U.S. Geological Survey Certificate of Analysis

Andesite, AGV-1

AGV-1 is an andesite, collected from the eastern side of Guano Valley in Lake County, Oregon, by George W. Walker of the U.S. Geological Survey. AGV-1 is aphanitic, finely porphyritic, with a trachytic texture. According to the chemical classification of Rittman (Rittman, 1952) this rock is a trachyandesite.

Element concentrations were determined by cooperating laboratories using a variety of analytical methods. Certificate values are based primarily on international data compilations (Gladney, 1983, Gladney and Roelandts, 1987, Govindaraju, 1994). Initial USGS studies (Flanagan, 1967) provide background information on this material.

Recommended Values | Certificate Information | Bibliography | Glossary | Notes


Oxide Wt % ± Oxide Wt % ±
SiO2 58.84 0.58 Fe2O3T 6.77 0.19
Al2O3 17.15 0.34 Na2O 4.26 0.12
CaO 4.94 0.14 K2O 2.92 0.37
MgO 1.53 0.093 TiO2 1.05 0.05
P2O5 0.50 0.03
Element µg/g ± Element µg/g ± Element µg/g ±
Ba 1230 16 Gd 5.0 0.6 Sc 12 1
Be 2.1 0.4 Ge 1.25 0.1 Sm 5.9 0.4
Ce 67 6 Hf 5.1 0.4 Sr 660 9
Cl 119 26 La 38 2 Ta 0.90 0.09
Co 15 1.2 Li 12 2 Tb 0.70 0.1
Cr 10 3 Lu 0.27 0.03 Th 6.5 0.5
Cs 1.3 0.1 Mn 710 50 U 1.92 0.15
Cu 60 6 Mo 2.7 0.9 V 120 11
Dy 3.6 0.4 Nd 33 3 Y 20 3
Eu 1.6 0.1 Pb 36 5 Yb 1.72 0.2
F 425 50 Rb 67 1 Zn 88 9
Ga 20 3 Sb 4.3 0.4 Zr 227 18
Oxide Wt % Other Wt %
FeO 2.06 H2O+ 0.78
Fe2O3 4.46 H2O 1.00
LOI 1.2
Element µg/g Element µg/g Element µg/g
Ag 0.078 Cd 0.069 Ni 16
As 0.88 Er 1.7 Pr 7.6
Au 0.00062 Hg 0.02 Sn 4.2
B 7.8 I 0.27 Tl 0.34
Bi 0.057 In 0.041 Tm 0.34
Nb 15 W 0.55

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Certificate Information

Denver, Colorado
revised March 1995

David B. Smith
Central Region Mineral Resources Team (formerly Branch of Geochemistry)

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Bibliography

Abbey, S., 1983, Studies in "Standard Samples" of Silicate Rocks and Minerals 1969-1982: Canadian Geological Survey paper 83-15, p. 114.

Flanagan, F.J., 1967, U.S. Geological Survey silicate rock standards: Geochimica et Cosmoshimica Acta, 31:289-308.

Flanagan, F.J., 1973, 1972 values for international geochemical reference samples: Geochimica et Cosmochimica Acta, 37:1189-1200.

Flanagan, F.J., 1974, Reference samples for the earth sciences: Geochimica et Cosmochimica Acta, 38:1731-1744.

Flanagan, F.J., 1986, Reference Samples in Geology and Geochemistry: U.S. Geological Survey Bulletin 1582, 70 p.

Govindaraju, K., 1994, 1994 Compilation of Working Values and Descriptions for 383 Geostandards: Geostandards Newsletter, 18:1-158.

Rittman, A., 1952, Nomenclature of volcanic rocks: Bull. Volcanoe. Series II, 12:76-102.

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Glossary

Symbol Definition
Fe2O3T Total iron expressed as Fe2O3
Ctot Total carbon concentration
Stot Total sulfur concentration
Wt % Percent of total element concentration
µg/g Total element concentration expressed as micrograms of element per gram of solid sample
± One standard deviation

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Notes

Unless otherwise indicated total element concentrations are reported for material on an as-received basis, i.e., no drying.

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Order and Pricing Information

This geochemical reference standard is no longer available.

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