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Mineral Resources On-Line Spatial Data

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National Geochronological Database

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Frequently anticipated questions:


What does this data set describe?

Title: National Geochronological Database
Abstract:
Radiometric ages of geological materials by K-Ar, Rb-Sr, Sm-Nd, fission track, and U-Th-Pb dating methods. A revision of DDS-14 correcting locations and providing the data in more convenient formats.
  1. How might this data set be cited?
    Sloan, Jan, Henry, Christopher D., Hopkins, Melanie, Ludington, Stephen D., Zartman, Robert E., Bush, Charles A., and Abston, Carl, 2003, National Geochronological Database: Open-File Report 03-236, U.S. Geological Survey, Menlo Park, California.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -179.119444
    East_Bounding_Coordinate: -67.021389
    North_Bounding_Coordinate: 71
    South_Bounding_Coordinate: 26.5625
  3. What does it look like?
    https://mrdata.usgs.gov/geochron/ofr-2003-236.png (PNG)
    Sample locations in the conterminous United States, (768 x 512 pixels)
  4. Does the data set describe conditions during a particular time period?
    Calendar_Date: 1995Currentness_Reference:
    Publication dates of the initial database (DDS-14) and the revision (OFR 2003-236).
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: relational database
  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 (18576)
    2. What coordinate system is used to represent geographic features?
      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. 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?
    main
    Sample locations and characteristics
    recno
    Record ID.

    Sample identifier, links site description with analytical results. Integer values. Int of width 5.
    Range of values
    Minimum:1
    Maximum:18669
    Resolution:1
    longitude
    Geographic longitude.

    Geographic longitude in decimal degrees, NAD27. Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 28 records have no value for longitude.
    Range of values
    Minimum:-179.119444
    Maximum:-67.021389
    latitude
    Geographic latitude.

    Geographic latitide in decimal degrees, NAD27. Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 28 records have no value for latitude.
    Range of values
    Minimum:26.5625
    Maximum:71
    longdeg
    Longitude degrees.

    Degrees of longitude, NAD27. Integer values. Int of width 5.
    ValueDefinition
    (no value)Information not available for this record. 28 records have no value for longdeg.
    Range of values
    Minimum:67
    Maximum:179
    Resolution:1
    longmin
    Longitude minutes.

    Minutes of longitude, NAD27. Integer values. Int of width 5.
    ValueDefinition
    (no value)Information not available for this record. 30 records have no value for longmin.
    Range of values
    Minimum:0
    Maximum:59
    Resolution:1
    longsec
    Longitude seconds.

    Seconds of longitude, NAD27. Integer values. Int of width 5.
    ValueDefinition
    (no value)Information not available for this record. 30 records have no value for longsec.
    Range of values
    Minimum:0
    Maximum:60
    Resolution:1
    west
    Longitude hemisphere.

    Hemisphere of longitude, E or W. Textual values of no more than 1 characters.
    ValueDefinition
    (no value)Information not available for this record. 29 records have no value for west.
    latdeg
    Latitude degrees.

    Degrees of latitude, NAD27. Integer values. Int of width 5.
    ValueDefinition
    (no value)Information not available for this record. 28 records have no value for latdeg.
    Range of values
    Minimum:25
    Maximum:71
    Resolution:1
    latmin
    Latitude minutes.

    Minutes of latitude, NAD27. Integer values. Int of width 5.
    ValueDefinition
    (no value)Information not available for this record. 31 records have no value for latmin.
    Range of values
    Minimum:0
    Maximum:60
    Resolution:1
    latsec
    Latitude seconds.

    Seconds of latitude, NAD27. Integer values. Int of width 5.
    ValueDefinition
    (no value)Information not available for this record. 30 records have no value for latsec.
    Range of values
    Minimum:0
    Maximum:60
    Resolution:1
    north
    Latitude hemisphere.

    Hemisphere of latitude, N or S. Textual values of no more than 1 characters.
    ValueDefinition
    (no value)Information not available for this record. 29 records have no value for north.
    country
    Country.

    Country of site (US). Textual values of no more than 2 characters.
    state
    State or province.

    State two letter postal abbreviation. Textual values of no more than 2 characters.
    county
    County.

    County name, occasionally more than one name is given. Textual values of no more than 35 characters.
    ValueDefinition
    (no value)Information not available for this record. 628 records have no value for county.
    quadscale
    Quadrangle map scale.

    Map quadrangle scale. Textual values of no more than 9 characters.
    ValueDefinition
    (no value)Information not available for this record. 63 records have no value for quadscale.
    quadname
    Quadrangle map name.

    Map quadrangle name. Textual values of no more than 69 characters.
    ValueDefinition
    (no value)Information not available for this record. 117 records have no value for quadname.
    sampsour
    Source of sample.

    General type of material sampled or geographic feature from which the sample was taken. Textual values of no more than 38 characters.
    ValueDefinition
    (no value)Information not available for this record. 371 records have no value for sampsour.
    rockname
    Rock name.

    Lithologic terms describing the sample. Textual values of no more than 35 characters.
    ValueDefinition
    (no value)Information not available for this record. 3 records have no value for rockname.
    descrip
    Description.

    Further description of the sampled material, often includes a geologic unit or structural element within the unit. Textual values of no more than 257 characters.
    ValueDefinition
    (no value)Information not available for this record. 2385 records have no value for descrip.
    labs
    Laboratories.

    Organizations whose laboratories provided the analyses. Textual values of no more than 107 characters.
    ValueDefinition
    (no value)Information not available for this record. 729 records have no value for labs.
    compiled
    Compiler name.

    Name of the person who compiled the data. Textual values of no more than 17 characters.
    datecomp
    Date compiled.

    Date record information was compiled, as year and month formatted as YYYY MM. Textual values of no more than 6 characters.
    locprec
    Precision of location.

    Comments on the precision of the location given. Textual values of no more than 65 characters.
    loccomm
    Location comment.

    General comments on the location given. Textual values of no more than 255 characters.
    ValueDefinition
    (no value)Information not available for this record. 2773 records have no value for loccomm.
    ref
    Reference.

    Primary bibliographic reference in which the dates were published. Textual values of no more than 469 characters.
    ValueDefinition
    (no value)Information not available for this record. 2 records have no value for ref.
    ref2
    Reference addition.

    Additional text of the bibliographic reference. Textual values of no more than 237 characters.
    ValueDefinition
    (no value)Information not available for this record. 17856 records have no value for ref2.
    FT
    Fission track dating results, observations, and parameters
    recno
    Record ID.

    Sample identifier, a value of main:recno. Integer values. Int of width 5.
    Range of values
    Minimum:1
    Maximum:18669
    Resolution:1
    ftrecno
    Analysis ID.

    Sequence number, for this sample, of this analysis. Integer values. Int of width 5.
    Range of values
    Minimum:1
    Maximum:5
    Resolution:1
    ftage
    Calculated age.

    Age estimate in millions of years. Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 21 records have no value for ftage.
    Range of values
    Minimum:0.02
    Maximum:2346
    fterr
    Age uncertainty.

    Uncertainty of the age estimate attributable to the analytical method, in millions of years. Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 189 records have no value for fterr.
    Range of values
    Minimum:0.04
    Maximum:1000
    ftmin
    Rock or mineral analyzed.

    Rock or mineral analyzed. Textual values of no more than 12 characters.
    ValueDefinition
    (no value)Information not available for this record. 11 records have no value for ftmin.
    ftlabno
    Lab sample ID.

    Identifier for this analysis assigned by the laboratory. Textual values of no more than 27 characters.
    ValueDefinition
    (no value)Information not available for this record. 9 records have no value for ftlabno.
    ftdeccon
    Decay constants.

    Radioactive decay constants used in calculations. Textual values of no more than 9 characters.
    ValueDefinition
    (no value)Information not available for this record. 547 records have no value for ftdeccon.
    trackdens
    Track density.

    Track density (count per square cm). Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 372 records have no value for trackdens.
    Range of values
    Minimum:0
    Maximum:1123
    fosstrack
    Fossil tracks counted.

    Fossil track density (count per square cm). Integer values. Int of width 5.
    ValueDefinition
    (no value)Information not available for this record. 435 records have no value for fosstrack.
    Range of values
    Minimum:1
    Maximum:4152
    Resolution:1
    indudens
    Induced track density.

    Induced track density (count per square cm). Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 372 records have no value for indudens.
    Range of values
    Minimum:0.0072
    Maximum:1479
    indutrack
    Induced tracks.

    Induced tracks counted. Integer values. Int of width 5.
    ValueDefinition
    (no value)Information not available for this record. 437 records have no value for indutrack.
    Range of values
    Minimum:1
    Maximum:10073
    Resolution:1
    ratiotrack
    Ratio of total to induced tracks.

    Ratio of spontaneous to induced tracks. Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 1277 records have no value for ratiotrack.
    Range of values
    Minimum:0.0083
    Maximum:20.874
    neutflux
    Neutron flux density.

    Thermal neutron flux used in irradiation (neutrons per square cm). Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 293 records have no value for neutflux.
    Range of values
    Minimum:0.122
    Maximum:8.8
    ft_u_ppm
    Uranium concentration.

    Total uranium concentration in the sample, in parts per million by weight. Textual values of no more than 8 characters.
    ValueDefinition
    (no value)Information not available for this record. 986 records have no value for ft_u_ppm.
    addref
    Bibliographic references.

    Additional bibliographic reference information for this analysis. Textual values of no more than 29 characters.
    ValueDefinition
    (no value)Information not available for this record. 1391 records have no value for addref.
    ftagecom
    Age comments.

    Comments on the age estimate, typically provides context for the age. Textual values of no more than 134 characters.
    ValueDefinition
    (no value)Information not available for this record. 404 records have no value for ftagecom.
    ftsampcom
    Sample comments.

    Comments on the sample analyzed. Textual values of no more than 75 characters.
    ValueDefinition
    (no value)Information not available for this record. 963 records have no value for ftsampcom.
    ftanalcom
    Analytical comments.

    Comments on the analytic method used. Textual values of no more than 134 characters.
    ValueDefinition
    (no value)Information not available for this record. 1140 records have no value for ftanalcom.
    ftothcom
    Other comments.

    Other comments pertinent to this analysis. Textual values of no more than 255 characters.
    ValueDefinition
    (no value)Information not available for this record. 811 records have no value for ftothcom.
    K_Ar
    Potassium-Argon and Argon-Argon radiometric age results, observations, and parameters
    recno
    Record ID.

    Sample identifier, a value of main:recno. Integer values. Int of width 5.
    Range of values
    Minimum:1
    Maximum:18669
    Resolution:1
    karrecno
    Analysis ID.

    Sequence number, for this sample, of this analysis. Integer values. Int of width 5.
    Range of values
    Minimum:1
    Maximum:6
    Resolution:1
    karage
    Calculated age.

    Age estimate in millions of years. Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 70 records have no value for karage.
    Range of values
    Minimum:-0.09
    Maximum:6882.45
    karerr
    Age uncertainty.

    Uncertainty of the age estimate attributable to the analytical method, in millions of years. Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 1752 records have no value for karerr.
    Range of values
    Minimum:0
    Maximum:940
    karmin
    Rock or mineral analyzed.

    Rock or mineral analyzed. Textual values of no more than 47 characters.
    ValueDefinition
    (no value)Information not available for this record. 127 records have no value for karmin.
    karanaltype
    Type of analysis.

    Specific type of analytic method used. Textual values of no more than 46 characters.
    ValueDefinition
    (no value)Information not available for this record. 83 records have no value for karanaltype.
    karlabno
    Lab sample ID.

    Identifier for this analysis assigned by the laboratory. Textual values of no more than 34 characters.
    ValueDefinition
    (no value)Information not available for this record. 10 records have no value for karlabno.
    kardeccon
    Decay constants.

    Radioactive decay constants used in calculations. Textual values of no more than 36 characters.
    ValueDefinition
    (no value)Information not available for this record. 5 records have no value for kardeccon.
    k2opct
    K2O concentration.

    Potash concentration as weight percent of the sample. Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 2562 records have no value for k2opct.
    Range of values
    Minimum:0
    Maximum:23233
    40arrad
    Radiogenic argon-40 concentration.

    Concentration of radiogenic 40Ar. Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 2622 records have no value for 40arrad.
    Range of values
    Minimum:-0.0063
    Maximum:2453
    pctradar
    Percent radiogenic argon.

    Percent of argon that is radiogenic. Integer values. Int of width 8.
    ValueDefinition
    (no value)Information not available for this record. 2194 records have no value for pctradar.
    Range of values
    Minimum:0
    Maximum:86868787
    Resolution:1
    sampsuit
    Sample suite number.

    Group identifier of related samples. Integer values. Int of width 5.
    ValueDefinition
    (no value)Information not available for this record. 14168 records have no value for sampsuit.
    Range of values
    Minimum:7
    Maximum:641
    Resolution:1
    addref
    Bibliographic references.

    Additional bibliographic reference information for this analysis. Textual values of no more than 51 characters.
    ValueDefinition
    (no value)Information not available for this record. 1391 records have no value for addref.
    karcomm
    Age comments.

    Comments on the age estimate, typically provides context for the age. Textual values of no more than 90 characters.
    ValueDefinition
    (no value)Information not available for this record. 2806 records have no value for karcomm.
    karsampcom
    Sample comments.

    Comments on the sample analyzed. Textual values of no more than 162 characters.
    ValueDefinition
    (no value)Information not available for this record. 11619 records have no value for karsampcom.
    karanalcom
    Analytical comments.

    Comments on the analytic method used. Textual values of no more than 255 characters.
    ValueDefinition
    (no value)Information not available for this record. 7491 records have no value for karanalcom.
    karothrcom
    Other comments.

    Other comments pertinent to this analysis. Textual values of no more than 373 characters.
    ValueDefinition
    (no value)Information not available for this record. 10041 records have no value for karothrcom.
    Rb_Sr
    Rubidium-Strontium radiometric dating results, observations, and parameters
    recno
    Record ID.

    Sample identifier, a value of main:recno. Integer values. Int of width 5.
    Range of values
    Minimum:1
    Maximum:18669
    Resolution:1
    rbsrrecno
    Analysis ID.

    Sequence number, for this sample, of this analysis. Integer values. Int of width 5.
    Range of values
    Minimum:1
    Maximum:24
    Resolution:1
    rbsrage
    Calculated age.

    Age estimate in millions of years. Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 991 records have no value for rbsrage.
    Range of values
    Minimum:0.71
    Maximum:7394.61
    rbsrerr
    Age uncertainty.

    Uncertainty of the age estimate attributable to the analytical method, in millions of years. Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 2299 records have no value for rbsrerr.
    Range of values
    Minimum:0.1
    Maximum:560
    87_86init
    Initial 87Sr/86Sr.

    Initial ratio of 87Sr to 86Sr in the sampled material. Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 1688 records have no value for 87_86init.
    Range of values
    Minimum:0.1037
    Maximum:124.2
    rbsrmin
    Rock or mineral analyzed.

    Rock or mineral analyzed. Textual values of no more than 46 characters.
    ValueDefinition
    (no value)Information not available for this record. 26 records have no value for rbsrmin.
    rbsranltyp
    Type of analysis.

    Specific type of analytic method used. Textual values of no more than 49 characters.
    ValueDefinition
    (no value)Information not available for this record. 923 records have no value for rbsranltyp.
    rbsrlabno
    Analysis ID.

    Identifier for this analysis assigned by the laboratory. Textual values of no more than 23 characters.
    ValueDefinition
    (no value)Information not available for this record. 5 records have no value for rbsrlabno.
    rbsrdeccon
    Decay constants.

    Radioactive decay constants used in calculations. Textual values of no more than 21 characters.
    ValueDefinition
    (no value)Information not available for this record. 35 records have no value for rbsrdeccon.
    rb_ppm
    Rubidium concentration.

    Rubidium concentration in parts per million by weight. Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 444 records have no value for rb_ppm.
    Range of values
    Minimum:0
    Maximum:164165
    sr_ppm
    Strontium concentration.

    Strontium concentration in parts per million by weight. Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 1093 records have no value for sr_ppm.
    Range of values
    Minimum:0.1
    Maximum:21210
    87srrad
    Radiogenic 87Sr.

    Radiogenic 87Sr. Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 6420 records have no value for 87srrad.
    Range of values
    Minimum:0.01
    Maximum:176
    87rb_86sr
    Ratio 87Rb/86Sr.

    Ratio of 87Rb to 86Sr counted by mass spectrometry. Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 1265 records have no value for 87rb_86sr.
    Range of values
    Minimum:0
    Maximum:62166
    87sr_86sr
    Ratio 87Sr/86Sr.

    Ratio of 87Sr to 86Sr counted by mass spectrometry. Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 689 records have no value for 87sr_86sr.
    Range of values
    Minimum:0.043
    Maximum:70758
    norm
    Normal?.

    T or N or empty; meaning of this field is not clear. Textual values of no more than 1 characters.
    ValueDefinition
    (no value)Information not available for this record. 1058 records have no value for norm.
    sampsuit
    Sample suite number.

    Group identifier of related samples. Integer values. Int of width 5.
    ValueDefinition
    (no value)Information not available for this record. 14168 records have no value for sampsuit.
    Range of values
    Minimum:7
    Maximum:641
    Resolution:1
    addref
    Bibliographic references.

    Additional bibliographic reference information for this analysis. Textual values of no more than 51 characters.
    ValueDefinition
    (no value)Information not available for this record. 1391 records have no value for addref.
    rbsragecom
    Age comments.

    Comments on the age estimate, typically provides context for the age. Textual values of no more than 87 characters.
    ValueDefinition
    (no value)Information not available for this record. 2721 records have no value for rbsragecom.
    rbsrsamcom
    Sample comments.

    Comments on the sample analyzed. Textual values of no more than 104 characters.
    ValueDefinition
    (no value)Information not available for this record. 6498 records have no value for rbsrsamcom.
    rbsranlcom
    Analytical comments.

    Comments on the analytic method used. Textual values of no more than 227 characters.
    ValueDefinition
    (no value)Information not available for this record. 1543 records have no value for rbsranlcom.
    rbsrothcom
    Other comments.

    Other comments pertinent to this analysis. Textual values of no more than 211 characters.
    ValueDefinition
    (no value)Information not available for this record. 4255 records have no value for rbsrothcom.
    Sm_Nd
    Samarium-Neodymium radiometric dating results, observations, and parameters
    recno
    Record ID.

    Sample identifier, a value of main:recno. Integer values. Int of width 5.
    Range of values
    Minimum:1
    Maximum:18669
    Resolution:1
    smndrecno
    Analysis ID.

    Sequence number, for this sample, of this analysis. Integer values. Int of width 5.
    Range of values
    Minimum:1
    Maximum:3
    Resolution:1
    smndage
    Calculated age.

    Age estimate in millions of years. Integer values. Int of width 5.
    ValueDefinition
    (no value)Information not available for this record. 1 records have no value for smndage.
    Range of values
    Minimum:178
    Maximum:575
    Resolution:1
    smnderr
    Age uncertainty.

    Uncertainty of the age estimate attributable to the analytical method, in millions of years. Integer values. Int of width 5.
    ValueDefinition
    (no value)Information not available for this record. 2 records have no value for smnderr.
    Range of values
    Minimum:21
    Maximum:75
    Resolution:1
    smndmin
    Rock or mineral analyzed.

    Rock or mineral analyzed. Textual values of no more than 21 characters.
    smndlabno
    Analysis ID.

    Identifier for this analysis assigned by the laboratory. Textual values of no more than 8 characters.
    smnddeccon
    Decay constants.

    Radioactive decay constants used in calculations. Real numbers stored in double precision.
    Range of values
    Minimum:0.00000654
    Maximum:0.00000654
    sm_ppm
    Samarium concentration.

    Samarium concentration in parts per million by weight. Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 27 records have no value for sm_ppm.
    Range of values
    Minimum:1.88
    Maximum:14.81
    nd_ppm
    Neodymium concentration.

    Neodymium concentration in parts per million by weight. Real numbers stored in double precision.
    Range of values
    Minimum:0.15
    Maximum:50.46
    143smrad
    Ratio 147Sm/144Nd.

    Ratio of counts of 147Sm to 144Nd in the sample, measured by mass spectrometry. Real numbers stored in double precision.
    Range of values
    Minimum:0.1074
    Maximum:0.3809
    143ndrat
    Ratio 143Nd/144Nd.

    Ratio of counts of 143Nd to 144Nd in the sample, measured by mass spectrometry. Real numbers stored in double precision.
    Range of values
    Minimum:0.51079
    Maximum:0.513212
    smndagecom
    Age comments.

    Comments on the age estimate, typically provides context for the age. Textual values of no more than 40 characters.
    smndothcom
    Other comments.

    Other comments pertinent to this analysis. Textual values of no more than 80 characters.
    ValueDefinition
    (no value)Information not available for this record. 32 records have no value for smndothcom.
    U_Th_Pb
    Radiometric age estimates, observations, and parameters using techniques involving isotopes of uranium, thorium, and lead.
    recno
    Record ID.

    Sample identifier, a value of main:recno. Integer values. Int of width 5.
    Range of values
    Minimum:1
    Maximum:18669
    Resolution:1
    upbrecno
    Analysis ID.

    Sequence number, for this sample, of this analysis. Integer values. Int of width 5.
    ValueDefinition
    (no value)Information not available for this record. 1 records have no value for upbrecno.
    Range of values
    Minimum:1
    Maximum:33
    Resolution:1
    206_238age
    Age 206Pb/238U.

    Age estimate in millions of years using the 206Pb-238U method. Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 575 records have no value for 206_238age.
    Range of values
    Minimum:0.1
    Maximum:16300
    err206_238
    Age uncertainty 206Pb/238U.

    Uncertainty of the age estimate by the 206Pb-238U method attributable to the analytical method, in millions of years. Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 2194 records have no value for err206_238.
    Range of values
    Minimum:0
    Maximum:1285
    207_235age
    Age 207Pb/235U.

    Age estimate in millions of years using the 207Pb-235U method. Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 611 records have no value for 207_235age.
    Range of values
    Minimum:-26.6
    Maximum:4460
    err207_235
    Age uncertainty 207Pb/235U.

    Uncertainty of the age estimate by the 207Pb-235U method attributable to the analytical method, in millions of years. Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 2186 records have no value for err207_235.
    Range of values
    Minimum:-350
    Maximum:2127
    207_206age
    Age 207Pb/206Pb.

    Age estimate in millions of years using the 207Pb-206Pb method. Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 12 records have no value for 207_206age.
    Range of values
    Minimum:-50000
    Maximum:4792.4
    err207_206
    Age uncertainty 207Pb/206Pb.

    Uncertainty of the age estimate by the 207Pb-206Pb method attributable to the analytical method, in millions of years. Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 2058 records have no value for err207_206.
    Range of values
    Minimum:1
    Maximum:320
    208_232age
    Age 208Pb/232Th.

    Age estimate in millions of years using the 208Pb-232Th method. Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 1994 records have no value for 208_232age.
    Range of values
    Minimum:24.5
    Maximum:13383
    err208_232
    Age uncertainty 208Pb/232Th.

    Uncertainty of the age estimate by the 208Pb-232Th method attributable to the analytical method, in millions of years. Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 2421 records have no value for err208_232.
    Range of values
    Minimum:1.8
    Maximum:210
    uintcpt
    Upper intercept.

    Upper intercept of the Concordia diagram. Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 1267 records have no value for uintcpt.
    Range of values
    Minimum:14.9
    Maximum:3900
    erruintcpt
    Upper intercept uncertainty.

    Uncertainty in the upper intercept. Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 1458 records have no value for erruintcpt.
    Range of values
    Minimum:1
    Maximum:550
    lintcpt
    Lower intercept.

    Lower intercept of the Concordia diagram. Textual values of no more than 8 characters.
    ValueDefinition
    (no value)Information not available for this record. 2172 records have no value for lintcpt.
    errlintcpt
    Lower intercept uncertainty.

    Uncertainty in the lower intercept. Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 2243 records have no value for errlintcpt.
    Range of values
    Minimum:0.8
    Maximum:900
    pbinitrat
    Initial lead isotopic composition.

    Initial ratios of lead isotopes in common lead, in sequence: 206Pb/204Pb, 207Pb/204Pb, 208Pb/204Pb. Textual values of no more than 24 characters.
    ValueDefinition
    (no value)Information not available for this record. 1253 records have no value for pbinitrat.
    upbmin
    Rock or mineral analyzed.

    Rock or mineral analyzed. Textual values of no more than 52 characters.
    ValueDefinition
    (no value)Information not available for this record. 8 records have no value for upbmin.
    upblabno
    Analysis ID.

    Identifier for this analysis assigned by the laboratory. Textual values of no more than 26 characters.
    ValueDefinition
    (no value)Information not available for this record. 7 records have no value for upblabno.
    upbdeccon
    Decay constants.

    Radioactive decay constants used in calculations. Textual values of no more than 35 characters.
    ValueDefinition
    (no value)Information not available for this record. 5 records have no value for upbdeccon.
    u_ppm
    Uranium concentration.

    Uranium concentration in parts per million by weight. Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 409 records have no value for u_ppm.
    Range of values
    Minimum:0
    Maximum:791000
    th_ppm
    Thorium concentration.

    Thorium concentration in parts per million by weight. Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 1894 records have no value for th_ppm.
    Range of values
    Minimum:0.1
    Maximum:414000
    pb_ppm
    Lead concentration.

    Lead concentration in parts per million by weight. Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 431 records have no value for pb_ppm.
    Range of values
    Minimum:0.01
    Maximum:170100
    204pb
    Isotopic concentration 204Pb.

    Concentration of 204Pb isotope in the sample. Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 812 records have no value for 204pb.
    Range of values
    Minimum:0
    Maximum:83.62
    206pb
    Isotopic concentration 206Pb.

    Concentration of 206Pb isotope in the sample. Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 786 records have no value for 206pb.
    Range of values
    Minimum:1.228
    Maximum:95.51
    207pb
    Isotopic concentration 207Pb.

    Concentration of 207Pb isotope in the sample. Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 787 records have no value for 207pb.
    Range of values
    Minimum:0.1455
    Maximum:46.02
    208pb
    Isotopic concentration 208Pb.

    Concentration of 208Pb isotope in the sample. Real numbers stored in double precision.
    ValueDefinition
    (no value)Information not available for this record. 787 records have no value for 208pb.
    Range of values
    Minimum:0.053
    Maximum:1889
    sampsuit
    Sample suite number.

    Group identifier of related samples. Integer values. Int of width 5.
    ValueDefinition
    (no value)Information not available for this record. 14168 records have no value for sampsuit.
    Range of values
    Minimum:7
    Maximum:641
    Resolution:1
    addref
    Bibliographic references.

    Additional bibliographic reference information for this analysis. Textual values of no more than 25 characters.
    ValueDefinition
    (no value)Information not available for this record. 1391 records have no value for addref.
    upbagecom
    Age comments.

    Comments on the age estimate, typically provides context for the age. Textual values of no more than 84 characters.
    ValueDefinition
    (no value)Information not available for this record. 1661 records have no value for upbagecom.
    upbsampcom
    Sample comments.

    Comments on the sample analyzed. Textual values of no more than 224 characters.
    ValueDefinition
    (no value)Information not available for this record. 699 records have no value for upbsampcom.
    upbanalcom
    Analytical comments.

    Comments on the analytic method used. Textual values of no more than 199 characters.
    ValueDefinition
    (no value)Information not available for this record. 1294 records have no value for upbanalcom.
    upbothrcom
    Other comments.

    Other comments pertinent to this analysis. Textual values of no more than 255 characters.
    ValueDefinition
    (no value)Information not available for this record. 757 records have no value for upbothrcom.
    datadxny
    Data dictionary, explaining tables and fields
    id
    Row ID.

    Row identifier within datadxny table. Integer values. Int of width 0.
    Range of values
    Minimum:1
    Maximum:149
    Resolution:1
    tblorder
    Table order.

    Order in which this table should appear in some presentations. Integer values. Int of width 0.
    Range of values
    Minimum:1
    Maximum:7
    Resolution:1
    tblname
    Table name.

    Name of the table. Textual values of no more than 20 characters.
    number
    Field order.

    Order in which this field occurs in the RDBMS. Integer values. Int of width 0.
    ValueDefinition
    (no value)Information not available for this record. 7 records have no value for number.
    Range of values
    Minimum:1
    Maximum:31
    Resolution:1
    label
    Field label.

    Label of the field in the RDBMS. Textual values of no more than 32 characters.
    ValueDefinition
    (no value)Information not available for this record. 7 records have no value for label.
    category
    Category.

    General category of information provided by the contents of the field. Textual values of no more than 50 characters.
    ValueDefinition
    (no value)Information not available for this record. 7 records have no value for category.
    short_desc
    Short description.

    Descriptive name of the field used in some presentations, not constrained by rules affecting the label. Textual values of no more than 40 characters.
    ValueDefinition
    (no value)Information not available for this record. 7 records have no value for short_desc.
    description
    Description.

    Longer description of the purpose and contents of the field. Textual values of no more than 4096 characters.
    link
    Link.

    URL providing more information about the field. Textual values of no more than 96 characters.
    ValueDefinition
    (no value)Information not available for this record. 149 records have no value for link.
    origin
    Origin.

    Abbreviation of an organization, data set, or other entity responsible for defining the field. Textual values of no more than 12 characters.
    ValueDefinition
    (no value)Information not available for this record. 149 records have no value for origin.
    sqltype
    SQL data type.

    Data type of the field as used in the RDBMS. Textual values of no more than 8 characters.
    ValueDefinition
    (no value)Information not available for this record. 7 records have no value for sqltype.
    dbftype
    DBF field type.

    Data type of the field when expressed in DBF. Textual values of no more than 1 characters.
    ValueDefinition
    (no value)Information not available for this record. 7 records have no value for dbftype.
    width
    DBF field width.

    Field width when expressed in DBF. Integer values. Int of width 0.
    ValueDefinition
    (no value)Information not available for this record. 7 records have no value for width.
    Range of values
    Minimum:0
    Maximum:4096
    Resolution:1
    prec
    DBF field precision.

    Precision of the field (places to right of decimal) when expressed in DBF, only for numeric fields. Integer values. Int of width 0.
    ValueDefinition
    (no value)Information not available for this record. 76 records have no value for prec.
    Range of values
    Minimum:0
    Maximum:6
    Resolution:1
    units
    Units.

    Units of measure of the field values. Textual values of no more than 64 characters.
    ValueDefinition
    (no value)Information not available for this record. 149 records have no value for units.


Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?

Why was the data set created?

This database is a minor revision of DDS-14, with some corrections.

How was the data set created?

  1. From what previous works were the data drawn?
    DDS-14 (source 1 of 1)
    Zartman, Robert E., Bush, Charles A., and Abston, C. C., 1995, National geochronological and natural radioelement data bases: Data Series 14, U.S. Geological Survey, Denver, Colorado.

    Type_of_Source_Media: digital files on CD-ROM
    Source_Contribution:
    Original database used by compilers of OFR-2003-236; corrections to some of the data are described at http://pubs.usgs.gov/of/2003/0236/
  2. How were the data generated, processed, and modified?
    Date: 21-Dec-2011 (process 1 of 1)
    Copied information from OFR 2003-236, added documentation, reformatted, and in some cases eliminated duplication, eliminated explicit uninformative values (for example "Unk" in many fields). Created specialized interfaces and report formats as well as web services and download packages. Person who carried out this activity:
    Peter N Schweitzer
    USGS ER GD
    Geologist
    12201 Sunrise Valley Drive
    Reston, VA
    USA

    703-648-6533 (voice)
    703-648-6252 (FAX)
    pschweitzer@usgs.gov
  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?
  2. How accurate are the geographic locations?
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
  5. How consistent are the relationships among the observations, including topology?

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 ER GD
    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? USGS Open-File Report 2003-236
  3. What legal disclaimers am I supposed to read?
    This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey (USGS) editorial standards or with the North American Stratigraphic Code. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

  4. How can I download or order the data?

Who wrote the metadata?

Dates:
Last modified: 07-Dec-2016
Metadata author:
Schweitzer, Peter, N
Eastern Mineral Resources Team
12201 Sunrise Valley Drive Mail Stop 954
Reston, VA
USA

703-648-6533 (voice)
pschweitzer@usgs.gov
Metadata standard:
Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)

This page is <https://mrdata.usgs.gov/metadata/ofr-2003-236.faq.html>

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