Francis J. Flanagan

1972 values for international geochemical reference samples

Abstract Best values for constituents determined in a rock analysis and for trace elements are collected for samples prepared by the Centre de Recherches Petrographiqueset Geochimiques, France, the Canadian Standard Reference Materials Project (formerly SSC), the Geological Survey of Japan, the National Institute for Metallurgy, South Africa, the U.S. Geological Survey and the Zentrales Geologisches Institut, D.D.R.

U.S. Geological Survey standards—II. First compilation of data for the new U.S.G.S. rocks☆

Abstract Rock analyses, determinations of major and minor constituents, and determinations of 57 trace elements reported by analysts throughout the world are presented for the new series of U.S. Geological Survey rock samples. Averages for both the constituents generally reported in a rock analysis and the trace elements are given. Variances of the distributions of data by rock analysts for several oxides in G-2 are compared with similar variances for G-l.

U.S. Geological Survey silicate rock standards

Abstract The U.S. Geological Survey has processed six silicate rocks to provide new reference samples to supplement G-1 and W-1. Complete conventional, rapid rock, and spectrochemical analyses by the U.S. Geological Survey are reported for a granite (replacement for G-1), a granodiorite, an andesite, a peridotite, a dunite, and a basalt. Analyses of variance for nickel, chromium, copper, and zirconium in each rock sample showed that for these elements, the rocks can be considered homogeneous. Spectrochemical estimates are given for the nickel, chromium, copper, and zirconium contents of the samples. The petrography of five of the six rocks is described and CIPW norms are presented.

X-Ray Fluorescence Analysis of the Light Elements in Rocks and Minerals

Recent advances in the x-ray fluorescence analysis of the light elements offer the advantage of speed and an accuracy approaching that of wet chemical procedures In addition to Fe, Mn, Ti, Ca, and K, the elements P, Si, Al, and Mg, previously considered too light to be determined quantitatively, can now be included in the scheme of analysis X-ray fluorescence analysis of these light elements is primarily confined to layers close to the surface, with the attendant problems of particle size, mineralogic history, and absorption differences owing to compositional variation among samples Fusion of the sample with a suitable flux eliminates problems of particle size and mineralogic differences Simple fusion, however, does not eliminate absorption differences due to variation in matrix By introducing into the fusion melt a strong absorber (La2O3) for the light elements, the variation in concentration of absorbing elements in the unknown sample will not materially affect the overall absorption of the fused mass for the elements being determined This permits the use of a single set of standards regardless of the rock type to be analyzed The x-ray fluorescence method has been applied to the analysis of a wide variety of rock types such as granite, diabase, dunite, limestone, dolomite, and phosphate rock, with results that compare favorably with chemical values

Reference samples for the earth sciences

Abstract A revised list of reference samples of interest to geoscientists has been extended to include samples for the agronomist, the archaeologist and the environmentalist. In addition to the source from which standard samples may be obtained, references or pertinent notes for some samples are included. The number of rock reference samples is now almost adequate, and the variety of ore samples will soon be sufficient. There are very few samples for microprobe work. Oil shales will become more important because of the outlook for world petroleum resources. The dryland equivalent of a submarine basalt might be useful in studies of sea-floor spreading and of the geochemistry of basalts. The Na- and K-feldspars of BCS (British Chemical Standards—Bureau of Analysed Samples), NBS (National Bureau of Standards), and ANRT (Association Kationale de la Recherche Technique) could serve as trace-element standards if such data were available. Similarly, the present NBS flint and plastic clays, as well as their predecessors, might be useful for archaeological pottery studies. The International Decade for Ocean Exploration may stimulate the preparation of ocean-water standards for trace elements or pollutants and a standard for manganese nodules.

Sources of geochemical standards—II

Abstract A revised and enlarged list of rock, mineral, ore, industrial product, counting, and isotopic standards of interest to those in geochemistry and geology is presented. Samples in process are also included. Sources from which the samples may be obtained are listed.

Semi-quantitative spectrographic analysis and rank correlation in geochemistry☆

Abstract The rank correlation coefficient, rs, which involves less computation than the product-moment correlation coefficient, r, can be used to indicate the degree of relationship between two elements. The method is applicable in situations where the assumptions underlying normal distribution correlation theory may not be satisfied. Semi-quantitative spectrographic analyses which are reported as grouped or partly ranked data can be used to calculate rank correlations between elements.