00799 - Petrography

Learning outcomes

At the end of the course, the student will acquire the basic knowledge on the genesis, structure and composition of the main igneous, sedimentary and metamorphic rocks. Particular attention will be give to the main marbles, granites, porphyries and stones used in historical times. In particular, the student is able to: recognize and classify, based on international recommendations, the main rock types used in cultural heritage; assess, on mineralogical-petrographic and structural grounds, the state of freshness / alteration of different rock types and stones; define, by direct observation of monuments, the nature and provenance of different rocks types and stones.

Course contents

Igneous rocks - The magma: physical and chemical features. Upwelling and solidification of magmas: intrusive vs. volcanic settings. Origin of mantle magmas. Igneous differentiation: fractional crystallization, gravitative setting and cumulus rocks, assimilation, mixing and mingling of different melts. Bowen's reaction series. Anatectic magmas and origin of granites. Mineralogical and chemical features of igneous rocks. Classification of igneous rocks. Magmatic series and their relation to different geodynamic settings.

Metamorphic rocks - Definition and its drivers: pressure, temperature, deformation and fluids. Meso/microstructures and their classification. How to classify a metamorphic rock. Netamorphic reactions and the record they left into the rocks. Metamorphic grade and facies. Metamorphic facies series. Geotherm and Pressure-Temperature-time paths. Regional metamorphism (subduction, orogenic and sea floor) and contact metamorphism. Analysis and interpretation of mineral assemblages in metabasites and metapelites.

Lab activities - Classification of hand-sized samples of igneous, and metamorphic rocks.  

Field Trip - Field trip with practical exercises of classification of igneous and metamorphic rocks

Readings/Bibliography

Klein C., Philpotts A. (2018) Mineralogia e Petrografia (1a ed. italiana), Bologna, Zanichelli. Pagine: 544. ISBN: 978880832060

which is the Italian translation of

Klein, C., & Philpotts, A. (2012). Earth Materials: Introduction to Mineralogy and Petrology. Cambridge: Cambridge University Press. doi:10.1017/CBO9781139028028

 

Teaching methods

Class lectures augmented by

• Home work
  
• Petrography Lab
• Field Excursion

The teaching methods of this course require that all students must attend the Module 1 and 2 of the Online courses on Health and Safety in Study and Research Areas - Module 1 and 2, while the Module 3 on health and safety is to be attended in class.

Information about Module 3 attendance and schedule is available on the website of your degree programme.

Assessment methods

The expected learning outcomes are:

• describing rock’s minerals and structures at different observation scales,
• applying acquired knowledge to describe and interpret samples at different observation scales,
• logically organising information obtained from the analysis of samples,
• using the petrogenetic concepts discussed in class to explain observations.

The skills assessment is by written test. Candidates will have 90 minutes to answer closed questions and 2 open questions. Candidates will have a station with hand samples, one or more thin sections and a polarizing microscope.

The open questions may refer to the assigned samples and thin sections or to verify the knowledge of the topics covered in class.

For closed questions, the maximum score is 20 points.

The two short texts expected in the open questions will be evaluated with the following levels (and score):

(a) excellent (5 points);

(b) very good (4 points);

(c) good (3 points);

(d) sufficient (1 to 2 points);

(e) insufficient (0 points)

The score obtained from the two open questions are added to that obtained in the closed answers.

The achievement of a thorough competence in recognizing and describing minerals and rock structures at the meso- and micro-scale, together with good skills to make simple petrogenetic interpretations and technical terminology proficiency will be evaluated excellent.

A solid ability to describe minerals and structures together with the ability to provide simple petrogenetic interpretations and a very good control of petrographic terminology will be evaluated very good.

A mostly mnemonic knowledge of the subject, a limited ability to use observations to make simple petrogenetic inferences and a correct but not always appropriate language will lead from good to sufficient evaluations.

Weak ability to recognize and describe rocks’ minerals and structures, and approximate or inappropriate technical language, will lead to insufficient judgment.

Teaching tools

• Video Projectors supporting on-screen presentations
• Document camera
  
• Hand-sized samples
• Polarizing petrographic microscopes
• Thin sections
  
• Mineral and rock collections of the Museo di Mineralogia Luigi Bombicci
  

Office hours

See the website of Roberto Braga