OFR 97-492: Salton Sea Quadrangle NURE HSSR Study

  About USGS /  Science Topics /  Maps, Products & Publications /  Education / Publication: FAQ

 

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 1,984 sediment samples (at 994 locations) and 79 water samples were collected in the Salton Sea quadrangle (except for areas within the Joshua Tree National Monument, the Colorado River Indian Reservation, and several military sites) during March and April of 1979 as part of the Savannah River Laboratory (SRL) Salton Sea 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 Salton Sea NURE HSSR quadrangle GJBX-217(80) abbreviated report. The 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. The supplemental analytical data were released by SRL in the Salton Sea quadrangle GJBX-113(80) supplemental data report. Two sediment fractions were collected at 990 of the sediment sampling locations; the S1 fraction (<100 mesh) and the S0 fraction (>100 mesh and <18 mesh). The second fraction was presumably collected to avoid windblown dust contamination.

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 Salton Sea quadrangle but the concentration values often differ from those reported in the GJBX-217(80) and GJBX-113(80) quadrangle reports. 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 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 68 of the Salton Sea 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 list of all sample types collected and reported for the NURE studies in the Salton Sea 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 Salton Sea quadrangle sample types.
Sediment Sample Type Number of Samples Water Sample Type Number of Samples
Dry Streams (S1 fraction) 123 Wells 68
Dry Streams (S0 fraction) 125 Springs 10
Soils (S1 fraction) 796 Other 1
Soils (S0 fraction) 792
Talus (S1 fraction) 70
Talus (S0 fraction) 69
Playa (S1 fraction) 1
Playa (S0 fraction) 1
Volcanic Neck (S1 fraction) 1
Volcanic Neck (S0 fraction) 1
Other (may include mine tailings - S1 fraction) 3
Other (may include mine tailings - S0 fraction) 2
Total Sediments 1,984 Total Waters 79

These Salton Sea 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-217(80) and GJBX-113(80) quadrangle reports 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.

In the sediment data file, the SRL analyses and the supplemental analyses were combined into a single record for each sample. Occasionally, an extra supplemental analysis record exists for some sediment samples. These sediment samples will then have 2 separate records - one record containing the SRL analysis and one set of supplemental analysis data, and one record containing the extra supplemental analysis data. The supplemental data reported in the GJBX-113(80) report included values for Th by an undocumented method. These extra Th values were NOT retained in the sediment data file TH_PPM field. Instead, the unused Th values were added as a comment in the REFORMAT comment field.

During the reformatting process, several problems were discovered between the sediment results reported in the GJBX-132(82) western U.S. summary report and the GJBX-217(80) quadrangle report.

  1. For many samples, the concentration values given for Ag, Ba, Be, Ca, Co, Cu, K, Li, Mg, Ni, Pb, Sn, Sr, and Zn in the western summary report are switched with respect to the ID-suffix tag when compared to the values given in the quadrangle report (i.e. the concentration values for an element in the S1 and S0 fraction samples from the western report corresponds with the concentration values given for that element in the S0 and S1 samples, respectively, in the quadrangle report). From the information available, it could not be determined which report was in error.
  2. For 2 samples, SSAD006 AND SSAE037, the values given for U_XX, Ag, As, Au, Ba, Be, Ca, Co, Cr, Cu, K, Li, Mg, Mo, Nb, Ni, P, Pb, Se, Sn, Sr, Y, and Zn in the western summary report are switched with respect to the ID-suffix tag when compared to the values given in the quadrangle report. (i.e. the concentration value assigned to the sample with an S0 fraction in the western report is found in the sample with an S1 fraction in the quadrangle report).
  3. Many of the values for Ag, Ba, Be, Ca, Co, Cu, K, Li, Mg, Ni, Pb, Sn, Sr, and Zn in the quadrangle report are the identical in both the S0 and S1 fraction records. This suggests that some data were duplicated and other data may be missing.
  4. Most of the values for Ce, Eu, Fe, Hf, La, Lu, Sc, Sm, Th, and Yb were missing in the western summary report. Because of the uncertainty associated with the switching problems noted above, the missing values were NOT added to the sediment file from the quadrangle report.

The problems noted here could not be satisfactorily resolved during the reformatting process. Note: the unused data from the GJBX-217(80) quadrangle report were saved as extra data files which may be accessed below.

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 water results reported in the GJBX-132(82) western U.S. summary report and the GJBX-217(80) quadrangle report.

  1. For most samples, the values given for U and V in the quadrangle report are double the values given in the western summary report. For the remainder of the U and V values, the value in the quadrangle report appears to be double the rounded value from the western summary report.
  2. For most samples, the values given for Br, Cl, F, Mg, Mn, and Na in the quadrangle report are double the values given in the western summary report.
  3. Most of the Al and Dy values were missing in the western summary report. The missing values were NOT added to the water file from the quadrangle report.
  4. Some of the values for Al in the western summary report are 10 times the value in the quadrangle report.

These problems could not be satisfactorily resolved during the reformatting process. Note: the unused data from the GJBX-217(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).

Salton Sea Quadrangle Sediment Data - 2,022 records
Salton Sea Quadrangle Water Data - 154 records
Under Construction Unused set of quadrangle sediment records - saltonsx.dbf.gz
Under Construction Unused set of quadrangle water records - saltonwx.dbf.gz



Notes for Data Users

SRL collected separate samples for two fractions at 990 of the sediment sampling locations. Samples with a suffix of "S0" on the SRLID consist of the fraction of sediment which passed a 18-mesh but did not pass a 100-mesh sieve. Samples with a suffix of "S1" on the SRLID consist of the fraction of sediment which passed a 100-mesh sieve. Due to fractionation of some elements between discretely sized sediment particles, analytical data may not be directly comparable for sediment samples with different sieve fractions.

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.

Many problems were discovered with the data from the Salton Sea quadrangle and have been identified above. Since there was no way to determine which of the data files contained the correct values, these problems could not be satisfactorily resolved. There may also be other problems that exist that have not been identified. The Salton Sea quadrangle data should therefore be used with caution.



Other NURE Geochemical Data for the Salton Sea Quadrangle

A report on the geology and mineral resources of the Salton Sea quadrangle prepared for the Savannah River Laboratory can be found in the GJBX-213(82) report. No geochemistry accompanies this report.

As noted above, many values for some elements were missing from the Salton Sea data files. These values have not been added to the data files at this time. This data can be found on the microfiche accompanying the GJBX-132(82) western U.S. summary report, and the GJBX-217(80) and GJBX-113(80) Salton Sea quadrangle reports.



Salton Sea Quadrangle NURE Bibliography



Links Within Open-File Report 97-492

Back to California NURE data
Back to Arizona 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

USA.gov logo