Petrology and Laboratory

PETROLOGY AND LABORATORY
Principles of phase petrology:
I) Composition Space: barycentric coordinates, choice of components, units of quantity (mass, atoms, oxygens, cations, oxides units), conservative and non-conservative units. Transformation of coordinate axes: projection into AFM diagram; determination of mineral in terms of end members; mass balanceII) Phase diagrams and phase equilibria: Lever rule, Phase Rule, Binary and ternary phase diagrams (complete and partial solid solutions, complete immiscibility, solvus, eutectic, peritectic and intermediate compounds); Equilibrium thermodynamics of heterogeneous and homogeneous systems, thermodynamic properties of solid solutions, Gibbs stability criterion and Gibbs Free energy, G-X, T-X, P-T-X diagrams, pseudosections.
Metamorphic processes: Calculations of metamorphic phase equilibria, the P-T-X-mu phase relations, the use of thermodynamic calculators: programs and databases; Geothermobarometry; symplectites; case studies.
Magmatic processes: This part of the course is focused on the petrology of Earth's mantle and the correlated magmatism. In particular, this set of lessons aimed to provide a whole and updated framework of the knowledge on petrologic processes acting in the mantle during the partial melting and melt migration at ocean-ridge and "plume"-derived settings. It has been argued how the chemical and isotopic composition of basalts extruded in these geodynamic environments can give information on mantle source composition.

Practicals: Experimental petrology: run setup and textural/chemical characterisation of minerals; thermodynamic modelling of phase relations at subsolidus and supersolidus conditions. Trips to outcrops of petrologic interest are programmed.
Lectures and practice exercises in classroom and laboratory. Field trips.