The Thermodynamics of Trace Element Distribution
Conventionally, elements are categorized as major, minor or trace depending upon their relative abundances in the system of interest. The divisions between these three categories have not been rigidly fixed, but the term trace element has frequently been used for any element whose abundance is 1000 ppm or less. At very low concentrations of a trace solute constituent, the thermodynamic behaviour of the solution may be expected to approach that of an ideal dilute solution. The concentration range over which Henry’s Law is obeyed by a given trace constituent cannot as yet be predicted and must be determined by experiment. It is unfortunate that the term trace element as currently used encompasses concentration ranges where departures from Henry’s Law may occur. As more data become available on the solution behaviour of trace elements some qualifications of the term may prove worthwhile.
KeywordsCrystallization Silicate Geochemistry Fractionation Olivine
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- Ames, L.L., Walsh, P.N., White, D. Jour. Phys. Chem., 71, 2707 (1967).Google Scholar
- Broecker, W.S., Oversby, V.M. “Chemical equilibria in the Earth”, McGraw Hill (1971).Google Scholar
- Carmichael, I.S.E., Turner, F.J., Veerhoogen, J. “Igneous petrology”, 739 pp. McGraw Hill (1974).Google Scholar
- Carmichael, I.S.E., Smith, A.L., Mineral., 55, 246 (1970)Google Scholar
- Drake, M.J., Weill, D.F., Geochim. Cosmochim. Acta, 39, 689 (1975)Google Scholar
- Kushiro, I. Jour. Petrology, 13, 311 (1972).Google Scholar
- Kushiro, I. Carneg. Inst. Wash. Yearb., 73, 248 (1974).Google Scholar
- Mysen, B., Earth Planet. Sci. Lett., 311 (1976)Google Scholar
- Nicholls, J., Carmichael, I.S.E., Stormer, J.C. Contr. Mineral. Petrol., 33 (1971).Google Scholar
- Wood, B.J., Fraser, D.G. “Elementary Thermodynamics for Geologists”, 303 pp. Oxford University Press, Oxford (1976).Google Scholar