Ministry of Energy, Mines and Pertoleum Resources

Digital Geology Map of British Columbia

BCMEMPR Open File 2005-02

by N.W.D. Massey, D.G. MacIntyre, P.J. Desjardins and R.T. Cooney

Digital regional compilations of the geology of B.C. at 1:250,000-scale were made by the staff of the BC Geological Survey in 1992-96 in support of the Mineral Potential Project. These were released as Open Files and digital downloads from the BCGS website (http://www.em.gov.bc.ca/geoscience). They were also used as the geology base for the Map Place (http://www.mapplace.ca).

However, numerous errors and inconsistencies were noted within these data sets. The Digital Geology Map of British Columbia Project was designed to address these problems and, in the process, try to produce a seamless digital map of the Province with consistent geological tagging. Where feasible, updates to the geology have also been incorporated during the editing process. However, some “scratch lines” remain in the data reflecting problems due to unresolved differences in geological designations in original sources.

Release of the recompilation is based on the same tiles as the Cordilleran GIS Map Library (Journeay and Williams, 1995) which conforms to the International Map of the World standard used for indexing 1:1,000,000-scale topographic maps. This differs from the numbering convention used for the National Topographic System maps. Preliminary versions of the tiled data were released in 2003, with updates in 2004. This new province-wide version, and associated tiled data, supersedes the earlier files.

All data sets are in shape file format that should be readily usable by most GIS software. They are provided in tiled form for nine regions of B.C. (see Figure) and as complete Provincial coverages. All data sets are presented as decimal degrees (suffix _ll) and BC Albers (suffix _alb), while tiled data are also available in UTM (suffix _utm) projections. All projections use NAD83 as the datum. The data sets are intended to be used at 1:250,000-scale and their use at greater scales is not recommended.

Digital Geology Coverage

Data sets
Each data set includes several topographic and geological shape files:

Topographic data:
	BC_road	important roads (excludes many roads in built-up areas); the legend file, e.g. BC_road_ll.avl, will symbolize for paved or gravel surface (lines).
	BC_rail	rail track; includes some disused lines (lines).
	BC_communities_2M	regional significant population centres; attributed for name (points).
	BC_250K_grid	1:250,000 NTS map sheet grid (polygons).
	BC_tiles	areas of tiled data (polygon).
	BC_ocean	coastline (polygon).
	BC_river	rivers (lines).
	BC_riverpoly	major rivers (as polygons).
	BC_lake	lakes (polygons).
	BC_ice	areas of permanent ice cover (polygons).
Geological line work: intended for cartographic purposes only:
	BC_fltln	faults, attributed for type of fault – fault, normal fault, thrust fault, extensional fault (lines).
Geological polygons:
	BC_quaternary	Quaternary alluvium and cover; note that the extensive Quaternary deposits of the Rocky Mountain foothills and the Peace River area have been omitted as they would completely cover and obscure the bedrock geology (polygons).
	BC_geology	Bedrock geology (polygons).

ESRI users (*.avl and BCDigitalMap.style)
Each data set includes several topographic and geological shape files: ArcView legend files are supplied for all data set files (e.g. BC_roads_ll.avl). These will automatically symbolize the data when loaded into ArcView. Geology can be symbolized in various ways depending upon the user’s requirements. The following legend files are supplied for this purpose.

	BC_basins1.avl	sedimentary basins: each with a unique colour.
	BC_basins2.avl	sedimentary basins: grouped by age.
	BC_lithology.avl	colours bedrock geology by lithology (ROCK_TYPE).
	BC_strat_2M.avl	colours bedrock geology by stratigraphy (units being grouped at a regional level, commensurate with a 1:2,000,000-scale); colours have been assigned based on stratigraphic age for all rock types.
	BC_tecass.avl	colours bedrock geology by tectonic assemblage (TECUNIT); colours are as close as possible to those used by Wheeler and McFeely (GSC Map 1712A).
	BC_terranes.avl	colours bedrock geology by tectono-stratigraphic terrane (TERRANE).

Tile specific versions of these legend files (e.g. NM10_tecass.avl) are also supplied with the tiled data. ArcMap 8.x users should use the supplied BCDigitalMap.style style sheet to symbolize all data sets except geology. The style sheet is included in all the zip files. The above avl files can be imported into ArcMap for geology symbolization.

A DVD containing all data sets is available for $25 from Crown Publications Inc.

Digital Bedrock Geology Downloads are also available.

Geoscience Map 2005-3 is a 1:1M Geology of BC map.

All printed publications of the BC Geological Survey are available for purchase through Crown Publications Inc. (and its agents).

For questions or more information on geology and minerals in British Columbia contact BCGS Mailbox or call toll free (BC Residents only).