REGIONAL-SCALE MODELING TO SUPPORT THE DEVELOPMENT OF A SUBSURFACE MODEL OF THE UNITED STATES: A CASE STUDY FROM THE POWDER RIVER BASIN REGION, WYOMING AND MONTANA, USA

A strategic goal of the USGS National Cooperative Geologic Mapping Program (NCGMP) is to develop a seamless three-dimensional body of subsurface geological data spanning the conterminous United States in a non-proprietary, consistent, and versionable format. In this case study, we present advances in our methodology to (1) synthesize and preserve subsurface geological data, (2) construct regional-scale volumetric 3D subsurface geologic models, and (3) serve these interpretations to the public in a manner that encourages broader scientific collaboration, facilitates informed decision-making in resource exploration and development, and promotes geologic education and outreach.

This case study applies our new methodology to the Powder River Basin region of Wyoming and Montana, spanning the data-dense core of the Powder River Basin to complexly faulted and data sparse terranes such as the central Bighorn Mountains and Hartville Uplift. Our research integrates a diverse range of data sources, including surficial geologic mapping, downhole information from water and hydrocarbon wells, raster datasets, geologic cross sections, seismic data, structure contour and isopach maps, polygons derived from geophysical data, and existing geological models. We present challenges associated with data compilation and preservation, complexities of surface and volume construction to a high degree of confidence, and address uncertainties related to the publication and upgradeability of this digital infrastructure.

Expansion of the case study model to the national scale will require a cooperative effort to develop a consensus on the broader regional stratigraphic correlation with partners at state geological surveys, as well as data inputs from both the public and private sectors with local expertise. Ultimately, these efforts will improve the public understanding of the subsurface of the United States, supporting a wide range of geological investigations, resource assessments, and land management decisions.