{"accessLevel": "public", "bureauCode": ["010:12"], "contactPoint": {"@type": "vcard:Contact", "fn": "Erick Burns", "hasEmail": "mailto:eburns@usgs.gov"}, "description": "The obthk_f grid represents the modeled thickness of the Overburden geomodel unit at \na 500 foot resolution. It is one grid of a geomodel that consists of eleven grids and a spatial extent polygon \nshapefile. As part of a U.S. Geological Survey Groundwater Resources Program study, a three-dimensional \ngeomodel was constructed for approximately 53,000 mi2 of the Columbia Plateau in Washington, Oregon, \nand Idaho. This geomodel was constructed to define the general aquifer system geometry for use in a regional \nnumerical groundwater flow model. Simplifications and assumptions consistent with this ultimate goal and the \nuncertainty in the available data were made. The geomodel units consist of Miocene age Columbia River Basalt \nGroup strata and younger alluvial overburden covering approximately 44,000 mi2. Data were compiled from \nnumerous databases and detailed studies completed during the past three decades. These data include \nstratigraphic interpretations made on more than 13,000 wells and a contiguous compilation of surficial geology \nand structural features spanning the study area. These data were simplified and used to construct piecewise-\nsmooth trend 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 of \neach surface resulting from data gaps, errors in borehole interpretations, errors in mapped contact locations, \nand uncertainty in the shape of the paleo-surface upon which flood basalts were emplaced. Using a rule-based \nalgorithm, surfaces were then recombined to construct a fully three-dimensional model with a 500-foot grid \nresolution that is consistent with the data and for which error estimates may be made. The modeling process \nyielded improved estimates of unit volumes, refinement of location of large structural features, and identification \nof features that may be important for ongoing groundwater studies.", "distribution": [{"@type": "dcat:Distribution", "accessURL": "https://doi.org/10.5066/P9FNN9TX", "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.707dacdc-072a-4b43-8a78-4fe4595df315.xml", "format": "XML", "mediaType": "text/xml", "title": "Original Metadata"}], "identifier": "http://datainventory.doi.gov/id/dataset/USGS_707dacdc-072a-4b43-8a78-4fe4595df315", "keyword": ["CPRAS", "Columbia Plateau", "Columbia Plateau Regional Aquifer System", "Columbia River Basin", "Idaho", "Oregon", "Pacific Northwest", "USGS:707dacdc-072a-4b43-8a78-4fe4595df315", "Washington", "geomodel", "inlandWaters", "overburden"], "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 Thickness of the Overburden Geomodel Unit (obthk_f)"}