IGNEOUS ROCKS, TERRANES AND GEON

The growth of continents is recognizably one of the more complex processes in geology. Characterization of the periodicity of continental growth through Wilson cycle processes requires integration of data from many disciplines and multiple events through geologic time. Through the GEOscienceNetwork (GEON) research initiative we are developing an ontologically driven query system under the semantics web model that makes it possible to integrate disciplinary databases from igneous rocks, geologic time, and geospatially referenced terranes of the mid-Atlantic Appalachian orogen.

Our database structure, developed to create an ontologically integrated concept space, uses data from the Baltimore Mafic Complex (subduction stage of Wilson cycle) in the central Appalachian Piedmont. The development of a GIS-based field oriented pluton schema utilizes knowledge engineering techniques for which the required ontology provides a vocabulary for describing the plutons, as well as the necessary documentation of table fields in the database for developing the semantic foundation. This database system of spatial features, related tables and hierarchical classification schemes (e.g., the geological time classification from the Geological Survey of Canada and rock classification scheme from Geoscience Australia; also British Geological Survey) will allow the user to query across the many properties and attributes that describe plutons, including locations, textures, fabrics, modes, geological and radiometric ages, and whole- rock and mineral geochemistry and isotopic properties. The design utilizes relational databases with a “middleware” for data processing, leading to a knowledge base (i.e., a semantic network). The ontologically aligned data has allowed the creation of “PlutonMatch,” a prototypical example of the “middleware” data processing tools to be included in the final GEON system. The PlutonMatch process is capable of qualitatively and quantitatively describing and comparing the similarities and differences between plutons. The results of the queries and processes initialized by the GEON user could be displayed in several formats, such as tables, graphs, charts, and maps, and can be added to the existing knowledge base for other geological researchers to “mine” with queries of their own.