OFR 97-492: Charlottesville Quadrangle NURE HSSR Study

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National Geochemical Database—Reformatted Data from the National Uranium Resource Evaluation (NURE) Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) Program

By Steven M. Smith
Version 1.40 (2006)

Brief History and Description of Data

[See History of NURE HSSR Program for a summary of the entire program.]

Virginia
Subcontractors for the Savannah River Laboratory (SRL) collected at least 5,667 stream-sediment, 2,598 surface-water, and 4,834 ground-water samples within 96 counties from Virginia as part of the NURE Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) program. The sediment samples were collected during July - October 1976; August - September 1977; and April - November 1978, and water samples were collected during December 1976 - September 1977; April - October 1978; and June - August 1979. Sample coverage included portions of the Baltimore, Bluefield, Charlottesville, Chincoteague, Cumberland, Currituck Sound, Greensboro, Jenkins, Johnson City, Norfolk, Richmond, Roanoke, Salisbury, Washington, and Winston-Salem 1:250,000-scale quadrangles. (A total of 844 stream-sediment, 747 surface-water, and 557 ground-water samples were collected within the Charlottesville quadrangle.) These samples were sent to SRL for analysis of uranium and additional elements (16 in sediments and 9 in waters). SRL was able to analyze 5,522 sediments and 7,416 waters from Virginia; this includes 840 sediment and 1,301 water samples from the Charlottesville quadrangle. The analytical and site location data for all Virginia samples were released in the Delaware, Maryland, Virginia, and West Virginia Data Report [GJBX-103(82)].

SRL sent 2,719 sediment samples from Virginia to an unnamed contract laboratory for "Supplemental Analyses." Supplemental analytical determinations for up to 23 elements were reported for 2,711 of these samples in the Delaware, Maryland, Virginia, and West Virginia Data Report [GJBX-103(82)]. The digital data file accompanying this report includes Supplemental Analyses for 198 Virginia sediment samples within the Charlottesville quadrangle.

West Virginia
Subcontractors for the Savannah River Laboratory (SRL) collected at least 2,965 stream-sediment, 2,910 surface-water, and 4,060 ground-water samples within 55 counties from West Virginia as part of the NURE Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) program. The sediment samples were collected during May - November 1978 and August - September 1979; water samples were collected during April - August 1977; May - September 1978; and July 1980. Sample coverage included portions of the Baltimore, Bluefield, Canton, Charleston, Charlottesville, Clarksburg, Columbus, Cumberland, Huntington, and Jenkins 1:250,000-scale quadrangles. (A total of 296 stream-sediment, 324 surface-water, and 288 ground-water samples were collected within the Charlottesville quadrangle.) These samples were sent to SRL for analysis of uranium and additional elements (16 in sediments and 9 in waters). SRL was able to analyze 2,919 sediments and 6,965 waters from West Virginia; this includes 296 sediment and 611 water samples from the Charlottesville quadrangle. The analytical and site location data for all West Virginia samples were released in the Delaware, Maryland, Virginia, and West Virginia Data Report [GJBX-103(82)].

SRL: Charlottesville Quadrangle
SRL released a separate quadrangle report for the Charlottesville NTMS quadrangle. The abstract reports that 1,196 stream-sediment, 1,071 stream-water and 823 ground-water samples were collected but the report includes data for only 1,140 stream-sediment, 1,071 stream-water and 823 ground-water samples. SRL released the analytical data as the Charlottesville Quadrangle GJBX-175(81) Abbreviated Data Report. Although these data are given on microfiche that accompanies the report, no digital data files were found for this reformatting effort. A cursory comparison of the [GJBX-175(81)] data suggests that there are some differences between this set of HSSR data and that found for corresponding samples in the Virginia and West Virginia State reports. One minor difference is that analytical data values found in the digital state files are slightly different from the hard copy tables. These variations are apparently due only to differences in rounding versus truncation of reported values or to differences in the number of recorded significant digits.

Gold Analyses
Data for gold analyses of sediments by SRL neutron activation were released in the GJBX-135(82) summary report. The introduction of that report states:

"This report contains previously unreported neutron-activation analyses of gold in sediment samples determined at SRL. These data were not included in the standard SRL NURE data reports because the gold spectrum was not measured in the original analytical procedure and the report format was designed without the gold analyses being included. Gold analyses became available as the analytical procedure was refined, but the report format was not modified to incorporate these data."

Only those sediment samples that had detectable concentrations of gold by neutron activation analysis were given in the GJBX-135(82) report. Sediment samples with concentrations below detection limits were not reported and can only be ascertained by identifying which samples were actually analyzed by neutron activation at SRL.

Summary Tables
Because of the various laboratories and analytical methods used, some SRL samples may have been analyzed once, twice, or not at all. The following table summarizes the analysis of Charlottesville quadrangle samples.

Combination of laboratories that analyzed samples for the Charlottesville quadrangle.
Laboratory Analysis Sediments Waters
Only SRL 938 1,912
Both SRL and Supplemental Labs 198 0
None 4 4
Total Samples 1,140 1,916
Total Data Records 1,140 1,916

The following is a list of all sample types collected and reported for NURE studies in the Charlottesville quadrangle.

Summary of Charlottesville quadrangle sample types.
Sediment Sample Type Number of Samples Water Sample Type Number of Samples
Wet Streams 1,140 Streams 1,071
    Wells 571
    Springs 274
Total Sediments 1,140 Total Waters 1,916

These Charlottesville quadrangle samples were analyzed by one or more of the following methods:

Sediment Samples

Water Samples



Discussion of the Reformatting Process for Charlottesville Quadrangle

Sediment Records
The Charlottesville quadrangle sediment data consist of reformatted records from the Virginia and West Virginia portions of the Delaware, Maryland, Virginia, and West Virginia Data Report [GJBX-103(82)]. The following problems were found and addressed during the comparison and reformatting stages for the Charlottesville quadrangle sediment data:

  1. During reformatting, contamination codes for "residential" and "recreation" were found to be missing from each State's CONTAMC field. The presence of one of these two codes was indicated only by a "." (period). The missing codes were assigned a value of "unknown" in the CONTAMC field within the final sediment data file.
  2. One stream-sediment sample was collected at a latitude of exactly 39°N, the dividing line between the Charlottesville quadrangle and the Cumberland quadrangle. A data record for this sample was found in the Charlottesville Quadrangle GJBX-175(81) Abbreviated Data Report, the Cumberland quadrangle files, and the Virginia State files. The data from all three sources were compared, combined, commented in the REFORMAT field, and then assigned to the Charlottesville quadrangle.
  3. Unlikely sample collection dates were found for five samples. These dates were removed from the SAMPDAT field. For each record, the original SAMPDAT value and the most likely correct value was added as a comment to the REFORMAT field.
  4. Gold concentrations from the GJBX-135(82) report were added to the appropriate sediment records. A value of -0.01 (<0.01 ppm Au) was added to all other sediment samples determined to have been analyzed by SRL neutron activation. This value was chosen because 0.01 is the lowest reported gold concentration in the entire report.

Water Records
The Charlottesville quadrangle water data consist of reformatted records from the Virginia and West Virginia portions of the Delaware, Maryland, Virginia, and West Virginia Data Report [GJBX-103(82)]. The following problems were found and addressed during the comparison and reformatting stages for the Charlottesville quadrangle water data:

  1. One stream-water sample was collected at a latitude of exactly 39°N, the dividing line between the Charlottesville quadrangle and the Cumberland quadrangle. A data record for this sample was found in the Charlottesville Quadrangle GJBX-175(81) Abbreviated Data Report, the Cumberland quadrangle files, and the Virginia State files. The data from all three sources were compared, combined, commented in the REFORMAT field, and then assigned to the Charlottesville quadrangle.
  2. The original NURE format for surface-water files did not include much information about the character of the sample location. This missing information includes observations taken at each site on the stream width, depth, and flow, water color, surrounding vegetation, local relief, weather, and possible contaminants. However, this information is given in records for stream-sediment samples that were collected at the same locations. The available site descriptive information for stream-water sites were compared with the corresponding stream-sediment site records. The missing site descriptive data were then added to stream-water records from corresponding stream-sediment sample records. Sources of data and any problems found are described in the REFORMAT comment field. Only 34 surface-water records did not have corresponding stream-sediment sample records.
  3. During reformatting, contamination codes for "residential" and "recreation" were found to be missing from each State's CONTAMC field. The presence of one of these two codes was indicated only by a "." (period). The missing codes were assigned a value of "unknown" in the CONTAMC field within the final sediment data file.
  4. Unlikely sample collection dates were found for seven samples. These dates were removed from the SAMPDAT field. For each record, the original SAMPDAT value and the most likely correct value was added as a comment to the REFORMAT field.
  5. Nineteen ground-water samples were identified with a SRLID in the 700's. All of these samples were missing latitude and longitude coordinates. Evidence from original sample site field notes strongly suggests that these are duplicate samples collected later from a previously sampled 500's series site (i.e. SRLID site number ABCD718R is the same location as ABCD518R). The coordinates from the original 500's series sites were added to the matching 700's records and this change was noted in the REFORMAT and COORDPRB comment fields.
  6. The latitude and longitude coordinates for 3 water samples collected within Warren(1) County in Virginia; and Pocahontas(2) County in West Virginia were not found in the data during the reformatting process. The records for these 3 samples cannot be retrieved on a geographical basis.


Download The Data

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 web sites, 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).

Charlottesville Quadrangle Sediment Data - 1,140 records
Charlottesville Quadrangle Water Data - 1,913 records



Notes for Data Users

In the eastern United States, SRL collected samples primarily by county. Often, not all counties within a quadrangle were completely sampled. Sample coverage in the Charlottesville quadrangle is complete and includes samples from Albemarle, Augusta, Bath, Culpeper, Fauquier, Greene, Highland, Louisa, Madison, Nelson, Orange, Page, Rappahannack, Rockbridge, Rockingham, Shenandoah, and Warren Counties in Virginia; and Barbour, Grant, Hardy, Pendleton, Pocahontas, Randolph, and Tucker Counties in West Virginia. The laboratory and analytical methods used also may vary by county such that adjacent counties often have very different analytical coverage.

Four sediment and four water samples within the Charlottesville quadrangle were not analyzed by any of the various laboratories. The following table summarizes the locations of those unanalyzed samples.

General locations of unanalyzed samples.
State County Sample Media Unanalyzed Samples Total Samples
Virginia Albemarle Water 1 77
Virginia Augusta Sediment 4 167
Virginia Bath Water 2 121
West Virginia Grant Water 1 37



Other NURE Geochemical Data for the Charlottesville Quadrangle

Charlottesville Quadrangle NURE Summary
A summary evaluation investigation was conducted by the Bendix Field Engineering Corporation to identify environments and delineate areas favorable for the occurrence of uranium deposits within the Charlottesville quadrangle [PGJ/F-114(82)]. This report contains elemental analyses for 161 rock, soil, and water samples listed within tables. In addition, the report contains a summary of radiometric surveys, gamma spectrometry, and emission spectroscopy data collected within the quadrangle. This summation suggests that favorable environments include vein-type deposits in metamorphic rocks within highly sheared portions of the Precambrian Lovingston Formation, and for allogenic uranium deposits within the Cambrian metasediments along the margins of the Green Springs and Ellisville intrusives.



Charlottesville Quadrangle NURE Bibliography



Links Within Open-File Report 97-492

Back to Virginia NURE data
Back to West Virginia NURE data
Frequently Asked Questions Concerning NURE Data
Home Page: USGS National Geochemical Database - NURE HSSR data



Page written by Bryan G. Moravec and Steven M. Smith.
Contact: Steven M. Smith (smsmith@usgs.gov)
Version 1.41: February 23, 2006

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