GENERALIZED GEOLOGY OF THE WORLD: BEDROCK DOMAINS AND MAJOR FAULTS IN GIS FORMAT
A small-scale world geology map with an extended geological attribute database
Geological Survey of Canada Open File 5529

Lesley Chorlton, Mineral Resources Division,
Geological Survey of Canada, Natural Resources Canada

BACKGROUND

The first version of the Generalized Geology of the World (Kirkham et al., 1994a), or GGW, was inspired by The World Atlas of Geology and Mineral Deposits (Derry, 1980), and was intended originally as a paper backdrop for the world distribution of sediment-hosted copper deposits (Kirkham et al., 1994b).  Its form as a digital geographic information system (GIS) data set evolved from a 1993-1994 study to see if it was feasible to employ a geological GIS with the essential attributes of the map legend captured in relational-style database form, instead of encoding cartographic symbols and labels directly into the geospatial features in the traditional way.  The intent was to produce a compound data set that was more flexible than the traditional digital maps of the time, and capable of producing a variety of thematic maps based on alternative subsets of the database information. Very basic age and rock or fault types were captured in database tables and linked to geospatial polygon and arc features.  Each geological attribute record was linked to one or more data sources captured in a bibliographic database; this required modest effort and proved useful for verification.

After the first GGW and databases for sediment-hosted copper (Kirkham et al., 1995) and seafloor  (Hannington et al., 1995) mineral deposits were published on CD-ROM (Geological Survey of Canada, 1995), exploration industry sponsorship was obtained to continue with the global compilation exercise.  The ensuing World Map Project (1995-1997) resulted in revisions to the geology and in substantial revision to its attribute database to accommodate much more detail. Databases for porphyry-related deposits (Kirkham and Dunne, 2000), nickel deposits (Eckstrand and Good, 2000), and VMS-Sedex deposits (Jenkins and Lydon, 2002) were compiled during the project.  The World Map Project was succeeded by the industry-sponsored World Minerals Geoscience Database Project (1998-2004), which established a common mineral deposit database schema for all deposit types.  New mineral deposit databases for iron oxide (+/-Cu+/-Au+/-U) deposits (Gandhi, unpublished), MVT and Sedex deposits (Sangster, unpublished), lode gold (Gosselin and Dubé, unpublished), Ni-Cu-PGE-Cr (Eckstrand et al., unpublished), and miscellaneous ‘Selected’ deposits (Kirkham and Rafer, 2003) were initiated, and the existing databases for sediment-hosted copper deposits and porphyry-related deposits were converted to the new schema and updated.  The geology was also considerably improved, and was used in preliminary form for backdrops of paper maps published with the nickel and porphyry deposit databases.

This version of the Generalized Geology of the World therefore represents an expansion of the scope of the original geological database schema to make the derivation of new thematic maps possible. The implications of ad hoc updates and information input from multiple sources were explored.  By the end of the World Map Project, the new GGW geological database schema was superseded by the North American Data Model (Johnson et al., 1997; <http://geology.usgs.gov/dm/> ), or NADM.  However, because the population of the enhanced GGW had so far proven successful for deriving useful thematic maps, and because of industry support, revisions were continued to complete this product.  Readers are directed to the Commission for the Geological Map of the World ( <http://perso.club-internet.fr/ccgm/index.html> ) for authoritative versions of world geology. However, they may find this very generalized world geology data set useful for small-scale geology diagrams, wall maps, and web map server presentations of global scope. 

CHANGES TO THE GGW SINCE 1995 RELEASE

Recognized defects in the original version of the GGW were addressed by: (a) replacing the geology in most areas with less generalized data and data from improved sources; (b) enhancing the data model to better handle age ranges and rock types; and (c) soliciting external reviews.  Revisions include:

(a)	Generalized geology of Greenland, North and South America, central and eastern Australia, Scandinavia, Svalbard, Spain, Portugal, France, Northeastern Siberia, North Africa, and Namibia have been completely replaced.
(b)	Spatial and attribute data for Central and Southeast Asia, Madagascar, Middle East, and attribute data for the Caribbean region were updated.
(c)	Age ranges (start age - end age) for rock unit and fault entities are accommodated in the database schema and populated for bedrock geology.  Age range data for faults are not widely depicted on small scale regional compilation maps, and therefore, age ranges could not be captured for many of the world’s major faults in the time-span of the project.
(d)	Extra tables for each basic rock type category (i.e., intrusive, sedimentary) were added to hold specialized information significant for that category, and populated for some areas of the world from both prior and new sources.  The addition of general igneous composition was emphasized in the population of these tables so that global igneous themes could be obtained.
(e)	The reference database was re-structured to allow flexibility in formatting output for the styles of various publications, comparable to the capabilities of EndNoteTM, a software package popular with scientists. References and specific geospatial features and attribute data were linked as before.
(f)	Coastlines and shorelines from ArcWorld™ in the original GGW have been replaced by those from the public domain World Data Bank II (WDBII) to make the data easier to distribute freely.

One of the peripheral objectives of the project was to see how easy it was to provide convenient custom map data sets from the relational style database.  Computer scripts were thus written to derive custom, cut-down, flat-file data sets that are easy to use with PC-based map viewing software, and that would be easy to use in mathematical modeling and decision support activities if the geospatial data were more detailed.  The derivative data sets provided as part of this publication are:

(a)	A general era level age-rock type theme based on the default records for each domain (gen folder within ArcView31 and MapInfo6 data directories). 
(b)	A Precambrian age-rock type theme, which distinguishes subdivided Archean where possible to highlight the presence of Paleoarchean and Mesoarchean crust, overlying a backdrop of  undivided Phanerozoic domains (pre folder within ArcView31 and MapInfo6 data directories).
(b)	A mafic-ultramafic igneous theme in which mafic and/or ultramafic igneous domains are classified as intrusive or extrusive and subdivided by era, overlying a backdrop of undivided  Precambrian and Phanerozoic domains (maf folder within ArcView31 and MapInfo6 data directories). 
(c) 	A felsic-intermediate igneous theme in which felsic and/or intermediate igneous domains are classified as intrusive or extrusive and subdivided by era, overlying a backdrop of undivided  Precambrian and Phanerozoic domains (fls folder within ArcView31 and Mapinfo6 data directories).
(d) 	Major world faults attributed with default fault type and age range where known (flt folder within ArcView31 and MapInfo6 data directories). 

Data sets are provided in the following formats: ESRI shape files for ArcView™3.1 or greater or ArcExplorer™,   MapInfo™ tab files for MapInfo™ 6.0 or greater, and MS-Access™ for the relational attribute databases associated with the uncut geospatial data sets for bedrock domains and faults.  ArcMap™9.1 project files utilize the ArcView™3.1 data sets and legend files. ArcReader™  and ArcReader™ project files are also supplied on this disk.  The geological attribute database schema is described in Appendix I and the full set of data sources used is listed in Appendix II. 

BASE, GEOREFERENCING, ACCURACY, AND GENERALIZATION LEVEL

Coastlines and shorelines were taken from the 25 million World Data Bank II (WDBII) public domain data set and formed the topographic base. These data were projected to the projection chosen for the GGW, the Van der Grinten projection, and bedrock geology was then integrated with them to form polygon coverages.  The van der Grinten projection was chosen over other common world projections as the base projection for the GGW because it offered a pleasing shape for cartographic layout, and because it was the projection used for the first version of the map (Kirkham et al., 1994a). The central meridian was set at ten degrees east so that few land masses would be split along the boundaries of the map.  Export files for use with desktop GIS software are provided in geographic projection for the convenience of users, because standard desktop packages of the 1990’s have been inflexible in accommodating other projections, especially for maps of global extent.   

The use of the van der Grinten projection for the base projection places a limitation on possible spatial accuracy. This projection is based on a sphere, rather than a model spheroid that more accurately represents the shape of the Earth.  This is adequate for data that are generalized to a high degree, but problematical if the data is used at greater than the intended 1:20 million to 1: 35 million range of paper scales.  Re-projecting portions of the geology into for a continental-sized or smaller area or applying more realistic model spheroid will not improve the positional accuracy.  However, because world projections represent area very poorly, area values may become more accurate depending on the qualities of the new projection and the geometry and orientation of the target region.

There are other reasons that the accuracy was limited and variable among regions.  First, regional and continental scale compilation maps used as sources for the spatial data had already been generalized to variable and non-quantifiable levels.  Secondly, the topographic base maps used for these sources vary in local referencing system employed for their topographical bases as well as in projection. Thirdly, projection and projection parameters were not provided with many sources, and had to be guessed from the geometry of the superimposed geographic grid - a matter of trial and error. Even if source parameters were known and utilized, the derived input data seldom fit the WDBII base perfectly.  Some mathematical adjustment (rubber-sheeting) was usually necessary for a final fit.  Finally, many of the paper source maps were folded and otherwise distorted, further contributing to inaccuracy.  All factors suggested that an overall high level of generalization should be maintained to avoid misleading users.

The generalization level was aimed at effective visual display of significant age-range-rock type domains at an approximately 1:35,000,000 scale suitable for a one sheet wall map.  An attempt was made to incorporate more graphical detail and greater accuracy than the first version of the GGW, but with the same overall goal of allowing the maximum distribution of items of most significance to be depicted, rather than replicating true geometry. A greater depth of attribute detail is supported by the structure of the new attribute database, and priority was placed on incorporating index-level compositional subdivision of volcanic and intrusive components where regional maps and other sources provided such distinctions. 

COMPILATION AND GENERALIZATION PROCESSING STEPS	

Data sources include regional geological and tectonic maps ranging from 1:1 million to 1:10 million scale, most in paper form.  Simplified geological maps were prepared on mylar sheets overlaid on paper map sources.  Critical portions of the shoreline and geographical (longitude - latitude) tics were transcribed as geospatial control points, and projection information (if recorded) was extracted from these source maps.  The mylar maps were either digitized or scanned, georeferenced, and re-projected to the base projection of the world map.  The projection parameters of some source maps had to be guessed, and several possible source projections were sequentially applied until the source projection providing the best fit to the WDBII shorelines could be selected.  In most cases, rubber-sheeting was necessary for a final fit. After cleaning up the line-work, unique polygon and fault keys (user-ids) were added.  The attribute database was then built with reference to the map legend and other geological data sources.

The process of simplification, or generalization, relied on several techniques.  The first was to simplify the map pattern by smoothing polylines (or polygon boundaries) and eliminating small features. The second was to represent broadly uniform domains where the map patterns of source units are intricate and visually un-resolvable at world scales as single polygons.  If the source units were similar in age range and general rock type content, one set of records may have been added to the attribute database. Otherwise, a set of records for each unit of the complex domain was added so that the attributes of all units would be available for a user-defined query. One record set was tagged as the default set for quick plots. Faults that are too close together to be resolved at world scale were treated similarly.  Thirdly, small bedrock bodies that are important to represent in some predicted thematic world maps, particularly small mafic or ultramafic intrusions, were either exaggerated in size or, if occurring in a cluster, collectively represented by one simplified polygon.  Attribute records for units that enclose the small features were added to the database as default record sets, followed by attribute records for these small features.  In that way, the polygon can be retrieved using the attributes of a subordinate, non-default unit if it is required for a specific theme.

Digital sources in GIS format were used if they were available at the time that replacement geology for the area was being prepared.  USA, Canada, New South Wales, central and eastern Australia, northeastern Siberia, and Costa Rica were generalized from digital sources.  The first area for which this was attempted was New South Wales, based on 1:1 million scale original GIS data (Scheibner et al., 1996).   The data was imported into ArcInfo and reprojected; then, coloured theme views were prepared using data fields in the GIS coverage representing age, rock type, and geological setting parameters. These views were used alternately as backdrop coverages over which generalized geological boundaries of domains containing contrasting information on composition, deposition, and setting were digitized on screen.  Then, unique keys were added to the polygons, and attribute data was added while switching among different source data backdrops on screen.  The results are too detailed to be consistent with the level of generalization needed for a global view, and serve as an illustration that generalization from one level to the other should occur in appropriate ‘steps’, i.e., a one million scale map should be generalized to 2.5 or 5 million before being generalized to 35 million scale. Additional simplification was later applied, based on the more generalized digital geology of Australia (Shaw et al., 1999).

The next area for which this was attempted was the 1:2.5 million scale generalized geology of the USA (King and Beikman, 1974), later made digital (Schruben et al., 1993).  It was when trying to generalize  ‘Basin and Range’ geology of the western USA while preparing the first GGW that it became apparent that for a flexible generalized map of global scale, it was necessary to allow one bedrock polygon to link to more than one rock unit in the attribute database. Different geological specialists would make different decisions concerning which type of unit should be represent on a custom output map. For example, one group of specialists may be interested in the distribution of Cenozoic rock types, another group might prefer to emphasize platform carbonates subdivided by age, and another might emphasize volcanic domains of all ages. To see if attaching attribute record sets for multiple units could be automated to any extent, the new generalized coverage line-work was digitized on screen in an edit session overlying the re-projected digital King and Beikman map, which was consulted in coloured paper form at the same time. The generalized coverage was then intersected with the original source using a GIS overlay function.  From the intersection coverage, a frequency table was prepared containing the GGW polygon ids and the Schruben et al. (1994) legend labels summarized on the ‘AREA’ attribute of the GIS data set. This table was sorted for each polygon id and legend label in order of descending cumulative area from which secondary ids were assigned. It was then translated into top-level rock unit records (Appendix I), after which insignificant records were weeded out while referring to the paper map. Additional data was then inserted into the GGW attribute database using scripts and an expansion of the USA labels.  Extra age and rock type attribute data, particularly for some of the mafic and ultramafic igneous domains, were obtained from DNAG volumes.  The same procedure was followed for the geology of Canada using Wheeler et al. (1997). 

Digital data for Australia (Shaw et al., 1998), Southeast Asia (Steinshouer et al., 1999), the Siberian portion of the North Pacific (Greninger et al., 1999), and Costa Rica (Schruben, 1997) were also used in replacing and/or revising the geology of these areas, but the intersection method for gathering rock units and attributes was abandoned in favour of manual data entry, which proved to be equally efficient.  A scanned and rubber sheeted version of the 1:10 million scale Geology of Europe (Luettig et al., 1980) was used to revise portions of the geology of Spain and France, and the digital generalized geological map of Finland (Anonymous, 1999) was used to replace Finnish geology, along with the 1:1 million scale paper map (Korsman et al., 1997). All data sources are listed in Appendix I, and the main data sources for each derived thematic data set are included for each continent as dBase™ and MS-Access™ files in each thematic folder.

Besides applying manual methods of spatial generalization described above, various forms of automated generalization were tested on some of the derived bedrock polygon products.  The first technique involved generalization using a plain buffering and aggregation tool developed for ArcInfo™ by Rupert Brooks  of Canadian Centre for Remote Sensing (Brooks, 1998).  Catherine Dussault enhanced this technique by adding a rule-based prioritizing mechanism that allowed the creators of generalized derivative data sets to prioritize the “units” to be represented on the resulting map (Brooks et al., 1999; Dussault, 1999).  Though exceedingly slow, this technique worked fairly well for small data sets in which the polygon shapes are relatively equant; it failed for polygons with highly elongate aspect ratios.  Preliminary tools that use fractals to automatically isolate polygons in a data set that are elongate, as well as those that are highly complex (many holes), for which tools other than buffering, must be applied were developed subsequently by Bruel (2000).  This approach is very promising, but the work was not completed because of a competing job opportunity. Because the buffering and prioritizing tools were too slow to allow any sort of efficiency to be achieved and because they could be applied only to derivative flat file data sets, the investigation was finally abandoned.

CONCLUSIONS

The creation of the Generalized Geology of the World was an experimental (not an institutional) exercise aimed at ultimately deriving some useful world geology map products while exploring the feasibility and implications of its database.  Experience gained during the exercise suggests some problems and pitfalls to be avoided.  In particular, it is recommended that legend information should by parsed into a geological data model (now the NADM data model) sheet by sheet as they are published (e.g. Davenport et al., 2002; Lauzière, 2004) instead of expecting to update them on an ad hoc basis as was attempted in this project.  Ad hoc update except from descriptive text accompanying source maps may produce inconsistencies in the database, or between the spatial data from one source and the attribute data from another. It can also make the currency of the data product difficult to communicate. On the other hand, if performed sparingly from information sources tied to source maps and applied only to the attribute data, it could help complete a level of detail not existing in an original source map.

One of the points of project was to assess the value of the relational database for housing bedrock geological information, and test its usability by submitting the database to ad hoc queries to locate features of interest.  The schema described in Appendix I served well for the storage of data and could respond to relatively simple ad hoc queries on limited subject matter, such as retrieving the distribution of a selection of lithologies, or alternatively selected age ranges in reasonable time. However, using the full data set to prepare multi-classed thematic derivative maps based on complex queries, that are complete and easy to use for desktop GIS or web map services, required very time-consuming automated processing.  Now, new techniques for data warehousing  (Imhoff et al., 2003), which likewise involve periodic loading of an intermediate read-only data ‘warehouse’ and transfer of data to specialized end-user data marts, could be used for particular decision support applications.  Implementing these concepts, at least in principle, might provide more flexibility and less compromise for the end user.

Success in compiling geological data into a database and using it relies not only on the schema, but how thoroughly and consistently it is populated.  The data sources for small scale, large area compilation maps themselves strongly influence level of detail can be attained.  Source maps were already generalized to at least 1: 1 million and smaller scales, and their compilers have consequently omitted much geological detail, which in turn implies that the world geology cannot not be too detailed or semantically complex.  It was also discovered during the project that fine semantic distinctions are particularly hard to implement consistently over time, even by the same compiler. Therefore, basic age ranges and very general rock types received most of the focus in this project to ensure satisfactory consistency in the final export products.  

ACKNOWLEDGMENTS

The writer is grateful for the considerable support provided by the following Earth Science Sector personnel: E. M. Hillary, W. D. Sinclair, R. V. Kirkham, J. M. Duke, A. Bourgeois, J. Bill, G. Labelle, P. Charlesworth, P. Huppé, T. West, M. Méthot, J. Pratt, V. Dohar, I. Kumar,  J. A. Grant, and C. W. Jefferson. Reviews, editorial suggestions, and help in compilation were gratefully received from Dr. William Muehlberger, Dr. Jan Escher, Dr. M. de Wit, Dr. Kristine Asch, Geoscience Australia, and Liangwei Xue.  Dr. Carlos Schobbenhaus is thanked for making the Geological map of South America available prior to its publication.    Dr. Alan Smith, Cambridge, UK is thanked for generously providing encouragement and a final review which paved the way for this open file publication.

The following sponsors are thanked for their financial support:  Anglo-American Corporation, Barrick Gold Corporation, BHP Minerals Canada Limited, BHP-Billiton International, Cyprus Amax Minerals Company, Falconbridge Limited, INCO Limited, Metal Mining Agency of Japan, Noranda Exploration Company Limited, North Limited, Phelps-Dodge Limited, Placer Dome Canada Limited, Rio Tinto Mining and Exploration Limited, and WMC International Limited. 

REFERENCES

Anonymous
1999:	Bedrock map of Finland; Geological Survey of Finland, scale 1:10,000,000, Internet.

Brooks, R.
1998:	Generalization research at the GeoAccess Division; Canadian Centre for Remote Sensing, Natural Resources Canada, unpublished information sheet, May, 1998, 1 p.

Brooks, R., Dussault, C., and Chorlton, L. B.
1999:	Automated generalization of multiclass area patches; International Cartographic Association, ICA’99 Conference, August, 1999, Ottawa, Canada, poster display.

Bruel, M.
2000:	Amélioration d’une procédure automatisée de généralisation de polygones pour la mise à jour de la compilation de cartes provenant de sources plus détaillées: Rapport final; Programme de perfectionement professional en géomatique, unpublished, 18. p.

Davenport, P.; Boisvert, E.; Quat, M.; Okulitch, A.; Brodaric, B.; Colman-Sadd,  S.; Nolan, L.; Struik, B.; MacIntyre, D.; Tzeng, P.; Scott, D.; Gilbert, C.; Abbott, G.; Bassan, A.; Journeay, M.; Francis, J.; Houlahan, T.:
2002:	A scalable, digital map database of bedrock geology for Canada; a progress report;  In Digital mapping techniques '02; workshop proceedings; edited by Soller, D. R., United States Geological Survey, Open-file Report 02-0370, 2002; pages 47-66

Derry, D. R.
1980:	World atlas of geology and mineral deposits; Mining Journal Books Ltd., John Wiley and Sons, 110 p.

Dunne, K. P. E. and Kirkham, R. V. (compilers)
2000:	World distribution of porphyry, porphyry-related skarn, and bulk-mineable epithermal deposits; Geological Survey of Canada, Open File 3792a, 26 pages.

Dussault, C.
1999:	Modification de l’outil de generalization cartographique AGG: Rapport final; Programme de perfectionement professional en géomatique, unpublished, 13. p.

Eckstrand, O. R. and Good, D. J. (compilers)
2000:	World distribution of nickel deposits; Geological Survey of Canada, Open File 3791a, 19 p. and 2 diskettes.

Eckstrand, O. R., Good, D. J., Yakubchuk, A., and Gall, Q. (compilers) 
2004:	World distribution of Ni, Cu, PGE, and Cr deposits and camps; Geological Survey of Canada, Internet.

Gandhi, S. S. (compiler)
2003:	World distribution of iron oxide +/- Cu +/- Au +/- U deposits; Geological Survey of Canada, in preparation.

Geological Survey of Canada
1995:	Generalized geological map of the world and linked databases; Geological Survey of Canada; Open File 2915d, CD-ROM.

Gosselin, P. and Dubé, B. (compilers)
2004:	Distribution, geological parameters and gold content of lode gold deposits of the world; Geological Survey of Canada, Open File in preparation.

Greninger, M. L., Klemperer, S. L., and Nokleberg, W. J.
1999:	Geographic Information Systems (GIS) compilation of geophysical, geologic, and tectonic data for the Circum-North Pacific; U. S. Geological Survey, Open File Report 99-422, CD-ROM.

Hannington, M. D., Petersen, I., Jonasson, I. R., and Franklin, J. M. (compilers)
1995:	Hydrothermal activity and associated mineral deposits of the seafloor; in Generalized geological map of the world and linked databases; Geological Survey of Canada, Open File 2915d.

Imhoff, C., Galemmo, N., and Geiger, J. G. 
2003	Mastering Data Warehouse Design: Relational and Dimensional Techniques; Wiley Publishing Inc, 438 p.

King, P. B. and Beikman, H. M. (compilers)
1974:	Geology of the conterminous United States (excluding Alaska and Hawaii); U.S. Geological Survey, scale 1:2,500,000.

Kirkham, R. V., Carrière, J. J., Garson, D. F., and Laramée, R. M. (compilers)
1994b:	World distribution of sediment-hosted, stratiform copper deposits and occurrences; Geological Survey of Canada, Open File 2915b, scale 1:35,000,000.

Kirkham, R. V., Carrière, J. J., Garson, D. F., and Laramée, R. M. (compilers)
1995:	World distribution of sediment-hosted, stratiform copper deposits and occurrences; in Generalized Geological map of the world and linked databases; Geological Survey of Canada, Open File 2915d.

Kirkham, R. V., Carrière, J. J., and Rafer, A. B. (compilers)
2003:	World distribution of sediment-hosted, stratiform copper deposits and occurrences; Geological Survey of Canada, unpublished.

Kirkham, R. V., Chorlton, L. B., and Carrière, J. J. (compilers)
1994a:	Generalized geology of the world: Age (Era)/ Rock type domains; Geological Survey of Canada, Open File 2915a, scale 35,000,000.

Kirkham, R. V., Chorlton, L. B., and Carrière, J. J. (compilers)
1995:	Generalized geology of the world: Age (Era)/ Rock type domains; in Generalized geological map of the world and linked databases; Geological Survey of Canada, Open File 2915d, CD-ROM.

Kirkham, R. V. and Dunne, K. P. E. (compilers)
2000:	World distribution of porphyry, porphyry-associated skarn, and bulk-tonnage epithermal deposits and occurrences; Geological Survey of Canada, Open File 3792a, 26 p. and a diskette.

Kirkham, R. V. and Rafer, A. B. (compilers)
2003:	Selected world mineral deposits database; Geological Survey of Canada, Open File 1801, document and diskette.

Korsman, K., Koistinen, T., Kohonen, J., Wennerstrom, M., Ekdahl, E., Honkamo, M., Idman, H., and Pekkala, Y.
1997:	Bedrock Map of Finland; Geological Survey of Finland, scale 1:1,000,000.

Jenkins, C. L. and Lydon, J. W. (compilers)
2002	A mineral deposit data base structure and a data base of VMS and Sedex deposits; Open File 4165, 2002.

Johnson, B. R., Brodaric, B., Raines, G., and Fitzgibbons, T.
1997:	Data models for digital geological maps; Version 2.4, January 13, 1997.

Lauzière. K.
2004:	Parsing legend data using MapLith, Geological Survey of Canada, DetailDocument.doc, available on demand.

Luettig, G., Zhamoida, A. I., Chanteux, P., Choubert, G., and Faure-Muret, A.
1980:	Geological World Atlas, Europe; Commission for the Geological Map of the World, UNESCO, Sheet 9, Scale 1:10,000,000.

Sangster, D. F. (compiler)
2004a:	World distribution of Mississippi Valley Type Zn-Pb deposits; Geological Survey of Canada, unpublished

Sangster, D. F. (compiler)
2004b:	World distribution of Sedimentary Exhalative (Sedex) Pb-Zn deposits; Geological Survey of Canada, unpublished

Scheibner, E., Suppel, D. Lewis, P., Hayward, D., and Gallagher, R.
1996:	The Lachlan Fold Belt data package, Version 1, January 1996; Department of Mineral Resources, Geological Survey of New South Wales, Scale 1:1,000,000, CD-ROM. 

Schruben, P. G.
1997:	Geology and resource assessment of Costa Rica at 1:500,000 scale - A digital representation of maps of the U. S. Geological Survey’s 1987 Folio 1-1865; U. S. Geological Survey, U. S. Geological Survey Digital Data Series DDS-19, CD-ROM.

Schruben, P. G., Arndt, R. E., and Bawiec, W. J. (digital compilers)
1994:	Geology of the conterminous United States at 1:2,500,000 Scale - A Digital representation of the 1974 P. B. King and H. M. Beikman Map; U.S. Geological Survey Digital Data Series DDS-11, CD-ROM.

Shaw, R. D., Yeates, A. N., Doutch, H. F., Palfreyman, D, and Blake, D.
1998:	Australia Geology; in National Digital Geoscience Datasets, Version 1.1; (ed.) Kilgour, B. and Wyborn, L.,  Australian Geological Survey Organization, CD-ROM.

Steinshouer, D. W., Qiang, J., McCabe, P. J., and Ryder, R. T.
1999:	Map showing geology, oil and gas provinces of the Asia Pacific Region; U. S. Geological Survey, Open File Report 97-470-F, CD-ROM.

Wheeler, J. O., Hoffman, P. F., Card, K. D., Davidson, A., Sanford, B. V., and Roest, W. R. (compilers)
1997:	Geological map of Canada (Version 1.0; Jan. 97); Geological Survey of Canada, Map D1860A, scale 1: 5,000,000, CD-ROM.

APPENDIX I: SCHEMA OF THE GEOLOGICAL GIS AND ITS ATTRIBUTE DATABASE

I. Introduction and overview of the data schema:

The geological schema underlying the Generalized Geology of the World has long been superseded by the North American Data Model (Johnson et al., 1997; <http://geology.usgs.gov/dm/> ), known as the NADM. The GGW schema is described here only to document the current data set and to mention classification dilemmas which might be encountered while populating geological databases of any schema. This schema was meant to accommodate those bedrock domain and fault descriptors which are commonly available in regional geological map legends and geological overviews, which are significant to mineral resources, and which might be of universal interest if the data were used as a global geological gazetteer.  The database schema was developed iteratively for the GGW and other concurrent projects, particularly for the Bathurst Mining Camp Extech II project (Wright, Chorlton, and Goodfellow, 1997; Chorlton and Wright, 1996), and was kept as simple as possible until project requirements forced its extension.  Several structural flaws that stem from on-the-fly development and simultaneous implementation were allowed to persist in order to finish projects without back-tracking and to avoid the ‘analysis paralysis’ syndrome.

The geology attribute database (Figure I-1) consists of four independent data systems:  (1) a bibliographic system for references; (2) a data dictionary;  (3) a rock unit system; and (4) a fault system.  Each independent system has its own series of unique numerical primary keys.  The first two systems are essentially metadata, or “data about the data”, whereas the last two are data. The bibliographic system is linked with the rock unit and fault systems though intersection (junction) tables, which handle the 

Figure I-1: Diagram illustrating the geological database schema of the Generalized Geology of the World with the GIS features at the root of the schema.  The notation 1,n indicates that there can be one or more than one entry in the table or system of tables represented underneath each entry in the parent data set. Each reference may have 0 to many (n) records in the junction tables linking them to faults or rock units.
 
inherent ‘many-to-many’ relationships that exist because information for one record set in the rock unit or fault system can be derived from multiple references, and each reference can provide information for multiple rock unit or fault record sets.  The data dictionary documents the database schema, content definitions, and constraints and is not depicted in Figure I-1. The database was implemented in INFO™, a program included in the ESRI ArcInfo™ GIS software.
 
II. Bibliographic system:
	
The bibliographic system is a stand-alone database with its own set of primary keys (Figure I-2a).  The core is the main reference table, REFMAIN, in which the primary key, a publication year, a title, and a code for type of publication make up a record.  Every reference record is linked in a one-to-many relationship to a 

Figure I-2a: Schema for the bibliographic data system, which in part recreates the publication style system provided by EndNotes™, as seen starting from REFMAIN (shaded) at the root.  Intersection tables RUXREF and FTXREF store the relationships between references and faults and/or rock units. This and subsequent schema diagrams were generated using Altova’s XMLSpy™ software.

table of authors through the primary key.  The author records consist of the primary key as a foreign key, a rank that reflects to the order in which the author is listed, a last name, and a first name or initials.  Because the extra information pertaining to different types of publication varies, additional reference information is stored in separate tables, one each for digital files, maps, reports, and articles in journals or symposium volumes (Figure I-2a).  References can be output in a wide variety of reference styles using custom queries and reports.

The bibliographic system is linked to the bedrock and fault systems through two intersection tables, RUXREF for rock units and FTXREF for faults (Figure I–2a). These tables also house tags that are essentially Boolean in nature (Y or N) to indicate which categories of information came from a reference (Figure I-2b), e.g., AGESRC or RXTPSRC. The reference-data intersection tables also house the key (UPDNO) that links to an update table recording data entry session type (attributes or GIS features), the time of each update; and who performed the update; it was assumed that no information would be added without a data source. The update key and records were inserted automatically for data entry performed using the matured data entry interface, but were not captured at all during the early stages of the project. 

Figure I-2b: Fields in the intersection table RUXREF that describe the relationship between individual references and bedrock units. 

III. Data dictionary: 
	
The data dictionary for the GGW comprises a full description of the database tables, table links, fields, and allowed values.  The data dictionary was prepared in the form of normal tables, rather than embedded in the database by the database management system (dbms) as hidden proprietary system tables.  In this way, the data dictionary remains completely portable and accessible to many programming languages for automated data transfer from one dbms to another.  The data dictionary tables include: 

(a)	Catalogues of all of the tables in the database for rock units (RU.CAT in Info™ and ruct in MS-Access™) and faults (FT.CAT in Info™ and ftct in MS-Access™), listing their functions, type of table, subsystem, primary and foreign keys. 
(b)	A links table cataloguing the links between tables.  
(c)	For each data table, a field definition table listing each field name, its data types and size, where the data should come from, (i.e., pick list, assigned by system applications, or typed in freely), and the intended use of the field.
(d)	For each non-numerical field for which values should be controlled, a pick list table of values allowed for that field.  

These tables can be used for standard documentation, export and backup routines, pick lists for data entry and for query, and status bar explanations for database elements in customized graphical user interfaces.

IV. Rock unit system:

Figure I-3 illustrates the general schema for rock units with the geological polygon features at the root. The attribute system linked to the GIS features is composed of a parent table, RU, that contain very basic identifiers for each bedrock unit, and child tables that contain related information for age range, rock types, unit name(s), geological province(s), tectonic setting(s, and significant commodities. There is only one age range per rock unit. There may be several general rock type components per parent record and age range. Entries for age range and for at least one rock type component are mandatory, except for cases where data sources provide absolutely no information for the domain.  The other information topics were made optional because it was impossible to populate the schema thoroughly with in the time available.

Figure I-3: Schema for rock units showing GIS features at the root linked to the rock unit master table (RU) and the general topics chosen to describe it: age range, rock type, names, tectonic setting, significant commodities contained, and links to data sources. 

a) Rock unit master table: 
	
The rock unit parent attribute table, RU (Figure I-4), is the hub of the rock unit data set.  Each rock unit record in this parent table represents a unit exposed within one geographic rock unit domain having one age range and sharing the same rock type components, stratigraphic makeup, geological provinces, and tectonic settings. Two or more such records may be related to a single polygon in the GIS data set because their unit outcrop patterns are complexly intermingled; this is fairly common in small-scale regional geological maps.  The polygon number, RUNO, and a secondary record number, ID2, is applied to each rock unit master record, and together they form a unique compound key. This key format was inherited from the compilation of the original GGW (Kirkham et al., 1995), when the original attributes were simple and housed in one table.  For convenience in forming joins with child tables when querying in ArcInfo™, a dependent but unique primary key, RUNO-ID2, was calculated from the compound key by the data entry interface. The compound nature of the primary key and its dependency on other keys in the table could have been avoided, but it was very helpful for verifying the various versions of the polygon coverages against the database in the early stages of the project.  Another verification field, RUCODE, is used to store legend codes or abbreviated descriptive text describing symbols, e.g., “brown dots”, on input source maps. The field DEFLT indicates which of potentially ore than one record is the default record for each polygon feature, which is convenient for quick plots and default export maps.  The field OFFSHORE indicates whether the polygon feature (and its unit) is exposed onshore or offshore.

Figure I-4: Elements of the master rock unit table.  Because the implementation of data types vary among database management systems, the characters Y and N were used for fields that are identified in this figure as Boolean to facilitate data transfer.

Each main rock unit record is linked in a many-to-many relationship to one or more data sources from the bibliographic system. The intersection table (Figure I-2a: item RUXREF) represents the relationship between the master rock unit record and references, and can be used to indicate which classes of subject matter, e.g. age, rock type, setting, or name (Figure I-2b), were derived from the reference.  

b) Age:
	
Each record in the main unit table RU is linked through the primary key, RUNO-ID2, to the age table, RUAGE (Figure I-3).  RUAGE contains one set of start and end ages for the rock unit in the time stratigraphic or chronostratic terms indicated by the data source.  The lookup table, AGETSMA, provides the drop-down list of allowed age terms which is available for data entry, and also records the start and end boundaries for these terms in millions of years.  The numerical boundaries are used to facilitate the query of age ranges, allowing units that overlap in age range but attributed using different age terms to be retrieved collectively with single queries. Boundary calibrations used are extracted primarily from Harland et al. (1990), which is an internally consistent and well-documented information source that conveniently covers most time terms encountered on international maps. Precambrian subdivisions and boundaries from Plumb (1996) were added.  The new IUGS timescale (Gradstein et al., 2004) should be used in future to revise the boundary calibrations, but does not yet include many of the terms used in the geological source maps.  

c) Rock type:
	
Each rock unit record in the master table is linked in a one-to-many relationship through the primary key RUNO-ID2 to a master lithological component table, RUTYPE. This table (Figure I-4) is the hub of a subsystem developed around attributes pertinent to rock type, and contains its own compound primary key, which combines the parent primary key and a secondary component number, COMPNO, that is assigned at this level.  Rock type components are very broadly classified as sedimentary, volcanic, volcano-sedimentary, intrusive, crystalline, or tectonic at this level. A rock type status field indicates whether only one rock type component was included in the parent unit (SIMPLE), or whether other rock type components are included in the parent unit (MIXED).  Fields for approximate percent proportion of the component and a user-ranked priority for the component were added to this table for employment in specific applications.  The proportion field was populated selectively over one fairly restricted area for one end-user purpose, which was to estimate the area of shale or mudstone at the bedrock surface of central and southern North America and calculate its very approximate capacity for supplying mercury contaminants to the lithosphere above it. 

Figure I-4: Elements of the rock type table, RUTYPE.

The choice of broad classification is not clear-cut for many components. There is considerable, and for the moment un-resolvable, ambiguity between units containing both volcanic and clearly sedimentary rocks, and rocks with both volcanic and sedimentary characteristic such as the distal, potentially re-deposited, portions of large ash-flows.   Pronounced metamorphism and tectonism give rise to other dilemmas. Although metamorphism and tectonism may be considered as overprints on other primary rock classes, tectonic or metamorphic reconstitution may obliterate the characteristics of the protoliths to the extent that their nature is speculative. It is therefore common practice to assign metamorphic and tectonic terms to legend units for which metamorphism or tectonism is the dominant characteristic, optionally adding probable protoliths in sub-text.  Metamorphic and tectonic categories are therefore entered into the RUTYPE table and the word DUAL was entered as the rock type status, or appended to MIXED/ if there are multiple significant components.  It is recognized that the RUTYPE table could have included a field for a general metamorphic classifier that could be applied to the metamorphic overprint on any rock type component. However, it was considered outside of the scope of the project because gathering this information consistently and adequately on a world scale would have been difficult, and because the representation of metamorphism might be better matched to a geological GIS data set representing metamorphic rather than rock unit features. 

Different parameters and value lists are used to describe each different rock type category. Therefore, additional details may be entered in category tables (Figure I-5).  Sedimentary details can be entered into a sedimentary table, SEDIMENT, volcanic details can be added to a volcanic table, VOLCANIC, intrusive details can be added to an intrusive table, INTRUSIV, crystalline metamorphic details can be added to a crystalline metamorphic table, CRYSTALL, and tectonic details can be added to a tectonic table, TECTONIC. If no information other than very general rock type category is available for a component, as is common for very small scale regional maps, the detail tables are not used.
 
Although Figure I-5 indicates that each rock type component leads to a single choice of detail tables, in reality volcano-sedimentary, crystalline metamorphic, and tectonic components can be described in more than one table. Volcanic and sedimentary descriptions could be applied to a volcano-sedimentary component, so that details could be entered in both sedimentary and volcanic tables.  Metamorphic domains can often be described both in metamorphic terms and in terms of their protolith category; they might therefore contain entries in the metamorphic table as well as sedimentary, volcanic, and/or intrusive tables. The rock type status value DUAL in the RUTYPE table is entered to hint that this is possible.  Note that the reverse situation, the linking of a detail record to more than one parent is not allowed.

Figure I-5:  Sub-schema for rock type components. Each broad class of components recorded in RUTYPE (shaded) leads to another set of tables that are customized for the particular types of details and pick lists commonly applied to that class in geological practice.

Attributes in the specialized detail tables consist of one general class, corresponding to the most common meaningful classification suitable for the category of rock type and generalization level of the database, plus a number of rock category specific qualifying fields and auxiliary tables for more detailed subject matter at a deeper level of the database (Figure I-5).  Many of the terms used to describe rock types reflect the generalization levels of regional data sources.   The auxiliary tables accommodate specific lithologies in the terms of the data source (suffix MEM, meaning members of the general class), internal syn-depositional or syn-emplacement structural features (suffix STRUC), external forms or morphology (suffix FORM), and depositional environments (CHREGIME: water-chemistry-related, and DPREGIME for sedimentary rocks).
	
For volcanic rocks (Figure I-6), general classifiers are entered into the field MAFRANGE, and include commonly used compositional terms such as ultramafic-mafic, mafic, mafic-intermediate, intermediate, intermediate-felsic, felsic, and bimodal.   For intrusive rocks (Figure I-7), an intrusive suite name is housed in the field INTCLASS, because intrusive rocks may range widely in composition internally.  Examples of these suite names are tonalite-granodiorite suite, anorthosite suite, gabbro-anorthosite suite, and gabbro suite, which are widely recognizable classifiers commonly found on map legends.  Both intrusive and extrusive igneous rocks could be further described by predominant magma series in field CHEMGRP. A depositional setting field, DEPSET, to capture whether the volcanics were deposited in a marine, shallow marine, or subaerial environment is provided in the volcanic table (Figure I-6).  True/false/unknown character fields have been added to both igneous detail tables. These contain either T or F if the component is known or known not to possess the attribute or association suggested by the field. If there is no relevant information, these fields retain the default value of U.  For volcanic components, the field INTEQU is used to indicate whether or not subvolcanic intrusions and the field METSED to indicate the presence of absence of metalliferous sediments.  For intrusive components, the field VOLEQU is used to indicate whether it is associated with volcanic rocks. The field DATED is used for all detail tables to flag the existence of age dates.  The occurrence of intrusive components in clusters or swarms of small intrusive bodies, the existence of significant aureoles and inclusions can also be flagged in the main intrusive detail table. Specific lithologies, internal structures (e.g., pillows, massive flows, layering), textures (e.g., ophitic, megacrystic), and external form  (e.g., dykes, domes, laccolith) are also important igneous details, and are accommodated in auxiliary tables at the next deeper level of the database.  Auxiliary tables describing metalliferous sediments, aureoles, and inclusions were also defined in the database schema as parameters that would be significant and of interest for a global geological gazetteer, but these were never populated.

Figure I-6: Attributes of the volcanic detail table.

Figure I-7: Attributes of the intrusive detail table.
	
The main sedimentary detail table (Figure I-8) includes one field to capture meaningful assemblages or associations of very general, commonly-applied sedimentary rock type terms. Suitable terms were chosen after looking at the legends of numerous maps of regional scale and determing which general terms are applied most commonly.  Terms a geologist would naturally use to filter the data sets for user-defined layers or data subsets were also considered. Possible terms include such associations as 'mudstone (includes shale)', 'mudstone-chert', 'conglomerate-sandstone-mudstone', and 'carbonate'.  Fine-tuning, which would result from greater use of the database and user feedback, will be needed to make the general classifiers satisfactory to most users.  A short, free text field is included in this table to capture qualifiers.  Flag fields indicate the presence of iron formation, evaporite, phosphate, coal, oil, or gas.  Whether or not the sedimentary component is dated is also flagged.  Specific lithologies, sedimentary structures, depositional environments and chemical regime details are captured in auxiliary tables at the next, deeper level of detail in the database (Figure I-5).

	
Figure I-8: Attributes of the sedimentary component detail table.

Highly metamorphosed domains, or more generally crystalline metamorphic rocks that contain mixtures of igneous and metamorphic material, are described the CRYSTALL series of tables.  The main detail table (Figure I-9) contains the usual, commonly applied general classifiers, such as metasedimentary schist, paragneiss, orthogneiss, migmatite, and metavolcanic schist.  Detailed lithologies are accommodated in a table at the next level of detail (Figure I-5).

Figure I-9: Attributes of the crystalline metamorphic component detail table.

There are few tectonic domains identified on the small-scale regional maps used as data sources.  Classification of these domains was kept to the bare minimum (Figure I-10), distinguishing only shear zones, mélanges, or subduction/trench complexes.  Even with this minimal classification there are overlaps and ambiguities.  For instance, a domain depicted on a map as a mélange may overlap in meaning with a domain classified as a subduction complex.  Compilers may lump and depict domains subjectively in different ways, and in many cases there may not be enough evidence to make fine distinctions or even strongly demonstrate a particular setting.

Figure I-10: Attributes of the tectonic component detail table.

d) Unit names:
	
Zero or more unit names at any level can be entered in the unit name table, RUNAME. The unit name(s) must apply to the entire master rock unit object.  The data entry interface allows the unit name to be typed in by the person building or modifying the database, or picked from a unique list of previously entered names in the database to ensure consistent spelling.  

e) Province, zone, or belt name:

Zero or more geologic province, zone, or belt names can be entered in the province table, RUPROV. The province, zone, or belt name(s) must apply to the entire master rock unit object as entered in the main master table, and can be typed in or picked from a list of previously entered names.  

f) Tectonic setting:

Zero or more records describing tectonic setting can be entered in the tectonic setting table, RUSET.  The values for the realm (oceanic, continental, etc.), regime (extensional, etc.), tectonic feature (arc, basin, trench, platform, etc.), and depth (surface, near surface, mantle, etc.) are entered from pick lists, and should apply to the entire master rock unit object.  This table has not been extensively populated.

In a late-stage and only partially complete evolution of the GGW data set, this information was added to an independent data system for geological provinces or zones, and the zones above were linked to the rock unit data set using an intersection table.

g) Known commodities:

Zero or more records listing commodities for which the rock unit is well known are stored in table RUMIN.DAT.  Commodity values are entered from a pick list. This table has been not been extensively populated.

V. Fault system:

Figure I-11 illustrates the general schema for faults with the geospatial features of the GIS data set at the root, to which the parent fault attribute table connects through the arc USER-ID (alias: FTNO). Child attribute tables that house information for age range, fault types, name(s), fault zone name(s), and tectonic setting(s).  At least one displacement component is mandatory, but the other attributes are optional because of the difficulty of obtaining the information in the time available. Many data sources do not distinguish fault types, and many faults have complex histories which are not interpreted with confidence.

Figure I-11: Schema for faults showing fault GIS features as the root, the linked fault event master table FT (shaded), and the general topics chosen to describe it: age range, fault type, names, tectonic setting, and links to data sources.  

a) Fault master table: 
	
The parent fault attribute table, FT, is the hub of the fault data set (Figure I-12).  Each master record represents a fault event with one age range of displacement, and shares the same fault names, fault system names, tectonic settings, and fault type and general displacement.  Two or more such events may be represented by a single GIS feature because it is usual for major faults to have undergone a complex displacement history.  A combination of the arc USER-ID under the alias FTNO and a secondary record number, ID2, is applied to each fault event to create a compound primary key, FTNO-ID2.

Figure I-12: Attributes of the master fault table.

The field DEFLT indicates with essentially Boolean values Y or N which master record should be the default plot record for the arc. The Boolean field OFFSHORE indicates whether it is exposed onshore or offshore.  Abbreviated descriptive text derived from source maps can be entered into the field FTCODE. 

Each main fault entity record is linked in a many-to-many relationship to one or more data sources from the bibliographic system. The intersection table is similar to the intersection table between references and rock unit entities (Figure 4), flagging what types of data (e.g. age, fault type, setting, name, etc.) were derived from the reference.  

b) Age:

Each record in the main fault table is linked by the main primary key, FTNO-ID2, to an age table, FTAGE, that records the start and end ages of the displacement on the fault entity in terms of the chronostratic scale as precisely as possible.  There may be no record in the age data table for many of the faults in the data set because ages were not available in data sources.  The previously described lookup table, AGETSMA, is used as a source of time terms and as a calibration table tool for age range querying for age range queries.

c) Fault type:
	
Each fault is linked through the primary key FTNO-ID2 to a table, FTTYPE, which can hold one-to-many fault movement components attributed by very basic fault type and displacement sense (Figure I-13). Fault type categories that are recorded in the FTCLASS field are normal, overthrust, high angle reverse, strike-slip, and unclassified. The latter reflects lack of attribution in source maps.  Values for the displacement sense, FTDISP, must be selected according to fault type.   Strike-slip faults can be either sinistral or dextral, obliqueness not yet being accommodated in lookup values.  The displacement senses for normal faults, overthrusts, and reverse faults are at present merely recorded by indicating the position of the upper wall by the eight points of the compass. 

Figure I-13: Attributes of the fault type table.

d) Fault names and fault zone names:
	
Zero or more unit names at any level can be entered in the unit name table, FTNAME.  Name(s) must apply to the entire master fault record.  The fault name can be typed in by the person populating the database, or it can be picked from a unique list of previously entered names in the database to assure consistent spelling.  

Likewise, zero or more fault zone or system names can be entered into FTZONE. The province, zone, or belt name(s) must apply to the entire master table fault record, and can be typed in or picked from a list of previously entered names.  

e) Tectonic setting:

Zero or more records describing tectonic setting can be entered in the tectonic setting table, FTSET.  Values for settings are entered from pick lists, and should apply to the entire master table fault record. The values for the realm (oceanic, continental, etc.), regime (extensional, etc.), and depth (surface, near surface, mantle, etc.) are derived from the same pick lists as identical fields in the analogous table for rock units.  Tectonically significant fault features, such as suture, mid-ocean ridge, or transform fault, required a pick list unique to major fault features. 

VI. Use-ability and potential future strategies

The Generalized Geology of the World data set was created with a relational database style so that geological compilers could enter the data without having the frustration of ‘trying to fit a round peg in a square hole’.  With the flexibility offered by a relational database, in contrast to a spreadsheet with a finite number of columns and traditionally only one row per entity/feature being described, compilers should not be tempted to force essential unpremeditated subject matter into fields meant for other types of information; a database can be extended with new table without affecting the existing structure. Moreover, compilers would not be forced to make arbitrary decisions about which important but alternative components of a geological unit or fault displacement to capture.  Nevertheless, geologists lacking the technical skills necessary find relational databases very difficult to use, particularly if they are not provided with graphical user interfaces that enable end-use data extraction.  It was important therefore to figure out how to provide end-user output in the form of flat files, or spreadsheets customized according to end-user requirements, while also allowing exploratory access and filter capability for the full contents of the database for those able to make use of it.  

The Generalized Geology of the World data set stands out from other regional geology maps because it was never meant to be used in its entirety for a single map, and there is no default symbology.  The granularity of attributes for ‘bedrock units’ is too inconsistent world-wide to provide one comprehensible map, and on the other hand, despite deliberate generalization, there is still too much spatial detail in the GIS features of the main data set for clear visualization at the 25-35 millions scale.  In addition, GIS features are commonly linked to more than one “unit” or “event” which would make representing the full data set in one plot impossible. It does however provide opportunities to represent very small but significant features that can be ignored for generalized maps but used for specialized purposes.1   The data set was thus intended solely for the production of derivative data sets or displays in the form of flat files or simple visual layers.   It can either be (1) queried on-the-fly to produce a distribution layer to answer a single question; or (2) pre-queried to prepare thematic world maps using the attributes that are relatively uniformly populated world-wide (namely age and rock or fault types) to produce complete coverages illustrating generalized themes.   

For on-the-fly query and display, a graphical user interface was built in ArcInfo™.  The interface worked satisfactorily, verifying the use-ability of the data schema, but even query creation (without the graphical polygon filling) was too slow to be adapted for the Internet if queries from two or more topics such as age and rock type are combined.  This signifies that relational design may not be the whole answer to ad hoc querying over the Internet or Intranet; some other optimization techniques may be necessary.

The full world map derivative data sets provided with this publication were created using Arc Macro Language custom scripts packaged as program files organized by task.  In the first group of tasks, each GIS coverage was copied to a new file, to which generalized attributes were attached.  Then the database was subjected to a series of age range and rock type queries that created selection sets; values were entered into the new generalized attributes for each set.  A second program was used to remove redundant contacts from the data set containing the generalized attributes.  The derivative data sets were then re-projected through the date-line to standard geographic projection and then exported to shape files so that they would be easy to use with desktop GIS.  Yet another program extracted the references used for each derivative data set and exported them to a text file.  This processing was very time-consuming, and was performed by running batch files overnight, but did provide map products that are directly suitable for Internet map display.

The preparation of full custom map coverages according to the law of planar enforcement, meaning every land polygon was classified, requires programming with a much deeper awareness of the complexities of the database than is required for simple ad hoc queries.  Thus, the decisions made for this exercise required general geological expertise and judgment about what compromises are acceptable for what specific end uses.  For the generalized age and rocks type and Precambrian age and rock type themes, the query scripts filtered out all but the record sets for default “units”.  The database was queried and reclassified for age ranges at the era level, and with the simplest level of rock type component classes and combinations.   For the specialized felsic-intermediate and mafic-ultramafic magmatic themes, default filters were not applied and the rock type queries created selections based on the top level classifiers in the volcanic and intrusive detail tables. The resulting generalized classes were further subdivided by age range. Conflicts are present for units that include both intrusive and volcanic components.   To deal with this, the selections were performed in reverse order of priority to ensure that the felsic-intermediate theme preferentially captured the volcanic attributes, and the mafic-ultramafic theme preferentially captured the intrusive attributes.  An alternative would have been to create a more complex legend which included values for mixed units. These rule-based compromises are analogous to those made in the preparation of any very small scale geology map for which compiler must decide which information to represent and which to suppress in areas with complex map patterns.  

For a combination of spatial data sets that are easy to visualize over the Internet but over which ad hoc queries can be applied, it may be possible to configure a web map service with the full attribute data set using a query tool similar to GQueryClient.exe (Laramée, 2005) or an emulation of GQuery used with a web map server serving simplified map layers as context.  GQueryClient is one of a suite of graphical user interfaces for data entry and query developed for the World Minerals Geoscience Database Project mineral deposit databases.  GQueryClient is currently downloadable, and the browser-based web map server is accessible, over the Internet by starting at www.gdr.nrcan.gc.ca and navigating to Mineral deposits and to Mineral Deposit Databases.  Both GQuery tools work through a mineral deposit database data dictionary, which is analogous to the GGW data dictionary. The full set of spatial features symbolized by default as invisible, or transparent to allow other map layers to peak through, until individual features are highlighted in response to a user query.   It is questionable still if the rendering of custom filtered polygons would be fast enough to be acceptable, even though the rendering of deposit points is rapid.

Information underlying bedrock and surficial geological map databases are critical input components for a wide variety of envisaged environmental and resource assessments, in combination with other data sets of inherently numerical nature.  The use-ability debate suggests that the geological relational database, or alternatively an NADM geology database is very effective in allowing compilers to capture much of the information that would be necessary for a reasonable selection of such purposes without trying to fit round pegs in square holes.  Both are also suitable for ad-hoc query with some optimization for speed if remote access is being considered.   But clearly, the comprehensive corporate data set does not suit all needs in the data supply, dissemination and end-use or decision support chain.  For convenient end user data sets for geologists and geo-mathematicians that wish to combine the data with other numerical data in real time, other robust solutions should be investigated even if they involve periodic replication and data redundancy.   The concept of creating specialized data warehouses and even more application specific data marts, which is the subject of a relatively new IT/IM field called data warehousing (Imhoff et al., 2003; Bédard, 2005), would be worth investigating.

REFERENCES

Bédard, Y.
2005: Analytical databases and spatial on-line analytical processing (SOLAP): New solutions for decision-support and geographic knowledge discovery; GEOIDE Summer School 2005, unpublished short course.

Chorlton, L. B. and Wright, D. F.
1996:	Developing and prototyping a flexible, long term geological GIS; Geomatics’96, Abstract 063, 1996 Geomatics’96 CD-ROM.

Gradstein, F. M. and Ogg, J.
1996:	A Phanerozoic time scale; Episodes, Volume 19, Nos 1&2, p. 3-5 and insert.

Gradstein, F. M., Ogg, J. G., Smith, A. G., Agterberg, F. P., Bleeker, W., Cooper, R. A., Davydov, V., Gibbard, P., Hinnov, L., House, M. R., Lourins, L., Luterbaker, H-P., McArthur. J., Melchin, M. J., Robb, L. J., Shergold, J., Villeneuve, M., Wardlaw, B. R., Ali, J., Brinkhuis, H., Hiljen, F. J., Hooker, J., Howarth, R. J., Knoll, A. H., Laskar, J., Monechi, S., Powell, J., Plumb, K. A., Raffi, I., Röhl, U., Sanfilippo, A., Schmitz, B., Shackleton, N. J., Shields, G. A., Strauss, H., Van Dam, J., Veizer, J., van Kolfschoten, Th., and Wilson, D.
2004:	A Geologic Time Scale, 2004; Cambridge University Press.

Harland, W. B., Armstrong, R. L., Cox, A.V., Craig, L. E., Smith, A. G., and Smith, D. G.
1990:	A geologic time scale 1989; Cambridge University Press, 263 p.

Imhoff, C., Galemmo, N., and Geiger, J. G. 
2003	Mastering Data Warehouse Design: Relational and Dimensional Techniques; Wiley Publishing Inc., 438 p.

Johnson, B. R., Brodaric, B., Raines, G., and Fitzgibbons, T.
1997: Data models for digital geological maps, Version 2.4, January 13, 1997.

Okulitch, A. V.
1995:	Geological Time Chart; Geological Survey of Canada, Open File 3040.

Plumb, K. A.
1991:	New Precambrian time scale; Episodes, v. 14, no. 2, p. 139-140.

Wright, D. F., Chorlton, L. B., and Goodfellow, W. F.
1997:	Geological map data management for the Bathurst Camp EXTECH II Project, Exploration ’97, Proceedings.

APPENDIX II:  DATA SOURCES USED FOR THE GENERALIZED GEOLOGY OF THE WORLD

26th International Geological Congress
1980:	Geology of the European Countries. (4 Volumes); Graham and Trottman, Ltd.
 
Academy of Geological Sciences, Beijing
1975:	Geological Map of Asia; Academy of Geological Sciences, Beijing, China, scale 1:5,000,000.
 
Addicott, W. O., and Grye, G.
1988:	Geologic Map of the Circum-Pacific Region, Northwest Quadrant; Circum-Pacific Council for Energy and Mineral Resources, scale 1:10,000,000.
 
Addicott, W. O.
1983:	Geologic Map of the Circum-Pacific Region, Northeast Quadrant; Circum-Pacific Council for Energy and Mineral Resources, Scale 1:10,000,000.
 
Addicott, W. O., and Grye, G.
1988:	Geologic Map of the Circum-Pacific Region, Southwest Quadrant; Circum-Pacific Council for Energy and Mineral Resources, Scale 1:10,000,000.
 
Ager, D. V.
1980:	The Geology of Europe; John Wiley and Sons, New York, 535 p.
 
Aghanabati, A.
1986:	Geological Map of the Middle East; Geological Survey of Iran, for Commission for the Geological Map of the World, Scale 1:5,000,000.
 
Aitken, J. D.
1993:	Proterozoic Sedimentary Rocks; in Sedimentary Cover of the Craton in Canada: Geology of Canada; (ed.) Stott, D. F. and Aitken, J. A., Geological Survey of Canada, p. 81-95.
 
Allaart, J. H.
1976:	Ketilidian Mobile Belt in South Greenland; in Geology of Greenland; (ed.) Escher, A., and Watt, W. S., The Geological Survey of Greenland, p. 120-151.
 
Anonymous
1986:	Metallogenic Map of South and East Asia; Commission for the Geological Map of the World, Unesco, Scale 1:5,000,000.
 
Anonymous
1937:	International Geological Map of Europe, Sheet B4; Commission de la Carte Géologique de l'Europe, scale 1:1,500,000.
 
Anonymous
1991:	Greenland: A Handbook for Investors in the Mining and Petroleum Industries, Mining Journal Research Services, A Division of the Mining Journal Ltd.
 
Anonymous
1996:	Mapa Geologico De Bolivia; Servico Naçional de Geológia y Mineria, Proyecto Multinational Andino Sergeomin - CIDA, scale 1:5,000,000
 
Anonymous
1999:	Bedrock Map of Finland; Geological Survey of Finland, scale 1:10,000,000, Internet.
 
Asklund, B., Mafnusson, N. H., Simonen, A., Duphorn, K., Grahle, H. O., Reum, H., and Muzylev, S. A.
1966:	International Geological Map of Europe, Sheet D3; Commission de la Carte Géologique de l'Europe, scale 1:1,500,000.
 
Avramtchev, L.
1985:	Carte Géologique du Québec; Ministère de l'Energie et des Ressources, Gouvernement de Québec, Carte 2000, scale 1:1,500,000.
 
Bailes, A. H., Corkery, M. T., Macek, J. J., Bezys, R. K., and McGregor, C. R.
1993:	Bedrock Geology, Compilation Map Series, Preliminary Edition, Wekusko Lake, NTS 63J; Manitoba Department of Energy and Mines, scale 1: 250,000.
 
Baker, D. M., Lillie, R. J., Yeats, R. S., Johnson, G. D., Yousuf, M., and Zamin, A. S. H.
1988:	Development of the Himalayan Frontal Thrust Zone: Salt Range, Pakistan; Geology, Vol. 16, p. 3-7.
 
Ballance, P. F. and Campbell, J. D.
1993:	The Murihiku arc-related basin of New Zealand (Triassic-Jurassic); in South Pacific Sedimentary Basins: Sedimentary Basins of the World; (ed.) Ballance, P. F., Elsevier Science Publishers B.V., p. 21-33.
 
Bamber, E. W., Henderson, C. M., Richards, B. C., and McGugan, A.
1991:	Carboniferous and Permian stratigraphy of the Foreland Belt, Upper Devonian to Middle Jurassic Assemblages; in Geology of the Cordilleran Orogen in Canada: Geology of Canada no. 4; (ed.) Gabrielse, H. and Yorath, C. J., Geological Survey of Canada, Geological Society of America, p. 242-265.
 
Bayer, K. C.
1983:	Generalized structural lithologic and physiographic provinces in the Fold and Thrust Belts of the United States; U. S. Geological Survey, scale 1:2,500,000.
 
Beck-Mannagetta, P., Frasi, G., Lemoine, M., Graindor, M-J., Lipparini, T., Reutter, K. J., Duphorn, K., Ciric, B., Spicher, A., Reum, H., Dudek, A., and Malkovsky, M.
1972:	International Geological Map of Europe, Sheet C5, Bern; Commission de la Carte Géologique de l'Europe, Sheet C5, scale 1:1,500,000.
 
Beikman, H. M.
1980:	Geologic Map of Alaska; U. S. Geological Survey, scale 1:2,500,000.
 
Bennet, G., Dressler, B. O., and Robertson, J. A.
1992:	Huronian Supergroup and associated intrusive rocks, Southern Province and Proterozoic Events; in Geology of Ontario; (ed.) Thurston, P. C., Williams, H. R., Sutcliffe, R. H., Stott, G. M., Ontario Geological Survey, Ministry of Northern Development and Mines, p. 549-591.
 
Bennison, A. P.
1978:	Geological highway map of the Great Lakes Region; The American Society of Petroleum Geologists, Map No. 11, scale 1:1,900,800.
 
Bennison, A. P.
1976:	Geological highway map of the Northeastern Region; The American Society of Petroleum Geologists, Map No. 10, scale 1:1,900,800.
 
Bennison, A. P. and Chenoweth, P. A.
1984:	Geological Highway Map of the Northern Great Plains Region; The American Society of Petroleum Geologists, Map No. 12, scale 1:1,900,800.
 
Bennison, A. P., Renfro, H. B., and Feray, D. E.
1973:	Geological Highway Map of the Pacific Northwest Region; The American Society of Petroleum Geologists, Map No. 6, scale 1:1,900,800
 
Bernstein, S., Rosing, M. T., Brooks, C. K., and Bird, D. K.
1992:	An ocean-ridge type magma chamber at a passive volcanic, continental margin: the Kap Edvard Holm Layered Gabbro Complex, East Greenland; Geological Magazine, Vol. 129, p. 437-456.
 
Berzin, N. A., Dobretsov, N. L., Skylarov, E. V., Avdeev, A. V., Tomurtegoo, O., Ghes', M. D., Khristov, E. V., Xiao, X. C., Wang, J., Coleman, R. G., Chang, E. Z., and Ying, D. X.
1995:	Tectonic transect map across Russia-Mongolia-China; Stanford-China Geosciences Industrial Affiliates Program, International Geological Correlation Project, 283, scale 1:2,500,000.
 
Biddle, K. T., Uliana, M. A., Mitchum Jr., R. M., Fitzgerald, M. G., and Wright, R. C.
1986:	The stratigraphic and structural evolution of the central and eastern Maggallanes Basin, southern South America, Circum-Pacific and Western Americas Section; in Foreland Basins: Special Publication No. 8; (ed.) Allen, P. A. and Homewood, P., International Association of Sedimentologists, Blackwell Scientific Publications Inc., p. 41-61.
 
Birkelund, T., and Perch-Nielsen, K.
1976:	Late Paleozoic-Mesozoic Evolution of Central East Greenland; in Geology of Greenland; (ed.) Escher, A. and Watt, W. S., The Geological Survey of Greenland, p. 304-339
 
Bjorlykke, H., Skjeseth, S., Asklund, B., Magnusson, N. H., Simonen, A., and Reum, H.
1966:	International Geological Map of Europe, Sheet D2; Commission de la Carte Géologique de l'Europe, scale 1:1,500,000.
 
Bloomstein, E. I. and Clark, J. B.
1990:	Geochemistry of the Ordovician high-calcium black shales hosting major gold deposits of the Getchel Trend in Nevada; in Metalliferous black shales and related ore deposits-Proceedings: International Geological Correlation Group Program Project 254, (ed.) Grauch, R. I. and Huyck, H. L. O., U. S. Geological Survey, United States Government Printing Office, p. 1-5.
 
Boone, E. and Hynes, A.
1990:	A Structural Cross-section of the Northern Labrador Trough, Eastern Segment Section, in The Early Proterozoic Trans-Hudson Orogen of North America; (ed.) Lewry, J. F. and Stauffer, M. R., Geological Association of Canada, p. 387-396.
 
Bostok, H. H.
1980:	Itchen Lake Area, District of Mackenzie; Geological Survey of Canada, Natural Resources Canada, Map 1473A, scale 1:250,000.
 
Bouillin, J. P., Deleau, P., Laffitte, R., Rassi, Ph., Rouire, J., Compagnoni, B., Manganelli, V., Valletta, M., Burollet, P. F., Castany, G., Hilly, J., Jauzein, A., and Rouvier, H.
1983:	International Geological Map of Europe, Sheet C6, Roma; Commission de la Carte Géologique de  l'Europe, scale 1:1,500,000.
 
Boyd, R., Nilsson, G., Papunen, H., Vorma, A., Zagorodny, V., and Robonen, W.
1985:	General Geological Map of the Baltic Shield; Geological Survey of Finland, Bulletin 333, scale 1:2,500,000.
 
Bridgewater, D., Keto, L., McGregor, V. R., and Myers, J. S.
1976:	Archean Gneiss Complex of Greenland; in Geology of Greenland, (ed.) Escher, A. and Watt, W. S., The Geological Survey of Greenland, p. 18-75.
 
Bridgewater, D.
1976:	Nagssugtoqidian Moble Belt in East Greenland; in Geology of Greenland; (ed.) Escher, A. and Watt, W. S., The Geological Survey of Greenland, p. 96-103.
 
Burchfiel, B. C., Cowan, D. S., and Davis, G. A.
1992:	Tectonic overview of the Cordilleran Orogen in the Western United States; in The Cordilleran Orogen: Conterminous U. S.: The Geology of North America: Volume G-3, (ed.) Burchfiel, B. C., Lipman, P. W.,and Zoback, M. L., Geological Society of America, p. 407-480.
 
Burchfiel, B. C., Lipman, P. W., and Zoback, M. L.
1992:	Introduction; in The Cordilleran Orogen: Conterminous U. S.: The Geology of North America: Volume G-3; (ed.) Burchfiel, B. C., Lipman, P. W., and Zoback, M. L., Geological Society of America, p. 1-7.
 
Burton, C. K.
1986:	Geological evolution of the Southern Philippines: Geosea V- Proceedings; Geology Society Malaysia, Bulletin, Vol. 1, p. 87-102.
 
Cameron, E. M. and Jonasson, I. R.
1972:	Mercury in Precambrian shales of the Canadian Shield; Geochimica et Cosmochimica Acta, Vol. 36, p. 985-1005.
 
Campbell, R. B., Dodds, C. J., Yorath, C. J., and Sutherland-Brown, A.
1991:	Structural Styles, Insular Belt; in Geology of the Cordilleran Orogen in Canada: Geology of Canada no. 4; (ed.) Gabrielse, H. and Yorath, C. J., Geological Survey of Canada, Geological Society of America, p. 574-581.
 
Cannon, W. F. and Nicholson, S. W.
1996:	Middle Proterozoic Midcontinent Rift System; in Archean and Proterozoic Geology of the Lake Superior Region, U.S.A., 1993; (ed.) Sims, P. K., and Carter, L. M. H., U. S. Geological Survey, p. 60-67.
 
Card, K. D., Frith, R. A., Poulsen, K. H., and Ciesielski, A.
1996:	Preliminary Litho-tectonic map of the Superior Province, Manitoba, Ontario, Quebec, and United States of America; Geological Survey of Canada, Open File 3227, scale 1: 2,500,000.
 
Card, K. D., Percival, J. A., and Sanford, B. V.
1989:	Geology, Lake Nipigon, Ontario-U.S.A; Geological Survey of Canada, The National Earth Science Series, NM-16-G, scale 1,000,000.
 
Cepeck, A. G., Kolbel, H., Lrenz, W., Lotsch, D., Watznauer, A., Bouckaert, J., Sorgenfrei, TH., Gry, H., Ruhle, E., and Teisseyre, H.
1972:	International Geological Map of Europe, Sheet C4, Berlin; Commission de la Carte Géologique de l'Europe,  scale 1:1,500,000.
 
Chantraine, J., Autran, A., Cavelier, C., Alabouvette, B., Barfety, J-C., Cecca, F., Clozier, L., Debrand-Passard, S., Dubreuilh, J., Feybesse, J-L., Guennoc, P., Ledru, P., Rossi, P., and Ternet, Y.
1996:	Carte géologique de la France, Service Géologique National, BRGM, scale 1:1,000,000.
 
Charvet, J., Cluzel, D., Faure, M., Caridroit, M., Liangshu, Shu, and Huafa, Lu
1999:	Some Tectonic Aspects of the pre-Jurassic Accretionary evolution of East Asia; in Gondwana Dispersion and Asian Accretion: IGCP 321 Final Results Volume; (ed.) Metcalfe, I., International Geological Correlation Program (IGCP), A. A. Balkema Publishers, Rotterdam. Netherlands, p. 37-66.
 
Chen, Tingyu, Li, Guangcen, and Xie, Liangzhen
1995:	Geologic Map of Antarctica, Chinese Antarctic Administration, Institute of Geology, Chinese Academy of Geological Sciences, scale 1:5,000,000.
 
Chesher, J. A.
1991:	Geology of the United Kingdom, Ireland, and the adjacent Continental Shelf (North Sheet); British Geological Survey, National Environment Research Council, scale 1:1,000,000.
 
Chesitev, G., Youshah, B. M., Moustafa, G. A., El Ramly, M. F., Moffat, H., Creutzburg, N., Coutsouveli, A., Mavridis, A., and Adelhardt, W.
1979:	International Geological Map of Europe, Sheet E7, Qahira, Commission de la Carte Géologique de l'Europe, scale 1:1500,000.
 
Choubert, G., Faure-Muret, A., Simpson, E. S. W., Shackleton, L., Segoufin, J., and Seguin, C.
1986:	International Geological Map of Africa; Commission for the Geological Map of the World, Unesco, scale 1:5,000,000.
 
Choubert, G., Faure-Muret, A., Bishop, D. W., Dubertret, L., Mestraud, J-L., Pallister, J. W., Truter, E., Van Eeden, and O. R., Sougy, J.
1968:	Tectonic Map of Africa, Commission for the Geological Map of the World, Unesco, scale 1:15,000,000.
 
Chown, E. H. and Caty, J. L.
1973:	Stratigraphy, petrography and paleocurrent analysis of the Aphebian clastic formations of the Mistassini-Otish Basin; in Huronian Stratigraphy and Sedimentation, (ed.) Young, G. M., The Geological Association of Canada, Pierre Des Marais, Inc., Montreal, p. 49-71.
 
Christiansen, R. L. and Yeats, R. S.
1992:	Post-Laramide geology of the U.S. Cordilleran Region; in The Cordilleran Orogen: Conterminous U. S.: The Geology of North America: Volume G-3; (ed.) Burchfiel, B. C., Lipman, P. W.,and  Zoback, M. L., Geological Society of America, p. 261-406.
 
Ciric, B., Beck-Mannagetta, P., Frasi, G., Jovtschev, J., Balogh, K., Ruhle, E., Wdowiarz, S., Dessila-Codarcia, M., Patrulius, D., Radulesco, D., Sandulescu, M., Chatalov, E. T., and Vialov, O. S.
1969:	International Geological Map of Europe, Sheet D5, Budapest; Commission de la Carte Géologique de l'Europe, scale 1:1,500,000.
 
Coffin, M. F. and Eldholm, O. V.
1994:	Large igneous provinces: crustal structure, dimensions, and external consequences; Reviews of Geophysics, Vol. 32, p. 1-36.
 
Collection of Experts
1990:	Geological map of the world; Commission for the Geological Map of the World, Unesco, Scale 25000000
 
Collinson, C., Sargent, M. L., and Jennings, J. R.
1988:	Illinois Basin Region, The eastern mid-continent region section; in Sedimentary Cover - North American Craton: U. S.: The Geology of North America; (ed.) Sloss, L. L., Geological Society of America, p. 383-426.
 
Colman-Sadd, S. P., Hayes, J. P., and Knight, I.
1990:	Geology of the Island of Newfoundland; Geological Survey Branch, Department of Mines and Energy, Government of Newfoundland and Labrador, Map 90-11, scale 1:1,000,000
 
Corvalan, J., Drummond, K. J., Craddock, C., McCoy, F. W., Swint, T. R., Richards, P. W., and Moore, G. W.
1985:	Geologic map of the Circum-Pacific Region, Southeast Quadrant; Circum-Pacific Council for Energy and Mineral Resources, scale 1:10,000,000.
 
Coward, M. P., Butler, R. W. H., Khan, M. A., and Knipe, R. J.
1987:	The tectonic history of Kohistan and its implications for Himalayan Structure; Journal of the Geological Society, London, Vol. 144, p. 377-391.
 
Craddock, C.
1970:	Geologic Map of Antarctica, American Geographical Society, scale 1:5,000,000.
 
Craddock, C., Corvalan, J., Palfreyman, W. D., Doutch, H. F., McCoy, F. W., Moore, G. W., Swint-Iki, T., and Richards, P. W.
1989:	Geologic map of the Circum-Pacific Region, Antarctic Sheet; Circum-Pacific Council for Energy and Mineral Resources, scale 1:10,000,000.
 
D'Addario, G. W., Palfreyman, W. D., Stewart, A. J., Bultitude, J. M., and Chan, R. A.
1982:	Australia Geology; Atlas of Australia Mineral Resources, Division of National Mapping, scale 1:5,000,000.
 
D'Addario, G. W., Swoboda, R. A., Bultitude, J. M., and Lamberts, I. T.
1976:	Australia; Bureau of Mineral Resources, Geology and Geophysics, Department of National Resources, Scale 1:2,500,000.
 
Dasgupta, A. K., Ghose, A., and Chakraborty, K. K.
1993:	Geological Map of India; Geological Survey of India, scale 1:5,000,000.
 
Dawes, P. R.
1976:	Precambrian to Tertiary of Northern Greenland; in Geology of Greenland, (ed.) Escher, A. and Watt, W. S., The Geological Survey of Greenland, p. 248-303.
 
De Almeida, F. F. M., Martin, C. F., Furque, G., Ferreira, E. O.
1978:	Tectonic map of South America; Commission for the Geological Map of the World, Unesco, scale 1:5,000,000.
 
De Medeiros Delgado, I., Pedreira, A. J., Santos, J. O. S., Araujo, O. J. B., Da Silva Filho, M. A., Dos Santos, R. A., Heineck, C. A., Da Silva, L. C., and De Lacerda Filho, J. V.
1995:	Tectono-Geological pap of Brazil; Ministerio de Minas e Energia, Secretaria de Minas e Metalurgia, Republica Federativa do Brasil, Companhia de Pesquisa de Recursos Minerais, scale 1:7,000,000.
 
De Wit, M., Jeffery, M., Bergh, H., and Nicolaysen, L.
1988:	Geological Map of Sectors of Gondwanaland, Reconstructed; Bernard Price Institute of Geophysical Research, University of Witwatersraand, scale 1:10,000,000.
 
Decelles, P. G.
1986:	Sedimentation in a tectonically partitioned, nonmarine foreland basin: the Lower Cretaceous Kootenai Formation, Southwestern Montana; Geological Society of America Bulletin, Vol. 97, p. 911-931.
 
Deer, W. A.
1976:	Tertiary igneous rocks between Scoresby Sund and Kap Gustav Holm, East Greenland; in Geology of Greenland; (ed.) Escher, A. and Watt, W. S., The Geological Survey of Greenland, p. 404-429.
 
Derry, D. R.
1980:	World atlas of geology and mineral deposits; Mining Journal Books Ltd., John Wiley and Sons, 110 p.
 
Dressler, B. O., Gupta, V. K., and Muir, T. I.
1992:	The Sudbury Structure, Southern Province and Proterozoic Events; in Geology of Ontario; (ed.) Thurston, P. C., Williams, H. R., Sutcliffe, R. H., and Stott, G. M., Ontario Geological Survey, Ministry of Northern Development and Mines, p. 593-625.
 
Easton, R. M.
1992:	The Grenville Province and the Proterozoic history of central and southern Ontario, Grenville Province; in Geology of Ontario; (ed.) Thurston, P. C., Williams, H. R., Sutcliffe, R. H., and Stott, G. M., Ontario Geological Survey, Ministry of Northern Development and Mines, p. 715-904.
 
Eckstrand, O. R.
1975:	Nickel potential of the Prince Albert Group, N. W. T.; Current Research, Part A, Vol. 75-1A, p. 253-255.
 
Edelman, S. H., Liu, A., and Hatcher, R. D.
1987:	The Brevard Zone in South Carolina and adjacent areas: An Alleghanian orogen-scale dextral shear zone reactivated as a thrust fault; Journal of Geology, Vol. 95, p. 793-806.
 
Eisbacher, G. H.
1985:	Pericollisional strike-slip faults and synorogenic basins, Canadian Cordillera; Strike-Slip Deformation, Basin Formation, and Sedimentation., Vol. 37, p. 265-282.
 
Emeleus, C. H. and Upton, B. G. J.
1976:	The Gardar Period in Southern Greenland; in Geology of Greenland; (ed.) Escher, A. and Watt, W. S., The Geological Survey of Greenland, p. 152-181.
 
Escher, J. C. and Pulvertaft, T. C.
1995:	Geological map of Greenland; Geological Survey of Greenland, scale 1:2,500,000.
 
Escher, A., Watt, W. S.
1976:	Summary of the Geology of Greenland, in Geology of Greenland, (ed.) Escher, A. and Watt, W. S., The Geological Survey of Greenland, p. 10-17.
 
Escher, A., Sorenson, K., and Zeck, H. P.
1976:	Nagssugtoqidian Mobile Belt in West Greenland; in Geology of Greenland; (ed.) Escher, A. and Watt, W. S., The Geological Survey of Greenland, p. 76-95
 
Escher, A., and Pulvertaft, T. C. R.
1976:	Rinkian Mobile Belt of West Greenland; in Geology of Greenland; (ed.) Escher, A. and Watt, W. S., The Geological Survey of Greenland, p. 104-119.
 
Feray, D. E. and Renfro, H. B.
1967:	Geological highway map of the Southern Rocky Mountain Region; The American Society of Petroleum Geologists, The American Society of Petroleum Geologists, Map No. 2, Scale 1900800
 
Feray, D. E., Oetking, P., and Renfro, H. B.
1968:	Geological highway map of the Pacific Southwest Region; The American Society of Petroleum Geologists, The American Society of Petroleum Geologists, Map No. 3, Scale 1900800
 
Fergusson, C. L., Gray, D. R., and Cas, R. A. F.
1986:	Overthrust terranes in the Lachlan Fold Belt, Southeastern Australia; Geology, Vol. 14, p. 519-522.
 
Ferreira-Filho, C. F., Kamo, S. L., Fuck, R. A., Krogh, T. E., and Naldrett, A. J.
1994:	Zircon and rutile U-Pb geochronology of the Niquelandia Layered Mafic and Ultramafic Intrusion, Brazil: Constraints for the timing of magmatism and high grade metamorphism; Precambrian Research, Vol. 68, p. 241-255.
 
Fisher, J. H., Barratt, M. W., Droste, J. B., and Shaver, R. H.
1988:	Michigan Basin, The Eastern Mid-Continent Region Section; in Sedimentary Cover - North American Craton: U. S.: The Geology of North America; (ed.) Sloss, L. L., Geological Society of America, p. 361-382.
 
Fontbote, J. M., De Almeida, F. M., Oliveira, T., and Toloczyki, M.
1989:	International Geological Map of Europe, Sheet A6, Lisboa; Commission de la Carte Géologique de l'Europe, scale 1:1,500,000.
 
Forjaz, V. H., Monjardino, J., and Santa Maria Fernandez, N.
1970:	San Jorge; Direcçao Geral de Minas e Services Geológicos, Carta Geológica de Portugal, scale 50,000.
 
Friend, C. R. L., Kinny, P. D., Rogers, G., Strachan, R. A., and Paterson, B. A.
1997:	U-Pb zircon geochronological evidence for Neoproterozoic events in the Glenfinnian Group (Moine Supergroup): the formation of the Ardgour granite gneiss, north-west Scotland; Contributions to Mineralogy and Petrology, Vol. 128, p. 101-113.
 
Fritz, W. H., Cecile, M. P., Norford, B. S., Morrow, D., and Geldsetzer, H. H. J.
1991:	Cambrian to Middle Devonian assemblages, in Geology of the Cordilleran Orogen in Canada: Geology of Canada no. 4; (ed.) Gabrielse, H. and Yorath, C. J., Geological Survey of Canada, Geological Society of America, p. 151-218
 
Furon, R., Daumain, G., Dubertret, L., and Lelubre, M.
1958:	Esquisse structurale provisoire de l'Afrique; Congres Géologique International, Association des Services Geologique Africains, Imprimeries Michard, Paris, scale 1:10,000,000.
 
Fyson, W. K. and Padgham, W. A.
1992:	Geology of the Slave Structural Province; NWT Geology Division, Indian and Northern Affairs, Canada, EGS1993-08, scale 1:1,000,000.
 
Gaal, G. and Gorbatchev, R.
1987:	An outline of the Precambrian evolution of the Baltic Shield; Precambrian Research, Vol. 35, p. 15-52.
 
Gabrielse, H., Monger, J. W. H., Tempelman-Kluit, D. J., and Woodsworth, G. J.
1991:	Part C. Intermontane Belt; in Geology of the Cordilleran Orogen in Canada: Geology of Canada no. 4; (ed.) Gabrielse, H. and Yorath, C. J., Geological Survey of Canada, Geological Society of America, p. 591-603.
 
Gabrielse, H., Monger, J., Yorath, C., and Dodds, C.
1991:	Part F. Transcurrent faults; in Geology of the Cordilleran Orogen in Canada: Geology of Canada no. 4; (ed.) Gabrielse, H. and Yorath, C. J., Geological Survey of Canada, Geological Society of America, p. 651-660.
 
Geological Survey of Namibia
2003:	The Geology of Namibia; Geological Survey of Namibia, Ministry of Mines and Energy, scale 17,000,000.
 
Gerbert, J. S.
1992:	Geology of the Hope Bay and Elu Inlet Metavolcanic Belts, Northeastern Slave Province, NWT; in Project Summaries: Canada-Northwest Territories Mineral Development Subsidiary Agreement 1987-1991; (ed.) Richardson, D. G. and Irving, M., Energy, Mines, and Petroleum Resources, Government of Northwest Territories, Geological Survey of Canada, p. 15-17.
 
Ghose, A., Chatterjee, D., and Banerjee, J.
1990:	Geological Map of South and East Asia; Commission for the Geological Map of the World, Unesco, scale 1:5,000,000.
 
Goodwin, A. M.
1991:	Precambrian Geology; Academic Press Ltd., 114 p.
 
Gordey, S. P.
1991:	Devonian-Mississippian clastics in the Foreland and Omineca Belts, Upper Devonian to Middle Jurassic Assemblages; in Geology of the Cordilleran Orogen in Canada: Geology of Canada no. 4; (ed.) Gabrielse, H. and Yorath, C. J., Geological Survey of Canada, Geological Society of America, p. 230-242.
 
Graham, B. K., Nichols, C., Johnson, N. E. A., and White, M. L.
1971:	Australia and Oceana; Commission for the Geological Map of the World, Unesco, Scale 1:5,000,000.
 
Greenough, J. D.
1995:	Mesozoic Rocks, in Geology of the Appalachian-Caledonian Orogen in Canada and Greenland: Geology of Canada, No. 6; (ed.) Williams, H., Geological Survey of Canada, The Geological Society of America, Inc., p. 567-600.
 
Greninger, M. L., Klemperer, S. L., and Nokleberg, W. J.
1999:	Geographic Information Systems (GIS) compilation of geophysical, geologic, and tectonic data for the Circum-North Pacific; U. S. Geological Survey, Open File Report 99-422, CD-ROM.
 
Griffin, T. J. and Myers, J. S.
1988:	A Proterozoic terrane boundary in the King Leopold Orogen, Western Australia; Australian Journal of Earth Sciences, Vol. 5, p. 131-132.
 
Gustavson, M., Perttunen, V., Siedlecka, A., Sjostrand, T., Stephens, M. B., and Zachrisson, E.
1987:	Geological Map, pre-Quaternary Rocks, Northern Fennoscandia; Geological Surveys of Finland, Norway, and Sweden, Publications Division of the National Board of Survey, Finland, scale 1:1,000,000.
 
Hall, W. E.
1983:	Stratigraphy of and mineral deposits in Middle and Upper Paleozoic rocks of the Black Shale Mineral Belt, Central Idaho; in Symposium on the Geology and Mineral Deposits of the Challis 1° X 2° Quadrangle, Idaho; (ed.) McIntyre, D. H., U. S. Geological Survey, p. 117-131.
 
Hamilton, W.
1987:	Plate tectonic evolution of the Western U.S.A.; Episodes, Vol. 10, p. 271-276.
 
Hamner, S. and Knopf, C.
1993:	The Snowbird Tectonic Zone in the District of Mackenzie, Northwest Territories; Current Research, Part C, Vol. 93C, p. 41-52.
 
Harrison, J. C., Fox, F. G., and Okulitch, A. V.
1991:	Late Devonian - Early Carboniferous deformation of the Parry Islands and Cape Robert Hills Fold Belts, Bathurst and Melville Islands; in Geology of the Innuition Orogen and Arctic Platform of Canada and Greenland; (ed.) Trettin, H. P., The Geological Society of America, Geological Survey of Canada, p. 321-333.
 
Hasenmueller, N. R., Martin, C. F., Soares, M. A., Vogel, S., and Petzall, C. Y.
1983:	Metallogenic Map of South America; Ministry of Energy and Mines, Venezuela, Commission for the Geological Map of the World, Scale 1:5,000,000.
 
Hasenmueller, N. R.
1993:	New Albany Shale (Devonian and Mississippian) of the Illinois Basin; in Petroleum Geology of the Devonian and Mississippian Black Shale of Eastern North America; (ed.) Roen, J. B.and Kepferle, R. C., U. S. Geological Survey, p. 1-19.
 
Henderson, G., Rosencrantz, A., and Schiener, E. J.
1976:	Cretaceous-Tertiary sedimentary rocks of West Greenland; in Geology of Greenland; (ed.) Escher, A. and Watt, W. S., The Geological Survey of Greenland, p. 340-363.
 
Henderson, R. A.
1980:	Structural outline and summary geological history for Northeastern Australia, Geological & Geophysical Context Section; in The Geology and Geophysics of Northeastern Australia; (ed.) Henderson, R. A. and Stephenson, P. J., Third Australian Geological Convention, Geological Society of Australia, Queensland Division, p. 1-26.
 
Henriksen, N. and Higgins, A. K.
1976: East Greenland Caledonian Fold Belt; in Geology of Greenland; (ed.) Escher, A. and Watt, W. S., The Geological Survey of Greenland, p. 182-247.
 
Heywood, W. W.
1967:	Geological notes, Northeastern District of Keewatin and Southern Melville Peninsula, District of Franklin, Northwest Territories (Parts of 46, 47, 56, 57); Geological Survey of Canada, 14-1966, scale 1:506,880.
 
Hibbard, J. P., St-Julien, P., and Trzcienski, Jr., W. E.
1995:	Humber Zone Internal; in Geology of the Appalachian-Caledonian Orogen in Canada and Greenland: Geology of Canada, No. 6; (ed.) Williams, H., Geological Survey of Canada and The Geological Society of America, p. 114-139.
 
Hiscott, R. N.
1995:	Middle Ordovician clastic rocks (Humber Zone and St. Lawrence Platform), Lower Paleozoic and Older Rocks; in Geology of the Appalachian-Caledonian Orogen in Canada and Greenland: Geology of Canada, No. 6; (ed.) Williams, H., Geological Survey of Canada, The Geological Society of America, p. 87-89.
 
Hoffman, P. and Hall, L.
1993:	Geology: Slave Craton and Environs, District of Mackenzie, Northwest Territories; Geological Survey of Canada, Open File 2559, scale 1:10,000,000.
 
Hoffman, P. F.
1988:	United Plates of America, the Birth of a Craton: Early Proterozoic Assembly and Growth of Proto-Laurentia; Annual Review of Earth and Planetary Sciences, Vol. 16, p. 543-603.
 
Hoffman, P. F.
1992:	Precambrian geology and tectonic history of North America; in The Geology of North America - An Overview: Decade of North American Geology; (ed.) Bally, A. W. and Palmer, A. R., The Geological Society of America, p. 447-512.
 
Hsu, K. J., Shu, S., Jiliang, L., Haihong, C., and Haipo, P.
1988:	Mesozoic overthrust tectonics in South China; Geology, Vol. 16, p. 418-421.
 
Jackson, G. D., Morgan, W. C., and Davidson, A.
1975:	Geology, Icebound Lake, District of Franklin; Geological Survey of Canada, Map 1451A, scale 1:250,000.
 
Jackson, G. D., Morgan, W. C., and Davidson, A.
1975:	Geology, Steensby Inlet, District of Franklin, Geological Survey of Canada, Map 1450A, scale 1:250,000.
 
Jackson, E. D., Silver, E. A., and Dalrymple, G. B.
1972:	Hawaiian-Emperor Chain and its relation to Cenozoic Circumpacific Tectonics; Geological Society of America Bulletin, Vol. 83, p. 601-618.
 
Jiawei, X., Guang, Z., Weixing, T., Kerei, C., and Qing, L.
1987:	Formation and Evolution of the Tancheng Lujiang Wrench Fault System: a Major Shear System to the Northwest of the Pacific Ocean., Tectonophysics, Vol. 134, p. 273-310
 
Johnson, P. R. and Vranas, G. J.
1984:	The Geotectonic Environments of the Late Proterozoic Mineralization in the Southern Arabian Shield; Precambrian Research, Vol. 25, p. 329-348,
 
Johnson, M. D., Armstrong, D. K., Sanford, B. V., Telford, P. G., and Rutka, M A.
1992:	Paleozoic and Mesozoic geology of Ontario; in Geology of Ontario, (ed.) Thurston, P. C., Williams, H. R., Sutcliffe, R. H., Stott, G. M., Ontario Geological Survey, Ministry of Northern Development and Mines, p. 907-1008.
 
Johnstone, R.
1996:	Geology of the Camsell Lake Supracrustal Belt; in Summary of the Geoscience Initiative of the Mineral Initiatives Program: Canada-Northwest Territories Economic Development Agreement (1991-1996); (ed.) Cherry, M. E. and Richardson, D. G., Indian and Northern Affairs, Canada, Geological Survey of Canada, p. 11-13.
 
Jones, W. R., Peoples, J. W., and Howland, A. L.
1960:	Igneous and tectonic structures of the Stillwater Complex Montana; Geological Survey Bulletin, Vol. 1071-H, p. 281-340.
 
Jovcev, J., Kostadinov, V., Ghenea, C., Sandulescu, M., Muzylev, S. A., Semenenko, V. N., Veklic, M. F., Aydin, Y., Ketin, I., and Tokay, M.
1983:	International Geological Map of Europe, Sheet E5, Bucaresti; Commission de la Carte Géologique de l'Europe,  scale 1:1,500,000.
 
Kamp, P. J. J.
1986:	The Mid-Cenozoic Challenger Rift System of Western New Zealand and its implication for the age of the Alpine Fault inception; Geological Society of America Bulletin, Vol. 97, p. 255-281,
 
Karig, D. E., Sarewitz, D. R., and Haeck, G. D.
1986:	Role of strike-slip faulting in the evolution of allochthonous terranes in the Philippines; Geology, Vol. 14, p. 852-855.
 
Keppie, J. D.
1979:	Geological Map of the Province of Nova Scotia; Nova Scotia Department of Mines and Energy, Government of Nova Scotia, scale 1:500,000.
 
Kerswill, J. A.
1996:	Geology and metallic mineral deposits, Slave Province; Colloquium'96, Abstracts.
 
Khan, M. A., Ahmed, R., Raza, H. A., and Kemal, A.
1986:	Geology of petroleum in the Kohat-Potwar Depression, Pakistan; The American Association of Petroleum Geologists, Vol. 70, p. 396-414.
 
Kilgour, B. and Wyborn, L. A. I.
1998:	National Digital Geoscience Datasets Version 1.1; Australian Geological Survey Organization, National Digital Geoscience Datasets, CD-ROM.
 
King, P. B. and Beikman, H. M.
1974:	Geologic map of the United States (exclusive of Alaska & Hawaii); United States Geological Survey, scale 1:2,500,000.
 
Kirschner, C. E.
1994:	Interior Basins of Alaska, Successor Basins; in The Geology of North America: Volume G-1: The Geology of Alaska; (ed.) Plafker, G. and Berg, H. C., The Geological Society of North America, p. 469-493
 
Knight, I. and Morgan, W. C.
1981:	The Aphebian Ramah Group; in Proterozoic Basins in Canada; (ed.) Campbell, F. H. A., Geological Survey of Canada, p. 313-330.
 
Kontinen, A.
1987:	An Early Proterozoic Ophiolite - the Jormua Mafic-Ultramafic Complex, Northeastern Finland; Precambrian Research, Vol. 35, p. 313-341.
 
Korsman, K., Koistinen, T., Kohonen, J., Wennerstrom, M., Ekdahl, E., Honkamo, M., Idman, H., and Pekkala, Y.
1997:	Bedrock Map of Finland; Geological Survey of Finland, scale 1:1,000,000.
 
Krohn, M. D., Evans, J., and Robinson, Jr., G. R.
1988:	Mineral-bound Ammonium in black shales of the Triassic Cumnock Formation, Deep River Basin, North Carolina, 1: Studies Related to early Mesozoic Sedimentary Rocks Section; in Studies of the Early Mesozoic Basins of the Eastern United States; (ed.) Froelich, A. J., and Robinson Jr., G. R., U. S. Geological Survey, p. 86-98.

Laramée, R. M. 
2005:	GlobalDBSystem; in Gold Deposits of the World: Distribution, Geological Parameters and Gold Content; (compilers) Gosselin, P., and Dubé, B. Geological Survey of Canada, Open File 4895.
 
Leclair, A. D., Ernst, R. E., and Hattori, K.
1993:	Crustal Scale Auriferous Shear Zones in the Central Superior Province, Canada; Geology, Vol. 21, p. 399-402.
 
Lee, C. Y., Wang Quan, Liu Xueya, and Tang, Y.
1982:	Tectonic Map of Asia, Research Institute of Geology; Chinese Academy of Geological Sciences, scale 1:8,000,000.
 
Li, Zhaonai, Wang, Bixiang, Shang, Ruxiang, Wu, Cailai, and Shi, Rendeng
1997:	Geological Map of igneous rocks of China; Institute of Geology, Chinese Academy of Sciences, Geological Publishing House, Beijing, China, P 1690, Scale 1:5,000,000.
 
Lopez de Azcona, J. M., Julivert, M., Moitinho De Almeida, F., Teixeira, C., and Zbyszewski, G.
1974:	International Geological Map of Europe, Sheet A5, La Coruna; Commission de la Carte Géologique de l'Europe, scale 1:1,500,000.
 
Luettig, G., Zhamoida, A. I., Chanteux, P., Choubert, G., and Faure-Muret, A.
1980:	Geological World Atlas, Europe; Commission for the Geological Map of the World, UNESCO, Sheet 9, Scale 1:10,000,000.
 
Macek, J. J., McRitchie, W. D., Bailes, A. H., Baldwin, D. A., and Lenton, P. G.
1989:	Bedrock Geology, Compilation Map Series, Preliminary Edition, Nelson House, NTS 63-O, Manitoba Department of Energy and Mines, Scale 250000
 
Macfarlan, J. M. B.
1991:	Mineral Resources of New Zealand, Resource Information Report 11; Energy and Resources Division, Ministry of Commerce, New Zealand.
 
Macgregor, A. G., Dunning, F. W., Robbie, J. A., Edwards, W. N., and Reum, H.
1966: 	International Geological Map of Europe, Sheet B3; Commission de la Carte Géologique de l'Europe, scale 1:1,500,000.
 
Magnusson, N. H., Bjorlykke, H., Skjeseth, S., Asklund, B., Simonen, A., and Reum, H.
1964:	International Geological Map of Europe, Sheet D1; Commission de la Carte Géologique de l'Europe, scale 1:1,500,000.
 
Magnusson, N. H., Skjeseth, S., Bjorlykke, H., and Asklund, B.
1964:	International Geological Map of Europe, Sheet C2; Commission de la Carte Géologique de l'Europe, Sheet C2, scale 1:1,500,000.
 
Major, R. B. and Conor, C. H. H.
1993:	Musgrave Block, Mesoproterozoic Section; in The Geology of South Australia: Volume 1:The Precambrian; (ed.) Drexel, J. F., Preiss, W. V., and Parker, A. J., South Australia Department of Mines and Energy, Geological Survey of South Australia, p. 156-167.
 
Mascle, A. and Letouzey, P.
1990:	Geologic map of the Caribbean; Institut francais du petrole, Beicip, scale 1:2,500,000.
 
Mascle, A., Letouzey, P, Biju-Duval, B., Becue, B., and Rossi, T.
1990:	Geological Map of the Caribbean; Institut francais du petrole, Beicip, scale 1:2,500,000.
 
Maung, H.
1987:	Transcurrent movements in the Burma-Andaman Sea region; Geology, Vol. 15, p. 911-912,
 
McBirney, A. R.
1989:	The Skaergaard Layered Series: I. Structure and average compositions; Journal of Petrology, Vol. 30, p. 363-397.
 
McCutcheon, S. R. and McLeod, M. J.
1995:	Avalon Zone-New Brunswick, Lower Paleozoic and Older Rocks; in Geology of the Appalachian-Caledonian Orogen in Canada and Greenland: Geology of Canada, No. 6; (ed.) Williams, H., Geological Survey of Canada and the Geological Society of America, p. 249-261.
 
McWhae, J. R.
1986:	Tectonic history of Northern Alaska, Canadian Arctic, and Spitsbergen regions since Early Cretaceous; The American Association of Petroleum Geologists Bulletin, Vol. 70, p. 430-450.
 
Metcalfe, I.
1999:	Gondwana Dispersion and Asian Accretion: An Overview,  , in Gondwana Dispersion and Asian Accretion: IGCP 321 Final Results Volume; (ed.) Metcalfe, I., International Geological Correlation Program (IGCP), A. A. Balkema Publishers, Rotterdam. Netherlands, p. 9-28.
 
Milesi, J. P., Feybesse, J. L., Ledru, P., Dommanget, A., Ouerdraogo, M. F., Marcoux, E., Prost, A., Vinchon, C., Sylvain, J. P., Johan., V., Tegyey, M., Calvez, J. Y., and Lagney, PH.
1989:	West African gold deposits in their Lower Proterozoic lithostructural setting; Chronacles Récherche Minière Francaise.
 
Milici, R. C. and de Witt, Jr., W.
1988:	The Appalachian Basin, The Eastern Mid-Continent Region; in Sedimentary Cover - North American Craton: U. S.: The Geology of North America; (ed.) Sloss, L. L., Geological Society of America, p. 427-469.
 
Molnar, P., Burchfiel, B. C., K'Uangyi, L., and Ziyun, Z.
1987:	Geomorphic Evidence for Active Faulting in the Altyn Tagh and Northern Tibet and Qualitative Estimates of its Contribution to the Convergence of India and Eurasia., Geology, Vol. 15, p. 249-253
 
Moore, P. F.
1993:	Devonian; in Sedimentary Cover of the Craton in Canada: Geology of Canada; (ed.) Stott, D. F. and Aitken, J. A., Geological Survey of Canada, p. 150-201.
 
Morey, G. B.
1996:	Continental Margin Assemblage, Early Proterozoic Penokean Orogen Section; in Archean and Proterozoic Geology of the Lake Superior Region, U.S.A., 1993; (ed.) Sims, P. K.and Carter, L. M. H., U. S. Geological Survey, p. 30-44.
 
Morey, G. B. and Sims, P. K.
1996:	Metallogeny; in Archean and Proterozoic Geology of the Lake Superior Region, U.S.A., 1993; (ed.) Sims, P. K., Carter, L. M. H., U. S. Geological Survey, p. 87-95.
 
Moseley, F.
1990: 	The Structure of Masirah Island, Oman, Geology and Tectonics of South Oman Section; in The Geology and Tectonics of the Oman Region: Geological Society Special Publication No. 49; (ed.) Robertson, A. H. F., Searle, M. P., and Ries, A. C., The Geological Society, London, Alden Press, Oxford, p. 665-671.
 
Muehlberger, W. R.
1992:	Tectonic Map of North America, Southeast Sheet; The American Association of Petroleum Geologists, Scale 1:5,000,000.
 
Muehlberger, W. R.
1996:	Tectonic Map of North America, Northwest Sheet; The American Association of Petroleum Geologists, Scale 1:5,000,000.
 
Muehlberger, W. R.
1992:	Tectonic Map of North America, Southwest Sheet; The American Association of Petroleum Geologists, Scale 1:5,000,000.
 
Muzylev, S. A., Kolosova, L. P., and Novitskaja, K. D.
1974:	International Geological Map of Europe, Sheet E4, Kijev; Commission de la Carte Géologique de l'Europe, scale 1:1,500,000.
 
Muzylev, S. A., Kolosova, L. P., and Novitskaja, K. D.
1974:	International Geological Map of Europe, Sheet F4, Astrachan'; Commission de la Carte Géologique de l'Europe, scale 1:1,500,000.
 
Muzylev, S. A., Kolosova, L. P., and Novitskaja, K. D.
1975:	International Geological Map of Europe, Sheet G4, Gurjev, Commission de la Carte Géologique de l'Europe, scale 1:1,500,000.
 
Muzylev, S. A., Kolosova, L. P., and Gudkova, M. V.
1973:	International Geological Map of Europe, Sheet E3, Moskva; Commission de la Carte Géologique de l'Europe, scale 1:1,500,000.
 
Muzylev, S. A., Kolosova, L. P., and Gudkova, M. V.
1973	 International Geological Map of Europe, Sheet F3, Kazan; Commission de la Carte Géologique de l'Europe, scale 1:1,500,000.
 
Muzylev, S. A., Kolospva, S. K., Gudkova, M. V., and Ksenofontov, O. K.
1976:	International Geological Map of Europe, Sheet G3, Magnitogorsk; Commission de la Carte Géologique de l'Europe, scale 1:1,500,000.
 
Muzylev, S. A., Kolosova, S. K., and Lebedeva, T. G.
1971:	International Geological Map of Europe, Sheet E1, Kanin; Commission de la Carte Géologique de l'Europe, scale 1:1,500,000.
 
Muzylev, S. A., Kolosova, S. K., and Romanova, L. L.
1971:	International Geological Map of Europe, Sheet E2, Archangel'sk; Commission de la Carte Géologique de l'Europe, scale 1:1,500,000.
 
Muzylev, S. A., Kolosova, L. P., Moldovantsev, Yu. E., and Lebedeva, T. G.
1974: 	International Geological Map of Europe, Sheet F1, Vorkuta; Commission de la Carte Géologique de l'Europe, scale 1:1,500,000.
 
Muzylev, S. A., Kolosova, L. P., Nikolaeva, M. G., and Smirnov, Yu. D.
1974:	International Geological Map of Europe, Sheet F2, Kirov; Commission de la Carte Géologique de l'Europe, scale 1:1,500,000.
 
Muzylev, S. A., Kolosova, L. P., Sokolova, T. S., and Smirnov, Yu. D.
1974:	International Geological Map of Europe, Sheet G2, Sverdlovsk; Commission de la Carte Géologique de l'Europe, scale 1:1,500,000.
 
Myers, J. S. and Hocking, R. M.
1988:	Geological Map of Western Australia; Geological Survey of Western Australia, Centennial Edition, scale 1:2,500,000.
 
Myers, J. S. and Barley, M. E.
1992:	Proterozoic tectonic framework and metal deposits of Southwestern Australia; Precambrian Research, Vol. 58, p. 345-354.
 
Namateba, C.
1986:	Irumide - the Kibaran Belt of Zambia; Geology for Economic Development, Newsletter, Vol. 5, p. 163-172.
 
Nguyen, D. H. and Rangin, C.
1999:	The Early Paleozoic paleogeography and tectonics of Vietnam/South China as markers for the Cenozoic tectonic offset along the Red River Fault Zone; in Gondwana Dispersion and Asian Accretion: IGCP 321 Final Results Volume; (ed.) Metcalfe, I., International Geological Correlation Program (IGCP), A. A. Balkema Publishers, Rotterdam. Netherlands, p. 297-314.
 
Nielsen, B. L.
1976:	Economic Minerals; in Geology of Greenland; (ed.) Escher, A. and Watt, W. S., The Geological Survey of Greenland, p. 460-487.
 
Nockleberg, W. J., Plafker, G., and Wilson, F. H.
1994:	Geology of South-Central Alaska, Regional Geology; in The Geology of North America: Volume G-1: The Geology of Alaska; (ed.) Plafker, G. and Berg, H. C., The Geological Society of North America, p. 311-366.
 
Noe-Nygaard, A.
1976: 	Tertiary igneous rocks Between Shannon and Scoresby Sund, East Greenland; in Geology of Greenland; (ed.) Escher, A. and Watt, W. S., The Geological Survey of Greenland, p. 386-403.
 
Norris, D. K.
1984:	Geology of the Northern Yukon and Northwestern District of Mackenzie; Geological Survey of Canada, Map 1581A, scale 1:500,000.
 
Nutman, A. P., Bennett, V. C., Kinny, P. D., and Price, R.
1993:	Large scale crustal structure of the Northwestern Yilgarn Craton, Western Australia: Evidence from Nd isotopic data and zircon geochronology; Tectonics, Vol. 12, p. 971-981.
 
Oetking, P., Feray, D. E., and Renfro, H. B.
1966:	Geological highway map of the Mid-Continent Region; The American Society of Petroleum Geologists, Map No. 1, scale 1:1,900,800.
 
Okulitch, A. V., Lopatin, B. G., and Jackson, H. R.
1989:	Circumpolar Geological Map of the Arctic; Geological Survey of Canada, Map 1765A, scale 1:6,000,000.
 
Okulitch, A. V., Packard, J. J., and Zolnai, A. I.
1991:	Late Silurian - Early Devonian Deformation of the Boothia Bay Uplift; in Geology of the Innuition Orogen and Arctic Platform of Canada and Greenland; (ed.) Trettin, H. P., The Geological Society of America, Geological Survey of Canada, p. 302-307.
 
Okulitch, A. V.
1991:	Geology of the Canadian Archipelago and North Greenland; Geological Society of North America, Geological Survey of Canada, Figure 2, scale 1:2,000,000.
 
Oliveira, J. T., Pereira, E., Ramalho, M., Antunes, M. T., Monteiro, J. H., Almeida, J. P., de Carvalho, D., Carvalhosa, A., Ferreira, J. N., Goncalves, F., Olivieira, M., Ribeiro, A., Ribeiro, M. L., Silva, A. F., Noronha, F., Young, T., Barbosa, B., Manupella, G., Pais, J., Reis, R. P., Rocha, R., Soares, A. F., Zbyszewski, G., Gaspar, L., and Moreira, A. P.
1992:	Carta Geologica de Portugal; Servicos Geologicos de Portugal, Ministerio da Industria e Energia, scale 1:500,000.
 
Ontario Geological Survey
1992:	Tectonic assemblages of Ontario, Northern Sheet; Ontario Geological Survey, Ministry of Northern Development and Mines, Government of Ontario, 2575, scale 1:1,000,000.
 
Ontario Geological Survey
1992:	Tectonic Assemblages of Ontario, West-Central Sheet; Ontario Geological Survey, Ministry of Northern Development and Mines, Government of Ontario, 2576, scale 1,000,000.
 
Ontario Geological Survey
1992:	Tectonic Assemblages of Ontario, East-Central Sheet; Ontario Geological Survey, Ministry of Northern Development and Mines, Government of Ontario, 2577, scale 1,000,000.
 
Ontario Geological Survey
1992:	Bedrock Geology of Ontario, Southern Sheet; Ontario Geological Survey, Ministry of Northern Development and Mines, Map 2544, scale 1,000,000.
 
Ontario Geological Survey
1992:	Bedrock Geology of Ontario, West-Central Sheet; Ontario Geological Survey, Ministry of Northern Development and Mines, Map 2542, scale 1,000,000.
 
Ontario Geological Survey
1992:	Bedrock Geology of Ontario, Northern Sheet; Ontario Geological Survey, Ministry of Northern Development and Mines, Map 2541, scale 1,000,000.
 
Ortega-Gutierrez, F., Mitre-Salazar, L. M., Roldan-Quintana, J., Aranda-Gomez, J., Moran-Zenteno, D., Alaniz-Alvarez, S., and  y Nieto-Samaniego, A.
1992:	Carta Géologica de la Republica Mexicana; Institut de Geológia, Consejo de Recursos Minerales, scale 1:2,000,000.
 
Otoh, S., Tsukada, K., Sano, K., Nomura, R., Jwa, Yong-Joo, and Yanai, S.
1999:	Triassic to Jurassic dextral ductile shearing along the eastern margin of Asia: A Synthesis; in Gondwana Dispersion and Asian Accretion: IGCP 321 Final Results Volume; (ed.) Metcalfe, I., International Geological Correlation Program (IGCP), A. A. Balkema Publishers, Rotterdam. Netherlands, p. 89-113
 
Parker, A. J.
1993:	Geological Framework; in The Geology of South Australia: Volume 1:The Precambrian; (ed.) Drexel, J. F., Preiss, W. V., and Parker, A. J., South Australia Department of Mines and  Energy, Geological Survey of South Australia, p. 9-31.
 
Parrish, R.
1992:	Precambrian basement rocks of the Canadian Cordillera; in Geology of the Cordilleran Orogen in Canada: Geology of Canada no. 4; (ed.) Gabrielse, H. and Yorath, C. J., Geological Survey of Canada, Geological Society of America, p. 89-96.
 
Pastukhov, V. G., Astakhov, K. N., Baginyan, M. K., Belous, I. R., Volfman, Yu. M., Klochkov, V. M., Kruglov, S. S., Pashkevich, I. K., Ribakov, V. N., Khvorova, G. P., Khizhnyakov, A. V., and Tsipko, A. K.
1993:	Geodynamic map of Ukraine, Ukrainian State Committee on Geology and Utilization of Mineral Resources, Geoprognoz, scale 1,000,000.
 
Patton, Jr., W. W., Box, S. E., and Grybeck, D. J.
1994	 Ophiolites and other mafic-ultramafic complexes in Alaska; in The Geology of North America: Volume G-1: The Geology of Alaska; (ed.) Plafker, G. and Berg, H. C., The Geological Society of North America, The Geological Society of America, Inc., p. 671-687.
 
Persits, F. M., Ulmashek, G. F., and Steinshouer, D. W.
1998:	Map showing geology, oil and gas fields, and geologic provinces of the Former Soviet Union; U. S. Geological Survey, Open File Report, 97-470E, CD-ROM.
 
Pinna, P., Jourde, J. Y., Calvez, J. P., Mroz, J. P., and Marques, J. M.
1993:	The Mozambique Belt in Northern Mozambique: Neoproterozoic (1100-850 Ma) Crustal growth and tectogenesis, and superimposed Pan-African (800-550 Ma) tectonism; Precambrian Research, Vol. 62, p. 1-59.
 
Plumb, K. A., Derrick, G. M., and Wilson, I. H.
1980:	Precambrian Geology of the McArthur River-Mount Isa Region, Northern Australia, Precambrian Geology Section; in The Geology and Geophysics of Northeastern Australia; (ed.) Henderson, R. A. and Stephenson, P. J., Third Australian Geological Convention, Geological Society of Australia, Queensland Division, p. 71-88.
 
Pratt, L. M., Shaw, C. A., and Burruss, R. C.
1988:	Thermal histories of the Hartford and Newark Basins inferred from maturation indices of organic matter, 1: Studies related to Early Mesozoic Sedimentary Rocks; in Studies of the Early Mesozoic Basins of the Eastern United States,;(ed.) Froelich, A. J. and Robinson, Jr., G. R., U. S. Geological Survey, p. 58-63.
 
Price, R. A.
1986:	The Southeastern Canadian Cordillera: Thrust faulting, tectonic wedging, and delamination of the lithosphere; Journal of Structural Geology, Vol. 8, p. 239-254.
 
Pubellier, M., Girardeau, J., and Tjashuri, I.
1999:	Accretion History of Borneo inferred from the polyphase structural features in the Meratus Mountains; in Gondwana Dispersion and Asian Accretion: IGCP 321 Final Results Volume, (ed.) Metcalfe, I., International Geological Correlation Program (IGCP), A. A. Balkema Publishers, Rotterdam. Netherlands, p. 141-160.
 
Rankin, D. W., Drake, Jr., A. A., and Ratcliffe, N. M.
1990:	Geologic map of the U. S. Appalachians showing the Laurentian Margin and the Taconic Orogen; The Geological Society of America, Plate 2, Scale 1:1,968,504.
 
Regional Geology Branch
1993:	Geological map of South Australia; South Australia Department of Mines and Energy, Freeman Press, scale 1:2,000,000.
 
Reichenbach, I.
1993:	Black shale as an environmental hazard: a review of black shales in Canada; Geological Survey of Canada, 62 p.
 
Relf, C.
1990:	Archean deformation and metamorphism of metasedimentary rocks; Current Research, Vol. 90-1, p. 97-106.
 
Ren, Jishun, Wang, Zuoxun, Chen, Bingwei, Jiang, Chunfa, Niu, Baogui, Li, Jinyi, Xie, Guanglian, He, Zhengjun, and Liu, Zhigang
1999:	The tectonics of China from a global view; Geological Publishing House, Beijing, 1 map, 32 p.
 
Ren, Jishun, Wang, Zuoxun, Chen, Bingwei, Jiang, Chunfa, and Niu, Baogui
1999:	The tectonic map of China and adjacent regions; Chinese Academy of Geological Sciences, Geological Publishing House, Beijing, P. 1802, scale 1:5,000,000.
 
Renfro, H. B. and Feray, D. E.
1970:	Geological highway map of the Mid-Atlantic Region; The American Society of Petroleum Geologists, Map No. 4, scale 1:1,900,800.
 
Renfro, H. B. and Feray, D. E.
1972:	Geological highway map of the Northern Rocky Mountains Region; The American Association of Petroleum Geologists, The American Society of Petroleum Geologists, Map No. 5, scale 1:1,900,800.
 
Renfro, H. B., Bennison, D. E., and King, P. B.
1973:	Geological highway map of Texas; The American Society of Petroleum Geologists, The American Society of Petroleum Geologists, Map No. 7, scale 1:1,900,800.
 
Ricou, L. E., Dercourt, J., Geyssant, J., Grandjacquet, C., and Lepvrier, C.
1986:	Geological constraints on the Alpine evolution of the Mediterranean Tethys; Tectonophysics, Vol. 123, p. 83-122.
 
Robertson, A. H. F. and Searle, M. P.
1990:	The Northern Oman Tethyan continental margin: Stratigraphy, structure, concepts and controversies; in The Geology and Tectonics of the Oman Region: Geological Society Special Publication No. 49, (ed.) Robertson, A. H. F., Searle, M. P., and Ries, A. C., The Geological Society, London, Alden Press, Oxford, p. 3-25.
 
Rogers, J. J. W.
1986:	The Dharwar Craton and the assembly of Peninsular India; Journal of Geology, Vol. 94, p. 129-143.
 
Rogers, G., Hyslop, E. K., Strachan, R. A., Paterson, B. A., and Holdsworth, R. E.
1998:	The structural setting and U-Pb geochronology of Knoydartian pegmatites in West Inverness-shire: evidence for Neoproterozoic tectonothermal events in the Moine of NW Scotland; Journal of the Geological Society, London, Vol. 155, p. 685-696.
 
Roser, B. P., Mortimer, N., Turnbull, I. M., and Landis, C. A.
1993:	Geology and geochemistry of the Caples Terrane, Otago, New Zealand: Compositional variations near a Permo-Triassic arc margin; in South Pacific Sedimentary Basins: Sedimentary Basins of the World, (ed.) Ballance, P. F., Elsevier Science Publishers B.V., p. 3-19.
 
Ruhle, E., Teisseyre, H., Wdowiarz, S., Chatalov, E. T., Vialov, O. S., Dudek, A., and Malkovsky, M.
1971:	International Geological Map of Europe, Sheet D4, Warszawa; Commission de la Carte Géologique de l'Europe, scale 1:1,500,000.
 
Ruitenberg, A. A.
1986:	Metallogenic map of New Brunswick; Department of Natural Resources, New Brunswick, scale 1:500,000.
 
Saleeby, J. B.
1992:	Petrotectonic and paleogeographic settings of U. S. Cordilleran ophiolites; in The Cordilleran Orogen: Conterminous U. S.: The Geology of North America: Volume G-3; (ed.) Burchfiel, B. C., Lipman, P. W., and Zoback, M. L., The Geological Society of America, p. 653-682.
 
Sanford, B. V.
1993:	St. Lawrence Platform - Geology; in Sedimentary Cover of the Craton in Canada: Geology of Canada; (ed.) Stott, D. F. and Aitken, J. A., Geological Survey of Canada, p. 723-786
 
Schau, M.
1975:	Komatiitic and other ultramafic rocks in the Prince Albert Group, Hayes River Region, N. W. T.; Current Research, Part A, Vol. 75-1A, p. 363-367
 
Schau, M.
1983:	Geology, Baker Lake, District of Keewatin, map and notes; Geological Survey of Canada, Open File 883, Scale 1:250,000.
 
Scheibner, E., Suppel, D., Lewis, P., Hayward, D., and Gallagher, R.
1996:	The Lachlan Fold Belt data package -Version 1- January 1996; Department of Mineral Resources, Geological Survey of New South Wales, CD-ROM.
 
Schenk, P. E.
1995:	Meguma Zone; in Geology of the Appalachian-Caledonian Orogen in Canada and Greenland: Geology of Canada, No. 6; (ed.) Williams, H., Geological Survey of Canada and The Geological Society of America, p. 261-307.
 
Schiener, E. J.
1976:	Coal Geology; in Geology of Greenland; (ed.) Escher, A. and Watt, W. S., The Geological Survey of Greenland, p. 505-517.
 
Schobbenhaus, C. and Bellizzia, A.
2000:	Geologic map of South America; National Department of Mineral Production - DPNM, Geological Survey of Brazil - CPRM, Commission for the Geological Map of the World, scale 1:5,000,000.
 
Schreiber, U. and Petzel, V.
2002:	Geologic Evolution of Namibia; Ministry of Mines and Energy, information poster.
 
Schruben, P. G.
1997:	Geology and resource assessment of Costa Rica at 1:500,000 Scale - A digital representation of maps of the U.S. Geological Survey's 1987 Folio 1-1865; U. S. Geological Survey, DDS-19, CD-ROM
 
Schruben, P. G., Arndt, R. E., and Bawiec, W. J.
1994:	Geology of the conterminous United States at 1:2,500,000 Scale - A digital representation of the 1974 P. B. King and H. M. Beikman map, U. S. Geological Survey, DDS-11, CD-ROM.
 
Searle, M. P.
1986:	Structural Evolution and Sequence of Thrusting in the High Himalayan Tibetan-Tethys and Indus Suture Zones of Zanskar and Ladakh, Western Himalaya., Journal of Structural Geology, Vol. 8, p. 923-936
 
Shergold, J. H. and Druce, E. C.
1980:	Upper Proterozoic and Lower Palaeozoic rocks of the Georgina Basin, Palaeozoic Geology; in The Geology and Geophysics of Northeastern Australia; (ed.) Henderson, R. A. and Stephenson, P. J., Third Australian Geological Convention, Geological Society of Australia, Queensland Division, p. 149-174.
 
Sigmond, E. M. O., Gustavson, M., and Roberts, D.
1984:	Bedrock Map of Norway; Norges Geoligiske Undersokelse, scale 1,000,000.
 
Sigmond, E. M. O.
1985:	Geological Map of Norway; Norwegian Rock Mechanics Group, Norges Geologiske Undersokelse, scale 1:3,000,000.
 
Sigmond, E. M. O.
1992:	Bedrock map of Norway and adjacent ocean areas; Geological Survey of Norway, Scale 1:3,000,000.
 
Smart, J. and Senior, B. R.
1980:	Jurassic-Cretaceous basins of Northeastern Australia, Mesozoic & Cainozoic geology; in The Geology and Geophysics of Northeastern Australia; (ed.) Henderson, R. A., Stephenson, P. J., Third Australian Geological Convention, Geological Society of Australia, Queensland Division, p. 315-328.
 
Soegaard, K. and Eriksson, K. A.
1985:	Evidence of tide, storm, and wave interaction on a Precambrian siliciclastic shelf: The 1,700 M.Y. Ortega Group, New Mexico; Journal of Sedimentary Petrology, Vol. 55, p. 672-684.
 
Soper, N. J. and Higgins, A. K.
1991:	Late Cretaceous - Early Tertiary deformation, East Greenland; in Geology of the Innuition Orogen and Arctic Platform of Canada and Greenland, (ed.) Trettin, H. P., The Geological Society of America, Geological Survey of Canada, p. 461-465.
 
Soper, N. J., Harris, A. L.,and  Strachan, R. A.
1998:	Tectonstratigraphy of the Moine Supergroup: a synthesis; Journal of the Geological Society, London, Vol. 155, p. 13-24.
 
Sorgenfrei, Th., Magnusson, N. H., Asklund, B., Skjeseth, S., and Bjorlykke, H.
1966:	International Geological Map of Europe, Sheet C3; Commission de la Carte Géologique de l'Europe, Scale 1:1,500,000.
 
Sorkhabi, R. B. and Stump, E.
1993:	Rise of the Himalaya: A geochronological approach; GSA Today, Vol. 3, p. 1-90.
 
St-Onge, M. R., Hanmer, S., Scott, D. J., and Wodicka, N.
1997:	Geology, Crooks Inlet, District of Franklin, Northwest Territories (South Half of 25M); Geological Survey of Canada, Natural Resources Canada, OF3397, Scale 1:100,000.
 
St. Onge, M. R. and Lucas, S. B.
1990:	Evolution of the Cape Smith Belt: Early Proterozoic continental underthrusting, ophiolite obduction and thick-skinned folding; Eastern Segment; in The Early Proterozoic Trans-Hudson Orogen of North America; (ed.) Lewry, J. F. and Stauffer, M. R., Geological Association of Canada, p. 313-351.
 
Steinshouer, D. W., Qiang, J., McCabe, P. J., and Ryder, R. T.
1999:	Maps Showing Geology, Oil, and Gas Fields, and Geologic Provinces of the Asia Pacific Region, U. S. Geological Survey, Open File Report, 97-470F, CD-ROM.
 
Stephens, M. B., Wahlgren, C-H., and Weihed, P.
1994:	Geological Map of Sweden, Geological Survey of Sweden, Geological Survey of Sweden, SGU BA 52, Scale 1:3,000,000.
 
Stephenson, P. J., Griffin, T. J., and Sutherland, F. L.
1980:	Cainozoic Volcanism in Northeastern Australia, Mesozoic & Cainozoic Geology Section, in The Geology and Geophysics of Northeastern Australia; (ed.) Henderson, R. A. and Stephenson, P. J., Third Australian Geological Convention, Geological Society of Australia, Queensland Division, p. 149-374.
 
Stocklin, J.
1991:	Rift-related basins and major tectonic alignments of the World; Petroconsultants Geneva, scale 1:32,000,000
 
Stoeser, D. B. and Camp, V. E.
1985:	Pan-African microplate accretion of the Arabian Shield; Geological Society of America Bulletin, Vol. 96, p. 817-826.
 
Suggate, R. G. and Grindley, G. W.
1972:	Geological Map of New Zealand; New Zealand Geological Survey, scale 1:1,000,000.
 
Sutcliffe, R. H.
1992:	Proterozoic Geology of the Lake Superior Area, Southern Province and Proterozoic Events; in Geology of Ontario; (ed.) Thurston, P. C., Williams, H. R., Sutcliffe, R. H., and Stott, G. M., Ontario Geological Survey, Ministry of Northern Development and Mines, p. 627-258,
 
Taylor, F. C.
1985:	Precambrian Geology of the Half Way Hills Area, District of Keewatin; Geological Survey of Canada, Map 1602A, scale 1:50,000.
 
Tegner, C. and Wilson, J. R.
1993:	A Late Ultramafic Suite in the Kap Edvard Holm Layered Gabbro Complex, East Greenland; Geological Magazine, Vol. 130, p. 431-442.
 
Teschke, H. J., and coauthors
1978:	Europe - Geology; Veb Hermann Haack, Geographisch-Kartographische Anstalt Gotha, scale 1:3,000,000.
 
Tessensohn, F., Escher, A., Henriksen, N., Saemundsson, K., and Johnson, G. L.
1977:	International Geological Map of Europe, Sheet B1, Scoresby Sund, Commission de la Carte Géologique de l'Europe, scale 1:1,500,000.
 
Tessensohn, F., Saemundsson, K., and Johnson, G. L.
1978:	International Geological Map of Europe, Sheet A2, Reykjavik; Commission de la Carte Géologique de l'Europe, scale 1:1,500,000.
 
Tessensohn, F., Saemundsson, K., and Johnson, G. L.
1978:	International Geological Map of Europe, Sheet B2, Akureyri; Commission de la Carte Géologique de l'Europe, scale 1:1,500,000.
 
Toloczyki, M., Trurnit, P., Voges, A., Boncvcev, E., Andronopoulos, V., Pantazis, Th., Papavassiliou, C., Papastravrou, S. E., Koutsouveli, A., Mavridis, A., Tekeli, O., Akay, E., Goncuoglu, M. C., Erendil, M., and Boray, A.
1995:	International Geological Map of Europe and the Mediterranean Regions, E8 Anakara; International Geological Congress, Bundesansalt fur Geowissenschaften und Rohstoffe et Unesco, scale 1:1,500,000.
 
Tremblay, A., Malo, M., and St-Julien, P.
1995:	Dunnage Zone-Quebec; in Geology of the Appalachian-Caledonian Orogen in Canada and Greenland: Geology of Canada, No. 6; (ed.) Williams, H., Geological Survey of Canada and The Geological Society of America, p. 179-197.
 
Trurnit, P., Voges, A., Hagipour, A., Aghanahate, A., Muzylev, S. A., Kolosova, L. P., and Mironenkova, V. M.
1988:	International Geological Map of Europe, Sheet G5, Baku; Commission de la Carte Géologique de l'Europe, scale 1:1,500,000.
 
Unrig, R.
1983:	The Lufilian Arc: A microplate in the Pan-African Collision Zone of the Congo and the Kalihari Cratons; Precambrian Research, Vol. 21, p. 181-196.
  
Van Staal, C. R. and Fyffe, L. R.
1995:	Dunnage Zone-New Brunswick; in Geology of the Appalachian-Caledonian Orogen in Canada and Greenland: Geology of Canada, No. 6; (ed.) Williams, H., Geological Survey of Canada and The Geological Society of America, Inc., p. 166-178.
 
Van Staal, C. and Fyffe, L. B.
1995:	Gander Zone-New Brunswick; in Geology of the Appalachian-Caledonian Orogen in Canada and Greenland: Geology of Canada, No. 6; (ed.) Williams, H., Geological Survey of Canada and The Geological Society of America, p. 216-223.
 
Voges, A., Toloczyki, M., Zitzmann, A., Wittekindt, H., and Trunit, P.
1993:	Geologische Karte der Bundesrepublik Deutschland; Bundesanstalt fur Geowissenschaften und Rohstoff, Ilh(Geocenter), Postfach, Stuttgart, scale 1,000,000.
 
von Gaertner, H. R. and Walther, H. W.
1971:	Carte Géologique Internationale de l'Europe et des régions reinverained de la Méditerranée, Feuille Ouest; Commission for the Geological Map of the World, Bundesanstalt für Bodenforschung and UNESCO, scale 1:5,000,000.
 
von Gaertner, H. R. and Walther, H. W.
1971:	Carte Géologique Internationale de l'Europe et des régions reinverained de la Méditerranée, Feuille Est; Commission for the Geological Map of the World, Bundesanstalt für Bodenforschung and UNESCO, scale 1:5,000,000.
 
von Gaertner, H-R., Walther, H. W., and Hoppe, P.
1973:	International Geological Map of Europe, Paris-Sud; Le Congrès Géologique International, Bundesanstalt fur Bodenforschung et l'Unesco, B5, scale 1:1,500,000.

Wager, L. R. and Brown, G. R.
1968:	Layered igneous rocks; Oliver and Boyd, Edinburgh and London, 588 pages
 
Wardle, R. J., Ryan, B., Nunn, G. A. G., and Mengel, F. C.
1990:	Labrador segment of the Trans-Hudson Orogen: Crustal development through oblique convergence and collision; in The Early Proterozoic Trans-Hudson Orogen of North America, (ed.) Lewry, J. F. and Stauffer, M. R., Geological Association of Canada, p. 353-369.
 
Wardle, R. J., Gower, C. F., Ryan, B., Nunn, G. A. G., James, D. T., and Kerr, A.
1997:	Geological Map of Labrador; Department of Mines and Energy, Government of Newfoundland and Labrador, Map 97-07, Scale 1,000,000.
 
Weidick, A.
1976:	Glaciation and the Quaternary of Greenland; in Geology of Greenland; (ed.) Escher, A. and Watt, W. S., The Geological Survey of Greenland, p. 430-459.
 
Wheeler, J. O. and McFeely, P.
1991:	Tectonic assemblage map of the Canadian Cordillera; Geological Survey of Canada, Map 1712A, scale 1:2,000,000.
 
Wheeler, J. O., Hoffman, P. F., Card, K. D., Davidson, A., Sanford, B. V., Okulitch, A. V., and Roest, W. R.
1994:	Geological Map of Canada, Geological Survey of Canada, Map 1860A, scale 1:5,000,000.
 
Wheeler, J. O., Hoffman, P. F., Card, K. D., Davidson, A., Sanford, B. V., Okulitch, A. V., and Roest, W. R.
1997:	Geological Map of Canada, Geological Survey of Canada, Open File D1860A, CD-ROM
 
White, C. G., Geist, D. J., Frost, C. D., and Verwoerd, W. J.
1989:	Petrology of the Vandfaldsdalen Macrodike, Skaergaard Region, East Greenland; Journal of Petrology, Vol. 30, p. 271-298.
 
Williams, H.
1978:	Tectonic lithofacies map of the Appalachian Orogen; Memorial University of Newfoundland, scale 1:2,000,000.
 
Williams, N.
1980:	Precambrian mineralization in the McArthur-Cloncurry region, with special Rrference to stratiform lead-zinc deposits; in The Geology and Geophysics of Northeastern Australia, (ed.) Henderson, R. A. and Stephenson, P. J., Third Australian Geological Convention, Geological Society of Australia, Queensland Division, p. 89-107.
 
Williams, H. R., Stott, G. M., Thurston, P. C., Sutcliffe, R. H., Bennett, G., Easton, R. M., and Armstrong, D. K.
1992:	Tectonic evolution of Ontario: Summary and synthesis; in Geology of Ontario; (ed.) Thurston, P. C., Williams, H. R., Sutcliffe, R. H., and Stott, G. M., Ontario Geological Survey, Ministry of Northern Development and Mines, p. 1254-1332.
 
Williams, H.
1995:	Taconic Allochthons; in Geology of the Appalachian-Caledonian Orogen in Canada and Greenland: Geology of Canada, No. 6, (ed.) Williams, H., Geological Survey of Canada and The Geological Society of America, p. 99-11.
 
Williams, H., O'Brien, S. J., King, A. F., and Anderson, M. M.
1995:	Avalon Zone-Newfoundland; in Geology of the Appalachian-Caledonian Orogen in Canada and Greenland: Geology of Canada, No. 6; (ed.) Williams, H., Geological Survey of Canada, The Geological Society of America, Inc., p. 226-237.
 
Windley, B. F.
1995:	The evolving continents; John Wiley and Sons, Ltd., 526 p.
 
Woodsworth, G. J., Monger, J. W. H., and Gabrielse, H.
1991:	Part B. Coast Belt; in Geology of the Cordilleran Orogen in Canada: Geology of Canada no. 4; (ed.) Gabrielse, H. and Yorath, C. J., Geological Survey of Canada and The Geological Society of America, p. 581-591.
 
Wu, F. T., Wang, P.
1988:	Tectonics of western Yunnan Province; Geology, Vol. 16, p. 153-157.
 
Xingyuan, M. and Daning, W.
1987:	Cenozoic Extensional Tectonics in China; Tectonophysics, Vol. 133, p. 243-255.
 
Zbyszewski, G. and Candido de Madeiros, A. C.
1968:	Flores; Direcçao Geral de Minas e Services Geológicos, Carta Geológica de Portugal, scale 1:25,000.
 
Zbyszewski, G. and Candido de Madeiros, A. C.
1971:	Graciosi; Direcçao Geral de Minas e Services Geológicos, Carta Geológica de Portugal, scale 1:25,000.
 
Zbyszewski, G.
1960:	Santa Maria; Direcçao Geral de Minas e Services Geológicos, Carta Geológica de Portugal, scale 1:50,000.
 
Zbyszewski, G.and Ribeiro Ferreire, C.
1962:	Pico; Direcçao Geral de Minas e Services Geológicos, Carta Geológica de Portugal, scale 1:50,000.
 
Zbyszewski, G.
1959:	Faial, Direcçao Geral de Minas e Services Geológicos, Carta Geológica de Portugal, scale 1:25,000.
 
Zbyszewski, G.
1959:	San Miguel; Direcçao Geral de Minas e Services Geológicos, Carta Geológica de Portugal, scale 1:50,000.
 
Zbyszewski, G. and Candido de Madeiros, A. C.
1974:	Madeira; Direcçao Geral de Minas e Services Geológicos, Carta Geológica de Portugal, scale 1:50,000.
 
Zhao, J.
1994:	Geochemical and isotopic study of amphibolites in the Southern Arunta Inlier; Precambrian Research, Vol. 65, p. 71-94.
 
Zimbabwe Geological Survey
1985:	Provisional geological map of Zimbabwe; Zimbabwe Geological Survey, Government of Zimbabwe, scale 1:1,000,000.