The map displays bedrock formations at or near the surface of the land, on the sea floor above the continental crust that forms the Canadian landmass, and oceanic crust surrounding the landmass. The bedrock units are grouped and coloured according to geological age and composition. The colours of offshore units and oceanic crust are paler and more generalized than those on land, although the constituent units offshore are still easily discernible from their dashed boundaries. This colour design, coupled with the use of a white buffer zone at the coast allows the coastline of Canada to be readily distinguished and still show the grand geological architecture of the Canadian landmass. The map also shows major faults that have disrupted the Earth's crust, onshore and offshore, and a variety of special geological features such as kimberlite pipes, which locally contain diamonds, impact structures suspected to have been caused by meteorites, and extinct and active spreading centres in the surrounding oceans.

This entry provides access to surficial geology maps that have been published by the Geological survey of Canada. Two series of maps are available: "A Series" maps, published from 1909 to 2010 and "Canadian Geoscience Maps", published since 2010. Three types of CGM-series maps are available: 1)Surficial Geology: based on expert-knowledge full air photo interpretation (may include interpretive satellite imagery, Digital Elevation Models (DEM)), incorporating field data and ground truthing resulting from extensive, systematic fieldwork across the entire map area. Air photo interpretation includes map unit/deposit genesis, texture, thickness, structure, morphology, depositional or erosional environment, ice flow or meltwater direction, age/cross-cutting relationships, landscape evolution and associated geological features, complemented by additional overlay modifiers, points and linear features, selected from over 275 different geological elements in the Surficial Data Model. Wherever possible, legacy data is also added to the map. 2)Reconnaissance Surficial Geology: based on expert-knowledge full air photo interpretation (may include interpretive satellite imagery, DEMs), with limited or no fieldwork. Air photo interpretation includes map unit/deposit genesis, texture, thickness, structure, morphology, depositional or erosional environment, ice flow or meltwater direction, age/cross-cutting relationships, landscape evolution and associated geological features, complemented by additional overlay modifiers, points and linear features, selected from over 275 different geological elements in the Surficial Data Model. Wherever possible, legacy data is also added to the map. 3)Predictive Surficial Geology: derived from one or more methods of remote predictive mapping (RPM) using different satellite imagery, spectral characteristics of vegetation and surface moisture, machine processing, algorithms etc., DEMs, where raster data are converted to vector, with some expert-knowledge air photo interpretation (training areas or post-verification areas), varying degrees of non-systematic fieldwork, and the addition of any legacy data available. Each map is based on a version of the Geological Survey of Canada's Surficial Data Model (https://doi.org/10.4095/315021), thus providing an easily accessible national surficial geological framework and context in a standardized format to all users. "A series" maps were introduced in 1909 and replaced by CGM maps in 2010. The symbols and vocabulary used on those maps was not as standardized as they are in the CGM maps. Some "A series" maps were converted into, or redone, as CGM maps, Both versions are available whenever that is the case. In addition to CGM and "A series" maps, some surficial geology maps are published in the Open File series. Those maps are not displayed in this entry, but can be found and accessed using the NRCan publications website, GEOSCAN:(https://geoscan.nrcan.gc.ca).

The map identifies surficial materials and associated landforms left by the retreat of the last glaciers and non glacial environments. The surficial geology is based on compilation of existing maps. This work provides new geological knowledge and improves our understanding ofthe distribution, nature and glacial history of surficial materials. It contributes to resource assessments and effective land use management. This new surficial geology map product represents the conversion of the map "Surficial Materials of Canada" (Fulton, 1995) and its legend, using the Geological Survey of Canada's Surficial Data Model (SDM version 2.0) which can be found in Open File 7631 (Deblonde et al.,2014). All geoscience knowledge and information from map 1880A that conformed to the current SDM were maintained during the conversion process. However, only terrestrial units are depicted on this map. Map units below modern sea level or major lake levels are not shown but are maintained in the digital data of this publication. Where additional information was required in certain regions of the Arctic and Cordillera, legacy geology map data were used. These maps are listed in the digital "Map Information" document. All other source maps used in map 1880A are not relisted here. The purpose of converting legacy map data to a common science language and common legend is to enable and facilitate the efficient digital compilation, interpretation, management and dissemination of geologic map information in a structured and consistent manner. This provides an effective knowledge management tool designed around a geo-database which can expand following the type of information to appear on new surficial geology maps.

Preliminary Interpretive Report 2019-3, Bedrock-geologic map, Alaska Highway corridor, Tetlin Junction, Alaska to Canada border, shows the distribution of bedrock units exposed at or near the surface in the corridor along the Alaska Highway in parts of the Tanacross A-1, A-2, A-3, and B-3 and Nabesna C-1, D-1, and D-2 quadrangles. It is the easternmost of three bedrock-geologic maps along the Alaska Highway corridor. It is part of a multi-year project conducted by the Alaska Division of Geological & Geophysical Surveys (DGGS) between 2006 and 2013. The project focused on investigating and reporting the geology and geologic hazards of the corridor. Bedrock units were mapped and structural elements were measured in the field; where bedrock units are covered by surficial units and vegetation, units were interpreted using airborne-magnetic and electromagnetic surveys published by DGGS in 2006. Rock names were assigned based on field and petrographic observations, modal-mineral percentages, and interpretations of geochemical data. The complete report, geodatabase, and ESRI fonts and style files are available from the DGGS website: http://doi.org/10.14509/30038.

This CD-ROM has been created as a companion to the 1996 printed Geological Map of Canada (Map 1860A). The CD-ROM is not just a digital version of Map 1860A: it contains a complete bilingual GIS spatial database from which a variety of thematic geological maps can be created. Map 1860A is just one of those themes. Included on the CD-ROM are all of the Arc/Info files used in the production of the printed map, including a bilingual database. In addition, the data is provided in several common interchange formats (*.E00, *.SHP). This CD-ROM also includes a limited edition of SurView, a viewing application for Microsoft Windows, developed at the Geological Survey of Canada and originally released as GSC Open File 2661. Surview can display, print, and query the *.SHP files. This provides an opportunity for those without specialized GIS software to delve into the realm of digital geoscience data and explore the new Geological Map of Canada on their own PC

Available at the Map and Data Library. CD #001.

These data present geologic map units for the United States (Horton and others, 2017; Wilson and others, 2015) and Australia (Raymond and others, 2012) reclassified to 31 generalized sub-type lithologic groups of igneous, metamorphic, and sedimentary rocks (Lawley and others, 2022). These generalized classifications are based on interpretation of map unit descriptions in the different map compilations. Given that map unit descriptions often contain multiple rock types, there were subjective calls necessary when assigning generalized lithologic classification. The data were developed as part of the tri-national Critical Minerals Mapping Initiative (Kelley, 2020) between the United States, Canada, and Australia, an effort to model and map prospectivity for basin-hosted Pb-Zn mineralization. A national-scale geologic map compilation for Canada is not publicly available. Therefore, Lawley and others (2021) compiled geologic source maps to produce a gridded model layer that is provided in this data release in the Child Items section “Gridded geology shapefiles for the United States, Canada, and Australia.” References Horton, J.D., San Juan, C.A., and Stoeser, D.B., 2017, The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States (ver. 1.1, August 2017): U.S. Geological Survey Data Series 1052, 46 p., https://doi.org/10.3133/ds1052. Kelley, K.D., 2020, International geoscience collaboration to support critical mineral discovery: U.S. Geological Survey Fact Sheet 2020-3035, 2 p., https://doi.org/10.3133/fs20203035. Lawley, C.J.M., McCafferty, A.E., Graham, G.E., Gadd, M.G., Huston, D.L., Kelley, K.D., Paradis, S., Peter, J.M., and Czarnota, K., 2021, Datasets to support prospectivity modelling for sediment-hosted Zn-Pb mineral systems: Natural Resources Canada Open File 8836, https://doi.org/10.4095/329203. Lawley, C.J.M., McCafferty, A.E., Graham, G.E., Huston, D.L., Kelley, K.D., Czarnota, K., Paradis, S., Peter, J.M., Hayward, N., Barlow, M., Emsbo, P., Coyan, J., San Juan, C.A., and Gadd, M.G., 2022, Data-driven prospectivity modelling of sediment-hosted Zn-Pb mineral systems and their critical raw materials: Ore Geology Reviews, v. 141, no. 104635, https://doi.org/10.1016/j.oregeorev.2021.104635. Raymond, O.L., Liu, S., Gallagher, R., Zhang, W., and Highet, L.M., 2012, Surface Geology of Australia 1:1 million scale dataset 2012 edition: Geoscience Australia, http://pid.geoscience.gov.au/dataset/ga/74619. Wilson, F.H., Hults, C.P., Mull, C.G., and Karl, S.M., comps., 2015, Geologic map of Alaska: U.S. Geological Survey Scientific Investigations Map 3340, 2 sheets, scale 1:1,584,000, 196-p. pamphlet, https://doi.org/10.3133/sim3340.

The map displays bedrock formations at or near the surface of the land, on the sea floor above the continental crust that forms the Canadian landmass, and oceanic crust surrounding the landmass. The bedrock units are grouped and coloured according to geological age and composition. The colours of offshore units and oceanic crust are paler and more generalized than those on land, although the constituent units offshore are still easily discernible from their dashed boundaries. This colour design, coupled with the use of a white buffer zone at the coast allows the coastline of Canada to be readily distinguished and still show the grand geological architecture of the Canadian landmass. The map also shows major faults that have disrupted the Earth's crust, onshore and offshore, and a variety of special geological features such as kimberlite pipes, which locally contain diamonds, impact structures suspected to have been caused by meteorites, and extinct and active spreading centres in the surrounding oceans.

The Canada Geological Map Compilation (CGMC) is a database of previously published bedrock geological maps sourced from provincial, territorial, and other geological survey organizations. The geoscientific information included within these source geological maps wasstandardized, translated to English, and combined to provide complete coverage of Canada and support a range of down-stream machine learning applications. Detailed lithological, mineralogical, metamorphic, lithostratigraphic, and lithodemic information was not previously available as onenational-scale product. The source map data was also enhanced by correcting geometry errors and through the application of a new hierarchical generalized lithology classification scheme to subdivide the original rocks types into 35 classes. Each generalized lithology is associated with asemi-quantitative measure of classification uncertainty. Lithostratigraphic and lithodemic names included within the source maps were matched with the Lexicon of Canadian Geological Names (Weblex) wherever possible and natural language processing was used to transform all of the available text-basedinformation into word tokens. Overlapping map polygons and boundary artifacts across political boundaries were not addressed as part of this study. As a result, the CGMC is a patchwork of overlapping bedrock geological maps with varying scale (1:30,000-1:5,000,000), publication year (1996-2023), andreliability. Preferred geological and geochronological maps of Canada are presented as geospatial rasters based on the best available geoscientific information extracted from these overlapping polygons for each map pixel. New higher resolution geological maps will be added over time to fill datagaps and to update geoscientific information for future applications of the CGMC.

During 2009, the Alaska Division of Geological & Geophysical Surveys continued a program, begun in 2006, of reconnaissance mapping of surficial geology in the proposed natural-gas pipeline corridor through the upper Tanana River valley. The study area is a 12-mi-wide (19.3-km-wide) area that straddles the Alaska Highway from the western boundaries of the Tanacross B-3 and A-3 quadrangles near Tetlin Junction eastward to the eastern boundaries of the Nabesna D-1 and C-1 quadrangles along the Canada border. Mapping during 2008-2009 in the Tanacross and Nabesna quadrangles linked with the mapping completed in the Tanacross, Big Delta and Mt. Hayes quadrangles in 2006-2008. Surficial geology was initially mapped in this third corridor segment by interpreting ~1:65,000-scale, false-color, infrared aerial photographs taken in July 1978 and August 1981 and plotting unit boundaries on acetate overlays. Verification of photo mapping was accomplished during the 2008 and 2009 summer field seasons, when map units were described, soil pits were hand dug, and samples were collected for analyses. The engineering-geologic map is derived electronically from the surficial-geologic map and shows the distribution of surficial-geologic and bedrock units grouped genetically with common properties that are typically significant for engineering applications.

Polygon features (Glaciofluvial, Outwash, Lacustrine, Littoral, Glacial, Veneer, etc.) from the new surficial geology map product (Geological Survey of Canada, Canadian Geoscience Map 195, 2014, 1 sheet, https://doi.org/10.4095/295462) that represents the conversion of the map "Surficial Materials of Canada" (Fulton, 1995) and its legend, using the Geological Survey of Canada's Surficial Data Model (SDM version 2.0) which can be found in Open File 7631 (Deblonde et al., 2014). All geoscience knowledge and information from map 1880A that conformed to the current SDM were maintained during the conversion process. However, only terrestrial units are depicted on this map. Map units below modern sea level or major lake levels are not shown but are maintained in the digital data of this publication. Where additional information was required in certain regions of the Arctic and Cordillera, legacy geology map data were used. These maps are listed in the digital "Map Information" document. All other source maps used in map 1880A are not relisted here. The purpose of converting legacy map data to a common science language and common legend is to enable and facilitate the efficient digital compilation, interpretation, management and dissemination of geologic map information in a structured and consistent manner. This provides an effective knowledge management tool designed around a geo-database which can expand following the type of information to appear on new surficial geology maps.

Linear features (eskers, moraines) extracted from the new surficial geology map product (Geological Survey of Canada, Canadian Geoscience Map 195, 2014, 1 sheet, https://doi.org/10.4095/295462) that represents the conversion of the map "Surficial Materials of Canada" (Fulton, 1995) and its legend, using the Geological Survey of Canada's Surficial Data Model (SDM version 2.0) which can be found in Open File 7631 (Deblonde et al., 2014). All geoscience knowledge and information from map 1880A that conformed to the current SDM were maintained during the conversion process. However, only terrestrial units are depicted on this map. Map units below modern sea level or major lake levels are not shown but are maintained in the digital data of this publication. Where additional information was required in certain regions of the Arctic and Cordillera, legacy geology map data were used. These maps are listed in the digital "Map Information" document. All other source maps used in map 1880A are not relisted here. The purpose of converting legacy map data to a common science language and common legend is to enable and facilitate the efficient digital compilation, interpretation, management and dissemination of geologic map information in a structured and consistent manner. This provides an effective knowledge management tool designed around a geo-database which can expand following the type of information to appear on new surficial geology maps.

The Quaternary Geologic Map of the Lake Superior 4° x 6° Quadrangle was mapped as part of the Quaternary Geologic Atlas of the United States. The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the earth. They make up the "ground" on which we walk, the "dirt" in which we dig foundations, and the "soil" in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as regolith, the mantle of fragmental and generally unconsolidated material that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale.

The Quaternary Geologic Map of the Lake Erie 4° x 6° Quadrangle was mapped as part of the Quaternary Geologic Atlas of the United States. The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the earth. They make up the "ground" on which we walk, the "dirt" in which we dig foundations, and the "soil" in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as regolith, the mantle of fragmental and generally unconsolidated material that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale.

"The Geological Society of America’s (GSA) Geologic Map of North America (Reed and others, 2005; 1:5,000,000) shows the geology of a significantly large area of the Earth, centered on North and Central America and including the submarine geology of parts of the Atlantic and Pacific Oceans. This map is now converted to a Geographic Information System (GIS) database that contains all geologic and base-map information shown on the two printed map sheets and the accompanying explanation sheet. We anticipate this map database will be revised at some unspecified time in the future, likely through the actions of a steering committee managed by the Geological Society of America (GSA) and staffed by scientists from agencies including, but not limited to, those responsible for the original map compilation (U.S. Geological Survey, Geological Survey of Canada, and Woods Hole Oceanographic Institute)."

Is best used for fault mapping and structural data, though is not ideal for finer details.

The Yukon Geological Survey (YGS) has compiled over 195 surficial geology maps into a standardized GIS format, providing approximately 80% coverage of the territory. The maps range in scales from 1:250,000 to 1:10,000 with spatial overlap between scales. The original maps were produced by various agencies, including the Geological Survey of Canada, YGS, Yukon Government, universities, and the City of Whitehorse. All original feature descriptions have been preserved and also converted to standardized values using the Yukon terrain classification system. The compilation includes 4 GIS datasets and supporting documents available for download via YGS integrated data system (YGSIDS) or GeoYukon. A .lyr file is provided to symbolize feature classes and differentiate overlapping maps at different scales. Additionally, there is a surficial geology map index. The polygon attributes captured include surficial material, texture, age, surface expression, and geomorphological processes. Line features include geological contacts, glacial limits, glacial landforms (cirques, arêtes, eskers, meltwater channels, moraines), and non-glacial landforms (faults, lineaments, landslides, escarpments). Point features include field station, fossil and sample locations, glacial landforms (erratics, kames, kettles, drumlins, flutings), permafrost features (pingos, palsas, patterned ground, thermokarst depressions), and other non-glacial landforms (landslides, tors). The map index provides information on each map publication such as author, map title, map scale, publisher. These data are valuable for land-use applications in the territory, including: mineral and placer exploration, geotechnical engineering, infrastructure planning, granular resource assessments, permafrost modeling, agricultural assessments, forest management, and biophysical or ecological land classification. Distributed from GeoYukon by the Government of Yukon . Discover more digital map data and interactive maps from Yukon's digital map data collection. For more information: geomatics.help@yukon.ca

The Yukon Geological Survey (YGS) has compiled over 195 surficial geology maps into a standardized GIS format, providing approximately 80% coverage of the territory. The maps range in scales from 1:250,000 to 1:10,000 with spatial overlap between scales. The original maps were produced by various agencies, including the Geological Survey of Canada, YGS, Yukon Government, universities, and the City of Whitehorse. All original feature descriptions have been preserved and also converted to standardized values using the Yukon terrain classification system. The compilation includes 4 GIS datasets and supporting documents available for download via YGS integrated data system (YGSIDS) or GeoYukon. A .lyr file is provided to symbolize feature classes and differentiate overlapping maps at different scales. Additionally, there is a surficial geology map index. The polygon attributes captured include surficial material, texture, age, surface expression, and geomorphological processes. Line features include geological contacts, glacial limits, glacial landforms (cirques, arêtes, eskers, meltwater channels, moraines), and non-glacial landforms (faults, lineaments, landslides, escarpments). Point features include field station, fossil and sample locations, glacial landforms (erratics, kames, kettles, drumlins, flutings), permafrost features (pingos, palsas, patterned ground, thermokarst depressions), and other non-glacial landforms (landslides, tors). The map index provides information on each map publication such as author, map title, map scale, publisher. These data are valuable for land-use applications in the territory, including: mineral and placer exploration, geotechnical engineering, infrastructure planning, granular resource assessments, permafrost modeling, agricultural assessments, forest management, and biophysical or ecological land classification. Distributed from GeoYukon by the Government of Yukon. Discover more digital map data and interactive maps from Yukon's digital map data collection.For more information: geomatics.help@yukon.ca

Geology is based on field work by Peter R. Dawes in 1971, 1975 and 1978. Compiled with photointerpretation 1988–89, with local revision based on field work in 2001. The coast was surveyed by boat with sporadic foot traverses, aided by helicopter in 1978 and 2001. GIS compilation: Katja T. Walentin, Samuel P. Jackson, Eva Willerslev and Mette S. Jørgensen. Cross section: Martin Sønderholm. Editorial handling: Thomas F. Kokfelt and Martin Sønderholm. Reviewed by John Grocott (Durham University, United Kingdom) and Marc R. St-Onge (Geological Survey of Canada). Detailed information on the map units is available in the GEUS Greenland Intrusive and Stratigraphic Database using the GU-codes shown in brackets in the legend (https://doi.org/10.22008/FK2/F9MBNJ). Information on mineral occurrences is available in the Greenland Mineral Resources Portal (https://www.greenmin.gl). Topographic base: Geodetic Institute maps at 1:200 000 from 1954 with major revision of the ice margin and glaciers based on 1:150 000 aerial photographs from 1985–1987 and Sentinel 2 satellite scenes from 2019. All heights are in metres. Additional lake heights are from the Danish Agency for Data Supply and Infrastructure (now the Danish Agency for Climate Data): Højdemodel Grønland (https://dataforsyningen.dk/data/4780, accessed September 2023). Ground exposed by ice retreat since initial compilation in 1988–1989 is identified in the legend. 1949 ice margins are from Geodetic Institute maps. Ice margins recorded during expeditions by Robert E. Peary in 1892 and Lauge Koch in 1922 are approximate. Ice altimetry and thickness are based on data from Morlighem et al. (2017), bathymetry is from Morlighem et al. (2022). Landslides are modified from GEUS internal data, for methodology see Svennevig (2019). Authorised place names are from Oqaasileriffik (The Language Secretariat of Greenland), with supplementary names from Laursen (1972). Projection: WGS 84 UTM Zone 20N. Copyright © Geological Survey of Denmark and Greenland. References: Dawes, P.R. 1997: The Proterozoic Thule Supergroup, Greenland and Canada: history, lithostratigraphy and development. Geology of Greenland Survey Bulletin 174, 150 pp. https://doi.org/10.34194/ggub.v174.5025 Dawes, P.R. 2006: Explanatory notes to the Geological map of Greenland, 1:500 000, Thule, Sheet 5. Geological Survey of Denmark and Greenland Map Series 2, 97 pp. + map sheet. https://doi.org/10.34194/geusm.v2.4614 Laursen, D. 1972: The place names of North Greenland. Meddelelser om Grønland 180(2), 443 pp. + 18 plates. Morlighem, M. et al. 2017: BedMachine v3 [Surface; Thickness]: Complete bed topography and ocean bathymetry mapping of Greenlandfrom multibeam echo sounding combined with mass conservation. Geophysical Research Letters 44, 11051–11061. https://doi.org/10.1002/2017GL074954 Morlighem, M. et al. 2022: IceBridge BedMachine Greenland, Version 5 [Bed]. NASA National Snow and Ice Data Center Distributed Active Archive Center. https://doi.org/10.5067/GMEVBWFLWA7X (accessed January 2024). Svennevig, K. 2019: Preliminary landslide mapping in Greenland. Geological Survey of Denmark and Greenland Bulletin 43,e2019430207. https://doi.org/10.34194/GEUSB-201943-02-07 Thomassen, B., Krebs, J.D. & Dawes, P.R. 2002: Qaanaaq 2001: mineral exploration in the Olrik Fjord – Kap Alexander region, North-West Greenland. Danmarks og Grønlands Geologiske Undersøgelse Rapport 2002/86, 72 pp. + map. https://doi.org/10.22008/gpub/18491

The Quaternary Geologic Map of the Winnipeg 4° × 6° Degree Quadrangle, United States and Canada, is a component of the U.S. Geological Survey Quaternary Geologic Atlas of the United States map series (Miscellaneous Investigations Series I-1420), an effort to produce 4° × 6° Quaternary geologic maps, at 1:1 million scale, of the entire conterminous United States and adjacent Canada. The map and the accompanying text and supplemental illustrations provide a regional overview of the areal distributions and characteristics of surficial deposits and materials of Quaternary age (~1.8 Ma to present) in parts of North Dakota, Minnesota, Manitoba, and Saskatchewan. The map is not a map of soils as soils are recognized in agriculture. Rather, it is a map of soils as recognized in engineering geology, or of substrata or parent materials in which agricultural soils are formed. The map units are distinguished chiefly on the basis of (1)genesis (processes of origin) or environments of deposition: for example, sediments deposited primarily by glacial ice (glacial deposits or till), sediments deposited in lakes (lacustrine deposits), or sediments deposited by wind (eolian deposits); (2) age: for example, how long ago the deposits accumulated; (3) texture (grain size)of the deposits or materials; (4) composition (particle lithology) of the deposits or materials; (5) thickness; and (6) other physical, chemical, and engineering properties. Supplemental illustrations show (1) temporal correlation of the map units, (2) the areal relationships of late Wisconsin glacial ice lobes and sublobes, (3) temporal and spatial correlation of late Wisconsin glacial phases, readvance limits, and ice margin stillstands, (4) temporal and stratigraphic correlation of surface and subsurface glacial deposits in the Winnipeg quadrangle and in adjacent 4° × 6° quadrangles, and (5) responsibility for state and province compilations. The database provides information related to geologic hazards (for example, materials that are characterized by expansive clay minerals; landslide deposits or landslide-prone deposits), natural resources (for example, sources of aggregate, peat, and clay; potential shallow sources of groundwater), and areas of environmental concern (for example, areas that are potentially suitable for specific ecosystem habitats; areas of potential soil and groundwater contamination). All of these aspects of the database relate directly to land use, management, and policy. The map, text, and accompanying illustrations provide a database of regional scope related to geologic history, climatic changes, the stratigraphic and chronologic frameworks of surface and subsurface deposits and materials of Quaternary age, and other problems and concerns.

Geology is based on field work by Peter R. Dawes in 1971, 1975 and 1978, the latter year with Allen P. Nutman. Compiled with photointerpretation 1988–89, with local revision based on field work in 2001. Apart from northernmost Kangerlussuaq (Inglefield Bredning), the coast was surveyed by boat with sporadic foot traverses, aided by helicopter in 1978 and 2001. Geology of Qaqujaarsuaq (Smithson Bjerge) is based on simplification of the 1:50 000 map by Allen P. Nutman (1984). GIS compilation: Katja T. Walentin, Samuel P. Jackson, Eva Willerslev and Mette S. Jørgensen. Cross sections: Martin Sønderholm; Smithson Bjerge section is based on Nutman (1984). Editorial handling: Thomas F. Kokfelt and Martin Sønderholm. Reviewed by John Grocott (Durham University, United Kingdom) and Marc R. St-Onge (Geological Survey of Canada). Detailed information on the map units is available in the GEUS Greenland Intrusive and Stratigraphic Database using the GU-codes shown in brackets in the legend (https://doi.org/10.22008/FK2/F9MBNJ). Information on mineral occurrences is available in the Greenland Mineral Resources Portal (https://www.greenmin.gl). Topographic base: Geodetic Institute maps at 1:200 000 from 1954 with major revision of the ice margin and glaciers based on 1:150 000 aerial photographs from 1985–1987 and Sentinel 2 satellite scenes from 2019. All heights are in metres. Additional lake heights are from the Danish Agency for Data Supply and Infrastructure (now the Danish Agency for Climate Data): Højdemodel Grønland (https://dataforsyningen.dk/data/4780, accessed September 2023). Ground exposed by ice retreat since initial compilation in 1988–1989 is identified in the legend. 1949 ice margins are from Geodetic Institute maps. Ice margins recorded during expeditions by Robert E. Peary in 1892 and Lauge Koch in 1922 are approximate. Ice altimetry and thickness are based on data from Morlighem et al. (2017), bathymetry is from Morlighem et al. (2022). Authorised place names are from Oqaasileriffik (The Language Secretariat of Greenland), with supplementary names from Laursen (1972). Projection: WGS 84 UTM Zone 20N. Copyright © Geological Survey of Denmark and Greenland. References: Dawes, P.R. 1997: The Proterozoic Thule Supergroup, Greenland and Canada: history, lithostratigraphy and development. Geology of Greenland Survey Bulletin 174, 150 pp. https://doi.org/10.34194/ggub.v174.5025 Dawes, P.R. 2006: Explanatory notes to the Geological map of Greenland, 1:500 000, Thule, Sheet 5. Geological Survey of Denmark and Greenland Map Series 2, 97 pp. + map sheet. https://doi.org/10.34194/geusm.v2.4614 Laursen, D. 1972: The place names of North Greenland. Meddelelser om Grønland 180(2), 443 pp. + 18 plates. Morlighem, M. et al. 2017: BedMachine v3 [Surface; Thickness]: Complete bed topography and ocean bathymetry mapping of Greenland from multibeam echo sounding combined with mass conservation. Geophysical Research Letters 44, 11051–11061. https://doi.org10.1002/2017GL074954 Morlighem, M. et al. 2022: IceBridge BedMachine Greenland, Version 5 [Bed]. NASA National Snow and Ice Data Center Distributed Active Archive Center. https://doi.org/10.5067/GMEVBWFLWA7X (accessed January 2024). Nutman, A.P. 1984: Precambrian gneisses and intrusive anorthosite of Smithson Bjerge, Thule district, North-West Greenland. Rapport Grønlands Geologiske Undersøgelse 119, 31 pp. + plate. https://doi:10.34194/rapggu.v119.7849 Thomassen, B. & Krebs, J.D. 2004: Mineral exploration of selected targets in the Qaanaaq region, North-West Greenland: follow-up on Qaanaaq 2001. Danmarks og Grønlands Geologiske Undersøgelse Rapport 2004/42, 64 pp. https://doi.org/10.22008/gpub/25622 Thomassen, B., Krebs, J.D. & Dawes, P.R. 2002: Qaanaaq 2001: mineral exploration in the Olrik Fjord – Kap Alexander region, North-West Greenland. Danmarks og Grønlands Geologiske Undersøgelse Rapport 2002/86, 72 pp. + map. https://doi.org/10.22008/gpub/18491

Geological map of Canada - Canadian bedrock - Geological Survey of Canada - Natural Resources Canada - 1:5M. Wheeler, J O; Hoffman, P F; Card, K D; Davidson, A; Sanford, B V; Okulitch, A V; Roest, W R. Geological Survey of Canada, "A" Series Map 1860A, 1996, ; 3 sheets; 1 CD-ROM, doi:10.4095/208175