A NEW MODEL FOR DIGITAL, INTEGRATED REGIONAL GEOLOGIC MAPS AND ASSOCIATED SUBSURFACE MODELS OF THE INTERMOUNTAIN WEST, USA

Geologic maps are fundamental base data for regional geologic models of Earth’s composition, structure, and evolution. Integrated with analytical data and numerical modeling of Earth’s physical systems, these maps underpin the analytical framework necessary to understand geologic processes critical to mineral, water, and energy resource management, environmental health, hazard mitigation, and ecosystem impact. Digital geologic map databases are consequently the starting point for all geologic research and natural resource assessments at local, regional, and national scales. However, existing regional-scale (1:100K to 1:250K) geologic map coverage of the Great Basin and Rocky Mountains is inconsistent, mismatched across map and administrative borders, and often decades out-of-date.

To further the USGS National Cooperative Geologic Mapping Program’s strategic goal of developing a geologic map database of the Nation, the Geologic Framework of the Intermountain West project was launched with the goal of producing a new digital geologic map database and 3D geologic model of a regional transect from the western Great Plains to the eastern Sierra Nevada (2 degrees latitude by 14 degrees longitude; centered on the 37th parallel), based on synthesis of existing geologic maps with new field and imagery-based mapping. The resulting database will include seamless vector geologic map data at a scale no less detailed than 1:250K—and as detailed as 1:100K where possible—together with geochronologic data, and a simplified 3D geologic model of the subsurface.

First-year results include an inventory and assessment of existing mapping within the regional transect and development of: 1) a multi-user enterprise GIS system and associated map production workflows; 2) the blueprint for a new USGS geochronology database; 3) an initial map compilation (GeMS compliant) in southern Colorado and northern New Mexico; and 4) a prototype 3D geologic model of the San Juan Basin. Priority efforts include: maximizing utility of geologic map data for research and resource management applications through extensive data attribution; establishing new procedures for reviewing and publishing large digital geologic data sets; and expanding project research capabilities to facilitate regional geologic framework model development.