Identification_Information:
  Citation:
    Citation_Information:
      Originator: Moore, David W.
      Originator: Diehl, Sharon F.
      Publication_Date: 2004
      Title: Surficial Geologic map of the Southwest Memphis quadrangle, 
        Shelby County, Tennessee
      Edition: version 1.0
      Geospatial_Data_Presentation_Form: map
      Series_Information:
        Series_Name: USGS Scientific Investigations Map
        Issue_Identification: Scientific Investigations Map 2823
      Publication_Information:
        Publication_Place: Denver, Colorado
        Publisher: U.S. Geological Survey
      Online_Linkage: http://pubs.usgs.gov/sim/2823
  Description:
    Abstract:
      This map is one of seven 1:24,000-scale (7.5-minute) quadrangle maps of 
        the surficial geology of the Memphis, Tennessee, area--part of a series 
        of urban hazard maps.  Wind-deposited silt and clayey silt (loess) is 
        the predominant surficial deposit in this quadrangle.  The loess was 
        deposited as dust during the last major continental glaciation of the 
        region and it covers the upland to depths of 4.5-16 m.  River alluvium 
         (unit Qal), which is chiefly a sandy and gravelly sand deposit about 30 
        m thick, underlies the Mississippi River floodplain.  This unit supports 
        extensive artificial fill and infrastructure used for shipping storage 
        and petroleum processing and storage.  Based on paleoliquefaction 
        structures (sand boils) documented in Mississippi River alluvium 
        elsewhere, this unit probably has the potential to liquefy during strong 
        earthquake shaking.  No paleoliquefaction structures were observed 
        within the Southwest Memphis quadrangle.  Another deposit in the 
        quadrangle is silty alluvium of the Nonconnah Creek floodplain, and is 
        1-10 m thick.  Sparse, unconsolidated pebbly sand deposits are 0.5-3 m 
        thick and make up point bars and channel deposits of Nonconnah Creek.
    Purpose:
      The surficial geologic map of the Southwest Memphis quadrangle is designed 
        to improve delineation of estimated intensities of ground motions and 
        susceptibility of materials to liquefaction during future strong 
        earthquakes.  Because Memphis lies about 50 km southeast of the New 
        Madrid Seismic Zone,it is in a high seismic risk zone.  This map is one 
        of a series of earthquake hazard maps made for the Memphis and Shelby 
        County Seismic Hazard Mapping Project.  Earthquake hazards mapping is a 
        multidisciplinary process requiring creation of surface and subsurface 
        geologic databases, and maps of ground motion amplification, 
        deterministic and probabilistic ground motions, and liquefaction hazard.  
        These maps are derived, in part, from geologic maps such as the present 
        report and will aid in qualifying the earthquake risk to Memphis and 
        will provide useful information to decision makers.  This work is part 
        of a larger program to assess earthquake hazards in the Central and 
        Eastern United States (CEUS).  The CEUS is the focus of the Earthquake 
        Hazards Program of the United States Geological Survey.  Earthquakes in 
        the CEUS are low-probability, high-impact events.  Large earthquakes in 
        this region can cause widespread damage because of low attenuation rates 
        and an aging building stock not designed to withstand strong earthquake 
        shaking.  CEUS earthquakes may affect densely populated cities such as 
        Memphis and St. Louis,as well as smaller cities in seven States.
    Supplemental_Information:
      Coverages included in this geospatial database:
      swgeol: polygon coverage of geologic units and contacts
      swcross: line coverage of cross section
      Georegistered images included in this geospatial database:
      swmem1r.tif (topography, planimetry, and drainages)
      swmem1r.tfw
      sw_wr.tif (open water)
      sw_wr.tfw
  Time_Period_of_Content:
    Time_Period_Information:
      Range_of_Dates/Times:
        Beginning_Date: 1998
        Ending_Date: 2003
    Currentness_Reference: publication date
  Status:
    Progress: complete
    Maintenance_and_Update_Frequency: none planned
  Spatial_Domain:
    Bounding_Coordinates:
      West_Bounding_Coordinate: -90.125095
      East_Bounding_Coordinate: -89.999905
      North_Bounding_Coordinate: 35.125015
      South_Bounding_Coordinate: 34.999984
  Keywords:
    Theme:
      Theme_Keyword_Thesaurus: American Geological Institute Glossary of 
        Geology
      Theme_Keyword: surficial geology
      Theme_Keyword: loess
      Theme_Keyword: sand
      Theme_Keyword: alluvium
      Theme_Keyword: river deposit
      Theme_Keyword: silty
      Theme_Keyword: liquefaction
      Theme_Keyword: Peoria Loess
      Theme_Keyword: gravel
      Theme_Keyword: artificial fill
      Theme_Keyword: seismic risk
      Theme_Keyword: ground shaking
      Theme_Keyword: earthquake
      Theme_Keyword: urban geology
      Theme_Keyword: environmental geology
      Theme_Keyword: drillers logs
      Theme_Keyword: drillers' logs
      Theme_Keyword: borehole logs
      Theme_Keyword: electric logs
      Theme_Keyword: groundwater
      Theme_Keyword: database
      Theme_Keyword: cross section
    Place:
      Place_Keyword_Thesaurus: Board of Geographic Names
      Place_Keyword: Memphis, Tennessee
      Place_Keyword: Shelby County
      Place_Keyword: Nonconnah Creek
      Place_Keyword: Mississippi River Valley
      Place_Keyword: Southwest Memphis quadrangle
      Place_Keyword: New Madrid
  Access_Constraints: none
  Use_Constraints: none.  Acknowledgment of the U.S. Geological Survey would 
    be appreciated in products derived from these data.
  Point_of_Contact:
    Contact_Information:
      Contact_Person_Primary:
        Contact_Person: Gomberg, Joan S
        Contact_Organization: U.S. Geological Survey
      Contact_Position: seismologist
      Contact_Address:
        Address_Type: mailing and physical address
        Address: 3876 Central Avenue, Suite 2
        City: Memphis
        State_or_Province: TN
        Postal_Code: 38152-3050
        Country: USA
      Contact_Voice_Telephone: (901)678-4858
      Contact_Facsimile_Telephone: (901)678-4734
      Contact_Electronic_Mail_Address: gomberg@usgs.gov
      Hours_of_Service: 0800 - 1630 Eastern Standard Time M-F
      Contact_Instructions: E-mail is preferred
  Browse_Graphic:
    Browse_Graphic_File_Name: 
      http://pubs.usgs.gov/sim/2823/2823.pdf
    Browse_Graphic_File_Description: graphic representation of map layout
    Browse_Graphic_File_Type: PDF
  Native_Data_Set_Environment: 
    Microsoft Windows NT Version 4.0 (Build 1381) Service Pack 6
    ESRI ArcCatalog 8.2.0.700
Data_Quality_Information:
  Attribute_Accuracy:
    Attribute_Accuracy_Report: 
      The database consists of newly generated data that were compiled on mylar 
      and then digitized in ARC/INFO. .  This map was thoroughly reviewed for 
      conformity with U.S. Geological Survey editorial standards and 
      stratigraphic nomenclature.
  Logical_Consistency_Report: 
    Map elements were visually checked by the authors and editor for overshoots, 
    undershoots, duplicate features, polygon attributes, and other errors.  
    Automated (ARC/INFO) routines were also used to check the databases for 
    polygon label errors and dangling arcs.  The coverages were cleaned in 
    ARC/INFO to ensure logical consistency that is topologically clean.  The map 
    was reviewed by other geologists for consistency with basic geologic 
    principles and general conformity to USGS mapping standards.
  Completeness_Report: 
    This dataset is complete and includes the spatial coverages pertaining to 
    the geologic map.
  Positional_Accuracy:
    Horizontal_Positional_Accuracy:
      Horizontal_Positional_Accuracy_Report: 50-200 m
  Lineage:
    Process_Step:
      Process_Description:
        Mapping was based on field observations, analysis of color aerial 
        photographs (scale 1:24,000, flown in 1997), topography, and drill-hole 
        data.  The authors delineated geologic units on aerial photographs, 
        supplemented by field inspection.  The linework was transferred to base 
        maps by inspection, and digitized manually, and the data were then 
        digitally registered to a digital version of the base map in ArcInfo.  
        Grain sizes were estimated by eye in the field using a comparative chart 
        that uses nomenclature of the modified Wentworth grade scale (American 
        Geological Institute, 1982).  A geologic cross section shows the 
        subsurface thickness of the units of interest.  The cross section was 
        constructed as follows:  depths to the boundaries between units were 
        obtained from drill hole data in the Shelby County Subsurface Database 
        of the Ground Water Institute (GWI), University of Memphis 
         (http://gwidc.gwi.memphis.edu/website/introduction).  Depths below 
        ground surface to boundaries between units were determined by 
        hydrologists and geologists who interpreted drillers' logs and borehole 
        electrical logs.  This was done before the authors of this geologic map 
        did the geologic mapping.
      Process_Date: 2000-2004
Spatial_Data_Organization_Information:
  Direct_Spatial_Reference_Method: Vector
Spatial_Reference_Information:
  Horizontal_Coordinate_System_Definition:
    Planar:
      Map_Projection:
        Map_Projection_Name: Transverse mercator
        Transverse_Mercator
          Scale_Factor_at_Central_Meridian: 0.999600
          Longitude_of_Central_Meridian: -90.062500
          Latitude_of_Projection_Origin: 0.000000
          False_Easting: 0.000000
          False_Northing: 0.000000
      Planar_Coordinate_Information:
        Planar_Coordinate_Encoding_Method: coordinate pair
        Coordinate_Representation:
          Abscissa_Resolution: 0.000032
          Ordinate_Resolution: 0.000032
        Planar_Distance_Units: meters
    Geodetic_Model:
      Horizontal_Datum_Name: North American Datum of 1927
      Ellipsoid_Name: Clarke 1866
      Semi-major_Axis: 6378206.400000
      Denominator_of_Flattening_Ratio: 294.978698
Entity_and_Attribute_Information:
  Overview_Description:
    Entity_and_Attribute_Overview:
      The data are supplied in ARC/INFO export format and ArcView shapefile 
      format.

      >Attribution of user-defined item GEO in swgeol.pat:
      >Qa
      >Qal
      >Ql
      >Qt
      >af

      >Attribution of user-defined item LINETYPE in swgeol.aat:
      >contact, relatively certain
      >map boundary

      >Attribution of user-defined item MEMSWCROSS in swcross.aat:
      >1 (trace of cross section A-A')

    Entity_and_Attribute_Detail_Citation: none

Distribution_Information:
  Distributor:
    Contact_Information:
      Contact_Organization_Primary:
        Contact_Organization: U.S. Geological Survey
      Contact_Address:
        Address_Type: mailing address
        Address: Central Publications Group
        Address: MS 902, Box 25046
        Address: Denver Federal Center
        City: Denver
        State_or_Province: Colorado
        Postal_Code: 80225
        Country: USA
      Contact_Voice_Telephone: (888)ASK-USGS
      Contact_Electronic_Mail_Address: webmaster@geology.cr.usgs.gov
  Distribution_Liability: 
    The U.S. Geological Survey (USGS) provides these geographic data "as is".  
    The USGS makes no guarantee or warranty concerning the accuracy of 
    information contained in the geographic data.  The USGS further makes no 
    warranties, either expressed or implied, as to any other matter whatsoever, 
    including, without limitation, the condition of the product, or its fitness 
    for any particular purpose.  The burden for determining fitness for use lies 
    entirely with the user.  Although these data have been processed 
    successfully on computers at the USGS, no warranty, expressed or implied, is 
    made by the USGS regarding the use of these data on any other system, nor 
    does the fact of distribution constitute or imply any such warranty.
  Standard_Order_Process:
    Digital_Form:
      Digital_Transfer_Information:
        Format_Name: ArcInfo interchange file and ArcInfo shapefile formats
        Format_Version_Number: ArcInfo version 8.3
        File_Decompression_Technique:
          .tar.gz - UNIX gzip-compressed TAR file - use GNU zip and TAR to 
          extract
          .ZIP - Windows ZIP archive - use Winzip, PKZip, or similar to extract
      Digital_Transfer_Option:
        Online_Option:
          Computer_Contact_Information:
            Network_Address:
              Network_Resource_Name: <http://pubs.usgs.gov/sim/2823/>
    Fees: None

Distribution_Information:
  Distributor:
    Contact_Information:
      Contact_Organization_Primary:
        Contact_Organization: U.S.Geological Survey
      Contact_Address:
        Address_Type: mailing address
        Address: USGS Information Services
        Address: Box 25286
        City: Denver
        State_or_Province: CO
        Postal_Code: 80225
        Country: United States
      Contact_Voice_Telephone: 1-888-ASK-USGS
  Resource_Description: Scientific Investigations Map 2823 (plot-on-demand)
  Distribution_Liability: none
  Standard_Order_Process:
    Non-digital_Form: 
      Available as one printed sheet.  Order from USGS at the address listed 
      above or see <http://rmmcweb.cr.usgs.gov/pub/mod/order.html/> for more 
      ordering information.
    Fees:
      For current prices please see
      <http://rmmcweb.cr.usgs.gov/public/mod/order.html/>

Metadata_Reference_Information:
  Metadata_Date: 20040402
  Metadata_Contact:
    Contact_Information:
      Contact_Person_Primary:
        Contact_Person: Tucker, Kathy
        Contact_Organization: Center for Earthquake Research and 
          Information (CERI)
      Contact_Address:
        Address_Type: mailing and physical address
        Address: Center for Earthquake Research and Information (CERI), 
          University of Memphis
        City: Memphis
        State_or_Province: TN
        Postal_Code: 38152-3050
      Contact_Voice_Telephone: (901)678-4814
      Contact_Facsimile_Telephone: (901)678-473
      Contact_Electronic_Mail_Address: tucker@ceri.memphis.edu
      Hours_of_Service: 0800 - 1630 Eastern Standard Time M-F
  Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
  Metadata_Standard_Version: FGDC-STD-001-1998
  Metadata_Access_Constraints: none
  Metadata_Use_Constraints: none