit at Blackhall and Walshestown, Naas, Co. Kildare. Thus “large” pits for the purposes of this project would be of the order of 50-70 ha. Deriving from this, the classes shown in the table below are used to score area. Scoring of Sand and Gravel bodies for Area Size Range Deposit potential/characteristics Score >750 ha Long-term extraction foreseen 10 500-750 ha Potential for 10 large pits 9 300-500 ha 5 to 10 large pits 8 150-300 ha 2 to 5 large pits 7 75-150 ha Not more than 2 large pits 6 50-75 ha Potential for 1 large pit 5 25-50 ha 1 pit of moderate size 4 5-25 ha 1 small pit 3 1-5 ha A small borrow pit, or one below Section 261 threshold for EIA* 2 ≤1 ha Very small resource 1 * EIA: Environmental Impact Assessment WEIGHTED SUM SCORE, PHASE 1 The fourth panel in the Granular AP Process Map sheet shows the effect of combining the previous three parameters, in the following weighted sum sub-total: [Genetic-Petrology score x 2] + [Pit Density score x 1.2] + [Area score x 2] This corresponds to the first part of the Granular AP scoring algorithm; its result is termed the Phase 1 Score in attribute tables thereafter. Phase 1 scores are divided into ten classes based roughly on an equal area distribution, with rounding off of decimals, and classes are then colour coded as shown on the panel. The spread of values, and hence the class breaks, varies from county to county due to the quality, number and size of S&G deposits. QUATERNARY THICKNESS MAP NATURE AND ORIGIN OF THE MAP The thickness of a sand and gravel body is of vital importance to its viability as a participant in the extractive operations of a county. Figures vary from country to country as to what constitutes a minimum viable thickness. On the upper end of the deposit thickness scale, distinctions may be made between thick – say 10m – and very thick – of the order of 20m or more. Clearly, a detailed hierarchy of thickness intervals could be erected for the purpose of scoring potential. The ready-made dataset which is available in Ireland for the modelling of deposit thickness, however, has a less complicated classification scheme. This is the set of county Depth to Bedrock maps compiled by GSI since the early 1990’s, with work ongoing. The depth ranges depicted on these maps are: < 1m, 1 – 3m, 3 – 5m, 5 – 10m, and > 10m. The DTB maps have the benefit of being amenable to uniform application across the APM area, and their use suits the time limitations of the project. The consultation of copious borehole logs, trench sections etc. has already been done, and the interpolation of contours carried out to the highest possible standard. APM analysis by this project applies scores out of 10 to the depth classes, seeing them as sediment thickness intervals, as displayed in the Table below. Scoring of Sand and Gravel for Thickness Deposit thickness Score Lake 0 <1m 1 1 – 3m 3 3 – 5m 5 5 – 10m 8 >10m 10 A score of 0 is applied to areas designated “Lake” on DTB maps. DTB is not known, but the presence of a waterbody in any case would normally preclude the extraction of gravel in the Irish context. DTB maps were compiled in one or two cases simply as part of Quaternary mapping. However, the real impetus in GSI for DTB mapping came from the preparation of Groundwater Protection Schemes (GWPS), carried out by the Groundwater Section of GSI under the sponsorship of local authorities from across the State. More recently, by EU mandate, local authorities are obliged to implement the Water Framework Directive (Directive 2000/60/EC), to which end GSI has contracted Tobin Consulting Engineers to accelerate the rate of completions of county surveys within the National Groundwater Programme. This programme maps groundwater vulnerability arising out of a classification of aquifers and a range of other procedures. A key element of that work is the compilation of DTB maps; essentially a thickness of Quaternary sediment, and especially of the more impermeable types such as till, is perceived as a protection against infiltration of pollutants into bedrock aquifers. The APM programme avails of these important DTB models for its own ends. There has been an issue in the currency of the project’s Quaternary Thickness Map in a number of counties, arising out of the timing of final checks and revisions to the DTB originals by GSI Groundwater staff. These checks have taken place after APMs were finished, so that what is now a penultimate version of DTB has been unfortunately used in the geoprocessing and scoring routines. These counties are CW, D, SO and WH. MODIFICATIONS TO PROCEDURE One county of those so far studied, Co. Laois, has not been included in DTB mapping by the GSI Groundwater Programme. A DTB map was compiled, nevertheless, as part of GSI’s Quaternary mapping of the county in 2004 (author A. Kilfeather). A drawback of this product is that the 5m contour was not interpolated. As a result of this it was decided to model DTB anew. Using a range of evidential data, ArcGIS Spatial Analyst was used to generate the full set of contour intervals, from which the Quaternary thickness display is then produced. In appearance, the computer-generated map is less pinnacled than that of Ms. Kilfeather. This results from an inevitable smoothing carried out by the interpolation method selected. The differential influence of broad areas without borehole data, and areas with a concentration of data also has its effect. Much of the data is concentrated in areas of shallow DTB and indeed on outcrop; the irregular distribution of information points is made more severe in the case of geotechnical boreholes and trial pits by being in linear arrays along major roads. During processing, there was an attempt to bring about a display as near as possible in appearance to the 2004 GSI map; several interpolation methods were tried and many trials of each carried out. In the end, the method used was Inverse Distance Weighting (IDW) to the third power, with the following parameter specifics: a variable search radius; twenty search points without a maximum search distance; and an output cell size of 100m. In addition to the new DTB display, all data points are shown on a second AO-sized sheet “Depth to Bedrock Map (detail) of County Laois”. The method is explained more fully in the side panel of that sheet also. FINAL GRANULAR AGGREGATE POTENTIAL MAP (PRELIMINARY) To the Phase 1 results table are added scores for Quaternary Thickness, Elevation, and Markets. Final scores are classified in turn into ten ranges on an equal area basis (Note: this is different to Quantile classification which groups according to equal number of polygons). Ranges are enumerated 1-10 in a separate field called Rank, and Ranks are grouped in twos to produce five Potentials, from Very High to Very Low. The final AP map shows areas colour-coded in accordance with these potential classes; boundaries of adjacent polygons of like potential have been dissolved. The AP process quite often creates a set of score values with a normal distribution. The highest frequency commonly occurs in the mid and upper 40’s. At times, there has been excessive clumping so that a strictly equal-area ten-fold classification would produce ranks of very reduced breadth e.g. …30-38, 38-42, 42-46, 46-47.5, 47.5-48.5, 48.5-51, 51-56 …. A decision was taken to fix a minimum interval of 3 in any rank, in order for it to preserve significance as an aggregate potential category compared to adjoining ranks. This flattens extremely peaked final score distributions somewhat, while departing – usually not noticeably – from the ideal of equal areas. As a consequence, any of the five Potential classes has a minimum score interval of 6 points; this represents 7% of the possible total range of scores in Granular AP processing (4.5 – 89). REFERENCES Bulfin, M., Farrelly, N., Fealy, R., Green, S., Loftus, M., Meehan, R., & Radford, T. The Irish Forest Soils Project (FIPS-IFS). The Irish Scientist Yearbook 2002, 46-47. Claringbold, K., Flegg, A., Magee, R., & Vonhof, J. (1994) Directory of Active Quarries, Pits, and Mines in Ireland. Geological Survey of Ireland Report Series RS 94/4 (Mineral Resources), 111 pp. Cooper, M.R., (2004) Strabane and Omagh (Local Government Districts): Mineral Resource Information in support of Development Plan - Sand and Gravel Resources. Report accompanying 1:50,000 scale maps Strabane/Omagh. Geological Survey of Northern Ireland, for the Planning Service, Department of the Environment for Northern Ireland. 10 pp., 2 maps. Doyle, E., Hinch, C., & Cox, W. (2001) Directory of Active Quarries, Pits and Mines in Ireland. Geological Survey of Ireland Report Series RS 01/1 (Minerals Programme), 469 pp. Gallagher, V. (2004) Wicklow Minerals Potential Mapping Project 2002-2004. Minerals Programme, Geological Survey of Ireland, 103 pp., 11 maps. Howes, M.J., Boland, M.A., Flegg, A.M., & McKenna, K. (1988) Quarry Directory – Active quarries and pits in Ireland. Geological Survey of Ireland Report Series RS 88/3 (Mineral Resources), 87 pp. Lally, P. (2004) Aggregate Potential Mapping of County Meath. Minerals Programme, Geological Survey of Ireland, 69 pp., 6 maps. Maher, P., McKeever, P., Cooke, R., Tynan, S., & Crean, E. (1996) The Mineral Development Potential of Counties Cavan and Fermanagh. A joint Geological Survey of Ireland (GSI)/Geological Survey of Northern Ireland (GSNI) cross-border coooperation project. Geological Survey of Ireland, 8 chaps, 4 maps. McCarron, S. (2002) Aggregate Potential Mapping of County Donegal. Minerals Programme, Geological Survey of Ireland, 48 pp., 5 maps. Philcox, M.E. (2008) An Assessment of the Gravel Potential in North Co. Kildare (Draft). Minerals Programme, Geological Survey of Ireland, 6 pp., 2 maps. Proudfoot, D.N. (1993) Drift Exploration and Surficial Geology of the Clusko River and Toil Mountain Map Sheets (93C/9, 16), (Contribution to the Interior Plateau Program, Canada – British Columbia Mineral Development Agreement 1991-1995). British Columbia Geological Survey Branch, Geological Fieldwork 1992, Paper 1993-1. In 2023 the data was imported into GSI’s ESRI enterprise database using ArcGIS Pro. Using ArcGIS Pro 3, the dataset was renamed as part of a GSI data standardisation process. Metadata was updated to the new GSI standard based on INSPIRE and ISO standards and validated using the INSPIRE validator.

Data quality report - Domain consistency:
Conformance test results:
Test passed: false
Meaning of the result: The INSPIRE Directive or INSPIRE lays down a general framework for a Spatial Data Infrastructure (SDI) for the purposes of European Community environmental policies and policies or activities which may have an impact on the environment.

Description of conformance requirements:
Title:  COMMISSION REGULATION (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services
Alternate titles:  D2.8.III.21 INSPIRE Data Specification on Mineral Resources –Technical Guidelines version 3.0

Reference date - publication:  2010-12-08

Data quality report - Domain consistency:
Conformance test results:
Test passed: false
Meaning of the result: See the reference specification

Description of conformance requirements:
Title:  COMMISSION REGULATION (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services
Alternate titles:  Regulation 1089/2010 COMMISSION REGULATION (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services

Reference date - publication:  2010-12-08

Data quality report - Domain consistency:
Conformance test results:
Test passed: true
Meaning of the result: See the reference specification

Description of conformance requirements:
Title:  COMMISSION REGULATION (EC) No 1205/2008 of 3 December 2008 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards metadata
Alternate titles:  COMMISSION REGULATION (EC) No 1205/2008 of 3 December 2008 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards metadata

Reference date - publication:  2008-12-04

Distribution Information:

Distributor:
Distributor information - publisher: 
Individual's name: Information Management
Organization's name: Geological Survey Ireland
Contact's position: Head of Information Management

Contact information:
Phone:
Voice: +353-1-6782896
Address:
Delivery point: Block 1, Booterstown Hall, Booterstown Avenue, Booterstown, Blackrock
City: Dublin
Postal code: A94 N2R6
Country:  IE
e-mail address: support@geodata.gov.ie
Online resource:
Name of resource: GSI Website
Online location:https://www.gsi.ie
Connection protocol: text/html
Function performed:  information
Description: GSI Website
Format:
Format name: Enterprise Geodatabase Feature Class
Format version: 10.7

Transfer options:

Metadata Information:

Metadata language:  eng
Metadata character set:  utf8


Last update:  2023-10-09
Maintenance:
Update frequency:  asNeeded



Metadata constraints:
Constraints:
Limitations of use: 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.https://creativecommons.org/licenses/by/4.0/https://creativecommons.org/licenses/by/4.0/legalcodeUnder the CC-BY Licence, users must acknowledge the source of the Information in their product or application.Please use this specific attribution statement: "Contains Irish Public Sector Data (Geological Survey Ireland) licensed under a Creative Commons Attribution 4.0 International (CC BY 4.0) licence".In cases where it is not practical to use the statement users may include a URI or hyperlink to a resource that contains the required attribution statement.

Metadata constraints:
Security constraints:
Classification:  unclassified

Metadata contact - pointOfContact: 
Individual's name: Information Management
Organization's name: Geological Survey Ireland
Contact's position: Head of Information Management

Contact information:
Phone:
Voice: +353-1-6782896
Address:
Delivery point: Block 1, Booterstown Hall, Booterstown Avenue, Booterstown, Blackrock
City: Dublin
Postal code: A94 N2R6
Country:  IE
e-mail address: support@geodata.gov.ie
Online resource:
Name of resource: GSI Website
Online location:https://www.gsi.ie
Connection protocol: text/html
Function performed:  information
Description: GSI Website
Scope of the data described by the metadata:  dataset
Scope name: dataset

Name of the metadata standard used: INSPIRE Metadata Implementing Rules: Technical Guidelines based on EN ISO 19115 and EN ISO 19119
Version of the metadata standard: V. 1.2

Metadata identifier: MD_MR_MineralOccurrence_IE_GeologicalSurveyIreland_AggregatePotentialMappingSandGravelScores_50k_Ireland_ITM