{
    "tag": 13300,
    "title": "Continental Margin Mapping Program (CONMAP) sediments grainsize distribution for the United States East Coast Continental Margin (CONMAPSG)",
    "pubdate": "200506",
    "sername": null,
    "series_name": null,
    "issue": "2005-1001",
    "publish": null,
    "publisher_name": null,
    "onlink": "https:\/\/cmgds.marine.usgs.gov\/catalog\/whcmsc\/open_file_report\/ofr2005-1001\/conmapsg.shp.faq.html",
    "format": null,
    "email": null,
    "descript": "Sediments off the eastern United States vary markedly in texture - the size, shape, and arrangement of their grains.  However, for descriptive purposes, it is typically most useful to classify these sediments according to their grain-size distributions. Starting in 1962, the U.S. Geological Survey (USGS) and the Woods Hole Oceanographic Institution (WHOI) began a joint program to study the marine geology of the continental margin off the Atlantic coast of the United States. As part of this program and numerous subsequent projects, thousands of sediment samples were collected and analyzed for particle size. The sediment map of the Continental Margin Mapping Program (CONMAP) series is a compilation of grain-size data produced in the sedimentation laboratory of the Woods Hole Science Center (WHSC) of the Coastal and Marine Geology Program (CMGP) of the U.S. Geological Survey (USGS) and from both published and unpublished studies.  Sediment was classified using the Wentworth (1929) grain-size scale and the Shepard (1954) scheme of sediment classification. Certain grain-size categories are combined because of the paucity of some sediment textures; blank parts of the maps indicate areas where data are insufficient to infer sediment type. Bathymetry is used as a guide in placing some of the contacts between different sediment types.  However, because the true boundaries between sediment types are probably highly irregular or gradational, because the extreme textural variability that characterizes some areas does not appear at this scale, and because the accuracy of the navigational systems used during the earlier studies is limited, all contacts should be considered to be inferred. The sediment classification for any given polygon (i.e. area) reflects the dominant surficial sediment type for that polygon.  It does not mean that other sediment types are not present within the polygon, only that the dominant sediment type is the one that is most common.",
    "lang": null,
    "journal": null,
    "pwid": null,
    "originator": [
        {
            "name": "U.S. Geological Survey",
            "role": "Author"
        },
        {
            "name": "Poppe, Lawrence J.",
            "role": "Author"
        },
        {
            "name": "Williams, S. Jeffress",
            "role": "Author"
        },
        {
            "name": "Paskevich, Valerie F.",
            "role": "Author"
        }
    ],
    "index_term": [
        {
            "thcode": 2,
            "code": "474",
            "name": "geospatial datasets",
            "scope": "Collections of related digital information that are geographically referenced."
        },
        {
            "thcode": 2,
            "code": "493",
            "name": "grain-size analysis",
            "scope": "Method of studying soils, sediments, sands, or rock by determining the size, distribution, and proportion of selected particles."
        },
        {
            "thcode": 2,
            "code": "706",
            "name": "marine geology",
            "scope": "Branch of geology concerned with the composition, geologic history, and earth processes of the ocean floor and the continental margin."
        },
        {
            "thcode": 2,
            "code": "2078",
            "name": "navigational data",
            "scope": "Geospatial data indicating the locations of instruments, vessels, aircraft, or other vehicles used to collect scientific observations.  These data include horizontal coordinates in sequence, and may include time or vertical position."
        },
        {
            "thcode": 2,
            "code": "1025",
            "name": "sea-floor characteristics",
            "scope": "Geomorphic features and geographic, compositional, and textural variation in the materials composing the ocean floor. Includes both large-scale structures (such as seamounts and rises) and fine-scale variations in rocks and deposits on the sea floor."
        },
        {
            "thcode": 15,
            "code": "003",
            "name": "boundaries",
            "scope": "Legal land descriptions, for example political and administrative boundaries, governmental units, marine boundaries, voting districts, school districts, international boundaries"
        },
        {
            "thcode": 15,
            "code": "008",
            "name": "geoscientificInformation",
            "scope": "Information pertaining to earth sciences, for example geophysical features and processes, geology, minerals, sciences dealing with the composition, structure and origin of the earth's rocks, risks of earthquakes, volcanic activity, landslides, gravity information, soils, permafrost, hydrogeology, groundwater, erosion"
        },
        {
            "thcode": 15,
            "code": "014",
            "name": "oceans",
            "scope": "Features and characteristics of salt water bodies (excluding inland waters), for example tides, tidal waves, coastal information, reefs, maritime, outer continental shelf submerged lands, shoreline"
        }
    ],
    "place_term": [],
    "image": [
        {
            "name": "https:\/\/pubs.usgs.gov\/of\/2005\/1001\/data\/conmapsg\/conmapsg-thumb.gif",
            "description": "Thumbnail image showing distribution and extent of data layer along the U.S. East Coast"
        }
    ],
    "fan": []
}