Domande d'esame VERIFICATO
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- The exam addresses factors influencing explosive volcanic eruptions, requiring an understanding of magma properties.
- It delves into the Fo-SiO2 binary system, asking for the composition of crystallized rocks from specific melts and the identification of the peritectic reaction involving Mg2SiO4, MgSiO3, and SiO2(L).
- Further questions on the Fo-SiO2 system involve describing crystallization sequences for different melt compositions (X and Z) and applying the phase rule to explain these processes.
- Igneous petrology topics include classifying igneous rocks into three main series and identifying which series exhibits an iron-enrichment trend in its evolved intermediate compositions.
- Students are asked to explain the factors that determine the structure of igneous rocks and define specific microstructures like myrmekitic texture, including where it is typically found.
- The exam also covers the macroscopic characteristics of volcanic rocks, specifically pumice and scoria.
- In metamorphic petrology, the concept of metamorphic facies needs to be defined.
- A microphotograph prompts analysis of a metamorphic reaction, requiring definition of the reaction type and evaluation of the associated P-T evolution, likely involving Al2SiO5 polymorphs (Andalusite, Sillimanite).
- AFM diagrams for pelitic rocks at different temperatures (596°C and 598°C) are presented, requiring identification of possible mineral parageneses within compositional fields and deduction of the mineralogical reaction occurring with increasing temperature.
- Finally, the exam probes why hydrated pelitic and quartz-feldspathic rocks typically do not reach granulite facies conditions and asks to describe the distinctive features of a hydrated basalt progressively metamorphosed to granulite facies, particularly in relation to a plagioclase and clinopyroxene-dominated protolith.