Digital Mapping Techniques '04— Workshop
U.S. Geological Survey Open-File Report 2004–1451
Report on Progress to Develop a North American Science-Language Standard for Digital Geologic-Map Databases
NOTE: the Science Language documents are Appendices to this report.
With the increasingly widespread production and use of digital geologic-map databases it has become clear that, to more effectively serve their constituencies, geoscience agencies need to develop several vital pieces of digital infrastructure:
A single uniform language to classify and describe earth materials and their genesis is especially needed because users of geoscience information apply names, terms, and icons to communicate information about geologic objects and concepts. To the extent possible in a world where words are used diversely and inconsistently, standardized terminology is useful to facilitate informationexchange among these users.
To address development of the infrastructure noted above, public-sector geologic-mapping entities in the United States and Canada formed a partnership called the North American Geologic Map Data Model Steering Committee (NADMSC, http://nadm-geo.org/). NADMSC is sponsored by cooperative agreements between the U.S. Geological Survey (USGS) and the Association of American State Geologists (AASG), and between USGS and the Geological Survey of Canada (GSC). In the United States, NADMSC is linked to the database and standards development activities of the USGS National Geologic Map Database (http://ngmdb.usgs.gov/); in Canada, NADMSC is linked to database-development activities under the auspices of the Canadian Geoscience Knowledge Network.
The NADMSC chartered technical teams to develop resources and prototype standards for geologic map databases. These include: 1) the Data Model Design Team, which recently published the design for a conceptual data model (NADM DMDT, 2004); 2) the Data Interchange Technical Team, which provides in these Proceedings a report of progress (Boisvert and others); and 3) the Science Language TechnicalTeam (SLTT), whose work is the subject of this report.
Between April 2000 and November 2004, the SLTT developed a prototype science language for the naming and describing of earth materials in geologic map databases produced by public-sector entities in North America. When the SLTT began its work, the intention was to produce a draft standard that could be evaluated, revised, and adopted by agencies and geologists working in North America. By the end of this process it became clear that, although this goal might be ultimately attainable, over the short term the SLTT’s resources and lack of administrative authority prevent it from facilitating and executing the ambitious scope it originally envisioned.
Some committee members have proposed that the SLTT documents be published in a peer-reviewed venue. This is a logical suggestion, considering that the science-language reports are a comprehensive resource. However, this would require that the documents undergo an extensive review, and the NADMSC neither had the resources to conduct such a process nor does it have the formal mandate or permanent mechanism for archiving its documents. Therefore, in December, 2004, the SLTT posted the prototype science language as a set of “working documents” (see http://nadm-geo-org/). Geologists and agencies are encouraged to evaluate and use the documents, to modify them as necessary for their purposes, andto offer recommendations for their modification.
In lieu of formal publication, the working documents are included in this open-file report in order to allow them to be permanently archived. The body of this report is an abbreviated summary of the SLTT’s results. The Team’s administrative procedures and the general nature of the science language classification were documented in a progress report at DMT’03 (NADM SLTT, 2003), and so are not repeated here. The appendices include the working documents and the executive summary from which this report was adapted. Because of their significant length, the appendices are available only in the web version of this open-file report.
The SLTT was formed in 2000, to identify and/or develop science language that allows information about geologic materials and geologic structures to be described in a standard way, and to promote wider use and more efficient exchange of geologic information. SLTT members were identified in the following ways:
The assembled group (Table 1) represents a cross section of public-sector geologic map producers and users in the United States and Canada.
|Table 1. NADMSC Science Language Technical Team committee members (Jonathan C. Matti, Chair)|
| Lee Allison ||Kansas Geological Survey||General scientific review|
|Brian Berdusco||Ontario Geological Survey||General scientific review|
|Richard C. Berg||Illinois State Geological Survey||Sedimentary subgroup|
|Thomas Berg||Ohio Geological Survey||General scientific review|
|Sam Boggs, Jr.||University of Oregon||Sedimentary subgroup|
|Eric Boisvert||Geological Survey of Canada||Sedimentary subgroup|
|Andrée Bolduc||Geological Survey of Canada||Sedimentary subgroup (co-chair)|
|Mark W. Bultman||U.S. Geological Survey||Sedimentary subgroup|
|William F. Cannon||U.S. Geological Survey||Metamorphic subgroup|
|Robert L. Christiansen||U.S. Geological Survey||Volcanic subgroup (co-chair)|
|Jane Ciener||U.S. Geological Survey||Geologic-map editorial standards|
|Stephen P. Colman-Sadd||Geological Survey of Newfoundland and Labrador||Metamorphic subgroup|
|Peter Davenport||Geological Survey of Canada||General scientific review|
||Geological Survey of Canada||Sedimentary subgroup (co-chair)|
|Lucy E. Edwards||U.S. Geological Survey||Sedimentary subgroup|
|Robert Fakundiny ||New York State Geological Survey||General scientific review|
Farrell ||North Carolina Geological Survey||Sedimentary subgroup|
|Claudia Faunt ||U.S. Geological Survey||Volcanic and sedimentary subgroups|
R. Garstang ||Missouri Department of Natural Resources||Sedimentary subgroup|
||National Park Service||General scientific review|
K. Hansel ||Illinois State Geological Survey||Sedimentary subgroup|
|Thomas D. Hoisch ||Northern Arizona University||Metamorphic subgroup|
|J. Wright Horton, Jr.
||U.S. Geological Survey||Metamorphic subgroup (co-chair)|
|David W. Houseknecht ||U.S. Geological Survey||Sedimentary subgroup|
|Bruce R. Johnson ||U.S. Geological Survey||Volcanic and metamorphic subgroups|
|Robert Jordan ||Delaware Geological Survey||General scientific review|
||U.S. Geological Survey||Plutonic subgroup (co-chair)|
|Alison Klingbyle ||Geological Survey of Canada||Geologic-map editorial standards|
|Dennis R. Kolata||Illinois Geological Survey||Sedimentary subgroup|
|Elizabeth D. Koozmin||U.S. Geological Survey||Geologic-map editorial standards|
|Hannan LaGarry||Natural Resources Conservation Service||Sedimentary subgroup|
|Diane E. Lane||U.S. Geological Survey||Geologic-map editorial standards|
|Victoria E. Langenheim ||U.S. Geological Survey||Plutonic and Sedimentary subgroups|
|Reed Lewis||Idaho Geological Survey||Plutonic and Volcanic subgroup|
|Stephen D. Ludington||U.S. Geological Survey||Volcanic subgroup (co-chair)|
|Jonathan C. Matti||U.S. Geological Survey||Sedimentary subgroup (co-chair)|
|James McDonald||Ohio Geological Survey||Sedimentary subgroup|
|David M. Miller||U.S. Geological Survey||Sedimentary subgroup (co-chair)|
|Andy Moore||Geological Survey of Canada||Sedimentary subgroup|
|Douglas M. Morton||U.S. Geological Survey||Plutonic subgroup|
|Patrick Mulvany||Missouri Department of Natural Resources||General scientific review|
|Carolyn Olson||Natural Resources Conservation Service||Sedimentary subgroup (co-chair)|
|Anne Poole||National Park Service||Plutonic and sedimentary subgroups|
|Stephen M. Richard||Arizona Geological Survey||Metamorphic subgroup (co-chair)|
|Andrew H. Rorick||U.S. Forest Service||Sedimentary subgroup|
|William Shilts||Illinois State Geological Survey||General scientific review|
|David R. Soller||U.S. Geological Survey||Sedimentary subgroup (co-chair)|
|Roy Sonenshein||U.S. Geological Survey||Sedimentary subgroup|
|William Steinkampf||U.S. Geological Survey||Volcanic and sedimentary subgroups|
|Douglas Stoeser||U.S. Geological Survey||Plutonic subgroup|
|Lambertus C. Struik||Geological Survey of Canada||General scientific review|
|John F. Sutter||U.S. Geological Survey||General scientific review|
|Harvey Thorsteinson||Minnesota State Geological||Survey Sedimentary subgroup|
|Robert J. Tracy||Virginia Polytechnic Institute and State University||Metamorphic subgroup|
|David Wagner||California Geological Survey||Volcanic subgroup|
|Richard Waitt||U.S. Geological Survey||Sedimentary subgroup|
|Peter D. Warwick||U.S. Geological Survey||Sedimentary subgroup|
|Richard Watson||U.S. Bureau of Land Management||General scientific review|
|Gerald A. Weisenfluh||Kentucky Geological Survey||Sedimentary subgroup (co-chair)|
|Carl Wentworth||U.S. Geological Survey||Sedimentary subgroup|
|Michael L. Williams||University of Massachusetts||Metamorphic subgroup|
|Ric Wilson||U.S. Geological Survey||Volcanic and plutonic subgroups|
|Robert P. Wintsch||University of Indiana||Metamorphic subgroup|
|Michael L. Zientek||U.S. Geological Survey||Plutonic and metamorphic subgroups|
Rationale for standard science language
Standardized science language is needed to increase the usability and comparability of information contained in geologic map databases. A map user might conclude that terms occurring in map-unit explanations and in database fields have identical meanings from map to map and from region to region. This certainly is true for some specialized terms, and especially for more generalized terms. However, for some terms used in geologic maps, subtle to significant differences in geologic meaning can occur from map to map. This happens for various reasons:
For these reasons, the vocabulary (science language) of both historic and current geologic maps can vary-in some instances enough to create uncertainty on the part of the map user as to whether earth materials and geologic structures in one map are similar to or different from those in another. To minimize this problem, standardized science language that classifies and describes earth materials and their genesis is helpful, especially to facilitate information exchange.
Purpose and Intended Use for the SLTT Prototype Standard
The SLTT prototype standard provides a logical, consistent, hierarchical framework for naming and classifying earth materials, and for describing their physical characteristics and genesis—based on the way geologic maps are made by the field geologist or assembled by a science compiler. It is intended for use by persons and agencies submitting digital geologic-map data into public-domain databases that are managed by various State/Provincial and Federal agencies. Intended users include:
It has been the SLTT’s intention to break down common terms for earth materials into their fundamental science concepts. This is based on our belief that it is not so much what an object or concept is called, but what the name means in terms of the science concepts it represents. The SLTT documents provide specific defined names for earth-material objects and concepts, with the hope that they will be familiar and palatable to the average geologic-map maker and map user. However, we understand that each map producer and map user will have their own favorite names, and that humans are reluctant to abandon terms and meanings with which they are comfortable. With that recognition, we believe SLTT will have served its purpose if it provides a yardstick against which terms can be compared and translated—the true meaning of a “standard.”
Related science-language efforts
SLTT deliberations benefited from previous and ongoing science-language efforts being conducted by other entities.
British Geological Survey
In 1999 the British Geological Survey (BGS) issued four reports that presented science language for earth materials from a geologic-mapping point of view:
The SLTT adopted major elements of the BGS approach, but found that in order to accommodate North American geologic-mapping traditions and approaches we had to develop slightly modified terminology and taxonomic hierarchies.
International Union of Geological Sciences (IUGS)
SLTT activities benefitted from a series of IUGS sub-commissions chartered to develop uniform classifications of earth materials:
Science language for glacial sedimentary materials
The International Union for Quaternary Research [INQUA] in the 1970’s sponsored a Commission on Genesis and Lithology of Glacial Quaternary Deposits (Commission C-2). The results of Commission C-2 were published in Goldthwait and Matsch (1988; see Commission summaries in Goldthwait and others, 1988, p. vii-ix, and Dreimanis, 1988, p. 19-25). The SLTT used this document to develop science language for sedimentary materials of glacial origin.
Geological Survey of Canada science language
Concurrent with SLTT activities, the Geological Survey of Canada (GSC) is developing science language for use by GSC projects producing digital geologic-map databases. Through a series of projects, GSC has investigated approaches to developing geological map databases, including prototype data models and user interfaces. Bedrock and surficial geological maps have to date been addressed separately. As part of data modeling, based on variants of NADM, several approaches have been tested to enable interoperability among maps that use varied, usually undefined and sometimes inconsistent science language, particularly for the earth-material constituents of map units.
Two main approaches have been tried, both relying on map context and geological experience as guides to the authors’ meaning. For surficial geological maps, the uncontrolled and variable terminology is reinterpreted within a controlled set of defined terms (a translation, in effect).
For bedrock maps, earth material names are “reverse-engineered” into the properties (genetic process, composition, texture, etc.) implied by each name (single word or phrase), using sets of keywords for these properties (Davenport and others, 2002). In both approaches, a hierarchical organization of terms is applied wherever possible to allow for categorization at variable levels of precision in accordance with the information available, and to enable efficient querying of the databases. For bedrock maps, Struik and others (2002) followed a different approach, recognizing that earth material names are multi-dimensional and can be organized in a variety of hierarchies depending on the choice of criteria (genetic process, composition, texture, etc.). The earth material names that Struik and others (2002) considered were uncontrolled terms gleaned from several published geological maps, but were neither exhaustive nor representative of the entire collection of published maps for Canada. This approach has been extended to collect earth material names in a master list as additional maps are brought into the database, and associate controlled keywords for earth material properties to each unique term (single word or phrase) through a data model that supports multiple ontologies. This enables map units to be searched or grouped by one or several of these keywords. User interfaces have been written to streamline the analysis of map unit descriptions, extraction of earth material types, and the assignment of keywords.
Federal Geographic Data Committee (FGDC) science language
Within the United States, an important science-language activity is occurring under auspices of the Federal Geographic Data Committee (FGDC) Geologic Data Subcommittee (http://ngmdb.usgs.gov/fgdc_gds/). The FGDC has developed a draft cartographic standard for polygon, line, and point symbols that depict geologic features on geologic maps and digital displays. Although primarily concerned with cartographic technical specifications, the FGDC cartographic standard contains science-language concepts that should be integrated with the science-language in these SLTT documents.
THE SLTT WORKING DOCUMENTS
Working documents versus a “standard”
As originally envisioned by the NADMSC and by the SLTT charter (see http://nadm-geo.org/), our intent was to develop formal science-language standards for evaluation and use by the North American geologic-mapping community. Based on the charter and early discussions among SLTT members, it seemed logical to pursue the following strategy:
This strategy proved unsupportable for the following reasons:
For these reasons, the NADMSC accepted the SLTT chair’s recommendation that formal publication of the science-language document be reconsidered. NADMSC agreed that the best approach was to post the various SLTT reports on the NADM website, and to present them as a work in progress (i.e., as “working documents”). The inclusion of the working documents as appendices to this report serves to fulfill a principal NADMSC objective—to publish and archive these documents as a permanent record of the SLTT’s endeavor.
This strategy allows the SLTT to conclude its responsibilities, and to present the North American geologic-mapping community with a range of science-language approaches and issues for their evaluation and discussion-pursuant to any next steps in the science-language process that are determined necessary by the NADMSC or by any geological survey.
A philosophical issue
Early in the SLTT process, tensions developed between two very different science-language goals and strategies:
These two objectives are equally legitimate. However, they reflect different philosophies and lead to different science-language strategies. Tensions between them were not resolved during the course of SLTT deliberations and, as a consequence, significant differences in scope, content, purpose, and philosophy exist among the various SLTT reports. This did not invalidate the SLTT effort, but it does illustrate the complexity and challenges of developing a standard science-language. Moreover, it should be a valuable lesson for agencies that conduct geologic mapping and that intend to develop local, regional, and national geologic-map databases that have uniform science content.
The composite-genesis and sedimentary subgroups concluded that their principal objective was to examine the science concepts embedded in geologic-map terminology, and to develop classification schema organized around that conceptual content. This philosophical approach forced a re-examination of how traditional map terms are used, and in some instances led these subgroups either not to adopt as controlled terms some familiar earth-material names, or to position these names in classification hierarchies in a different place than where some workers might expect to find them. For future geologic-mapping activities and their resulting databases, this probably will not create any long-term problems—provided future geologic mappers understand and agree with SLTT approaches. For legacy geologic-map information, the approach adopted by the composite-genesis and sedimentary groups might require some decision making on the part of the information compiler: (1) for a legacy term whose original meaning was not clear, the map compiler might have to use a higher-level, more generalized SLTT term instead, or (2) where a legacy term is understood to have a different meaning than the SLTT rendering of the same term, the map compiler may have to use a different SLTT term for the same concept.
The classification adopted by the SLTT follows this high-level architecture for earth-material name (see also Appendix A):
Igneous earth material
lithologic class based on composition
lithologic class based on texture
lithologic class based on emplacement characteristics
Hypabyssal rock (BGS classification, Gillespie and Styles, 1999)
Plutonic rock (BGS classification, Gillespie and Styles, 1999)
Sedimentary earth material (unconsolidated, consolidated)
Sedimentary material, unclassified
Terrigenous-clastic sedimentary material
Carbonate sedimentary material
Organic-rich sedimentary material
Non-clastic siliceous sedimentary material
Noncarbonate-salt sedimentary material
Phosphate-rich sedimentary material
Iron-rich sedimentary material
Composite-genesis earth material
Metamorphic rock (traditional sense) (including hydrothermally-altered rock)
foliated metamorphic rock
These high-level categories fundamentally are genetic: they reflect how earth material was formed (genetic process, crustal depth, etc.). This raises the irony that, while deeper levels of the earth-material classification hierarchy are based on what the mapping geologist can see in the outcrop (empirical factors such as composition, structure, and texture), upper-level categories are based on interpretations about how the material was formed. Once this choice is made, an earth material is classified in more detail based on textural or compositional criteria—criteria that actually can be satisfied on the basis of empirical observation.
The use of standardized science language in digital geologic-map databases is a new frontier that is likely to evolve with time and experience. With this in mind, we developed classifications of earth materials that we believe reflect not only how mapping geologists view them but also how such materials might be queried and analyzed in geologic-map databases. No single classification of earth materials will please all workers. However, the schemes we propose hopefully will be clearly understandable, internally consistent, and usable by both data-producer and data-user.
The volcanic SLTT document (see Appendix D) provides a concise look at the science language of unconsolidated and consolidated volcanogenic earth materials. The goal of the volcanic subgroup was:
“...to develop standardized nomenclature for use in digital geologic map databases, specifically to describe lithologies in volcanic rock units. Although this nomenclature takes the form of a hierarchy of terms, it is important to note that this is not the same as a formal rock-naming system....
We consider it critical to remember that the purpose of our hierarchical subdivision of terms is to describe the lithologic characteristics of geologic map units. [Our hierarchical subdivision] is to be used to logically retrieve or select those map units that contain a specified set of lithologic characteristics. Thus, it must be flexible enough to accommodate the extremely varied and unsystematic way in which map units are described and defined by various authors. This report groups lithologic features necessary to adequately characterize volcanic materials in the map units of a geologic map database into three fundamental classes based on composition, texture, and emplacement characteristics.
No one of these classes is primary, and any or all may be used to select the lithologies of map units. The subdivision of any one of the fundamental classes consists of a list of words, arranged in a hierarchy that can be used to select lithologies. The words that describe these subdivisions are not given formal definitions here, but brief descriptions are given in the appendices. Many of the words have multiple, sometimes conflicting definitions and have been used differently over the years by different map authors. We have attempted to make the hierarchy sufficiently comprehensive, especially at the higher levels, to allow adequate lithologic characterization and to accommodate the vast majority of lithologic descriptions on existing geologic map legends.”
The volcanic SLTT subgroup focused on how to bring the variable and inconsistent usage of legacy geologic maps into a modern database. To accomplish this, they characterize volcanic materials using three fundamental classes: composition, texture, and emplacement characteristics. Their report provides informal characterizations of volcanogenic materials in terms of these three aspects, but does not provide formal material descriptions, deferring instead to other sources (such as Le Maitre and others, 2002). The report does not provide a comprehensive listing of petrologic descriptors, as the subgroup felt it was beyond their mandate.
Owing to conflicting agency science-project obligations, members of the plutonic SLTT subgroup were unable to conclude their deliberations and were unable to develop plutonic science-language standards for use by geologic-mapping projects in North America. In the interim, the NADMSC recommends that the British Geological Survey report on plutonic science language (Gillespie and Styles, 1999) be used for North American geologic-map databases.
The sedimentary subgroup produced a comprehensive analysis of the attributes for sedimentary earth materials, both consolidated and unconsolidated (see Appendix C), that includes the following components:
Science language for metamorphic rocks and for other earth materials that form through modification of pre-existing earth material owing to the effects of temperature, pressure, and deformation, is discussed in the SLTT report on composite-genesis materials (see Appendix B). The domain of this classification system includes metamorphic rocks as commonly understood, as well as impact metamorphic rocks, hydrothermally altered rocks, mylonite-series rocks, and cataclastic rocks. These composite-genesis rocks are classified according to descriptive properties that are interpreted to reflect processes that made the rock composite.
The Composite-genesis subgroup members discussed whether or not to include within the composite-genesis domain earth material such as pedogenic soil that forms at the earth’s surface through low temperature-pressure processes that modify pre-existing sediment and rock. No consensus was reached on this subject, hence pedogenic materials are not currently included in any of the SLTT science-language documents, except as a modifier to describe the upper surface of sedimentary earth materials.
Preliminary results of the SLTT process
The SLTT process was an experiment with mixed outcomes:
The NADMSC believes the SLTT documents will be of significant value to the North American geologic-mapping community: hopefully, the effort will stimulate discussion about how the content of geologic-map databases is used, how it is accessed, and how it can be structured and represented through the use of standard science language. Such discussions could lead to future work that will build on SLTT accomplishments.
Finally, and because the SLTT process was conducted to support agency needs for standardized map databases, we offer the following recommendations to high-level science managers in agencies that execute geologic mapping:
If these four requirements are not advocated and facilitated, then science-language standards will be neither robust nor comprehensive, and most likely they will not be viewed seriously by a workforce that may (or may not) be asked to adopt them.
The SLTT chair (Jon Matti) prepared the summary document (Appendix A) in coordination with the SLTT subgroup leaders (Table 2), each of whom contributed to the SLTT subgroup narratives in this report. Dave Soller assisted with preparation of this report by adapting it from the summary document.
Table 2. SLTT Subgroup leaders who contributed to this report.
|Robert L. Christiansen||U.S. Geological Survey||Volcanic subgroup|
|Andrée Bolduc||Geological Survey of Canada||Sedimentary subgroup|
|Ron DiLabio||Geological Survey of Canada||Sedimentary subgroup|
|J. Wright Horton, Jr.||U.S. Geological Survey||Metamorphic subgroup|
|Stephen D. Ludington||U.S. Geological Survey||Volcanic subgroup|
|Jonathan C. Matti||U.S. Geological Survey||Sedimentary subgroup|
|David M. Miller||U.S. Geological Survey||Sedimentary subgroup|
|Carolyn G. Olson||Natural Resources Conservation Service||Sedimentary subgroup|
|Stephen M. Richard||Arizona Geological Survey||Metamorphic subgroup|
|David R. Soller||U.S. Geological Survey||Sedimentary subgroup|
|Gerald A Weisenfluh||Kentucky Geological Survey||Sedimentary subgroup|
Davenport, P., and others, 2002, A Scalable, Digital Map Database of Bedrock Geology for Canada: A Progress Report, in Soller, D.R., ed., Digital Mapping Techniques ’02—Workshop Proceedings: U.S. Geological Survey Open-File Report 02–370, p. 47-66, accessed at http://pubs.usgs.gov/of/2002/of02-370/davenport.html.
Dreimanis, A., 1988, Tills: their genetic terminology and classification, in Goldthwait, R.P., and Matsch, C.L., eds., Genetic classification of glacigenic deposits (Final report of the Commission on Genesis and Lithology of Glacial Quaternary Deposits of the International Union for Quaternary Research [INQUA]): Rotterdam, A.A. Balkema, p. 17–83.
Foley, S.F., Venturelli, G., Green, D.H., and Toscanni, L., 1987, The ultra potassic rocks: characteristics, classification and constraints for petrographic models: Earth Science Reviews, v. 24, p. 81–134.
Gillespie, M.R., and Styles, M.T., 1999, Classification of igneous rocks: Volume 1 of the BGS rock classification scheme: British Geological Survey Research Report Number RR 99–06, 52 p.
Goldthwait, R.P., and Matsch, C.L., eds., 1988, Genetic classification of glacigenic deposits (Final report of the Commission on Genesis and Lithology of Glacial Quaternary Deposits of the International Union for Quaternary Research [INQUA]): Rotterdam, A.A. Balkema, 294 p.
Goldthwait, R.P., Matsch, and Dreimanis, A., 1988, Preface, in Goldthwait, R.P., and Matsch, C.L., eds., Genetic classification of glacigenic deposits (Final report of the Commission on Genesis and Lithology of Glacial Quaternary Deposits of the International Union for Quaternary Research [INQUA]): Rotterdam, A.A. Balkema, p. vii––ix.
Hallsworth, C.R., and Knox, R.W.O’B., 1999, Classification of sediments and sedimentary rocks: Volume 3 of the BGS rock classification scheme: British Geological Survey Research Report Number RR 99–03, 44 p.
Heiken, G., and Wohletz, K.H., 1985, Volcanic ash: Berkeley, University of California Press. IUGS (International Union of Geological Sciences Subcommission on the Systematics of Igneous Rocks), 1973, Plutonic rocks: Geotimes, v. 18, no. 10, p. 26–30.
Le Bas, M.J., and Streckeisen, A., 1991, The IUGS systematics of igneous rocks: Journal of the Geological Society of London, v. 148, p. 825–833.
Le Bas, M.J., Le Maitre, R.W., Streckeisen, A., and Zanettin, B., 1986, A chemical classification of volcanic rocks based on the total alkali-silica diagram: Journal of Petrology, v. 27, p. 745–750.
Le Maitre, R.W., and 11 others (editors), 1989, A classification of igneous rocks and glossary of terms: Recommendations of the International Union of Geological Sciences Subcommission on the Systematics of Igneous Rocks: Oxford, Blackwell Scientific Publications.
Le Maitre, R.W. (editor), Streckeisen, A., Zanettin, B., Le Bas, M.J., Bonin, B., Bateman, P., Bellieni, G., Dudek, A., Efremova, S., Keller, J., Lameyre, J., Sabine, P.A., Schmid, R., Sørensen, H., and Woolley, A.R., 2002, Igneous rocks: A classification and glossary of terms: Recommendations of the International Union of Geological Sciences Subcommission on the Systematics of Igneous Rocks: Cambridge, Cambridge University Press, 236 p.
MacDonald, R., 1974, Nomenclature and petrochemistry of the peralkaline oversaturated extrusive rocks: Bulletin Volcanologique, v. 38, p. 498–516.
McMillan, A.A., and Powell, J.H., 1999, Classification of artificial (man-made) ground and natural superficial deposits: applications to geological maps and datasets in the UK: v. 4 of the BGS rock classification scheme: British Geological Survey Research Report Number RR 99–04, 65 p.
NADM DMDT (North American Geologic Map Data Model Steering Committee Data Model Design Team, 2004, NADM Conceptual Model 1.0—A Conceptual Model for Geologic Map Information: U.S. Geological Survey Open-File Report 2004-1334, 58 p., accessed at http://pubs.usgs.gov/of/2004/1334/.
NADM SLTT (North American Geologic Map Data Model Steering Committee Science Language Technical Team), 2003, Science Language for Geologic-Map Databases in North America: A Progress Report, in Soller, D.R., ed., Digital Mapping Techniques ’03—Workshop Proceedings: U.S. Geological Survey Open-File Report 03–471, p. 109-138, accessed at http://pubs.usgs.gov/of/2003/of03-471/matti/.
Robertson, S., 1999, Classification of metamorphic rocks: Volume 2 of the BGS rock classification scheme: British Geological Survey Research Report Number RR 99–02, 24 p.
Schmid, R., 1981, Descriptive nomenclature and classification of pyroclastic deposits and fragments: Recommendations of the IUGS Subcommission on the Systematics of Igneous Rocks: Geology, v. 9, p. 41–43.
Streckeisen, A., 1974, Classification and nomenclature of plutonic rocks: Recommendations of the IUGS Subcommission on the Systematics of Igneous Rocks: Geologische Rundschau Internationale Zeitschrift für Geologie: Stuttgart, v. 63, p. 773–785.
Streckeisen, A., 1976, To each plutonic rock its proper name: Earth Science Reviews, v. 12, p. 1–33.
Streckeisen, A., 1978, IUGS Subcommission on the Systematics of Igneous Rocks: Classification and nomenclature of volcanic rocks, lamprophyres, carbonatites and melilitic rocks. Recommendations and suggestions: Neues Jahrbuch für Mineralogie, v. 134, p. 1–14.
Streckeisen, A., 1979, Classification and nomenclature of volcanic rocks, lamprophyres, carbonatites and melilitic rocks: recommendations and suggestions of the IUGS Subcommission on the Systematics of Igneous Rocks: Geology, v. 7, p. 331–335.
Struik, L.C., Quat, M.B., Davenport, P.H., and Okulitch, A.V., 2002, Multi-hierarchical rock classification for use with thematic computer-based query systems: a preliminary scheme: Geological Survey of Canada, Current Research 2002D, 9 p.
(NOTE: these Appendices are only available in the Web version of the document.)
Philosophical and operational guidelines for developing a North
American science-language standard for digital geologic-map
[ PDF - 784 KB | Microsoft Word - 392 KB ]
Appendix B. Classification of metamorphic and other composite-genesis rocks, including hydrothermally altered, impact-metamorphic, mylonitic, and cataclastic rocks.
[ PDF - 2.8 MB | Microsoft Word - 332 KB | Microsoft Access glossary of terms - 200KB ]
Appendix C. Sedimentary materials: Science language for their classification, description, and interpretation in digital geologic-map databases.
[PDF - 36.4 MB | Microsoft Word-Adobe Illustrator - 47.7 MB ] This file includes:
Volcanic materials: Science language for their naming and
characterization in digital geologic-map databases.
[ PDF - 168 KB | Microsoft Word - 100 KB | Microsoft Excel picklist of volcanic terms - 24 KB ]