OPTIMASBA: A Microsoft Excel workbook to optimise the mass-balance modelling applied to magmatic differentiation processes and subsolidus overprints

► AFC, FC, partial melting and magma mixing processes are modelled from mass balance. ► Different parents, minerals, daughters or contaminants can be modelled simultaneously. ► Geological and statistical criteria are used to limit the solutions to one or none. ► Modelling of metasomatized rocks is done by removing elements, which improves the fit.