L- and LL-chondritic models of the chemical composition of Io

A geologically admissible range for the density of Io's mantle, its chemica l and mineral compositions in the Na2O-TiO2-CaO-FeO-MgO-Al2O3-SiO2 system, and the size of an Fe-FeS core are determined by mathematical simulation ba sed on the fitting of the calculated mass and moment of inertia of lo to th e experimental data. It is demonstrated that the bulk chemical composition of Io (crust + mantle + core) most closely resembles the composition of ord inary L and LL chondrites. The densities of mineral assemblages in the mant le and the iron concentration in the core, calculated on the basis of the L - and LL-chondritic models, meet the geophysical constraints on the mass an d the moment of inertia of Io. The core radius is estimated to be 590-640 k m for the Fe core (8-10% of Io's mass) and 820-890 km for the Fe-FeS eutect ic core (13.5-17%).