A refined method for trace element modelling of nonmodal batch partial melting processes: The Cenozoic continental volcanism of Calatrava, central Spain

A refined method for quantitative trace element modelling of partial melting processes is proposed here. This method is based on a two-part approach: (1) From binary diagrams and a minimal number of assumptions, a set of constrained values of the parameters (F, D-0(i), P-L(i), C-0(i)) are constrained for selected trace elements; (2) A simultaneous best-fit solution is obtained for those elements, which is then used to calculate the parameters for the remaining trace elements. This approach eliminates much of the mathematical complexity of other inversion techniques as well as the necessity of assuming values for poorly constrained parameters (e.g., mineral/liquid distribution coefficients). This method was succesfully applied to the primary melilitites, nephelinites, and olivine basalts from Calatrava, central Spain. The results of this calculation suggest that this basaltic suite was generated from a homogeneous garnet Iherzolite with phlogopite that was enriched relative to chondrites up to 18 times for the highly incompatible elements and about 3 times for the moderately incompatible. This source underwent progressively higher melting degrees between 5% (melilitites) and 17% (olivine basalts).