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Geochemical analyses of samples of rock, stream-sediment, and panned heavy-mineral concentrate, Hoover Wilderness and adjacent study areas, California

1980; United States Department of the Interior; Linguagem: Inglês

10.3133/ofr8079

2332-4899

M.A. Chaffee, C.A. Bannister, Justin Bernard, J.R. Giusso, R. H. Hill, William J. Keith, J.F. Seitz, Wendy S. Speckman, S.J. Sutley,

Heavy metals in environment

All three types of samples were analyzed for Fe, Mg, Ca, Ti, Mn, Ag, As, Au, B, Ba, Be, Bi, Cd, Co, Cr, Cu, La, Mo, Nb, Ni , Pb, Sc, Sn, Sr, V, W, Y, Zn, Zr, and Th using a six-step semiquantitative emission soectroaraohic method (Grimes and Marranzino, 1968).Because of matrix interference problems, the technique has been modified for the panned heavy-mineral concentrates.As a result the lower limits of detection for this type of sample are all raised two reporting values above the normal lower limit value (table 1).The rock and stream-sediment samples were also analyzed for As usinn a colorimetric method (Ward, Lakin Canney, and others, 1963), for Zn by atomic-absorption spectrometry (Ward and others, 1969), for Sb by atomic-absorption spectrometry (Welsch and Chao, 1975), and for Cd and Bi by a single digestion atomicabsorption spectrometric technique (Viets, 1978).Because of a limited amount of sample material, the panned heavy-mineral concentrates were only analyzed spectrographically.Analysis for all three sample types was done partly in the field and partly in U.S. Geological Survey laboratories in Denver.Because they were not detected in the spectrographic analyses for the rock samples (table 2), the elements As, Au, and Cd have been deleted as have the elements As, Au, Cd, and Sn from the stream-sediment samples (table 3).Because of the formatting used in the computer program that produced tables 2 through 4, some of the elements listed in these tables (Fe, Mq, Ca, Ti, Be, AA-Cd, and AA-Bi) carry one or more nonsignificant digits to the right of the significant digits.The analysts did'not determine these elements to the accuracy suggested by the'nonsignificant digits. 1 .00 1 .50 .30 .50 1 .00 .