IMPLEMENTATION OF A GEOLOGIC DATA MODEL: PLAINS 30’ X 60’ QUADRANGLE, WESTERN MONTANA

New developments in Geographic Information Systems software and methodology aid in the utilization of data models that can be used to create, maintain, and analyze complex sets of geologic information. The ArcGIS geodatabase structure maintains datasets with a variety of integrated geographic and attribute relationships. Although geodatabase models have been designed and utilized in many other fields, the complexity of geologic data has been a restriction on full implementation of a digital geologic data model.

This project serves as a case study focused on developing a complete geologic dataset within the geodatabase structure. The map area, located in the western Montana thrust belt, encompasses geologic units within the Proterozoic Belt-Purcell Supergroup and Quaternary sediments. Map data from the Plains Quadrangle (1:100,000) was extracted into digital format using new tools for on-screen digitizing and topology. Associated geologic attributes, including rock type, unit/formation name, and age were used to populate the relational database fields. The map data and attribute information were applied to existing geologic data models within the geodatabase structure. These models were then evaluated with regards to strengths and weaknesses in conceptual design, as well as real-world implementation. Results from this study may provide advancements in the assembly and maintenance of digital geologic data.