British Columbia Digital Geology

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British Columbia Digital Geology
Release 2.1, August, 2013
Y. Cui, F. Katay, J.L. Nelson, T. Han, P.J. Desjardins, and L. Sinclair
British Columbia Geological Survey
KEYWORDS: digital geology, bedrock, data integration, British Columbia, BC,
MapPlace, spatial database, data quality, updating, PostGIS
Introduction
British Columbia Digital Geology is the data source used to create the digital BC
Geological Map, which is produced by the British Columbia Geological Survey for
clients in mineral exploration, mining, land use planning, and other areas.
This release consists of integrated datasets including: geological contacts that
delineate bedrock units and structures as linear features associated with
descriptions or attributions; and bedrock as polygons formed from the geological
contacts and attributed with descriptions of the geological units. It also contains:
tables for geological units and colours (RGB); ESRI layer files containing the bedrock
colour symbols, compatible to various versions of ArcGIS (designated by suffix _a##_#
in file names); and a map of British Columbia illustrating the suggested colour theme for
the bedrock polygons.
The digital data are available on MapPlace
(http://www.em.gov.bc.ca/Mining/Geoscience/MapPlace/Pages/default.aspx) and as data
download.
The source data for this digital data package includes the bedrock polygons and fault
lines that were released in 2005 (Massey et al., 2005, and complete reference in
Appendix II), previously unpublished contacts, and recently updated geological maps for
QUEST (Logan et al., 2010), North Coast (Nelson et al., 2012), Terrace (Nelson, 2008).
The stability and usability of this dataset was improved by data quality assurance, content
standardization, and proper integration of geological boundaries and geological units.
Accordingly

lines are simple and valid according to OGC Simple Features Specification (OGC,
1999)

duplicates are removed and partially overlapping lines are fixed

lines are connected (i.e., noded) properly at intersections
1

overshoots and undershoots are either fixed or verified

short lines are checked and removed

lines with an unnecessary density of coordinates or very short segments (e.g.,
distance between coordinates less than 3 metres) are processed to reduce the
redundant coordinates, while still maintaining the geometry

the unit of precision for coordinates is reduced to the appropriate mapping scale
or resolution (e.g., to the equivalent of decimetres)

sharp spikes or slivers along a lineString and sharp angles between two
lineStrings are removed, and linesStrings are checked and free of other geometric
irregularities

“data boundaries” are correctly coded at map extents, where knowledge
boundaries are present and necessary in the dataset
The bedrock polygons are regenerated from the improved contacts and fault lines to
ensure topological validity between geological units.
Metadata
Table 1. Descriptions of metadata
Metadata
Data format:
Coordinates of spatial data
Mapping scales
Recommended use
Release version and date
Description
ESRI® shapefile format
Decimal degrees in geographic coordinates (suffix _ll83)
Decimetre in BC Albers projection (suffix _alb)
Varying from 1:50 000 to 1:250 000
At a scale of 1:250 000 province wide; up to a scale of 1:50 000 for
areas where details are sufficient
2.0, January 2013
Descriptions of Attributes
Table 2. Column descriptions for bedrock attributes
Attribute
pid
strat_unit
area_m2
Description
Unique ID for bedrock polygons generated from centroids of polygons
Recommended geological unit code in standard label format consisting of age,
lithostratigraphic or lithodemic unit (Formation or Group), and lithology. Age and
stratigraphic codes are listed in BC_Stratcode_Components.xls; lithological codes
are listed in BC_Lithology.xls
Polygon area in square metres
2
era
period
strat_age
strat_name
gp_suit
formation
rock_type
rock_class
original_d
age_max_g
age_min_g
age_max_ma
age_min_ma
age_desc
project
remarks
belt
terrane
basin
basin_age
edit_ref
Geological Era within which the unit lies
Geological Period within which the unit lies
Stratigraphic age range of unit
Stratigraphic name of unit; Group and/or Formation where assigned
Group or Suite name
Formation or lithodeme name
Generalized lithological description
Intrusive, volcanic, sedimentary, metamorphic or ultramafic rocks
Original author’s description of the unit; from the Mineral Potential Geological
Compilations, plus original author’s descriptions for new additions and
amendments
Maximum age of unit
Minimum age of unit
Maximum age of unit (Ma)
Minimum age of unit (Ma)
Description of age data
Original Mineral Potential Project area, or other major project
Any significant comments about unit and its attributes
Morphotectonic belt
Name of tectono-stratigraphic terrane
Name of sedimentary basin
Age of basin
Edition reference of data release
Table 3. Column descriptions for geological boundaries
Attribute
Description
ulid
Unique line ID generated from the first and second coordinates in BC Albers,
rounded to the nearest metres and packed as X1-Y1-X2-Y2
Feature class of geological boundary
Feature type of geological boundary
Confidence or reliability of survey observation or measurement of geological
boundary
Named fault or other boundary, if available
Remarks on feature
Fault offset amount in metres
Length of geological boundary line in metres
Edition reference of data release
f_class
f_type
f_conf
f_name
f_remark
offset_amt
f_length
edit_ref
Appendix I: References of data sources
Bellefontaine, K., Alldrick, D. and Desjardins, P.J., 1994: Mid Coast (all or parts of 92F,
G, J, K, L, M, N; 93D; 102P; 103A), Ministry of Energy, Mines and Petroleum
Resources, Open File 1994-17.
Bellefontaine, K., Legun, A., Massey, N.W.D. and Desjardins, P.J., 1995: Mineral
Potential Project, Digital Geological Compilation NEBC South half, (83D, E; 93F,
G, H, I, J, K, N, O, P), Ministry of Energy, Mines and Petroleum Resources, Open
File 1995-24.
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Desjardins, P.J., 1994; Digital Geology Polygons; Vancouver Island Region (matches OF
1994-6) Kootenay Region (matches OF 1994-8) Cariboo - Chilcotin Region
(matches OF 1994-7), Ministry of Energy, Mines and Petroleum Resources, Open
File 1994-27.
Höy, T., Church, B.N., Legun, A., Glover, K., Gibson, G., Grant, B., Wheeler, J.O.,
Dunne, K.P.E., Cunningham, J. and Desjardins, P.J., 1994: Kootenay Area (82E, F,
G, J, K, L, M, N, O; 83C, D), Ministry of Energy, Mines and Petroleum Resources,
Open File 1994-8.
Journeay, J.M. and Williams, S.P., 1995: GIS map Library: a window on Cordilleran
geology (version 1.0); Geological Survey of Canada, Open File 2948.
Logan, J.M. Schiarizza, P., Struik, L.C., Barnett, C., Nelson, J.L., Kowalczyk, P., Ferri, F.,
Mihalynuk, M.G., Thomas, M.D., Gammon, P., Lett, R., Jackaman W., and Ferbey,
T. (2010): Bedrock Geology of the QUEST map area, central British Columbia;
B.C. Ministry of Energy and Mines, British Columbia Geological Survey,
Geoscience Map 2010-1.
MacIntyre, D.G., Ash, C. and Britton, J., 1994: Nass-Skeena (93/E, L, M; 94/D; 103/G, H,
I, J, P; 104/A, B), Ministry of Energy, Mines and Petroleum Resources, Open File
1994-14.
MacIntyre, D.G., Legun, A., Bellefontaine, K. and Massey, N.W.D., 1995: B.C. Mineral
Potential Project: Digital Geological Compilation, Northeast British Columbia 94A,
B, C, F, G, H, I, J, K, N, O, P), Ministry of Energy, Mines and Petroleum Resources,
Open File 1995-6.
Massey, N.W.D., Desjardins, P.J. and Grunsky, E.C., 1994: Vancouver Island (92B, C, E,
F, G, K, L; 102I), Ministry of Energy, Mines and Petroleum Resources, Open File
1994-6.
Mihalynuk, M., Bellefontaine, K., Brown, D., Logan, J., Nelson, J., Legun, A. and
Diakow, L., 1996: Digital Geology, NW British Columbia (94/E, L, M; 104/F, G, H,
I, J, K, L, M, N, O, P; 114/I, O, P), Ministry of Energy, Mines and Petroleum
Resources, Open File 1996-11.
Nelson, J.L. and Diakow, L.D., 2013, Geology of the north and central coast of British
Columbia; BC Geological Survey Open File, in preparation, scale 1:150,000.
Schiarizza, P., Panteleyev, A., Gaba, R.G., Glover, J.K., Desjardins, P.J. and
Cunningham, J., 1994: Cariboo - Chilcotin Area (92J, K, N, O, P; 93A, B, C, F, G,
H), Ministry of Energy, Mines and Petroleum Resources, Open File 1994-7.
Schiarizza, P. and Church., N., 1996: The Geology of the Thompson - Okanagan Mineral
Assessment Region, Ministry of Energy, Mines and Petroleum Resources, Open File
1996-20.
Appendix II: Reference for BC digital geology data release 1.0, January 2005
Massey, N.W.D., MacIntyre, D.G., Desjardins, P.J. and Cooney, R.T., 2005: Digital
Geology Map of British Columbia, B.C. Ministry of Energy and Mines, Open File
2005-2, DVD.
Massey, N.W.D., MacIntyre, D.G., Desjardins, P.J. and Cooney, R.T., 2005: Digital
Geology Map of British Columbia: Whole Province, B.C. Ministry of Energy and
Mines, Geofile 2005-1, scale 1:250,000.
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Massey, N.W.D., MacIntyre, D.G., Desjardins, P.J. and Cooney, R. T., 2005: Digital
Geology Map of British Columbia: Tile NM9 Mid Coast, B.C. Ministry of Energy
and Mines, Geofile 2005-2, scale 1:250,000.
Massey, N.W.D., MacIntyre, D.G., Desjardins, P.J. and Cooney, R.T., 2005: Digital
Geology Map of British Columbia: Tile NM10 Southwest B.C., B.C. Ministry of
Energy and Mines, Geofile 2005-3, scale 1:250,000.
Massey, N.W.D., MacIntyre, D.G., Desjardins, P.J. and Cooney, R.T., 2005: Digital
Geology Map of British Columbia: Tile NM11 Southeast B.C., B.C. Ministry of
Energy and Mines, Geofile 2005-4, scale 1:250,000.
Massey, N.W.D., MacIntyre, D.G., Haggart, J.W., Desjardins, P.J., Wagner, C.L. and
Cooney, R.T., 2005: Digital Geology Map of British Columbia: Tile NN8-9 North
Coast and Queen Charlotte Islands/Haida Gwaii, B.C. Ministry of Energy and Mines,
Geofile 2005-5, scale 1:250,000.
Massey, N.W.D., MacIntyre, D.G., Desjardins, P.J. and Cooney, R.T., 2005: Digital
Geology Map of British Columbia: Tile NN10 Central B.C., B.C. Ministry of
Energy and Mines, Geofile 2005-6, scale 1:250,000.
Massey, N.W.D., MacIntyre, D.G., Desjardins, P.J. and Cooney, R.T., 2005: Digital
Geology Map of British Columbia: Tile NN11 Mid Rockies, B.C. Ministry of
Energy and Mines, Geofile 2005-7, scale 1:250,000.
Massey, N.W.D., MacIntyre, D.G., Desjardins, P.J. and Cooney, R.T., 2005: Digital
Geology Map of British Columbia: Tile NO8 Northwest B.C., B.C. Ministry of
Energy and Mines, Geofile 2005-8, scale 1:250,000.
Massey, N.W.D., MacIntyre, D.G., Desjardins, P.J. and Cooney, R.T., 2005: Digital
Geology Map of British Columbia: Tile NO9 North Central B.C., B.C. Ministry of
Energy and Mines, Geofile 2005-9, scale 1:250,000.
Massey, N.W.D., MacIntyre, D.G., Okulitch, A.V., Desjardins, P.J. and Cooney, R.T.,
2005: Digital Geology Map of British Columbia: Tile NO10 Northeast B.C., B.C.
Ministry of Energy and Mines, Geofile 2005-10, scale 1:250,000.
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Appendix III. Reference to earlier provincial geology compilation
Dawson, G.M. (1901): Geological Map of the Dominion of Canada (western sheet);
Multicoloured Map, 783 (1:3,168,000).
Anonymous (1948): Geological Map of British Columbia; Geological Survey of Canada,
Map 932A (1:1,267,200).
Anonymous (1962): Geological Map of British Columbia; Geological Survey of Canada,
Map 932A, 2nd edition, (1:1,267,200).
Jackson, E.V. (1976): Generalized Geological Map of the Canadian Cordillera 48ºN to
65ºN; BC.
MEMPR Miscellaneous Map A, prepared to accompany CIM Special Volume 15
(1:2,500,000).
Tipper, H.W., (1978): Tectonic Assemblage, Map of the Canadian Cordillera; Geological
Survey of Canada, Open File 572 (1:3,000,000).
Tipper, H.W., Woodsworth, G.J. and Gabrielse, H. (1981): Tectonic Assemblage Map of
the Canadian Cordillera and Adjacent Parts of the United States of America:
Geological Survey of Canada, Map 1505A (1:2,000,000).
Jackson, E.V. (1982): British Columbia Geological Highway Map, MEMPR
Miscellaneous Map 2, (1:1,250,000).
Wheeler, J.O. and McFeely, P. (1987): Tectonic Assemblage Map of the Canadian
Cordillera and Adjacent Parts of the United States of America: Geological Survey of
Canada, Open File 1565 (1:2,000,000).
Wheeler, J.O. and McFeely, P. (1991): Tectonic Assemblage Map of the Canadian
Cordillera and Adjacent Parts of the United States of America: Geological Survey of
Canada, Map 1712A (1:2,000,000).
Wheeler, J.O., Brookfield, A.J., Gabrielse, H., Monger, J.W.H., Tipper, H.W. and
Woodsworth, G.J. (1991): Terrane Map of the Canadian Cordillera/Carte des
Terranes de la Cordillère Canadienne, Geological Survey of Canada, Map 1713A
(1:2,000,000).
Journeay, J.M. and Williams, S.P. (1995): GIS Map Library: a Window on Cordilleran
Geology (version 1.0), Geological Survey of Canada, Open File 2948, - digital
version of Wheeler and McFeely (1991).
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