{"accessLevel": "public", "bureauCode": ["010:12"], "contactPoint": {"@type": "vcard:Contact", "fn": "Margaret E. Berry", "hasEmail": "mailto:meberry@usgs.gov"}, "description": "The Weldona 7.5' quadrangle is located on the semiarid plains of\nnortheastern Colorado, along the South Platte River corridor where the\nriver has incised into Upper Cretaceous Pierre Shale. The Pierre Shale is\nlargely covered by surficial deposits that formed from alluvial, eolian,\nand hillslope processes operating in concert with environmental changes\nfrom the Pleistocene to the present. The South Platte River, originating\nhigh in the Colorado Rocky Mountains, has played a major role in shaping\nsurficial geology in the map area, which is several tens of kilometers\ndownstream from where headwater tributaries join the river. Recurrent\nglaciation (and deglaciation) of basin headwaters has affected river\ndischarge and sediment supply far downstream, influencing deposition of\nalluvium and river incision in the Weldona quadrangle. During the\nPleistocene the course of the river within the map area shifted\nprogressively southward as it incised, and by late middle Pleistocene the\nriver was south of its present position, cutting and filling deep\npaleochannels now covered by younger alluvium. The river shifted back to\nthe north during the late Pleistocene. Kiowa and Bijou Creeks are\nunglaciated tributaries originating in the Colorado Piedmont east of the\nFront Range that also have played a major role in shaping surficial\ngeology of the map area. Periodically during the late Pleistocene, major\nflood events on these tributaries deposited large volumes of sediment at\ntheir confluences, forming a broad, low-gradient fan of sidestream\nalluvium that could have occasionally dammed the river for short periods\nof time. Eolian sand deposits of the Sterling (north of river) and Fort\nMorgan (south of river) dune fields cover much of the quadrangle and\nrecord past episodes of sand mobilization during times of prolonged\ndrought. With the onset of irrigation and damming during historical\ntimes, the South Platte River has changed from a broad, shallow, and\nsandy braided river with highly variable seasonal discharge to a much\nnarrower, deeper river with braided-meandering transition morphology and\nmore uniform discharge.", "distribution": [{"@type": "dcat:Distribution", "accessURL": "https://doi.org/10.5066/F7610Z63", "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.595290c8e4b062508e3c76db.xml", "format": "XML", "mediaType": "text/xml", "title": "Original Metadata"}], "identifier": "http://datainventory.doi.gov/id/dataset/USGS_595290c8e4b062508e3c76db", "keyword": ["Bijou Creek", "Bijou No 2 Reservoir", "Broadway Alluvium", "Bull Lake glaciation", "Colorado", "Cretaceous", "Empire Reservoir", "Fort Morgan", "Front Range", "Greeley", "Holocene", "Jackson Reservoir", "Kersey", "Kiowa Creek", "Laramie Formation", "Louviers Alluvium", "Masters", "Milliron Draw", "Morgan County", "OSL", "Orchard", "Pierre Shale", "Pinedale glaciation", "Piney Creek Alluvium", "Pleistocene", "Quaternary", "Rocky Flats Alluvium", "Slocum Alluvium", "South Platte River", "U-series", "USA", "USGS:595290c8e4b062508e3c76db", "United States", "Verdos Alluvium", "Weld County", "Weldona", "Wildcat Creek", "alluvium", "argillic B horizon", "braided", "colluvium", "discharge", "dune", "eolian", "floodplain", "geologic map", "lignite", "luminescence", "meandering", "radiocarbon", "sand sheet", "sheetflood", "soil", "terrace"], "modified": "2022-08-29T00:00:00Z", "publisher": {"@type": "org:Organization", "name": "U.S. Geological Survey"}, "spatial": "-104.00000, 40.25000, -103.87500, 40.37500", "theme": ["geospatial"], "title": "Data release for the geologic map of the Weldona 7.5' quadrangle, Morgan County, Colorado"}