Applications of the crystal-field theory to the inclusion of trace transition elements in minerals during magmatic differentiation

Abstract

The modification, due to Ringwood, of Goldschmidt's rules dealing with the distribution of trace elements in minerals is difficult to apply to the transition elements. This is because the ionic radii and electronegativity effects, as described by Ringwood, trend in opposite directions throughout the series. It is extremely difficult to predict from purely theoretical considerations which effect will be the greater. A new approach to the problem, that of the crystal field theory, is used in this paper and predicts semiquantitatively the relative orders in which all the transition elements will be concentrated during magmatic differentiation. Data from the Skaergaard Intrusion is re-examined in light of the above, and demonstrates that the crystal field forces are dominant in determining trace element behaviour.