Trace element discrimination, copper

Trace Element Discrimination of Discrete Sources of Native Copper... 

Rapp, George, Jr., J. Albert, and E. Henrickson. 1984. Trace element discrimination of discrete sources of native copper. In Archaeological Chemistiy HI. J.P. Lambert (ed.), pp. 273-292. Washington, D.C. American Chemical Society. 

Activation analysis is used to establish trace element gerprints of geologic deposits of native copper. By using the statistical techniques of discriminant analysis and K-means cluster analysis and the trace element concentrations in artifact copper, an assignment of probable geographic and(or) geologic source of the artifact raw material can be made. 

Rapp has thus shown that the six trace elements determined in copper by Friedman s group in the 1960 s and 70 s can by the use of more refined (and more time-consuming) NAA techniques be greatly expanded and since in general numerical taxonomy and group discrimination all improve, the greater the number of elements considered it is likely that future studies will employ lar numbers of trace elements in the analytical scheme. 

As LA-MC-ICP-MS becomes more accessible, provenance studies may begin to combine elemental and isotopic characterization. Some time ago, Stos-Gale [114] suggested that metal provenance studies could be based on combined lead isotope and trace element analyses, and the same kind of combined approach would seem desirable in the case of turquoise as well as other, seldom analyzed materials such as ceramic glazes. Cooper et al. [115] combined trace element and LA-MC-ICP-MS lead isotope analysis of native copper from North America, but found that the lead isotopes were of little use in source discrimination. 

Several elements, particularly zinc and copper, could play a role as trace nutrients for phytoplankton. They are known to be important for growth of terrestrial plants, but neither the requirement for these nutrients nor the elemental distributions in seawater are well known. The biological availability of both zinc and copper is controlled by their complexation with organic material. Analytical methods that have the distinction of being able to discriminate chemical forms of the metal are needed. These measurements reflect the chemical reactivity and biological availability or toxicity of the metal more accurately. 

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