Science Center Objects

The USGS Intermountain West project was launched with the goal of producing an new digital geologic map database and 3D geologic model of a transect from the Rio Grande rift to the Basin and Range, based on a synthesis of existing geologic maps with new targeted new mapping, subsurface data, and other data sets. This database will integrate disparate map data, resolve inconsistent stratigraphic assignments, and develop an integrated regional geologic map database to further the NCGMP’s strategic goal of mapping the Nation. This effort will require development of new techniques for digital compilation and new procedures for reviewing and publishing large digital geologic data sets.

 

Digital Geologic Map Database

Geologic maps are the fundamental base data for regional geologic models of the 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 nation 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Great Basin and Rocky Mountains is inconsistent, mismatched across map and administrative borders, and often decades out-of-date.

Footprint of the Intermountain West project in the western United States

Map showing footprint (area within red outline) of the Intermountain West project in the western United States.

Creating a digital, data-rich, geologic map database of an area the size of the Intermountain West transect requires innovative new database frameworks and map compilation workflows, while serving the database to the public will require new approaches to the review and publication process. Our mapping strategy is based on digital synthesis of the best available geologic information at a compilation scale no less detailed than 1:250K—and as detailed as 1:100K, where possible—along a crustal transect that spans many administrative boundaries and thus forces reconciliation across borders. This strategy requires coordination of a large research team at a level considerably beyond previous FEDMAP projects, as well as the development of new technical infrastructure and database frameworks that could ultimately provide a template for National-scale data sets. Our goal is to produce a peer-reviewed digital database that is regularly updated with new content and revisions, served digitally to users on a variety of platforms.

Diagram illustrating a proposed all-digital workflow for map database production to publication

Diagram illustrating a proposed all-digital workflow for map database production to publication.​​​​​​​

 

 

 

Research Themes

Magmatism in the western United States—The transect area encompasses the full range of continental magmatic systems, including batholiths, explosive silicic calderas, and bimodal volcanic fields. Better understanding of the timing, style, and extent of magmatism will further our understanding of how mineral resources form and where new resources are likely to be found in the future.

Tectonic evolution of the Cordillera—The transect area includes rocks that record all of the major episodes of orogeny, magmatism, continental extension, and basin formation that have shaped the Cordillera since the Early Paleozoic. Better understanding of the timing and style of deformation along the transect will allow us to understand the role of faulting in formation and post-ore disruption of mineral deposits and the formation of structural basins that hold water and energy resources.

Landscape evolution—The weathering, transport, and deposition that shaped the topography of Intermountain West transect also governs the enrichment and availability of critical mineral deposits, the extent of groundwater resources, and the distribution of nutrients critical to ecosystems and agriculture. Better understanding how surface processes have been influenced by tectonics and climate will improve the knowledge base necessary to make effective land-use decisions.

Stratigraphy and basin evolution—Older stratified rocks along the transect are key stratigraphic markers but pose challenges with respect to long-distance correlation, and younger basin fill is the most important repository of energy and water resources. Better regional correlation and stratigraphic synthesis combined with new data on age, provenance, and sedimentary environments will enhance our understanding of regional tectonic evolution and provide a critical building block for groundwater models.

Regional subsurface structure—3D geologic models have been constructed at the site or basin scale, but no regional-scale models exist for the western U.S. The project will begin building a data warehouse of subsurface data to enable construction of regional 3D geologic models, but better understanding of the subsurface structure is needed, particularly in the many areas that lack control from well data.

Geochronology and isotope geochemistry—Understanding the timing of geologic processes and events as well as quantifying rates and timescales is key to geologic mapping, mineral and energy resource assessments and natural hazard assessments. While collecting new data, the project is working to compile existing geochronology data into an accessible database to support research and geologic mapping.

Database development and visualization—Regional compilation of geologic mapping and other data sets at this scale requires new workflows and data infrastructure to allow efficient synthesis of new and existing data and provide data to stakeholders and the public in a useful and timely manner.