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LASL: San Juan Mountains Study Area
Geochemical samples were collected during May-July 1976 as part of the Los Alamos Scientific Laboratory (LASL) San Juan Mountains NURE Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) study. This rectangular study area encompassed parts of the Cortez, Durango, Moab, and Montrose quadrangles. A total of 1,982 sediment and 1,706 water samples were collected from 1,995 sites and analyzed for uranium. These data were published in the San Juan Mountains NURE HSSR study GJBX-22(77) report. The Durango quadrangle part of the San Juan Mountains study was the area between 37°N to 38°N latitude and 107°W to 108°W longitude and contained 929 sediment and 822 water samples.

LASL: Durango Quadrangle
The remainder of the Durango quadrangle was sampled during March-April and July 1976 (east of 107°W longitude). These additional 675 sediment and 696 water samples were also analyzed for uranium content. These sample data plus those from the Durango quadrangle part of the San Juan Mountains study were released as the Durango Quadrangle NURE Uranium HSSR study GJBX-10(79) report. In this quadrangle report the original San Juan Mountains study samples were given new ID numbers and in some records, errors were apparently corrected. All of these sediment samples were later reanalyzed by LASL for uranium and up to 42 additional elements and the data were released in the Durango Quadrangle NURE Multielement HSSR study GJBX-139(80) report.

LASL: Vallecito Creek Detailed Study
A follow-up, intermediate-density geochemical survey collected an additional 545 stream-sediment and 1,082 stream-water samples from 545 locations in the Vallecito Creek Detailed Study area of the Durango quadrangle during July-August 1979. The objective of this study was to evaluate the uranium potential of the Precambrian quartz-pebble conglomerates of the Needle Mountains, Colorado. The samples were analyzed for uranium content and up to 46 additional elements. The data from these detailed study samples were released in the Vallecito Creek Detailed Study GJBX-217(81) report.

Summary Tables
The following is a list of NURE sample types collected for all studies within the Durango quadrangle.

The Durango quadrangle samples were analyzed by one or more of the following methods:

Sediment Samples

• LA1: Los Alamos Delayed-Neutron Counting Analysis of sediments for U.
• LA2: Los Alamos Energy Dispersive X-Ray Fluorescence Analysis of sediments for Ag, Bi, Cd, Cu, Nb, Ni, Pb, Sn, and W. (Quadrangle Study samples only.)
• LA3: Los Alamos Energy Dispersive X-Ray Fluorescence Analysis of sediments for Ag, As, Bi, Cd, Cu, Nb, Ni, Pb, Se, Sn, W, and Zr. (Also includes Mo.) (Detailed Study samples only.)
• LA4: Los Alamos Arc-Source Emission Spectrography Analysis of sediments for Be and Li.
• LA5: Los Alamos Neutron Activation Analysis of sediments for Al, Au, Ba, Ca, Ce, Cl, Co, Cr, Cs, Dy, Eu, Fe, Hf, K, La, Lu, Mg, Mn, Na, Rb, Sb, Sc, Sm, Sr, Ta, Tb, Th, Ti, V, Yb, and Zn.

Water Samples

• LA6-DN: Los Alamos Delayed-Neutron Counting Analysis of waters for U.
• LA6-FL: Los Alamos Fluorometry Analysis of waters for U.

Discussion of the Reformatting Process for Durango Quadrangle

The Durango quadrangle sediment and water data consist of reformatted records from the Durango Quadrangle NURE Multielement HSSR study GJBX-139(80) report combined with records from the Durango Quadrangle NURE Uranium HSSR study GJBX-10(79) and the San Juan Mountains NURE HSSR study GJBX-22(77) reports plus reformatted records from the Vallecito Creek Detailed Study GJBX-217(81) report. The following problems were found and addressed during the comparison and reformatting stages for the Durango quadrangle data:

1. During the NURE sample collection phase, LASL sites and samples were initially assigned a 6-digit integer Identification Number (LASLID) starting with 000001. After 1977, most LASL sites were reassigned a new 1-letter+5-digit Identification Number starting with A00001. All LASL samples and the early LASL reports use the 6-digit integer LASLID. Most of the later reports only use the 1-letter+5-digit LASLID. Although both sets of numbers were usually assigned sequentially, they do not correspond one to one with each other: 100001 does not equal C00001, etc. Whenever possible, the 1-letter+5-digit LASL Identification Number was saved in the LASLID field. When the corresponding 6-digit site number could be determined from sample number translation key lists or other sources, this Identification Number was saved in the SITE field.
2. The correlation of the two LASL Identification Numbers for samples in the Durango quadrangle was first solved by comparing records from the San Juan Mountains NURE HSSR study GJBX-22(77) report with those from the Durango Quadrangle NURE Uranium HSSR study GJBX-10(79) report. Later a LASL Identification Number translation key was found for the Durango quadrangle sediment samples and the values were confirmed. Additional 1-letter+5-digit LASL Identification Number values were found int the translation key for the 675 sediment samples collected in the quadrangle after the San Juan Mountains NURE HSSR study. The 1-letter+5-digit LASL Identification Number was saved in the LASLID field and the corresponding 6-digit site number was manually added to the SITE field. Therefore, the LASLID field contains the Identification Number found in the Durango Quadrangle NURE Uranium HSSR study GJBX-10(79) and Durango Quadrangle NURE Multielement HSSR study GJBX-139(80) reports. The SITE field contains the corresponding LASL Identification Number used to label the original field maps, field notes, and sample containers and reported in the San Juan Mountains NURE HSSR study GJBX-22(77) report.
3. No LASL Identification Number translation key was found for the Vallecito Creek Detailed Study sediment samples. The 6-digit LASL Identification Number found in LASLID was also added to the SITE field. Therefore, the value found in the LASLID and SITE fields is same LASL Identification Number used to label the original field maps, field notes, and sample containers as well as the value published in the Vallecito Creek Detailed Study GJBX-217(81) report.
4. Corresponding records for 929 sediment samples were found in the San Juan Mountains NURE HSSR study GJBX-22(77), Durango Quadrangle NURE Uranium HSSR study GJBX-10(79), and Durango Quadrangle NURE Multielement HSSR study GJBX-139(80) reports. Each set of 3 corresponding records were compared and combined into a single composite record.
5. Additional corresponding records for 675 sediment samples were found in the Durango Quadrangle NURE Uranium HSSR study GJBX-10(79) and Durango Quadrangle NURE Multielement HSSR study GJBX-139(80) reports. Each set of 2 corresponding records were compared and combined into a single composite record.
6. When combining corresponding sediment records from the San Juan Mountains NURE HSSR study GJBX-22(77), Durango Quadrangle NURE Uranium HSSR study GJBX-10(79), and Durango Quadrangle NURE Multielement HSSR study GJBX-139(80) reports, some differences between corresponding records were found in the relief(RELIEF), sample collection hour(SAMPHR), scintillometer reading(SCIN), rock color(ROCLCLR), or rock type(ROCKTYP) fields. These differences appear to be due to corrections added to the later Durango Quadrangle NURE Uranium HSSR study GJBX-10(79) and Durango Quadrangle NURE Multielement HSSR study GJBX-139(80) reports. Therefore when differences were found, the value from the Durango Quadrangle NURE Multielement HSSR study GJBX-139(80) report was retained in the field and the differing value from the earlier reports was added as a comment to the REFORMAT field. However, when values for these fields were missing in records from the Durango Quadrangle study but present in records from the San Juan Mountains study, the San Juan Mountains study values were added to the combined record. These changes were also noted in the REFORMAT comment fields.
7. When combining corresponding sediment records from the San Juan Mountains NURE HSSR study GJBX-22(77), Durango Quadrangle NURE Uranium HSSR study GJBX-10(79), and Durango Quadrangle NURE Multielement HSSR study GJBX-139(80) reports, differences in latitude(LAT) and longitude(LONG) coordinates were found for 644 sediment samples. These differences appear to be due to corrections added to the later Durango Quadrangle NURE Uranium HSSR study GJBX-10(79) and Durango Quadrangle NURE Multielement HSSR study GJBX-139(80) reports. Therefore when differences were found, the coordinate values from the Durango Quadrangle NURE Multielement HSSR study GJBX-139(80) report was retained in the fields and the differing values from the earlier reports were added as a comment to the COORDPRB field.
8. When combining corresponding sediment records from the San Juan Mountains NURE HSSR study GJBX-22(77), Durango Quadrangle NURE Uranium HSSR study GJBX-10(79), and Durango Quadrangle NURE Multielement HSSR study GJBX-139(80) reports, it was found that the reported concentrations of uranium were often slightly different. Rather than discarding one of the values in the combined records, the concentration of uranium (analyzed by delayed neutron activation analysis) from the San Juan Mountains NURE HSSR study GJBX-22(77) report was added to the extra uranium field (U_XX_PPM).
9. An unlikely sample collection date was found for one sample. This date was removed from the SAMPDAT field and the original SAMPDAT value with the most likely correct value was added as a comment to the REFORMAT field.
10. Eight stream-sediment samples in this quadrangle share the same latitude-longitude coordinates with one other sample (4 distinct coordinate sites). It is unclear whether this represents sets of samples collected at the same four sites or single samples collected at separate sites so close together that the coordinate precision was insufficient to distinguish locations.
11. During the process of reformatting the Vallecito Creek Detailed Study sediment samples, handwritten comments from the field notes were added to the COMMENTS field for each record.

1. The correlation of the two LASL Identification Numbers for samples in the Durango quadrangle was first solved by comparing records from the San Juan Mountains NURE HSSR study GJBX-22(77) report with those from the Durango Quadrangle NURE Uranium HSSR study GJBX-10(79) report. Later a LASL Identification Number translation key was found for the Durango quadrangle water samples and the values were confirmed. Additional 1-letter+5-digit LASL Identification Number values were found int the translation key for the 696 water samples collected in the quadrangle after the San Juan Mountains NURE HSSR study. The 1-letter+5-digit LASL Identification Number was saved in the LASLID field and the corresponding 6-digit site number was manually added to the SITE field. Therefore, the LASLID field contains the Identification Number found in the Durango Quadrangle NURE Uranium HSSR study GJBX-10(79) and Durango Quadrangle NURE Multielement HSSR study GJBX-139(80) reports. The SITE field contains the corresponding LASL Identification Number used to label the original field maps, field notes, and sample containers and reported in the San Juan Mountains NURE HSSR study GJBX-22(77) report.
2. No LASL Identification Number translation key was found for the Vallecito Creek Detailed Study water samples. The 6-digit LASL Identification Number found in LASLID was also added to the SITE field. Therefore, the value found in the LASLID and SITE fields is same LASL Identification Number used to label the original field maps, field notes, and sample containers as well as the value published in the Vallecito Creek Detailed Study GJBX-217(81) report.
3. Corresponding records for 822 water samples were found in the San Juan Mountains NURE HSSR study GJBX-22(77), Durango Quadrangle NURE Uranium HSSR study GJBX-10(79), and Durango Quadrangle NURE Multielement HSSR study GJBX-139(80) reports. Each set of 3 corresponding records were compared and combined into a single composite record.
4. Additional corresponding records for 696 water samples were found in the Durango Quadrangle NURE Uranium HSSR study GJBX-10(79) and Durango Quadrangle NURE Multielement HSSR study GJBX-139(80) reports. Each set of 2 corresponding records were compared and combined into a single composite record.
5. When combining corresponding water records from the San Juan Mountains NURE HSSR study GJBX-22(77), Durango Quadrangle NURE Uranium HSSR study GJBX-10(79), and Durango Quadrangle NURE Multielement HSSR study GJBX-139(80) reports, some differences between corresponding records were found in the relief(RELIEF), sample collection hour(SAMPHR), and scintillometer reading(SCIN), rock color(ROCKCLR), or rock type(ROCKTYP) fields. These differences appear to be due to corrections added to the later Durango Quadrangle NURE Uranium HSSR study GJBX-10(79) and Durango Quadrangle NURE Multielement HSSR study GJBX-139(80) reports. Therefore when differences were found, the value from the Durango Quadrangle NURE Multielement HSSR study GJBX-139(80) report was retained in the field and the differing value from the earlier reports was added as a comment to the REFORMAT field. However, when values for these fields were missing in records from the Durango Quadrangle study but present in records from the San Juan Mountains study, the San Juan Mountains study values were added to the combined record. These changes were also noted in the REFORMAT comment fields.
6. When combining corresponding water records from the San Juan Mountains NURE HSSR study GJBX-22(77), Durango Quadrangle NURE Uranium HSSR study GJBX-10(79), and Durango Quadrangle NURE Multielement HSSR study GJBX-139(80) reports, differences in latitude(LAT) and longitude(LONG) coordinates were found for 573 water samples. These differences appear to be due to corrections added to the later Durango Quadrangle NURE Uranium HSSR study GJBX-10(79) and Durango Quadrangle NURE Multielement HSSR study GJBX-139(80) reports. Therefore when differences were found, the coordinate values from the Durango Quadrangle NURE Multielement HSSR study GJBX-139(80) report was retained in the fields and the differing values from the earlier reports were added as a comment to the COORDPRB field.
7. Unlikely sample collection dates were found for three 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.
8. Eight stream-water samples in this quadrangle share the same latitude-longitude coordinates with one other sample (4 distinct coordinate sites). It is unclear whether this represents sets of samples collected at the same four sites or single samples collected at separate sites so close together that the coordinate precision was insufficient to distinguish locations.
9. During the process of reformatting the Vallecito Creek Detailed Study sediment samples, handwritten comments from the field notes were added to the COMMENTS field for each record.

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).

Durango Quadrangle Sediment Data - 2,149 records
Durango Quadrangle Water Data - 2,600 records

Notes for Data Users

The water samples from the Vallecito Creek Detailed Study were collected by 2 different methods, with respect to filtering and acidification. (See the SAMPTYP coding explanation in the On-Line Manual for USGS-Reformatted NURE HSSR Data Files for descriptions of different Sample Types). Analytical data may not be directly comparable for water samples collected by different methods.

Other NURE Geochemical Data for the Durango Quadrangle

Durango Quadrangle NURE Summary
A summary evaluation report was prepared for the Durango quadrangle by the Bendix Field Engineering Corp. [GJQ-011(81)]. As part of the evaluation, an additional 156 rock, 118 stream-sediment, 73 stream water, 239 well water, 7 spring water, 1 lake water, 54 mine water, and 1 drill hole water samples were collected from selected areas of the quadrangle. The analytical data for these samples were released only as appendices on microfiche accompanying the summary report.

Needle Mountains Precambrian Pebble Conglomerate Study
Colorado State University conducted a study of the Vallecito Conglomerate in the Needle Mountains of southwestern Colorado to evaluate the uranium potential of a possible uraniferous Precambrian pebble conglomerate [GJBX-118(80)]. During this study, 502 rock samples were collected and analyzed. A partial data listing for these rock samples is available as an appendix to the report.

Uranium Resource Assessment Using Statistical Analysis of Durango, Montrose, Pueblo, and Trinidad Quadrangles Data
The University of Georgia, under subcontract to Bendix Field Engineering Corp., evaluated the Durango, Montrose, Pueblo, and Trinidad quadrangles to "develop a practical system for quantitatively assessing the uranium resources in individual quadrangles based upon the HSSR data and tonnage/grade data for occurrences." No additional geochemical data accompany this statistical analysis GJBX-140(81) report.

Vallecito Creek Detailed Study
The Vallecito Creek Detailed Study also had some additional digital site data that was not incorporated into the USGS-Reformatted NURE data files. These additional data describe the proximity of geologic rock units and faults within the vicinity of sampled sites. The data were saved as a separate file with its own format. This partially reformatted data file is available by request from Steven M. Smith (smsmith@usgs.gov).

Durango Quadrangle NURE Bibliography

• Burns, L.K., Ethridge, F.G., Tyler, N., Gross, A.S., and Campo, A.M., 1980, Geology and uranium evaluation of the Precambrian quartz-pebble conglomerates of the Needle Mountains, Southwest Colorado; final report: U.S. Department of Energy, Grand Junction, Colo., GJBX-118(80), 161 p.
• Dawson, H.E., and Weaver, T.A., 1979, Uranium hydrogeochemical and stream sediment reconnaissance of the Durango NTMS quadrangle, Colorado: Los Alamos Scientific Laboratory informal report LA-7346-MS, Los Alamos, N.M., U.S. Department of Energy, Grand Junction, Colo., GJBX-10(79), 111 p.
• Koch, G.S., Jr., Howarth, R.J., and Schuenemeyer, J.H., 1981, Uranium resource assessment through statistical analysis of exploration, geochemical, and other data; final report: U.S. Department of Energy, Grand Junction, Colo., GJBX-140(81), 145 p.
• Maxwell, J.C., 1977, Uranium hydrogeochemical and stream sediment reconnaissance in the San Juan Mountains, southwestern Colorado: Los Alamos Scientific Laboratory informal report LA-6651-MS, Los Alamos, N.M., U.S. Department of Energy, Grand Junction, Colo., GJBX-22(77), 104 p.
• Shannon, S.S., Jr., 1980, Uranium hydrogeochemical and stream sediment reconnaissance of the Durango NTMS quadrangle, Colorado, including concentrations of forty-two additional elements: Los Alamos Scientific Laboratory informal report LA-7346-MS Supplement, Los Alamos, N.M., U.S. Department of Energy, Grand Junction, Colo., GJBX-139(80), 147 p.
• Theis, N.J., Madson, M.E., Rosenlund, G.C., Reinhart, W.R., and Gardner, H.A., 1981, National Uranium Resource Evaluation, Durango quadrangle, Colorado: Bendix Field Engineering Corporation, U.S. Department of Energy, Grand Junction, Colo., GJQ-011(81), 48 p.
• Warren, R.G., Gallimore, D.L., Martell, C.J., Sandoval, W.F., Garcia, S.R., Minor, M.M., and McInteer, Carlotta, 1981, Data release for intermediate-density hydrogeochemical and stream sediment sampling in the Vallecito Creek Special Study Area, Colorado, including concentrations of uranium and forty-six additional elements: Los Alamos Scientific Laboratory informal report LA-8483-MS, Los Alamos, N.M., U.S. Department of Energy, Grand Junction, Colo., GJBX-217(81), 101 p.

Links Within Open-File Report 97-492

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

Page written by Steven M. Smith (smsmith@usgs.gov)
Version 1.10: July 29, 1999
Version 1.20: August 07, 2000
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