Learning objectives
At the end of this part of the course, the students will be able to apply their knowledge and skills to understanding so as to
identify, by examination of hand samples and thin sections, the three principal groups of rocks (igneous, metamorphic, sedimentary) outcropping on the Earth’s surface.
Prerequisites
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Course unit content
Laboratory activity. The activity will be held in the class by the teacher, with the possibility of following the lessons through electronic means of communication (synchronously, via Teams; remotely, on Elly).
1) Basic methods used to describe and identify hand specimens of the Earth’s crust and mantle rocks (i.e., igneous, metamorphic and sedimentary rocks).
2) Optical mineralogy methods used to identify the common rock-forming minerals in thin section, by use of polarizing optical microscope.
3) Classification of the magmatic, metamorphic and sedimentary rocks according to their mineral content and texture, following the schemes proposed by the International Union of Geological Sciences.
Full programme
What a rock is.
How minerals forming a rock can be identified.
The three rock types (igneous, sedimentary and metamorphic) forming the Earth’s crust and mantle.
The minerals forming the rocks observed under the polarizing optical microscope: quartz; feldspars; feldspathoids; olivine; pyroxene; amphiboles; micas; garnet; polymorphs of Al2SiO5; staurolite; cordierite; epidotes; the accessory and secondary minerals.
Textures of igneous and metamorphic rocks.
The International Union of Geological Sciences (IUGS) classification of igneous intrusive rocks based on mineral contents determined from modal analysis of the rock.
The International Union of Geological Sciences (IUGS) classification of igneous extrusive rocks based total alkalis and silica contents of the rock.
The classification of metamorphic rocks according to metamorphic facies and zones.
The classification of sedimentary rocks (an introduction).
Bibliography
Klein C., Philpotts A. (2017), EARTH MATERIALS: introduction to mineralogy and petrology, 2nd edition. Cambridge University Press
Klein C., Philpotts A. (2018), Mineralogia e petrografia (edizione italiana). Zanichelli
A. Peccerillo & D. Perugini (2003). Introduzione alla Petrografia ottica. Morlacchi Ed., Perugia
Teaching methods
The 12 credits of this course amount to a total of 120 hours, distributed as follows: 80 hours of laboratory-based exercises and 40 hours of lectures. In the laboratory part, the student performs exercises on the identification of hand specimens of rocks and a strong training on the use of the microscope; formative evaluation will be done informally with discussions during each lesson, in order to check how much students have been understood. Written evaluations will be carried out periodically, in order to monitor the achievement of the training objectives. The teacher uses PowerPoint files that display the sequence of course topics. The files are available on Elly.
Assessment methods and criteria
The exam is made of a written part and an oral part.
In the written part, the student describes the mineral assemblage and the texture observed in 3 thin sections (1 for a intrusive igneous rock; 1 for an effusive igneous rock; 1 for a metamorphic rock), using microscope techniques; then, by using this petrographic information, the student classifies the rock. The written part will also be carried out during the course. The minimum score to pass the written part is 18/30.
After the correction of the written part, the student takes the oral part of the exam. If the health emergency persists, the examination will be carried out remotely, via Teams.
Other information
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