Learning outcomes of the course unit
Provide the knowledge and concepts necessary for understanding the magmatic process and the metamorphic process and for describing and classifying igneous and metamorphic rocks
Course contents summary
Programme of the course:
Recognition and determination of igneous rock minerals under a microscope:
- mention of morphological crystallography and optics. The transmitted light microscope and thin sections for the study of rocks. Observations under parallel light with polarizer only, with crossed nicols, and under convergent light with crossed nicols;
- main optical, crystallographic and chemical characteristics of the basic minerals of igneous rocks ; methods for the recognition and determination of plagioclases, microcline, orthoclase, sanidine, anorthoclase, quartz, feldspathoids, melilite, micas, olivine, pyroxenes, amphiboles.
- structure and composition of the Earth's crust, mantle and nucleus. The rock cycle. Notes on plate tectonics and petrogenetic processes.
- notes on nomenclature and criteria for the study of igneous rocks. Mineralogical, chemical, and normative composition. Basic petrochemical concepts.
- magma: structure, composition, temperature, density, viscosity, volatile components.
- equilibriums between solid, liquid and vapour phases in magmatic systems: Clapeyron equation, examples of P-T diagrams, influence of H2O pressure.
- phase diagrams and examples of petrographic applications: phase rule; single-component phase diagrams (H2O, C, SiO2, Al2SiO5); two-component phase diagrams (Di-An, An-Ab, Or-Ab); lever rule; crystallization and melting to equilibrium; fractional crystallization and melting; two-component phase diagrams with intermediate compound with congruent (Ne-SiO2) and incongruent (Lc-SiO2 and Fo-SiO2) melting; three-component phase diagrams (Fo-SiO2-An, Di-Ab-An and Fo-SiO2-Di); influence of H2O and CO2 pressure on Fo-SiO2-Di and Fo-SiO2-Ne phase diagrams.
- partial melting of the upper mantle. Classification and genesis of basaltic magmas.
- the granitic system. Partial melting of the continental crust.
- the residual petrogenetic system. Magmatic crystallization in the ternary feldspathic system. The plagioclase effect and peralkaline rocks.
- influence of O2 pressure on magmatic crystallization.
- magmatic differentiation. Assimilation. Mixing of magmas.
- variation diagrams. Magmatic series and associations.
- orogenic associations. Alkaline associations. Tholeitic associations. Ophiolites
- definition, factors and mechanisms of metamorphism.
- chemographic representation of metamorphic parageneses. Notes on nomenclature and criteria for the study of metamorphic rocks. Metamorphic reactions. Prograde and retrograde metamorphism. Metamorphic facies, isograds, facies series and thermal gradients.
- anchimetamorphism. Zeolite facies.
- contact metamorphism. Abukuma-type and Barrovian regional metamorphism. Burial metamorphism.
- notes on ocean floor metamorphism.
- granulites and eclogites. Migmatites and crustal anatexis.
- metamorphic processes, crustal and tectonic evolution of plates.
Armienti P. (by, 1993): La determinazione dei plagioclasi al microscopio polarizzante. Servizio Editoriale Universitario di Pisa, pp.40.
Best M.G. (1982): Igneous and metamorphic petrology. Freeman & C, pp. 630.
Cox K.G., Bell J.D.& Pankhurst, R.J. (1979): The interpretation of igneous rocks. George Allen & Unwin, pp. 450.
D'Amico C., Innocenti F.& Sassi F.P. (1987): Magmatismo e metamorfismo. UTET, pp. 536.
D'Argenio B.! , Innocenti F.& Sassi F.P. (1994): Introduction to the study of rocks. UTET, pp. 162.
Roubault M. (1963): Determination des mineraux des roches aux microscope polarisant. Lamarre-Poinat, pp. 364.
Shelley D. (1992): Igneous and metamorphic rocks under the microscope. London, Chapman & Hall, pp. 445.
Zezza U. (1976): Petrografia microscopica. La Goliardica Pavese, pp.295.