Identification_Information:
  Citation:
    Citation_Information:
      Originator: Ashley, Roger P.
      Originator: Rytuba, James J.
      Title: Mercury geochemistry of gold placer tailings, sediments, bedrock, and waters in the lower Clear Creek area, Shasta County, California; report of investigations, 2001-2003
      Publication_Date: 2008
      Series_Information:
        Series_Name: Open-File Report
        Issue_Identification: 2008-1122
      Publication_Information:
        Publication_Place: Menlo Park, California
        Publisher: Geological Survey (U.S.)
      Online_Linkage: http://pubs.usgs.gov/of/2008/1122/
  Description:
    Abstract:
      Total mercury and methylmercury measured in sediments, tailings, and
      water in an area where historical gold mining has occurred; proposed
      habitat restoration work may release some of the mercury that is
      currently buried there.
    Purpose:
      Identify sources, transport, and dispersal of mercury in the lower
      Clear Creek area and identify environments in which bioavailable
      methylmercury is produced.
  Time_Period_of_Content:
    Time_Period_Information:
      Range_of_Dates/Times:
        Beginning_Date: 2001
        Ending_Date: 2003
    Currentness_Reference: Ground condition.  Samples were collected during this period.
  Status:
    Progress: Complete
    Maintenance_and_Update_Frequency: None planned
  Spatial_Domain:
    Bounding_Coordinates:
      West_Bounding_Coordinate: -122.523867
      East_Bounding_Coordinate: -122.379433
      North_Bounding_Coordinate: 40.5144
      South_Bounding_Coordinate: 40.49105
  Access_Constraints: none
  Use_Constraints: none
  Keywords:
    Theme:
      Theme_Keyword_Thesaurus: Alexandria Digital Library Feature Type Thesaurus
      Theme_Keyword: mine sites
    Place:
      Place_Keyword_Thesaurus: Augmented FIPS 10-4 and FIPS 6-4
      Place_Keyword: f06089 = Shasta
    Theme:
      Theme_Keyword_Thesaurus: General glossary for mineral resources spatial data
      Theme_Keyword: comma-delimited text
      Theme_Keyword: Microsoft Excel format
      Theme_Keyword: shapefile
      Theme_Keyword: tab-delimited text
    Theme:
      Theme_Keyword_Thesaurus: USGS Thesaurus
      Theme_Keyword: atomic emission spectroscopy
      Theme_Keyword: geochemistry
      Theme_Keyword: geospatial datasets
      Theme_Keyword: mass spectroscopy
      Theme_Keyword: mercury
      Theme_Keyword: mercury contamination
      Theme_Keyword: mine drainage
  Point_of_Contact:
    Contact_Information:
      Contact_Person_Primary:
        Contact_Person: Roger P Ashley
        Contact_Organization: USGS WR SW GD
      Contact_Position: Emeritus
      Contact_Address:
        Address_Type: mailing address
        Address:
          345 Middlefield Road
          Mail Stop 901
        City: Menlo Park
        State_or_Province: CA
        Postal_Code: 94025
        Country: USA
      Contact_Voice_Telephone: 650-329-5416
      Contact_Facsimile_Telephone: 650-329-5491
      Contact_Electronic_Mail_Address: ashley@usgs.gov
Spatial_Data_Organization_Information:
  Direct_Spatial_Reference_Method: Point
  Point_and_Vector_Object_Information:
    SDTS_Terms_Description:
      SDTS_Point_and_Vector_Object_Type: Entity point
      Point_and_Vector_Object_Count: 61
Spatial_Reference_Information:
  Horizontal_Coordinate_System_Definition:
    Geographic:
      Geographic_Coordinate_Units: decimal degrees
    Geodetic_Model:
      Horizontal_Datum_Name: North American Datum of 1983
      Ellipsoid_Name: Geodetic Reference System 80
      Semi-major_Axis: 6378137
      Denominator_of_Flattening_Ratio: 298.257
Entity_and_Attribute_Information:
  Detailed_Description:
    Entity_Type:
      Entity_Type_Label: table1.dbf
      Entity_Type_Definition: Locations and descriptions of sample sites in and near the lower Clear Creek area
    Attribute:
      Attribute_Label: FIELD_SITE
      Attribute_Definition: Field site identifier
    Attribute:
      Attribute_Label: SAMPLE
      Attribute_Definition: Sample identifier
    Attribute:
      Attribute_Label: DATE
      Attribute_Definition: Date sample was collected
    Attribute:
      Attribute_Label: LATITUDE
      Attribute_Definition: Geographic latitude of the sample location
    Attribute:
      Attribute_Label: LONGITUDE
      Attribute_Definition: Geographic longitude of the sample location
    Attribute:
      Attribute_Label: SITE_DESC
      Attribute_Definition: Site description
    Attribute:
      Attribute_Label: SAMP_DESC
      Attribute_Definition: Sample description
    Attribute:
      Attribute_Label: BLK_BD_FRN
      Attribute_Definition: Bulk sediment or bedrock sample analyzed by Frontier Geosciences, Inc.
    Attribute:
      Attribute_Label: BLK_BD_CMX
      Attribute_Definition: Bulk sediment or bedrock sample analyzed by ALS Chemex, Inc.
    Attribute:
      Attribute_Label: GR_2_CMX
      Attribute_Definition: Sediment sample greater than 2mm grain diameter, analyzed by ALS Chemex, Inc.
    Attribute:
      Attribute_Label: LT_2_FRN
      Attribute_Definition: Sediment sample less than 2mm grain diameter, analyzed by Frontier Geosciences, Inc.
    Attribute:
      Attribute_Label: LT_2_CMX
      Attribute_Definition: Sediment sample less than 2mm grain diameter, analyzed by ALS Chemex, Inc.
    Attribute:
      Attribute_Label: LT_63_FRN
      Attribute_Definition: Sediment sample less than 63µm grain diameter, analyzed by Frontier Geosciences, Inc.
    Attribute:
      Attribute_Label: RU_HG_FRN
      Attribute_Definition: Unfiltered, unacidified sample analyzed for mercury
    Attribute:
      Attribute_Label: FU_AN_US
      Attribute_Definition: Filtered, unacidified sample analyzed for anions
    Attribute:
      Attribute_Label: FA_MET_US
      Attribute_Definition: Filtered, acidified sample analyzed for metals
    Attribute:
      Attribute_Label: RA_MET_US
      Attribute_Definition: Unfiltered, acidified sample analyzed for metals
    Attribute:
      Attribute_Label: FU_ALK_US
      Attribute_Definition: Filtered, unacidified sample analyzed for alkalinity
    Attribute:
      Attribute_Label: RU_TC_US
      Attribute_Definition: Unfiltered, unacidified sample analyzed for total carbon
  Overview_Description:
    Entity_and_Attribute_Overview:
      Additional data tables, provided in comma-separated value (CSV), tab-
      delimited text, and Microsoft Excel (XLS) format give the
      observations.  Since the column headings do not conform to shapefile
      conventions, the meanings of the columns are given here to indicate
      the contents of those fields.

      Table 3: Mercury and methylmercury concentrations in dredge tailings and sediment samples

      > Field site
      > Subsamples
      > Material sampled
      > Sample size fraction
      > Total Hg, ng/g by CVAAS
      > Total Hg, ng/g by CVAFS
      > Methyl Hg, ng/g by CVAFS

      Table 4: Concentrations of major and minor elements in dredge tailings and sediment samples, determined by ICP-MS and ICP-AES

      > Subsample
      > Field site
      > Material
      > Au concentration expressed in units mg/g
      > Ag concentration expressed in units mg/g
      > Al concentration expressed in units wt %
      > As concentration expressed in units mg/g
      > Ba concentration expressed in units mg/g
      > Be concentration expressed in units mg/g
      > Bi concentration expressed in units mg/g
      > Ca concentration expressed in units wt %
      > Cd concentration expressed in units mg/g
      > Ce concentration expressed in units mg/g
      > Co concentration expressed in units mg/g
      > Cr concentration expressed in units mg/g
      > Cs concentration expressed in units mg/g
      > Cu concentration expressed in units mg/g
      > Fe concentration expressed in units wt %
      > Ga concentration expressed in units mg/g
      > Ge concentration expressed in units mg/g
      > Hf concentration expressed in units mg/g
      > In concentration expressed in units mg/g
      > K concentration expressed in units wt %
      > La concentration expressed in units mg/g
      > Li concentration expressed in units mg/g
      > Mg concentration expressed in units wt %
      > Mn concentration expressed in units mg/g
      > Mo concentration expressed in units mg/g
      > Na concentration expressed in units wt %
      > Nb concentration expressed in units mg/g
      > Ni concentration expressed in units mg/g
      > P concentration expressed in units mg/g
      > Pb concentration expressed in units mg/g
      > Rb concentration expressed in units mg/g
      > Re concentration expressed in units mg/g
      > S concentration expressed in units wt %
      > Sb concentration expressed in units mg/g
      > Se concentration expressed in units mg/g
      > Sn concentration expressed in units mg/g
      > Sr concentration expressed in units mg/g
      > Ta concentration expressed in units mg/g
      > Te concentration expressed in units mg/g
      > Th concentration expressed in units mg/g
      > Ti concentration expressed in units wt %
      > Tl concentration expressed in units mg/g
      > U concentration expressed in units mg/g
      > V concentration expressed in units mg/g
      > W concentration expressed in units mg/g
      > Y concentration expressed in units mg/g
      > Zn concentration expressed in units mg/g
      > Zr concentration expressed in units mg/g

      Table 5: Field parameters for water sample sites and concentrations of major anions, mercury, and methylmercury in waters

      > Field site
      > Sample
      > Date
      > pH (in situ)
      > Temperature                 °C (in situ)
      > Conductivity                µS (in situ)
      > Turbidity                   NTU (in situ)
      > Dissolved oxygen            mg/L (percent)
      > Redox potential             mV
      > Alkalinity                  mg/L, as CaCO3  Filtered
      > Total Hg                    ng/L            Unfiltered
      > Total Hg                    ng/L            Filtered
      > Methyl Hg                   ng/L            Unfiltered
      > Methyl Hg                   ng/L            Filtered
      > Chloride (Cl)               mg/L            Filtered
      > Fluoride (F)                mg/L            Filtered
      > Sulfate (SO4)               mg/L            Filtered
      > Nitrate (NO3)               mg/L            Filtered
      > Total organic carbon (TOC)  mg/L            Unfiltered

      Table 6: Concentrations of major and minor elements in waters, determined by ICP-MS and ICP-AES

      > Field site
      > Subsample number
      > Ag    mg/L    ICP-MS
      > Al    mg/L    ICP-MS
      > As    mg/L    ICP-MS
      > B     mg/L    ICP-AES
      > Ba    mg/L    ICP-AES
      > Be    mg/L    ICP-MS
      > Bi    mg/L    ICP-MS
      > Ca    mg/L    ICP-AES
      > Cd    mg/L    ICP-MS
      > Ce    mg/L    ICP-MS
      > Co    mg/L    ICP-MS
      > Cr    mg/L    ICP-MS
      > Cs    mg/L    ICP-MS
      > Cu    mg/L    ICP-MS
      > Dy    mg/L    ICP-MS
      > Er    mg/L    ICP-MS
      > Eu    mg/L    ICP-MS
      > Fe    mg/L    ICP-AES
      > Fe    mg/L    ICP-MS
      > Ga    mg/L    ICP-MS
      > Gd    mg/L    ICP-MS
      > Ge    mg/L    ICP-MS
      > Ho    mg/L    ICP-MS
      > K     mg/L    ICP-AES
      > La    mg/L    ICP-MS
      > Li    mg/L    ICP-MS
      > Lu    mg/L    ICP-MS
      > Mg    mg/L    ICP-AES
      > Mn    mg/L    ICP-MS
      > Mo    mg/L    ICP-MS
      > Na    mg/L    ICP-AES
      > Nb    mg/L    ICP-MS
      > Nd    mg/L    ICP-MS
      > Ni    mg/L    ICP-MS
      > P     mg/L    ICP-MS
      > Pb    mg/L    ICP-MS
      > Pr    mg/L    ICP-MS
      > Rb    mg/L    ICP-MS
      > Sb    mg/L    ICP-MS
      > Sc    mg/L    ICP-MS
      > Se    mg/L    ICP-MS
      > Si    mg/L    ICP-AES
      > Sm    mg/L    ICP-MS
      > SO4   mg/L    ICP-MS
      > Sr    mg/L    ICP-MS
      > Ta    mg/L    ICP-MS
      > Tb    mg/L    ICP-MS
      > Th    mg/L    ICP-MS
      > Ti    mg/L    ICP-MS
      > Tl    mg/L    ICP-MS
      > Tm    mg/L    ICP-MS
      > U     mg/L    ICP-MS
      > V     mg/L    ICP-MS
      > W     mg/L    ICP-MS
      > Y     mg/L    ICP-MS
      > Yb    mg/L    ICP-MS
      > Zn    mg/L    ICP-MS
      > Zr    mg/L    ICP-MS
    Entity_and_Attribute_Detail_Citation: http://pubs.usgs.gov/of/2008/1122/of2008-1122.pdf
Distribution_Information:
  Distributor:
    Contact_Information:
      Contact_Organization_Primary:
        Contact_Organization: USGS Information Services
      Contact_Address:
        Address_Type: mailing
        Address: Box 25286, Denver Federal Center
        City: Denver
        State_or_Province: Colorado
        Postal_Code: 80255-0046
        Country: USA
      Contact_Voice_Telephone: 1-888-ASK-USGS
      Contact_Facsimile_Telephone: 1-303-202-4695
      Contact_Electronic_Mail_Address: infoservices@usgs.gov
  Resource_Description: USGS Open-File Report 2008-1122
  Distribution_Liability:
    This report is preliminary and has not been reviewed for
    conformity with U.S. Geological Survey editorial standards (or
    with the North American Stratigraphic Code).  Any use of trade,
    product, or firm names is for descriptive purposes only and does
    not imply endorsement by the U.S. Government.
  Standard_Order_Process:
    Digital_Form:
      Digital_Transfer_Information:
        Format_Name: Shapefile
        Format_Version_Number: 1.0
        Format_Information_Content: Sample locations and chemical analyses
        File_Decompression_Technique: unzip
      Digital_Transfer_Option:
        Online_Option:
          Computer_Contact_Information:
            Network_Address:
              Network_Resource_Name: http://pubs.usgs.gov/of/2008/1122/data/2008-1122.zip
    Fees: none
Metadata_Reference_Information:
  Metadata_Date: 20081003
  Metadata_Contact:
    Contact_Information:
      Contact_Person_Primary:
        Contact_Person: Peter N Schweitzer
        Contact_Organization: USGS ER GD
      Contact_Position: Geologist
      Contact_Address:
        Address_Type: mailing address
        Address: 12201 Sunrise Valley Drive
        City: Reston
        State_or_Province: VA
        Postal_Code: 20192-0002
        Country: USA
      Contact_Voice_Telephone: 703-648-6533
      Contact_Facsimile_Telephone: 703-648-6252
      Contact_Electronic_Mail_Address: pschweitzer@usgs.gov
  Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata
  Metadata_Standard_Version: FGDC-STD-001-1998