Internet mapping applications have changed the way geologic data is viewed, distributed, and updated. These web-based GIS applications allow simultaneous data delivery and collection, enabling quick data modification while easily and efficiently supplying the end-user with information. Utilizing web-based technologies transformed the Colorado Geological Survey’s “Colorado Late Cenozoic Fault and Fold Database” from a monothematic, non-spatial Microsoft Access database into a complex information set incorporating multiple data sources. The resulting user-friendly format supports easy analysis and browsing.

The core of the application is the Microsoft Access database, which contains information compiled from available literature about faults and folds that are known or suspected to have moved during the late Cenozoic (approximately the last 23.7 million years). The database contains non-spatial fields such as structure type, age, and rate of movement. Geographic locations of the fault and fold traces were compiled from previous studies at 1:250,000-scale to form a spatial database containing information such as length, strike and paleoseismic investigation sites. Assimilation of the two databases allowed both spatial and non-spatial information to be presented on the Internet as a single dataset (http://geosurvey.state.co.us/pubs/ceno/). The user-friendly interface enables the data to be viewed and queried in an integrated manner, thus providing users multiple ways to locate desired information. Retaining the digital data format also allows continuous data updating and quick delivery of newly acquired information.

This dataset is a valuable resource to anyone interested in earthquake hazards and the activity of faults and folds in Colorado. The broad time span of Cenozoic structures allows evaluation of all structures with orientations favorable for slip in the modern stress environment. Likewise, additional geologic hazard layers and imagery may aid in decision support and hazard evaluation. The up-to-date customizable database and maps are invaluable resources for researchers or the public.