Two methods for estimating the degree of melting and trace element concentrations in the sources of primary magmas

The degree of partial melting of primary magmas can be estimated using the ratios of trace element concentrations of lavas with different compositions. In addition, the source concentrations of the trace elements can be estimated. Two methods are demonstrated that use either linear or hyperbolic regression of trace element pairs. The accuracy of the methods is mainly limited by the assumption of constant source concentration ratios, and the accuracy of the applied distribution coefficients. The degrees of melting of nephelinite and alkali olivine basalt from Kauai, Hawaii are estimated as about 9% and 12%, respectively. Presently, the accuracy of estimates of the degrees of partial melting is rather limited by the accuracy of the available distribution coefficients.