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Chemical analyses of soils and other surficial materials of the conterminous United States

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Frequently anticipated questions:

What does this data set describe?

Title:
Chemical analyses of soils and other surficial materials of the conterminous United States
Abstract:
This data set contains geochemical data from soils and other regoliths collected and analyzed by Hans Shacklette and colleagues beginning in 1958 and continuing until about 1976. Geochemical point-symbol maps were plotted from these data and published as U.S.G.S. Professional Paper 1270 entitled "Element Concentrations in Soils and Other Surficial Materials of the Conterminous United States". The samples were collected at a depth of about 20 cm from sites that, insofar as possible, had surficial materials that were very little altered from their natural condition and that supported native plants. The sample material at most sites could be termed "soil" because it was a mixture of disintegrated rock and organic matter. Some of the sampled deposits, however, were not soils as defined above, but were other regolith types. These included desert sands, sand dunes, some loess deposits, and beach and alluvial deposits that contained little or no visible organic material. The samples were chemically analyzed by a variety of techniques in the U.S. Geological Survey laboratories in Denver, CO.
  1. How might this data set be cited?
    Boerngen, Josephine G., and Shacklette, Hansford T., 1981, Chemical analyses of soils and other surficial materials of the conterminous United States: U.S. Geological Survey Open-File Report 81-197, U.S. Geological Survey, Denver, CO.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -125
    East_Bounding_Coordinate: -67
    North_Bounding_Coordinate: 49
    South_Bounding_Coordinate: 25
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 1958
    Ending_Date: 1976
    Currentness_Reference:
    ground condition
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: tabular data
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a Point data set. It contains the following vector data types (SDTS terminology):
      • Entity point
    2. What coordinate system is used to represent geographic features?
      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.017. Longitudes are given to the nearest 0.017. Latitude and longitude values are specified in Decimal degrees. The horizontal datum used is North American Datum of 1927.
      The ellipsoid used is Clarke 1866.
      The semi-major axis of the ellipsoid used is 6378206.4.
      The flattening of the ellipsoid used is 1/294.98.
  7. How does the data set describe geographic features?
    Geochemical sample
    Table rows consist of information about each sample and its chemical composition. (Source: this dataset)
    PRIME_ID
    Primary ID or field number (Source: USGS Open-File Report 81-197)
    ValueDefinition
    GCxxxxxxField number
    Range of values
    Minimum:GC000250
    Maximum:GC280550
    SECND_ID
    Secondary ID. Unique identification number assigned by the laboratory. This attribute is blank for this data set. (Source: this dataset) This attribute is blank for all rows of this dataset.
    LAT_DMS
    Latitude in degrees, minutes, seconds (blank for this data set). (Source: this dataset)
    ValueDefinition
    0(no value stored for this field)
    LON_DMS
    Longitude in degrees, minutes, seconds (blank for this data set). (Source: this dataset)
    ValueDefinition
    0(no value stored for this field)
    State
    State in which sample was collected. (Source: USGS Open-File Report 81-197)
    ValueDefinition
    XX2-letter state abbreviation
    County
    County in which sample was collected. (Source: USGS Open-File Report 81-197) Place names not abbreviated.
    LAT
    Latitude of sample site in decimal degrees. (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:25.8333
    Maximum:44.7000
    Units:Decimal degrees.
    LONG
    Longitude of sample site in decimal degrees. (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:67.2833
    Maximum:124.4000
    Units:Decimal degrees.
    Date Collected
    Date the sample was collected. (Source: USGS Open-File Report 81-197)
    ValueDefinition
    MM/YYmonth (MM) and year (YY)
    AL_
    Aluminum concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:0.07
    Maximum:>10
    Units:Per cent
    AS_PPM
    Arsenic concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:<0.10
    Maximum:97
    Units:Parts per million (PPM)
    B_PPM
    Boron concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:<20
    Maximum:300
    Units:Parts per million (PPM)
    BA_PPM
    Barium concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:10
    Maximum:5,000
    Units:Parts per million (PPM)
    BE_PPM
    Beryllium concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:<1
    Maximum:15
    Units:Parts per million (PPM)
    BR_PPM
    Bromine concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:<0.50
    Maximum:10.8
    Units:Parts per million (PPM)
    C_
    Total carbon concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:0.06
    Maximum:37
    Units:Per cent
    CA_
    Calcium concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:0.01
    Maximum:32
    Units:Per cent
    CE_PPM
    Cerium concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:<150
    Maximum:300
    Units:Parts per million (PPM)
    CO_PPM
    Cobalt concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:<3
    Maximum:70
    Units:Parts per million (PPM)
    CR_PPM
    Chromium concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:1
    Maximum:2,000
    Units:Parts per million (PPM)
    CU_PPM
    Copper concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:<1
    Maximum:700
    Units:Parts per million (PPM)
    F_
    Fluorine concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:<0.001
    Maximum:0.37
    Units:Per cent
    FE_
    Iron concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:0.01
    Maximum:>10
    Units:Per cent
    GA_PPM
    Gallium concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:<5
    Maximum:70
    Units:Parts per million (PPM)
    GE_PPM
    Germanium concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:<0.1
    Maximum:2,500
    Units:Parts per million (PPM)
    HG_PPM
    Mercury concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:<0.01
    Maximum:4.6
    Units:Parts per million (PPM)
    I_PPM
    Iodine concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:<0.5
    Maximum:9.6
    Units:Parts per million (PPM)
    K_
    Potassium concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:0.005
    Maximum:6.3
    Units:Per cent
    LA_PPM
    Lanthanum concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:<30
    Maximum:200
    Units:Parts per million (PPM)
    LI_PPM
    Lithium concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:<5
    Maximum:140
    Units:Parts per million (PPM)
    MG_
    Magnesium concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:0.005
    Maximum:>10
    Units:Per cent
    MN_PPM
    Manganese concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:<2
    Maximum:7,000
    Units:Parts per million (PPM)
    MO_PPM
    Molybdenum concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:<3
    Maximum:15
    Units:Parts per million (PPM)
    NA_
    Sodium concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:<0.05
    Maximum:10
    Units:Per cent
    NB_PPM
    Niobium concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:<10
    Maximum:100
    Units:Parts per million (PPM)
    ND_PPM
    Neodymium concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:<70
    Maximum:300
    Units:Parts per million (PPM)
    NI_PPM
    Nickel concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:<5
    Maximum:700
    Units:Parts per million (PPM)
    P_
    Phosphorus concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:<0.002
    Maximum:0.68
    Units:Per cent
    PB_PPM
    Lead concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:<10
    Maximum:700
    Units:Parts per million (PPM)
    RB_PPM
    Rubidium concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:<20
    Maximum:210
    Units:Parts per million (PPM)
    S_
    Sulfur concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:<0.08
    Maximum:4.78
    Units:Per cent
    SB_PPM
    Antimony concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:<1
    Maximum:8.8
    Units:Parts per million (PPM)
    SC_PPM
    Scandium concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:<5
    Maximum:50
    Units:Parts per million (PPM)
    SE_PPM
    Selenium concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:<0.1
    Maximum:4.3
    Units:Parts per million (PPM)
    SI_
    Silicon concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:1.69
    Maximum:44.9
    Units:Per cent
    SN_PPM
    Tin concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:<0.1
    Maximum:10.2
    Units:Parts per million (PPM)
    SR_PPM
    Strontium concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:<5
    Maximum:3,000
    Units:Parts per million (PPM)
    TI_
    Titanium concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:0.007
    Maximum:2.0
    Units:Per cent
    TH_PPM
    Thorium concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:2.15
    Maximum:30.8
    Units:Parts per million (PPM)
    U_PPM
    Uranium concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:0.29
    Maximum:10.7
    Units:Parts per million (PPM)
    V_PPM
    Vanadium concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:<7
    Maximum:500
    Units:Parts per million (PPM)
    Y_PPM
    Yttrium concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:<10
    Maximum:200
    Units:Parts per million (PPM)
    YB_PPM
    Ytterbium concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:<1
    Maximum:50
    Units:Parts per million (PPM)
    ZN_PPM
    Zinc concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:<5
    Maximum:2,900
    Units:Parts per million (PPM)
    ZR_PPM
    Zirconium concentration (Source: USGS Open-File Report 81-197)
    Range of values
    Minimum:<20
    Maximum:2,000
    Units:Parts per million (PPM)

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Boerngen, Josephine G.
    • Shacklette, Hansford T.
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    Smith, David B.
    U.S. Geological Survey
    Research Geologist
    U.S. Geological Survey
    Box 25046, MS 973
    Denver, Colorado
    United States of America

    303-236-1849 (voice)
    303-236-3200 (FAX)
    dsmith@usgs.gov

Why was the data set created?

These data provide an ultra-low-density geochemical baseline for soils and other surficial materials in the conterminous United States. The data set contains 1,323 samples for a sampling density of approximately 1 sample per 6,000 square kilometers. The data set is currently the only national geochemical data set collected and analyzed according to standardized protocols. The data are most appropriately used to provide information on background concentrations of elements in soil. The major drawback with the data set is its extremely low number of samples for the entire conterminous US.

How was the data set created?

  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
    Date: 1999 (process 1 of 1)
    The data were generated by the analytical laboratories of the USGS over several years, beginning in the early-mid 1960's when data were not stored in digital databases. In about 1980, upon completion of the sampling and analysis, the data were keypunched and stored in the PLUTO database. At about this same time, the data were put into .CIM format. In about 1996, a copy the data in .CIM was converted to .dbf format. In 1998, the data in .dbf format was converted to Microsoft ACCESS format (.mdb) and then to ARC-INFO format.
  3. What similar or related data should the user be aware of?

How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?
    The soil samples were chemically analyzed by a variety of techniques over a period of time from the mid-1960's to the late 1970's. Details of the methods are given in the references listed in USGS Open-File Report 81-197 and USGS Professional Paper 1270.

    In summary, the methods used were:

    1) Emission spectrography (Myers and others, 1961; Neiman, 1976) for Al, Ba, Be, B, Ca, Ce, Cr, Co, Cu, Ga, Fe, La, Pb, Mg, Mn, Mo, Nd, Ni, Nb, P, K, Sc, Na, Sr, Ti, V, Yb, Y, Zn, and Zr;

    2) EDTA titration for Ca;

    3) colorimetric methods for P and Zn (Ward and others, 1963);

    4) flame photometry for K (Ward and others, 1963);

    5) flame atomic absorption (Huffman and Dinnin, 1976) for Hg, Li, Mg, Na, Rb, and Zn;

    6) flameless atomic absorption for Hg (Vaughn, 1967);

    7) X-ray fluorescence spectrometry (Wahlberg, 1976) for Ca, Ge, Fe, K, Se, Ag, S, and Ti;

    8) Combustion (Huffman and Dinnin, 1976) for total carbon; and neutron activation (Millard, 1975, 1976) for U and Th.

    The accuracy varies with the analytical methodology and with the concentration of the element being analyzed. A small portion of the database contains qualified data. The types of qualifiers in this data set are:

    "N", meaning that the element was not detected at concentrations above the detection limit-this is shown in the data set as, for example, 5.000N meaning that the element was not detected at a concentration of 5 concentration units (ppm or %), the detection limit of the technique.

    "L", meaning that the element was detected by the technique, but at a level below the detection limit-this is shown in the data set as, for example, 1.000L meaning that the element was detected by the instrument, but at a level that could not be quantified at or above the detection limit, 1 concentration unit.

    "B", meaning that there is no data for that particular element in a given sample-this is shown in the data set as .0000B.

    "G", meaning that the element was measured at a concentration greater than the upper determination limit for the technique-this is shown in the data set as, for example, 10.0000G, meaning that the element was measured at a concentration greater than 10 concentration units.
  2. How accurate are the geographic locations?
    Sample locations were determined from USGS topographic maps of various scales. The sites are estimated to be accurate to the nearest minute of latitude and longitude.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    Where chemical data is lacking for a given element in a given sample, ".0000B" is shown as the concentration value. Virtually every element in the data set has some samples in which the element was not analyzed. This may have been a conscious decision on the part of the investigators or it may have been the result of insufficient sample to complete all the analytical procedures. This lack of data is most common for the elements Br, C, Ge, I, Rb, S, Sb, Si, Sn, Th, and U.
  5. How consistent are the relationships among the observations, including topology?
    USGS Open-File Report 81-197 gives analytical values for 46 elements analyzed by a variety of methods. For some elements, the methods of chemical analysis were the same throughout the study, while for others, the methods changed as analytical technology improved. However, all the methods used were specifically designed to give the total contents of the element analyzed. Therefore, the results of earlier analysis should be comparable with results of more recent analyses.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints: None
Use_Constraints: None
  1. Who distributes the data set? (Distributor 1 of 1)
    Peter N Schweitzer
    USGS Geology, Energy, and Minerals Science Center
    Geologist
    12201 Sunrise Valley Drive
    Reston, VA
    USA

    703-648-6533 (voice)
    703-648-6252 (FAX)
    pschweitzer@usgs.gov
  2. What's the catalog number I need to order this data set?
  3. What legal disclaimers am I supposed to read?
    The U.S. Geological Survey (USGS) provides these 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.
  4. How can I download or order the data?
    • Availability in digital form:
      Data format: Geochemical sample locations and analytic results in format shapefile (version 1.0) Size: 0.125
      Network links: https://mrdata.usgs.gov/ussoils/ussoils.zip
    • Cost to order the data: none

Who wrote the metadata?

Dates:
Last modified: 19-Jan-2021
Metadata author:
Peter N Schweitzer
USGS Geology, Energy, and Minerals Science Center
Geologist
12201 Sunrise Valley Drive
Reston, VA
USA

703-648-6533 (voice)
703-648-6252 (FAX)
pschweitzer@usgs.gov
Metadata standard:
Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)
This page is <https://mrdata.usgs.gov/metadata/ofr-81-197.faq.html>
Generated by mp version 2.9.50 on Tue Jan 19 10:03:49 2021