Metadata:
  Identification_Information:
    Citation:
      Citation_Information:
        Originator: Peter G. Chirico
        Originator: Jessica D. DeWitt
        Originator: Sarah E. Bergstresser
        Publication_Date: 2018
        Title: The Central African Republic Diamond Database (2018) - Geomorphology
        Geospatial_Data_Presentation_Form: GIS data
        Publication_Information:
          Publication_Place: Reston, VA
          Publisher: U.S. Geological Survey
        Online_Linkage: https://doi.org/10.5066/F7P26X1D
        Larger_Work_Citation:
          Citation_Information:
            Originator: DeWitt, Jessica D.
            Originator: Chirico, Peter G.
            Originator: Bergstresser, Sarah E.
            Originator: Clark, Inga E.
            Publication_Date: 2018
            Title: The Central African Republic Diamond Database – A Geodatabase of Archival Diamond Occurrences and Areas of Recent Artisanal and Small-scale Diamond Mining
            Geospatial_Data_Presentation_Form: Open File Report
            Publication_Information:
              Publication_Place: Reston, VA
              Publisher: U.S. Geological Survey
    Description:
      Abstract: This GIS raster dataset describes the spatial extent of geomorphic landforms in the Central African Republic (CAR). Although national-scale geologic data, published by Lescuyer and Milesi (2004), provides some geologic context for CAR, this dataset does not provide information regarding the quaternary surficial geology that hosts alluvial placer diamond deposits in CAR. The artisanal and small-scale mining (ASM) of diamonds that occurs in these alluvial and low colluvial landforms is of international interest, due to its potential links to conflict diamonds and illicit trade networks. The dataset published here indicates the geospatial extent of alluvium, terraces, and colluvial hillslopes throughout the country, and thus serves as the best-available data of areas potentially containing alluvial placer diamond deposits and associated ASM activity.
      Purpose: This GIS dataset was created to describe the spatial extent of geomorphology in the Central African Republic. The raster contains 3 values: 1 - alluvium, 2 - terrace, 3 - colluvial hillslope. All other areas have a value of 'no data'.
    Time_Period_of_Content:
      Time_Period_Information:
        Single_Date/Time:
          Calendar_Date: 2018
      Currentness_Reference: publication date
    Status:
      Progress: Complete
      Maintenance_and_Update_Frequency: Unknown
    Spatial_Domain:
      Bounding_Coordinates:
        West_Bounding_Coordinate: 14.150390620846
        East_Bounding_Coordinate: 27.861328120298
        North_Bounding_Coordinate: 11.048608926563
        South_Bounding_Coordinate: 2.8548257978541
    Keywords:
      Theme:
        Theme_Keyword_Thesaurus: USGS Thesaurus
        Theme_Keyword: geomorphology
        Theme_Keyword: unconsolidated deposits
      Theme:
        Theme_Keyword_Thesaurus: Lithologic classification of geologic map units
        Theme_Keyword: alluvium
        Theme_Keyword: alluvial terrace
        Theme_Keyword: floodplain
      Place:
        Place_Keyword_Thesaurus: Geographic Names Information System (GNIS)
        Place_Keyword: Central African Republic
      Temporal:
        Temporal_Keyword_Thesaurus: USGS Thesaurus
        Temporal_Keyword: Quaternary
    Access_Constraints: none
    Use_Constraints: Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. The U.S. Geological Survey requests to be acknowledged as originator of these data in future products or derivative research.
    Point_of_Contact:
      Contact_Information:
        Contact_Person_Primary:
          Contact_Person: Peter G. Chirico
          Contact_Organization: U.S. Geological Survey
        Contact_Address:
          Address_Type: mailing and physical
          Address: 12201 Sunrise Valley Dr.
          City: Reston
          State_or_Province: VA
          Postal_Code: 20192
          Country: USA
        Contact_Voice_Telephone: 703-648-6950
        Contact_Electronic_Mail_Address: pchirico@usgs.gov
    Data_Set_Credit: U.S. Department of State, U.S. Agency for International Development
    Cross_Reference:
      Citation_Information:
        Originator: DeWitt, Jessica D.
        Originator: Chirico, Peter G.
        Originator: Bergstresser, Sarah E.
        Publication_Date: 2018
        Title: The Central African Republic Diamond Database (2018) - Hydrologically Corrected Digital Elevation Model (30 m)
        Publication_Information:
          Publication_Place: Reston, VA
          Publisher: U.S. Geological Survey
  Data_Quality_Information:
    Attribute_Accuracy:
      Attribute_Accuracy_Report: No formal attribute accuracy tests were conducted
    Logical_Consistency_Report: No formal logical accuracy tests were conducted
    Completeness_Report: Data set is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details.
    Positional_Accuracy:
      Horizontal_Positional_Accuracy:
        Horizontal_Positional_Accuracy_Report: No formal positional accuracy tests were conducted
      Vertical_Positional_Accuracy:
        Vertical_Positional_Accuracy_Report: No formal positional accuracy tests were conducted
    Lineage:
      Process_Step:
        Process_Description: The processing methods were adapted from the methods of Chirico and Malpeli (2013), and divided the quaternary-aged landscape into alluvium, terrace, colluvial hillslope. A 3-part process was used to model geomorphology: 1) geomorphic ‘zones’ are segmented from relative elevation; 2) a slope-based path distance analysis characterizes erosive and depositional environments; and 3) the geomorphic zones are combined with the path distance analysis to provide geomorphic detail in the surficial geology. For complete description of the methods used to create the Surficial Geology and Geomorphology model, see the OFR by DeWitt and others (2017).
        Process_Date: 2017
        Process_Contact:
          Contact_Information:
            Contact_Person_Primary:
              Contact_Person: Peter G. Chirico
              Contact_Organization: U.S. Geological Survey
            Contact_Address:
              Address_Type: mailing and physical
              Address: 12201 Sunrise Valley Dr.
              City: Reston
              State_or_Province: VA
              Postal_Code: 20192
              Country: USA
            Contact_Voice_Telephone: 703-648-6950
            Contact_Electronic_Mail_Address: pchirico@usgs.gov
  Spatial_Data_Organization_Information:
    Direct_Spatial_Reference_Method: Raster
  Spatial_Reference_Information:
    Horizontal_Coordinate_System_Definition:
      Planar:
        Map_Projection:
          Map_Projection_Name: Transverse Mercator
          Transverse_Mercator:
            Scale_Factor_at_Central_Meridian: 0.9996
            Longitude_of_Central_Meridian: 15.0
            Latitude_of_Projection_Origin: 0.0
            False_Easting: 500000.0
            False_Northing: 0.0
        Planar_Coordinate_Information:
          Planar_Coordinate_Encoding_Method: row and column
          Coordinate_Representation:
            Abscissa_Resolution: 30.0
            Ordinate_Resolution: 30.0
          Planar_Distance_Units: METERS
      Geodetic_Model:
        Horizontal_Datum_Name: D_WGS_1984
        Ellipsoid_Name: WGS_1984
        Semi-major_Axis: 6378137.0
        Denominator_of_Flattening_Ratio: 298.257223563
  Entity_and_Attribute_Information:
    Detailed_Description:
      Entity_Type:
        Entity_Type_Label: Table
        Entity_Type_Definition: Values of the raster
        Entity_Type_Definition_Source: USGS Artisanal and Conflict Minerals Project
      Attribute:
        Attribute_Label: Value
        Attribute_Definition: Numeric identifier for a unit of surficial geology or geomorphology
        Attribute_Definition_Source: Producer-defined
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: 1
            Enumerated_Domain_Value_Definition: Alluvium - a geomorphic unit of negative or low relative elevation that typically exhibits comparatively deep unconsolidated surficial sediments and gravels deposited by hydrologic processes
            Enumerated_Domain_Value_Definition_Source: Producer-defined
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: 2
            Enumerated_Domain_Value_Definition: Terrace - which are micro-relief features located in close proximity to the alluvium and the current or paleo channel; created through the deposition or erosion of sediments during flood conditions, and can provide evidence of previous channel locations
            Enumerated_Domain_Value_Definition_Source: Producer-defined
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: 3
            Enumerated_Domain_Value_Definition: colluvial hillslope - the surficial weathered or weakened rock which is primarily affected by gravity-driven erosion and is underlain by undifferentiated bedrock
            Enumerated_Domain_Value_Definition_Source: Producer-defined
  Distribution_Information:
    Distributor:
      Contact_Information:
        Contact_Person_Primary:
          Contact_Person: Peter G. Chirico
          Contact_Organization: U.S. Geological Survey
        Contact_Address:
          Address_Type: mailing and physical
          Address: 12201 Sunrise Valley Dr.
          City: Reston
          State_or_Province: VA
          Postal_Code: 20192
          Country: USA
        Contact_Voice_Telephone: 703-648-6950
        Contact_Electronic_Mail_Address: pchirico@usgs.gov
    Distribution_Liability: Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. The U.S. Geological Survey requests to be acknowledged as originator of these data in future products or derivative research.
    Technical_Prerequisites: This dataset is formatted as a .tif raster. It requires the user to have geospatial software such as ESRI ArcGIS, Blue Marble Global Mapper, Que GIS, GRASS, or other GIS software.
  Metadata_Reference_Information:
    Metadata_Date: 20180409
    Metadata_Contact:
      Contact_Information:
        Contact_Person_Primary:
          Contact_Person: Jessica DeWitt
          Contact_Organization: U.S. Geological Survey
        Contact_Address:
          Address_Type: mailing and physical
          Address: 12201 Sunrise Valley Dr.
          City: Reston
          State_or_Province: VA
          Postal_Code: 20192
          Country: USA
        Contact_Voice_Telephone: 703-648-6926
        Contact_Electronic_Mail_Address: jdewitt@usgs.gov
    Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata
    Metadata_Standard_Version: FGDC-STD-001-1998
