DEVELOPING A STRATIGRAPHIC LEXICON FOR ONTARIO

In recent years, a co-ordinated effort to develop a North American Data Model (NADM) for geologic map databases has been undertaken by agencies in Canada and the United States (i.e., USGS, AASG, Geological Survey of Canada (GSC)). Amongst the descriptive components forming any geologic model is stratigraphy, for which a standardized lexicon is required.

In the United States, the USGS is the gatekeeper for stratigraphic nomenclature, an online version of which is provided through StratLex. However, in Canada, there has been no centralized clearinghouse and no single source of information exists for geological names.

The Canadian Geoscience Knowledge Network (CGKN) is an initiative to provide an Internet portal to Canadian geoscience information. Under the auspices of the CGKN, the GSC began work on the Canadian Stratigraphic Lexicon. In 2004, the GSC approached the Ontario Geological Survey (OGS) about participation and co-operation in this project.

For Ontario, there is no complete lexicon of stratigraphic names; what is available is not current and, for the most part, is represented only by a limited names list. In late 2004, tentative approval was given to OGS staff to contact the GSC to obtain the Ontario portion of the StratLex/WebLex data for preliminary evaluation. The GSC provided their existing Ontario data (initially as a spreadsheet; later, as the Oracle database). The initial spreadsheet information was merged with the OGS list and examined to establish the quantity of unique terms and quality of data in a first-stage “triage”, which was completed late in 2005. This exercise yielded ~4300 terms to be examined; however, this does include some geologic features (e.g., faults, greenstone belts). Evaluation by a peer review committee will be based on criteria such as current (approved) names, alternate (historical or invalid) names, location of type section, reference(s) for the publication in which the name was defined formally, etc. A detailed project proposal for the “Stratigraphic Lexicon for Ontario” has been submitted.

By instituting the Lexicon project and provincial stratigraphic review committee, OGS will contribute to geoscience nationally and internationally providing stakeholders access to consistent terminology for use in map creation and databases.