OFR 97-492: Grand Canyon 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)
Under Construction This page is currently being rewritten to the Version 1.41 format.

Brief History and Description of Data

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

Totals of 1,013 sediment and 97 water samples were collected in the Grand Canyon quadrangle (except for areas within Grand Canyon National Park and Grand Canyon National Monument) during May - November, 1979 as part of the Savannah River Laboratory (SRL) Grand Canyon Quadrangle NURE Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) study. These samples were analyzed by SRL for uranium and other elements (16 additional elements in sediments and 9 in waters) and the analytical data were released in the Grand Canyon NURE HSSR quadrangle GJBX-142(80) report. The water samples were then sent to other laboratories, including the Oak Ridge Gaseous Diffusion Plant, for "supplemental analyses" of 23 elements in sediments and 31 elements in waters. SRL did not release the supplemental analytical data as a separate report.

In 1982, SRL released a summary report and data files for 50 quadrangles in the Western United States. This report, GJBX-132(82), contains both the SRL analytical data and the supplemental analytical data from the Grand Canyon quadrangle but the concentration values often differ from those reported in the GJBX-142(80) quadrangle report. The introduction section of the GJBX-132(82) summary report states:

"The data in the present report may not be identical to those reported previously. This is due to the use of different "scrub" procedures for the preparation of the data for release. The differences should be minor."

However, during the reformatting process several major differences were discovered between the two data sets.

SRL analyses of light hydrocarbons (methane, ethane, propane, and butane) in ground waters were released in the GJBX-131(82) summary report for 44 western quadrangles and 3 eastern quadrangles within the United States. This report includes data for 82 of the Grand Canyon quadrangle ground water samples.

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.

The following is a general listing of all sample types collected and reported for NURE studies in the Grand Canyon quadrangle. The actual number of records in the NEW-FORMAT NURE data files may be greater because of the multiple records needed to preserve all the data.

Summary of Grand Canyon quadrangle sample types.
Sediment Sample Type Number of Samples Water Sample Type Number of Samples
Wet Streams 7 Streams 6
Dry Streams 70 Wells 40
Soils 922 Springs 50
Talus 11 Other 1
Other (may include mine tailings) 3
Total Sediments 1,013 Total Waters 97

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

Sediment Samples

Water Samples

Composition of the NEW-FORMAT NURE Data Files

The data in the NEW-FORMAT NURE data files consist of records from all of the above reports. In order to reduce the number of records, a decision was made to primarily use the data from the GJBX-132(82) western U.S. summary report. The rationale for choosing this data set was that (1) it represents a later compilation of the data and (2) it should be more consistent across quadrangle boundaries because of the common "scrubbing procedure." Every record was checked against the "equivalent" record in the earlier GJBX-142(80) quadrangle report and any major differences were noted in the REFORMAT comment field. These different but unused quadrangle report records were combined and saved as extra files which may be accessed below.

For the sediment data file, the SRL analyses and the supplemental analyses were combined into a single record for each sample. Unfortunately, in the water data file the SRL analyses and supplemental analyses could NOT be combined because of overlapping determinations for 5 elements. Each water sample may therefore have 2 separate records - one for the SRL analysis and one for the supplemental analysis.

During the reformatting process, several problems were discovered between the results reported in the GJBX-132(82) western U.S. summary report and the GJBX-142(80) quadrangle report.

These problems could not be satisfactorily resolved during the reformatting process. Note: the unused data from the GJBX-142(80) quadrangle report were saved as extra data files which may be accessed below.

Hydrocarbon data from the GJBX-131(82) report were added to fields in the appropriate ground water records and this addition was noted for each record in the REFORMAT comment field.

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.

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 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).

Grand Canyon Quadrangle Sediment Data - 1,013 records
Grand Canyon Quadrangle Water Data - 191 records
Under Construction Unused set of quadrangle sediment records - grdcansx.dbf.gz
Under Construction Unused set of quadrangle water records - grdcanwx.dbf.gz

Notes for Data Users

Many records contain analytical values with insignificant digits. Most data should only have 2 or 3 significant digits and differences after the second or third digit should be ignored.

Other NURE Geochemical Data for the Grand Canyon Quadrangle

A summary evaluation report was prepared for the Grand Canyon quadrangle by the Bendix Field Engineering Corporation of Grand Junction, Colorado [PGJ/F-020(82)]. Additional samples of 182 rocks and soils, and 92 waters were collected in the quadrangle to "identify environments and delineate areas favorable for the occurrence of uranium deposits." All samples were analyzed for uranium oxide by fluorometry, and 176 of the rock and soil samples were analyzed for 35 elements by emission spectrometry. The rock samples also underwent gamma spectrometry for eK, eU, and eTh. These data were released only as microfiche appendices accompanying the summary report.

Grand Canyon Quadrangle NURE Bibliography

Links Within Open-File Report 97-492

Back to Arizona NURE data
Back to Nevada NURE data
Back to Utah NURE data
Frequently Asked Questions Concerning NURE HSSR Data
Home Page: USGS National Geochemical Database - NURE HSSR data

Page written by Andrew W. Holt and Steven M. Smith
Contact: 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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