OFR 97-492: Williams Quadrangle NURE HSSR Study
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This page is currently being rewritten to the Version 1.41 format.
[See History of NURE HSSR Program for a summary of the entire program.]
The Lawrence Livermore Laboratory was responsible for the collection and analysis of NURE samples from the Williams quadrangle. Contractors were hired to collect the reconnaissance samples. A total of 1,647 sediment samples (1,469 reconnaissance samples, 128 site duplicate samples, and 50 analytical duplicate samples) and 156 water samples (142 reconnaissance samples and 14 site duplicate samples) were collected between August, 1977 and January, 1978. LLL crews reportedly resampled about 5% of the project sites (but no resampled sites were recognized in the data). All samples were analyzed by LLL for uranium and several other elements and the analytical data were released in the LLL Williams Quadrangle NURE Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) study GJBX-071(79) report.
The following is a list of all sample types (including site and analytical duplicates) collected in the Williams quadrangle.
| Sediment Sample Type | Number of Samples | Water Sample Type | Number of Samples |
|---|---|---|---|
| Wet Streams | 51 | Streams | 5 |
| Dry Streams | 1,595 | Wells | 104 |
| Lakes or Ponds | 1 | Springs | 47 |
| Total Sediments | 1,647 | Total Waters | 156 |
These Williams quadrangle samples were analyzed by one or more of the following methods:
Sediment Samples
Water Samples
The data in the NEW-FORMAT NURE data files consist of records from the LLL GJBX-071(79) report. Any problems or changes to records were noted in the REFORMAT comment field.
Unlike data from other laboratories, the original LLL sediment data files do not indicate when elemental concentrations fall below analytical determination limits. Other laboratories usually report these values as "less than the lower analytical determination limit" (represented by a negative number). These data (negative values) were added to the NEW-FORMAT NURE data files based upon the approximate lower limits of detection given in Table 2 of the GJBX-071(79) report.
The original LLL files also contained numerical estimates of the absolute error associated with each elemental concentration. These data were not included in the NEW-FORMAT NURE data files but were placed into additional supplemental data files. The Absolute Error Extra Data Format is explained later in this document.
The NURE HSSR data are now available online in two databases: The sediment database (also includes data for soils and some rocks) at http://tin.er.usgs.gov/nure/sediment/ and the water database at http://tin.er.usgs.gov/nure/water/. From these two websites, NURE HSSR data can be selected, examined, summarized, and downloaded by political boundaries (State and County), by quadrangle (1:250,000-scale, 1:100,000-scale, and 1:63,360-scale for Alaska or 1:24,000-scale for the Lower 48 States), and by hydrologic unit (drainage region, subregion, river basin, or sub-basin). Selected data can be downloaded as a dBase file, a shapefile, an HTML table, or ASCII text (tab- or comma-delimited).
Williams Quadrangle Sediment Data - 1,647 records
Williams Quadrangle Water Data - 155 records
LLL Error Estimates Data for Sediment Analyses - willmssx.dbf.gz
LLL Error Estimates Data for Water Analyses - willmswx.dbf.gz
The sediment samples collected by LLL were sieved at -18 mesh (1000 microns) and +35 mesh (500 microns); the finer fractions were removed from the sample to avoid windblown contamination. Analytical data from these samples may not be directly comparable to that in nearby quadrangles where different sieve size fractions were used.
Note that the site duplicate water samples were collected differently, with respect to filtering and acidification, than the reconnaissance samples. (See the SAMPTYP coding explanation in the On-Line Manual for New-Format NURE HSSR Data Files for descriptions of different Sample Types). Analytical data may not be directly comparable for water samples collected by different methods.
Users of past versions of the Williams quadrangle sediment data have had problems with LLL data because the fields were blank when the element concentration fell below the lower analytical determination limits. This absence of the lower end of the data population was responsible for skewing the data in statistical and contouring programs to levels that were higher than expected. As described above, the NEW-NURE FORMAT attempts to solve this problem by replacing those blanks with "less than" values based on reported lower determination limits.
The Bendix Field Engineering Corporation of Grand Junction, Colorado prepared a summary evaluation of the Williams quadrangle [GJQ-009(81)]. An additional 261 rock, 7 soil, and 13 water samples were collected as part of this assessment. The samples were analyzed for uranium and several additional elements and the data were released only as microfiche appendices that accompany the summary report.
Explanations are only included here for fields unique to these files. For the explanation of common fields consult the On-Line Manual for New-Format NURE HSSR Data Files. After each field name is a format code. A format code of (N) means that the field is formatted as an Numeric field.
A statistical estimate of measurement uncertainty associated with quantifying the corresponding uranium concentration determined by Delayed-Neutron Counting Analysis. (expressed as a percentage of the uranium concentration found in field U_DN_PPM for sediment data or U_DN_PPB for water data in the NEW-NURE FORMAT data files).
(Where EL represents different element symbols.) A numerical estimate of the uncertainties associated with quantifying the corresponding elemental concentration determined by Neutron Activation Analysis. (expressed in the same concentration units as the element concentration found in the NEW-NURE FORMAT data files).
Back to Arizona NURE data
Frequently Asked Questions Concerning NURE HSSR Data
Home Page: USGS National Geochemical Database - NURE HSSR data
Page written by Steven M. Smith (smsmith@usgs.gov)
Version 1.10: July 29, 1999
Version 1.20: August 07, 2000
Version 1.30: September 11, 2001
Version 1.40: January 13, 2006
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