{"accessLevel": "public", "bureauCode": ["010:12"], "contactPoint": {"@type": "vcard:Contact", "fn": "Jennifer S. Stanton", "hasEmail": "mailto:jstanton@usgs.gov"}, "description": "This geodatabase includes spatial datasets which represent the Lower Cretaceous \naquifer system in the States of Iowa, Kansas, Minnesota, Montana, Nebraska, \nNorth Dakota, South Dakota, and Wyoming. Included are: (1) a polygon dataset \nthat represents the aquifer system extent, (2) raster datasets for the altitude of \neach aquifer subarea, (3) altitude and thickness contours (plus thickness fault \nlines) used to generate the surface rasters, (4) georeferenced images of the \nfigures that were digitized to create the altitude and thickness contours. The \nimages and digitized contours are supplied for reference. \n\t\t\nThe extent of the Lower Cretaceous aquifer for all subareas was produced from \nthe linework of the Lower Cretaceous aquifers maps in U.S. Geological Survey \nProfessional Paper 1414-E (USGS PP 1414-E) Plate 6, U.S. Geological Survey \nWater-Resources Investigations Report 84-4153 (USGS WRIR 84-4153) Plate 1, \nand the U.S. Geological Survey Hydrologic Atlas 730 (USGS HA-730). A digital \nversion of the HA-730 Lower Cretaceous aquifer extent is presented in the \nGroundwater Atlas of the United States (the U.S. Geological Survey Hydrologic \nAtlas 730-D,(USGS HA 730-D), 730-I (USGS HA 730-I), and 730-J (USGS HA 730-J. \n\t\t\nThe Lower Cretaceous Aquifer System has 4 aquifer subareas: (SA1) Great Plains \naquifer, (SA2) Iowa aquifer, (SA3) Minnesota aquifer, and (SA4) Northern Great \nPlains aquifer. \n\t\t\nThe altitude lines for the top of SA1 and SA4 were digitized from georeferenced \nfigures of altitude contours in USGS PP 1414-E Plate 4 and USGS PP 1402-B \nPlate 1. Altitude lines for the top of SA3 were digitized from WRIR 84-4153 \nFigure 5. The top of SA2 was derived from the thickness contours for SA2, \nUSGS PP 1414-E Figure 16. Areas of overlap between subareas were deleted, \nbased on available original data. The altitude values and thickness values were \ninterpolated into surface rasters within a GIS using tools that create hydrologically \ncorrect surfaces from contour data, derives the altitude from the thickness (depth \nfrom the land surface), and merge the subareas into a single surface. The primary \ntool was \"Topo to Raster\" used in ArcGIS, ArcMap, Esri 2014. The raster surfaces \nwere corrected for the areas where the altitude of the top of the aquifer exceeded \nthe land surface, and where the bottom of an aquifer exceeded the altitude of the \ncorrected top of the aquifer. For a more detailed description of the processes used \nby the data compiler, please see the Supplementary Information section.", "distribution": [{"@type": "dcat:Distribution", "accessURL": "https://doi.org/10.5066/P99NHURK", "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.65051c26-cc12-4a4e-8dfc-e246093b74a2.xml", "format": "XML", "mediaType": "text/xml", "title": "Original Metadata"}], "identifier": "http://datainventory.doi.gov/id/dataset/USGS_65051c26-cc12-4a4e-8dfc-e246093b74a2", "keyword": ["Colorado Group", "Dakota Formation", "Great Plains aquifer", "Iowa", "Iowa aquifer", "Kansas", "Lower Cretaceous aquifer", "Minnesota", "Minnesota aquifer", "Montana", "Nebraska", "North Dakota", "Northern Great Plains aquifer", "South Dakota", "USGS:65051c26-cc12-4a4e-8dfc-e246093b74a2", "United States", "Wyoming", "aquifer", "aquifer system", "extent", "groundwater", "inlandWaters"], "modified": "2020-11-17T00:00:00Z", "publisher": {"@type": "org:Organization", "name": "U.S. Geological Survey"}, "spatial": "-113.63899573, 35.328618628, -92.574513785, 50.047904809", "theme": ["geospatial"], "title": "Geodatabase of the datasets used to represent the 4 subareas of the Lower Cretaceous aquifer, Iowa, Kansas, Minnesota, Montana, Nebraska, North Dakota, South Dakota, and Wyoming"}