OFR 97-492: Del Rio 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.]

ORGDP: Texas Wide-Spaced Uranium Geochemical Survey
Early in the NURE Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) program, personnel from the Oak Ridge Gaseous Diffusion Plant (ORGDP) sampled several areas with a wide-spaced sample coverage (Phase I sampling). Phase I samples were generally collected in stream basins averaging 250 square kilometers in area and from wells at about a 16 km spacing. The purpose of the Phase I sampling was to define uranium provinces that warranted additional sampling at a higher density (Phase II sampling). These samples were sent to the ORGDP and analyzed for uranium and other elements. For many 1:250,000-scale 2-degree quadrangles, Phase I samples were included with later Phase II samples and utilized in the individual HSSR basic data quadrangle reports. Some Phase I samples were never utilized in basic data quadrangle reporting. ORGDP issued the Hydrogeochemical and Stream Sediment Wide-Spaced Sample Basic Data Release for Texas GJBX-131(81) report for several of these Phase I samples. This report includes data for 261 stream sediment and 406 water samples collected during 1976-77 in the Abilene, Austin, Brownwood, Corpus Christi, Del Rio, Eagle Pass, Houston, Llano, San Angelo, Sonora, and Waco quadrangles. The Wide-Spaced Sample Basic Data Release for Texas GJBX-131(81) report only contains data tables for Phase I samples; no explanatory text accompanies this report. The Wide-Spaced Sample Basic Data Release for Texas GJBX-131(81) report includes data records for 1 stream-sediment sample and 1 stream-water sample collected within the borders of the Del Rio quadrangle. ORGDP apparently did not collect any Phase II samples in the Del Rio quadrangle by the time that NURE funding ended in the early 1980's. Therefore no specific NURE HSSR study exists for this quadrangle.

ORGDP: Trans-Pecos Detailed Geochemical Survey
As part of the NURE program, detailed surveys were initiated to supply comprehensive geochemical data from specific target areas. The Trans-Pecos Detailed Study was designed to characterize the hydrogeochemistry, stream sediment geochemistry and radiometric patterns of known or potential uranium occurrences in southwest Texas. The Oak Ridge Gaseous Diffusion Plant (ORGDP) collected 1,434 stream sediment, 14 soil, 509 rock, and 595 ground water samples from 7 project areas within the Del Rio, Emory Peak, Fort Stockton, Marfa, Presidio, and Sonora quadrangles. These samples were analyzed by the ORGDP for uranium and other elements. During sample collection, radiometric readings for eU, eK, and eTh were obtained in the field at several locations. (Almost all of the rock and soil samples as well as a few stream sediment samples appear to be sites where only radiometric readings were taken.) In selected Survey Areas, ORGDP used portable field methods to determine concentrations of uranium, fluorine, sulfate, and total iron in water. In the interpretations and Detailed Study reports, ORGDP also included data from 541 stream sediment and 248 ground water samples collected during earlier Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) studies in the Emory Peak and Presidio quadrangles. The analytical data were released in seven parts as the Hydrogeochemical and Stream Sediment Detailed Geochemical Survey for Trans-Pecos, Texas report.

  1. Terrell Survey Area GJBX-29(80)-Part 1: 62 stream sediments and 4 ground waters plus 13 rocks or radiometric readings were collected during January of 1979 within the Del Rio, Emory Peak, Fort Stockton, and Sonora quadrangles. Additional data for 99 stream-sediment and 32 ground-water samples from the Emory Peak Quadrangle NURE HSSR study were included.
  2. Solitario Survey Area GJBX-29(80)-Part 2: 165 stream sediments, 1 soil, and 12 ground waters plus 57 rock or radiometric readings and 5 field analyses of water were collected during January of 1979 within the Emory Peak and Presidio quadrangles. Additional data for 355 stream-sediment and 115 ground-water samples from the Emory Peak quadrangle and Presidio quadrangle NURE HSSR studies were included.
  3. Sierra Vieja Survey Area GJBX-29(80)-Part 3: 246 stream sediments and 60 ground waters plus 64 rocks or radiometric readings and 30 field analyses of water were collected between February and March of 1979 within the Marfa quadrangle.
  4. Tascotal Survey Area GJBX-29(80)-Part 4: 533 stream sediments, 11 soils, and 451 ground waters plus 143 rocks or radiometric readings and 220 field analyses of water were collected between March and April of 1979 within the Emory Peak, Fort Stockton, Marfa, and Presidio quadrangles. Additional data for 87 stream-sediment and 101 ground-water samples from the Emory Peak quadrangle and Presidio quadrangle NURE HSSR studies were included.
  5. Chinati Mountains Survey Area GJBX-29(80)-Part 5: 122 stream sediments and 24 ground waters plus 78 rocks or radiometric readings were collected between January and February of 1980 within the Marfa and Presidio quadrangles.
  6. Stillwell Mountains Survey Area GJBX-29(80)-Part 6: 228 stream sediments, 2 soils, and 10 ground waters plus 142 rocks or radiometric readings were collected between January and February of 1980 within the Emory Peak quadrangle.
  7. Dryden Survey Area GJBX-29(80)-Part 7: 78 stream sediments and 34 ground waters plus 12 rocks or radiometric readings were collected during February of 1980 within the Del Rio, Emory Peak, Fort Stockton, and Sonora quadrangles.

Within the Del Rio quadrangle, the Trans-Pecos Detailed studies include:

Texas Gulf Coast Detailed Geochemical Survey
Between May and June of 1979, ORGDP conducted a detailed study along the outcrop of Lower Tertiary sediments of the Wilcox and Claiborne Groups in the Texas Gulf Coast area. A total of 125 stream-sediment samples and 821 ground-water samples were collected from the San Antonio, Seguin, Crystal City, and Del Rio quadrangles by ORGDP personnel. Of these samples, only 1 well-water sample was collected within the Del Rio quadrangle. ORGDP analyzed these samples for uranium and several additional elements. Some ground-water samples were also shipped to Furman University, Greenville, S.C. for helium and neon analyses. The analytical data were released with the Texas Gulf Coast Detailed Study GJBX-34(80) report.

Summary Tables
The following is a list of NURE sample types collected in the Del Rio quadrangle.

Summary of Del Rio quadrangle sample types.
Sediment Sample Type Number of Samples Water Sample Type Number of Samples
Wet Streams 2 Streams 1
Dry Streams 8 Wells 5
Total Sediments 10 Total Waters 6

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

Sediment Samples

Water Samples



Discussion of the Reformatting Process for Del Rio Quadrangle

Sediment Records
The Del Rio quadrangle sediment data consist of reformatted records from the Wide-Spaced Sample Basic Data Release for Texas GJBX-131(81) report plus reformatted records from the Trans-Pecos Detailed Study's Terrell Survey Area GJBX-29(80)-Part 1 report. No problems were found during the reformatting stages for the Del Rio quadrangle sediment data.

Water Records
The Del Rio quadrangle water data consist of reformatted records from the Wide-Spaced Sample Basic Data Release for Texas GJBX-131(81) report, reformatted records from the Trans-Pecos Detailed Study's Terrell Survey Area GJBX-29(80)-Part 1 report, plus reformatted records from the Texas Gulf Coast Detailed Study GJBX-34(80) report. The following problems were found and addressed during the comparison and reformatting stages for the Del Rio quadrangle water data:

  1. Three records for Terrell Survey Area water samples collected in the Del Rio quadrangle were found in the digital data file but were not listed in the Trans-Pecos Detailed Study Terrell Survey Area GJBX-29(80)-Part 1 report. A comment in the REFORMAT field identifies these records.
  2. The record for the one well-water sample collected in Del Rio quadrangle for the Texas Gulf Coast Detailed Study GJBX-34(80) report was also found in the digital data from the Trans-Pecos Detailed Study Terrell Survey Area GJBX-29(80)-Part 1 report. This pair of records were compared and combined into a single record.
  3. Four separate water samples in this quadrangle have the same two SITE values but have slightly differing latitude-longitude coordinates. It is unclear whether this represents two pairs of samples collected at the same sites with small precision errors in the coordinates or if these samples were actually collected at separate sites very close to each other.
  4. Partial data from 4 water records found only in the tables on microfiche accompanying the Trans-Pecos Detailed Study Solitario Survey Area GJBX-29(80)-Part 2 report were added to the digital data file during the reformatting process. A comment in the REFORMAT field identifies these records.
  5. Partial data from 1 water record found only in the tables on microfiche accompanying the Trans-Pecos Detailed Study Tascotal Survey Area GJBX-29(80)-Part 4 report was added to the digital data file during the reformatting process. A comment in the REFORMAT field identifies this record.
  6. A total of 256 water records were found in the digital data file that were not listed in any of the Trans-Pecos Detailed Study reports. A comment in the REFORMAT field identifies each of these records.
  7. Data from the analysis of water samples for helium and neon were saved as an extra data file accessible below. (The Texas Gulf Coast Helium/Neon data format is explained later in this document.)


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).

Del Rio Quadrangle Sediment Data - 10 records
Del Rio Quadrangle Water Data - 6 records



Notes for Data Users

Except for two water samples that were acidified in the field (SAMPTYP 08), most of the ORGDP water samples were reportedly collected in the field without any filtering or acidification. (See the SAMPTYP coding explanation in the On-Line Manual for USGS-Reformatted NURE HSSR Data Files for descriptions of different Sample Types). However, the samples were filtered later in the laboratory through a 0.45 micron membrane filter before analysis. Therefore, the samples were not true "untreated water" samples and the analytical data may not be directly comparable for other quadrangle water samples of the same SAMPTYP when collected by a different laboratory. Since this was the standard procedure for Oak Ridge, water data from other Oak Ridge quadrangles should be comparable.

Latitude-longitude coordinates were reported in the original data files, as decimal degrees, to only 3 decimal places. Therefore, the precision of these coordinates is limited to +/- 0.001 degrees or +/- 3.6 seconds. This translates to a minimum precision of +/- 363 feet (111 m) for latitude values and between +/- 343 feet (101 m) to +/- 331 feet (97 m) for longitude values (calculated at latitudes of 25° and 30°N, respectively.)



Other NURE Geochemical Data for the Del Rio Quadrangle

None found.



Del Rio Quadrangle NURE Bibliography



Links Within Open-File Report 97-492

Back to Texas NURE data
Frequently Asked Questions Concerning NURE HSSR 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 1.20: August 07, 2000
Version 1.30: September 11, 2001
Version 1.41: February 23, 2006

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