Determination of Fluorine, Chlorine and Water in Eight USGS Reference Samples

Eight reference samples from the U.S. Geological Survey have been analysed for their contents of F, Cl and water. After pyrolysis F was determined with an ion-selective electrode, Cl by colorimetry and water by Karl-Fischer titration.     

USGS Reference Samples Attapulgite ATT-1 and Bentonite CSB-1

The U.S. Geological Survey has prepared an attapulgite and a bentonite as reference samples because of their economic importance. The attapulgite (ATT-1) is from the Meigs-Attapulgite-Quincy fuller's earth district of Georgia and Florida, and the bentonite (CSB-1) is from the Northern Black Hills bentonite district of Wyoming, Montana, and South Dakota. The chemical and mineralogical properties of these two samples are quite different. Provisional values calculated from the few analytical data and the X-ray diffraction mineralogy are presented for those who wish to use the clays as reference samples.     

Flameless Atomic Absorption Determination of Platinum, Palladium, and Rhodium in Geologic Materials

Platinum, palladium and rhodium have been determined in 18 U.S. Geological Survey reference materials by graphite furnace atomic absorption spectrometry after preconcentration by the classical leadfree assay technique. A comparison with literature values shows clearly the need for additional data on these samples before "best" values can be assigned.     

Some Trace-Element Contents of Biotite, Btt-1, and Hornblende, Hbl-I, by Semiquantitative Spectrographic Analysis and by Instrumental Neutron Activation Analysis

Some trace-element contents of U.S. Geological Survey (USGS) samples, biotite Btt-1 and hornblende Hbl-1, were determined by both computerized semi-quantitative spectrographic analysis and instrumental neutron activation analysis. An equal number of portions of the Centre de Recherches Pétrographiques et Géochimiques (CRPG) samples, biotite Mica-Fe and phlogopite Mica-Mg, were randomized with portions of the USGS samples and analyzed simultaneously to allow direct comparisons of trace elements in the biotites. Mica-Fe has concentrations of Cs, Hf, Ta and Zn that are greater by factors of 3 or more than those in Btt- 1. Although the Co contents of the two biotites are nearly equal, the amounts of Cr, Sc, La and the rare earth elements are significantly greater in Btt-1. Mica-Mg contains larger amounts of Cs and Rb than does Hbl-1, whereas the Cr content of Hbl-1 is 15 times that of Mica-Mg. Btt-1 and Hbl-1 may be useful as comparison samples for the analysis of biotites and hornblendes after other data are available.     

Instrumental Neutron Activation Analysis Of 37 Geochemical Reference Samples

37 geochemical reference samples, issued mostly by the U.S. Geological Survey and the "Centre de Recherches Pétrographiques et Géochi-miques", have been analysed for more than twenty trace elements using instrumental neutron activation technique. The results are compared with published data; in most oases, the agreement is good.     

Determination of Trace Elements (Ag, B, Ge, Mo, Sn, W, Tl) in Reference Samples of Soils and Bottom Sediments by Atomic Emission Spectrometry: A Traceability and Fitness-for-Purpose Study

Reference samples of soils from the Institute of Applied Physics, Irkutsk (RIAP), the Institute of Geochemistry, Irkutsk (IGI) and the United States Geological Survey, Reston (USGS) were analysed with the aim of determining Ag, B, Ge, Mo, Sn, Tl and W abundances by an atomic emission method with air-stabilised D.C. arc excitation. Two series of reference samples of soils and bottom sediments, GSS-1-8 and GSD-1-12 (IGGE), were used to ensure the traceability link for the analytical results. Traceability was also demonstrated through the comparison of measured results by AES and ICP-MS methods. It is shown that the reference samples GSS-1-8 and GSD-1-12 satisfied the "fitness-for-purpose" criterion (uncertainty U of the certified value should be one-third to one-tenth the magnitude of routine laboratory data uncertainty S (S/U > 3-10)) and can be applied for calibrating AES techniques.     

U.S.G.5. II Revisited*

Based on the most recent compilation of analytical data, a new set of “usable values” is calculated for six of the best known silicate rock reference samples produced by the U.S. Geological Survey. The latest version of the “best laboratories” method is described and results are compared with other recently published values.     

http://www.sciencedirect.com/science/article/pii/S1674987112000886

Six national-scale, or near national-scale, geochemical data sets for soils or stream sediments exist for the United States. The earliest of these, here termed the ‘Shacklette’ data set, was generated by a U.S. Geological Survey (USGS) project conducted from 1961 to 1975. This project used soil collected from a depth of about 20 cm as the sampling medium at 1323 sites throughout the conterminous U.S. The National Uranium Resource Evaluation Hydrogeochemical and Stream Sediment Reconnaissance (NURE-HSSR) Program of the U.S. Department of Energy was conducted from 1975 to 1984 and collected either stream sediments, lake sediments, or soils at more than 378,000 sites in both the conterminous U.S. and Alaska. The sampled area represented about 65% of the nation. The Natural Resources Conservation Service (NRCS), from 1978 to 1982, collected samples from multiple soil horizons at sites within the major crop-growing regions of the conterminous U.S. This data set contains analyses of more than 3000 samples. The National Geochemical Survey, a USGS project conducted from 1997 to 2009, used a subset of the NURE-HSSR archival samples as its starting point and then collected primarily stream sediments, with occasional soils, in the parts of the U.S. not covered by the NURE-HSSR Program. This data set contains chemical analyses for more than 70,000 samples. The USGS, in collaboration with the Mexican Geological Survey and the Geological Survey of Canada, initiated soil sampling for the North American Soil Geochemical Landscapes Project in 2007. Sampling of three horizons or depths at more than 4800 sites in the U.S. was completed in 2010, and chemical analyses are currently ongoing. The NRCS initiated a project in the 1990s to analyze the various soil horizons from selected pedons throughout the U.S. This data set currently contains data from more than 1400 sites. This paper (1) discusses each data set in terms of its purpose, sample collection protocols, and analytical methods; and (2) evaluates each data set in terms of its appropriateness as a national-scale geochemical database and its usefulness for national-scale geochemical mapping.     

Uranium, Thorium and Potassium Contents In Eighteen Geochemical Reference Samples Issued from the Geological Survey of Japan

Uranium, thorium and potassium contents in eighteen geochemical reference samples issued from the Geological Survey of Japan have been measured by non-destructive gamma-ray spectrometry using germanium semiconductor detectors. Results are generally in good agreement with recent values measured by various methods.     

THREE NEW GSJ ROCK REFERENCE SAMPLES: RHYOLITE JR-3, GABBRO JGB-2 AND HORNBLENDITE JH-1

Three new rock reference samples, Rhyolite JR-3, Gabbro JGb-2 and Hornblendite JH-1 have been prepared by the Geological Survey of Japan for collaborative studies on their chemical composition. Twenty-eight major, minor and trace elements were determined and presented. The results of homogeneity tests showed that all elements are considered to be distributed homogeneously in each reference sample. Geological and mineralogical characteristics are also described.     

1972 values for international geochemical reference samples

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.     

Flameless atomic-absorption determination of gold in geological materials

Gold in geologic material is dissolved using a solution of hydrobromic acid and bromine, extracted with methyl isobutyl ketone, and determined using an atomic-absorption spectrophotometer equipped with a graphite furnace atomizer. A comparison of results obtained by this flameless atomic-absorption method on U.S. Geological Survey reference rocks and geochemical samples with reported values and with results obtained by flame atomic-absorption shows that reasonable accuracy is achieved with improved precision. The sensitivity, accuracy, and precision of the method allows acquisition of data on the distribution of gold at or below its crustal abundance.     

An Evaluation of USGS III

"Usable values" based on evaluation by the "select laboratories" method are presented for concentrations of many constituents of eight reference rocks from the U.S. Geological Survey. Comparisons are made between the derived values and those published earlier.     

1996 COMPILATION OF ANALYTICAL DATA ON NINE GSJ GEOCHEMICAL REFERENCE SAMPLES, "SEDIMENTARY ROCK SERIES"

Analytical data compiled on nine Geological Survey of Japan (GSJ) reference samples, "Sedimentary rock series" received by February 1996 are reported. After excluding outliers and examining critically the analytical procedures employed, the data were evaluated statistically. Recommended or preferable values for fifteen major and sixty minor and trace elements are proposed.     

NEW TRACE ELEMENT AND REE DATA IN THIRTEEN GSF REFERENCE SAMPLES BY ICP-MS

Analytical data on 34 geochemically significant trace elements (Sc, V, Cr, Co, Ni, Cu, Zn, Ga, Rb, Sr, Y, Zr, Nb, Cs, Ba, Hf, Ta, Pb, The, U and REE) by using Inductively Coupled Plasma Mass Spectrometry (ICP-MS), for 13 reference rock samples obtained from the Geological Survey of Finland are presented. For many elements, especially most of the heavy-REE, concentrations are reported here for the first time.     

1994 COMPILATION OF ANALYTICAL DATA FOR MINOR AND TRACE ELEMENTS IN SEVENTEEN GSJ GEOCHEMICAL REFERENCE SAMPLES, "IGNEOUS ROCK SERIES"

Analytical data for minor and trace elements published or communicated to us, on seventeen GSJ (Geological Survey of Japan) reference samples, "Igneous rock series" received up to April 1994 are compiled. The data were evaluated statistically in consideration of analytical methods. Based on the selected available data, 1994 recommended and proposed values for 65 minor and trace elements are presented.     

Nitrogen in Chinese coals

Three hundred and six coal samples were taken from main coal mines of twenty-six provinces,autonomous regions,and municipalities in China,according to the resource distribution and coal-forming periods as well as the coal ranks and coal yields.Nitrogen was determined by using the Kjeldahl method at U.S.Geological Survey(USGS),which exhibit a normal frequency distribution.The nitrogen contents of over 90% Chinese coal vary from 0.52% to 1.41% and the average nitrogen content is recommended to be 0.98%.Nitrogen in coal exists primarily in organic form.There is a slight positive relationship between nitrogen content and coal ranking.