{"accessLevel": "public", "bureauCode": ["010:12"], "contactPoint": {"@type": "vcard:Contact", "fn": "Erick Burns", "hasEmail": "mailto:eburns@usgs.gov"}, "description": "The grtop_f grid represents the modeled elevation of the top of the Grande Ronde Basalt geomodel unit \nat a 500 foot resolution. It is one grid of a geomodel that consists of eleven grids and a spatial extent \npolygon shapefile. As part of a U.S. Geological Survey Groundwater Resources Program study, a \nthree-dimensional geomodel was constructed for approximately 53,000 mi2 of the Columbia Plateau \nin Washington, Oregon, and Idaho. This geomodel was constructed to define the general aquifer system \ngeometry for use in a regional numerical groundwater flow model. Simplifications and assumptions \nconsistent with this ultimate goal and the uncertainty in the available data were made. The geomodel \nunits consist of Miocene age Columbia River Basalt Group strata and younger alluvial overburden \ncovering approximately 44,000 mi2. Data were compiled from numerous databases and detailed \nstudies completed during the past three decades. These data include stratigraphic interpretations \nmade on more than 13,000 wells and a contiguous compilation of surficial geology and structural \nfeatures spanning the study area. These data were simplified and used to construct piecewise-smooth \ntrend surfaces that represent upper and lower subsurface geomodel unit boundaries in this complex \nfolded and faulted terrain.  The smoothness of the surfaces implicitly represents uncertainty in prediction \nof each surface resulting from data gaps, errors in borehole interpretations, errors in mapped contact \nlocations, and uncertainty in the shape of the paleo-surface upon which flood basalts were emplaced. \nUsing a rule-based algorithm, surfaces were then recombined to construct a fully three-dimensional \nmodel with a 500-foot grid resolution that is consistent with the data and for which error estimates \nmay be made. The modeling process yielded improved estimates of unit volumes, refinement of \nlocation of large structural features, and identification of features that may be important for ongoing \ngroundwater studies.", "distribution": [{"@type": "dcat:Distribution", "accessURL": "https://doi.org/10.5066/P9CU1Y9K", "description": "Landing page for access to the data", "format": "XML", "mediaType": "application/http", "title": "Digital Data"}, {"@type": "dcat:Distribution", "description": "The metadata original format", "downloadURL": "https://data.usgs.gov/datacatalog/metadata/USGS.8fe47743-0fad-4793-8cb5-ea9983548cd3.xml", "format": "XML", "mediaType": "text/xml", "title": "Original Metadata"}], "identifier": "http://datainventory.doi.gov/id/dataset/USGS_8fe47743-0fad-4793-8cb5-ea9983548cd3", "keyword": ["CPRAS", "Columbia Plateau", "Columbia Plateau Regional Aquifer System", "Columbia River Basalt", "Columbia River Basin", "Grande Ronde Basalt", "Idaho", "Oregon", "Pacific Northwest", "USGS:8fe47743-0fad-4793-8cb5-ea9983548cd3", "Washington", "geomodel", "inlandWaters"], "modified": "2020-11-17T00:00:00Z", "publisher": {"@type": "org:Organization", "name": "U.S. Geological Survey"}, "spatial": "-121.844957854, 44.261075488, -115.367389272, 48.419366654", "theme": ["geospatial"], "title": "Modeled Top of the Grande Ronde Basalt Geomodel Unit (grtop_f)"}