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Modeled Top of the Grande Ronde Basalt Geomodel Unit (grtop_f)

Metadata Updated: April 6, 2024

The grtop_f grid represents the modeled elevation of the top of the Grande Ronde Basalt geomodel unit at a 500 foot resolution. It is one grid of a geomodel that consists of eleven grids and a spatial extent polygon shapefile. As part of a U.S. Geological Survey Groundwater Resources Program study, a three-dimensional geomodel was constructed for approximately 53,000 mi2 of the Columbia Plateau in Washington, Oregon, and Idaho. This geomodel was constructed to define the general aquifer system geometry for use in a regional numerical groundwater flow model. Simplifications and assumptions consistent with this ultimate goal and the uncertainty in the available data were made. The geomodel units consist of Miocene age Columbia River Basalt Group strata and younger alluvial overburden covering approximately 44,000 mi2. Data were compiled from numerous databases and detailed studies completed during the past three decades. These data include stratigraphic interpretations made on more than 13,000 wells and a contiguous compilation of surficial geology and structural features spanning the study area. These data were simplified and used to construct piecewise-smooth trend surfaces that represent upper and lower subsurface geomodel unit boundaries in this complex folded and faulted terrain. The smoothness of the surfaces implicitly represents uncertainty in prediction of each surface resulting from data gaps, errors in borehole interpretations, errors in mapped contact locations, and uncertainty in the shape of the paleo-surface upon which flood basalts were emplaced. Using a rule-based algorithm, surfaces were then recombined to construct a fully three-dimensional model with a 500-foot grid resolution that is consistent with the data and for which error estimates may be made. The modeling process yielded improved estimates of unit volumes, refinement of location of large structural features, and identification of features that may be important for ongoing groundwater studies.

Access & Use Information

Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

Downloads & Resources

Dates

Metadata Created Date June 1, 2023
Metadata Updated Date April 6, 2024

Metadata Source

Harvested from DOI EDI

Additional Metadata

Resource Type Dataset
Metadata Created Date June 1, 2023
Metadata Updated Date April 6, 2024
Publisher U.S. Geological Survey
Maintainer
@Id http://datainventory.doi.gov/id/dataset/bb01e1b66c257e94e23e619f11d134dc
Identifier USGS:8fe47743-0fad-4793-8cb5-ea9983548cd3
Data Last Modified 20201117
Category geospatial
Public Access Level public
Bureau Code 010:12
Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
Metadata Catalog ID https://datainventory.doi.gov/data.json
Schema Version https://project-open-data.cio.gov/v1.1/schema
Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
Harvest Object Id b1022267-27f9-4f8a-ba5f-65ea223507bc
Harvest Source Id 52bfcc16-6e15-478f-809a-b1bc76f1aeda
Harvest Source Title DOI EDI
Metadata Type geospatial
Old Spatial -121.844957854,44.261075488,-115.367389272,48.419366654
Publisher Hierarchy White House > U.S. Department of the Interior > U.S. Geological Survey
Source Datajson Identifier True
Source Hash 94007ee2f52996823705754674b5987844288bd17842af7d61e0dca94a3572cd
Source Schema Version 1.1
Spatial {"type": "Polygon", "coordinates": -121.844957854, 44.261075488, -121.844957854, 48.419366654, -115.367389272, 48.419366654, -115.367389272, 44.261075488, -121.844957854, 44.261075488}

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