PETROMODELER (Petrological Modeler): a Microsoft® Excel© spreadsheet program for modelling melting, mixing, crystallization and assimilation processes in magmatic systems

PETROMODELER (Petrologic Modeler) is a Microsoft® Excel© spreadsheet program which numerically and graphically models magmatic processes including melting, crystallization, assimilation and mixing by using trace elements and isotopic ratios. Melting models include (a) batch, (b) dynamic (continuous) and (c) fractional melting for (1) instantaneous and (2) cumulate melts, (3) residual solid and (4) total residue. These models can also be used to treat modal and non-modal melting. Crystallization processes modelled in the program include: (1) perfect equilibrium and (2) perfect fractional crystallization (PEC and PFC), (3) equilibrium crystallization-imperfect fractional crystallization (EC-IFC), (4) zoned crystallization-imperfect fractional crystallization (ZC-IFC), and (5) combined assimilation and fractional crystallization (AFC). Mixing between two end-member compositions can also be modelled by the program. The main advantages of the program are that; (1) crystallization and mixing processes can be performed on a starting composition which may be chosen from; (a) any melting model result, or (b) any sample composition entered into the 'samples' tables, (2) the results of any model can be exported as a graphic file (GIF) and as tables, (3) changes in any parameters are simultaneously updated onto all diagrams and tables. PETROMODELER also calculates other useful parameters, such as normative mineralogy, Mg#, Eu/Eu*, eSr and eNd, s(DM) (depleted mantle Nd model ages) of a given sample. Some classification diagrams for volcanic rocks are also included in the program. Conversion of element abundances on the basis of wt% and ppm can also be performed.

Keywords:

Geochemical modelling, magmatic petrology, trace elements, melting, crystallization magma mixing,

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