Managing Geochemical Data - Development of An Appropriate Database and Delivery Mechanism

The management of geochemical data is inherently complex because of the multitude of sample media, preparation methods and analytical techniques. Geological Survey of Canada staff has developed a universal model for the storage of geochemical data in relational databases. It is currently being used to manage a large amount of legacy data. The model has a very comprehensive set of tables for capturing metadata on all aspects of a geochemical survey (sample types, analytical procedures, etc.).

The data model provides a solid foundation on which to build computational procedures for managing the data. The procedures rely on a combination of SQL scripts and XML output. Fully automated ETL (extract, transform and load) procedures are used to convert data from legacy formats into a format that is easy to maintain, and then into formats that are easy to use. A sophisticated website comprising several thousand XHTML pages, KML files and spreadsheets is derived directly from the relational database (http://gdr.nrcan.gc.ca/geochem).

The management system is designed to be platform-independent, multilingual (currently English and French) and standards-based. It has been tested on several commercial RDBMSs. The system delivers CSDGM-compliant metadata to Z39.50 servers. A map-based query tool using University of Minnesota MapServer allows public geospatial searches.

The major development effort so far has focused on (a) methods to load legacy data into the database, and (b) transformation into web pages for end-users. We are now focusing on integrating the system with a laboratory information management system (LIMS). The existing LIMS will be redesigned to be more adaptable to the evolving needs of the organisation. It will be based on a logical n-tier (or n-layer) architecture. The system will be configurable for both internal GSC applications and external users via a web service.