OFR 97-492: Currituck 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.]

North Carolina
Subcontractors for the Savannah River Laboratory (SRL) collected at least 6,666 stream-sediment, 295 surface-water, and 5,778 ground-water samples within 100 counties from North Carolina as part of the NURE Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) program. The sediment samples were collected during June - December 1976; July - August 1977; and April - May 1978, and water samples were collected during December 1976 - August 1977 and June - July 1978. Sample coverage included portions of the Beaufort, Charlotte, Chattanooga, Currituck Sound, Florence, Georgetown, Greensboro, Greenville, Johnson City, Knoxville, Manteo, Norfolk, Raleigh, Rocky Mount, Rome, Spartanburg, and Winston-Salem 1:250,000-scale quadrangles. (A total of 1 stream-sediment and 22 ground-water samples were collected within the Currituck Sound 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 6,597 sediments and 6,040 waters from North Carolina; this includes all sediment and water samples from the Currituck Sound quadrangle. The analytical and site location data for all North Carolina samples were released in the North and South Carolina Data Report [GJBX-102(82)].

SRL sent 4,677 sediment samples from North Carolina to an unnamed contract laboratory for "Supplemental Analyses." Supplemental analytical determinations for up to 23 elements were reported for 4,660 of these samples in the North and South Carolina Data Report [GJBX-102(82)]. The digital data file accompanying this report does not include any Supplemental Analyses for the North Carolina sediment sample collected within the Currituck Sound quadrangle.

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 3 stream-sediment and 5 ground-water samples were collected within the Currituck Sound 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 all sediment and water samples from the Currituck Sound 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 does not include Supplemental Analyses for any Virginia sediment samples within the Currituck Sound quadrangle.

SRL: Norfolk and Southern Eastville Quadrangles
SRL released a separate quadrangle report for the Norfolk and Southern Eastville (Currituck Sound) NTMS quadrangles. The abstract reports that 840 stream-sediment samples and 1,008 ground-water samples were collected but the report includes data for 843 stream-sediment and 1,008 ground-water samples. Of these, 4 stream-sediment and 27 ground-water samples were collected from the Currituck Sound quadrangle. SRL released the analytical data as the Norfolk and Southern Eastville Quadrangle GJBX-283(81) Preliminary Basic 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-283(81)] data suggests that there are some minor differences between this set of HSSR data and that found for corresponding samples in the Virginia and North Carolina State reports. The report often lists 'not detected' values for Dy and Yb that are missing in the State reports. Uranium values differ very slightly between the two reports. These variations appear to be due to differences in rounding versus truncation of reported values.

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

Summary of Currituck Sound quadrangle sample types.
Sediment Sample Type Number of Samples Water Sample Type Number of Samples
Wet Streams 4 Wells 27
Total Sediments 4 Total Waters 27

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

Sediment Samples

Water Samples



Discussion of the Reformatting Process for Currituck Sound Quadrangle

Sediment Records
The Currituck Sound quadrangle sediment data consist of reformatted records from the North Carolina portion of the North and South Carolina [GJBX-102(82)] Data Report and the Virginia portion of the Delaware, Maryland, Virginia, and West Virginia [GJBX-103(82)] Data Report. The following problems were found and addressed during the comparison and reformatting stages for the Currituck Sound 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. 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 ppm is the lowest reported gold concentration in the entire report.

Water Records
The Currituck Sound quadrangle water data consist of reformatted records from the North Carolina portion of the North and South Carolina [GJBX-102(82)] Data Report and the Virginia portion of the Delaware, Maryland, Virginia, and West Virginia [GJBX-103(82)] Data Report>]. The following problems were found and addressed during the comparison and reformatting stages for the Cumberland quadrangle water data:

  1. An analysis of latitude-longitude site coordinates identified several stream-sediment samples that were missing coordinates, did not plot within expected state, county, or map boundaries, or had differing coordinates in corresponding records. To correct or confirm sample coordinates, the original field collection maps for Dare County, North Carolina were obtained and re-digitized. The newly re-digitized coordinates were added to the database and the coordinates from the original file(s) were recorded in the COORDPRB comment field. When the newly re-digitized coordinates were not significantly different, that confirmation of the site location was also noted in the COORDPRB comment field.
  2. After re-digitizing, ten well-water samples from Dare County, North Carolina originally located in the Currituck Sound quadrangle now plot in the adjacent Manteo quadrangle.


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).

Eastville Quadrangle Sediment Data (Chincoteague and Currituck Sound quadrangles) - 69 records
Eastville Quadrangle Water Data (Chincoteague and Currituck Sound quadrangles) - 123 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 Currituck Sound quadrangle is complete and includes samples from Currituck and Dare Counties in North Carolina; and Nasemond County in Virginia. The laboratory and analytical methods used also may vary by county such that adjacent counties often have very different analytical coverage.



Other NURE Geochemical Data for the Currituck Sound Quadrangle

None found.



Currituck Sound Quadrangle NURE Bibliography



Links Within Open-File Report 97-492

Back to North Carolina NURE data
Back to 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 1.30: September 11, 2001
Version 1.41: February 23, 2006

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