교육데이터 활용•지원 서비스

Selected archived sample splits collected as part of the National Uranium Resource Evaluation (NURE) Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) program, were reanalyzed by the U.S. Geological Survey (USGS) as part of a NURE-HSSR Reanalysis project (Smith and others, 2018). A small amount (approximately 0.25 grams [g]) of sieved less than 75-micron sample material was retrieved from the USGS National Geochemical Sample Archive for geochemical analysis. These samples were analyzed for 51 elements under a Technical Assistance Agreement with a third party by ALS Global laboratories using their ultra-trace four-acid-digestion dual-mode inductively coupled plasma-optical emission spectrometry/mass spectrometry (ICP-OES/MS) (ALS ME-MS61L) method (Ag, Al, As, Ba, Be, Bi, Ca, Cd, Ce, Co, Cr, Cs, Cu, Fe, Ga, Ge, In, K, La, Li, Mg, Mn, Mo, Na, Nb, Ni, P, Pb, Rb, Re, S, Sb, Sc, Se, Sn, Sr, Ta, Te, Th, Ti, Tl, U, V, W, Y, Zn, Hf_p, Zr_p, Au_sq, Pt_sq, Pd_sq). Blind standard reference materials (SRM), blanks, and sample duplicates were inserted by the USGS into every job of 36 samples to ensure the quality of the data. The results from these quality control (QC) samples, along with QC samples inserted by the laboratory, were evaluated for every job by a QC Manager. Only data that passed these checks were approved for release. Samples with analytical results that failed to pass the QC checks were reanalyzed and re-evaluated before the data were approved for release. The archived sample splits came from the NURE program, which began in 1973 with a primary goal of identifying uranium resources in the United States. As one of nine components of the NURE program, the HSSR project systematically sampled the United States between 1976 and 1980 under the direction of four U.S. Department of Energy (DOE) national laboratories. Although there was some collaboration, each DOE laboratory developed its own sample collection, analytical, and data management methodologies, and hired contractors to do much of the actual work. Initially, Lawrence Livermore Laboratory (LLL) was responsible for the western states of Arizona, California, Idaho, Nevada, Oregon, Utah, and Washington; Los Alamos Scientific Laboratory (LASL) was responsible for the Rocky Mountain States (Colorado, Montana, New Mexico, and Wyoming) as well as Alaska; the Oak Ridge Gaseous Diffusion Plant (ORGDP) was responsible for 12 central Plains and upper Great Lakes States; and Savannah River Laboratory (SRL) was responsible for the remaining 23 states along the Eastern Seaboard, lower Great Lakes, Appalachians, and Gulf Coast. However, by 1979 the areas of responsibility had changed from state lines to 2-degree quadrangle boundaries and SRL had taken over the responsibility for completing the seven western states formerly assigned to LLL. Thus, quadrangles in the western third of the U.S. were variously sampled and analyzed by LLL, LASL, and SRL. Due to the enormous number of samples collected by these laboratories, some were also sent to ORGDP for additional chemical analyses (Information Systems Programs, 1985; Smith, 1997). Geochemical samples were collected from multiple sources (78 percent stream-, 8 percent lake-, and 2 percent spring-sediments, and 12 percent soils). Analytical methods differed between laboratories and evolved over time so that 29 single- and multi-element analytical procedures, or variations thereof, were used during the project. The NURE-HSSR sediment and soil database compiled by Smith (1997) provides analytical results for 54 different elements (Ag, Al, As, Au, B, Ba, Be, Bi, Br, Ca, Cd, Ce, Cl, Co, Cr, Cs, Cu, Dy, Eu, F, Fe, Hf, Hg, K, La, Li, Lu, Mg, Mn, Mo, Na, Nb, Ni, P, Pb, Pt, Rb, Sb, Sc, Se, Sm, Sn, Sr, Ta, Tb, Th, Ti, U, V, W. Y, Yb, Zn, and Zr). However, no sample was analyzed for more than 46 elements, some were analyzed for uranium only, and a few samples were never analyzed at all. Funding cuts after 1980 curtailed the NURE-HSSR sampling