BASEMENT GEOLOGY WITH SURVEY

The metamorphic geology course generally aims to provide the main principles of the metamorphic and magmatic processes at the base of the continental crust formation within different geological and geodynamic contexts. 

Following the Dublin descriptors, the course specifically aims to:

Knowledge and understanding skills:

(a) understand the basic principles of solid-state rheology as well as the elastic and mechanical properties of the main rock types constituting the continental crust;

(b) understand the factors controlling strain in monomineralic and polymineralic rocks;

(c) understand the evolution of crustal shear zones through the rheological-kinematic evolution of fundamental minerals (quartz, feldspars, and micas). 

Ability to apply knowledge and comprehension:

(a) describe and classify the different types of deformation structures, reconstructing the setting and the space-time evolution;

(b) collect, process, and map disaggregated structural data, identifying the style and reconstructing the space-time evolution;

(c) read and interpret geological maps in the crystalline basement areas;

(d) reconstruct the deformation-blastesis relationships that occurred during the tectonic-metamorphic evolution of metamorphic units;

(e) determine, with the integration of suitable geotermobarometric techniques, the changes in pressure and temperature registered by the basement rocks, reconstructing the P-T trajectories;

(f) contextualize within the Paleozoic-Oligocene Mediterranean geodynamics the kinematic of the Calabro-Peloritani microplates.

Autonomy of judgment:

The student will be encouraged to deepen his or her knowledge of the topics covered independently and to maintain a constant discussion with other students and the teacher so that he or she can critically monitor his or her learning process.

Communication skills:

Attending lectures and reading handouts and recommended texts will help the student acquire adequate technical-scientific language through learning specific terms, definitions, acronyms, and concepts inherent to the topics covered. Through constant interaction with the lecturer, the student will learn to expound with rigor and clarity of the knowledge acquired.

Learning skills:

The student will be guided in the process of perfecting his or her study method. In particular, through appropriate guided exercises, he or she will be able to deal independently with new topics and update the knowledge acquired in the discipline through the reading of texts and/or scientific articles.

• Know the classification principles of igneous and metamorphic rocks;

• Know the principles of optical microscopy for the recognition of fundamental minerals;

• Know the theoretical basis of the use of stereographic projections;

• Know the foundations of the current central Mediterranean geological-geodynamic structure.

Frontal theory module: 3 CFUs (21 hours)

FIRST PART

INTRODUCTION

Principles and purposes of the Metamorphic Geology. Description of the main orogenetic processes. The geothermal gradient and its influence on the genesis of crystalline basements.

SECOND PART

MECHANICAL PROPERTIES OF ROCKS

Principles of rheology of the solid state: Analysis of stress and strain. History of the strain: total strain, incremental strain, progressive deformation. Coaxial and non-coaxial deformation. The rheological behaviour of minerals and rocks: Inter and intracrystalline deformation mechanisms; Strain control factors in mono- and Polymineralic rocks. Recovery process. The main flow laws in the solid state rheology. Inter-and intra-crystalline deformational mechanisms. Mineral Preferred Orientation: Shape and Lattice Preferred Orientation and their interrelationships. 

THIRD PART

WESTERN MEDITERRANEAN GEODYNAMICS FROM THE END OF PALEOZOIC TO THE PLIOCENE-PLEISTOCENE PHASES

The geological-geodynamic evolution of the Calabrian Peloritani Orogen  (CPO). The Variscan vs.  Alpine orogenic cycle. The role of crustal-scale shear zones in the present-day structure of the CPO. CPO palinspastic reconstructions up to the Oligocene-Miocene transition.

Laboratory Module 1: 1 CFU (12 hours)

FOURTH PART

RECONSTRUCTION OF THE BLASTO-DEFORMATIONAL RELATIONSHIPS, THE CONCEPT OF TEXTURAL EQUILIBRIUM, GEOTHERMOBAROMETRY OVERVIEW, P-T-d-t TRAJECTORIES RECONSTRUCTION.

Foliations and lineations. Description and classification of the folds. Theoretical models of folding. Distribution of strain in the folds. Reconstruction of the blasto-deformational relationships: Chronology of deformational events. Chronology of the blastic events. Elements of Petrochronology: The reconstruction of the P-T-d path. Mineralogical renewal during metamorphic processes and the concept of the sequence of paragenesis. 

Survey module (2 field trips Peloritani Mountains area): 1 CFU (12 hours)

FIFTH PART

FIELD TECHNIQUES

Field measurements: arrangement of linear and planar elements. Cartographic representation with an encoded symbology. Stations measurement and process structural data. Reconstruction of space-time deformation events. Time-related distinction of structural symbols on thematic maps. Textural and structural characterization of deformation structures. Recognition of mesoscopic paragenetic assemblage in basement rocks. Penetrativity and pervasiveness of deformation structures. Genetics setting of deformation structures. Detection and interpolation of the boundaries between the units. Examples of graphic reconstruction of the limits and the limits on the validity of interpolation. 

Laboratory Module 2: 1 CFU (12 hours)

SIXTH PART

MESO-MICROSTRUCTURAL INVESTIGATIONS AND STRUCTURAL DATA REPRESENTATION

Examples of representation of structural elements through stereographic projections. Concepts of symmetry of structural data set. Rotation and statistical processing of structural data. Dispersion of the structural elements. Geometry and structural types of interference. Methods of structural analysis in areas characterized by poly-deformational evolution. Definition of shear zone. Classification of fault rocks and their location in different crustal levels. The kinematic indicators. Microstructural analysis of cataclastic and mylonitic rocks. The pseudotachylite.  Recognition and interpretation of metamorphic microstructures. 

1. Barker J. – Introduction to metamorphic textures and microstructures. (Blackie USA, Chapman & Hall) 1998.
2. Passchier C. W. & Trouw R. A. J. – Microtectonics. (2nd ed. xvi + 366 pp. + CD-ROM. Berlin, Heidelberg, New York: Springer-Verlag). ISBN 3 540 64003 7.
3. Vernon R. H. – A practical guide to rock microstructure. (Cambridge University Press) 2004. 594 pp. ISBN: 9780521891332
4. WINTER (2001) An Introduction to Igneous and Metamorphic Petrology. Prentice Hall. 
5. Fossen H. – STRUCTURAL GEOLOGY. (Cambridge University Press) 2010. 463 pp. ISBN: 9780521516648
6. Handouts and notes distributed in class during the course.

The final evaluation relating to the course of Metamorphic Geology provides the possibility (optional) to carry out an ongoing test on the principles of solid-state rheology during the course. At the end of the course, the assessment of the ongoing test will be integrated with the production of an end-of-course work group, normally developed in groups of maximum four students, relating to the statistical processing of structural measurements taken autonomously during the field-related surveys in Villafranca Tirrenica or Scifì (ME), contextualized within the central Mediterranean geological-geodynamic framework from the Palaeozoic to the Oligo-Miocene passage.

This work can be presented in paper form or with a PowerPoint presentation.

During and at the end of the presentation of the paper, the teacher will ask the students a whole series of basic theoretical notions, among those dealt with during the course.

The final grade will include a balanced synthesis between the judgment of the synthesis and expository skills demonstrated and the degree of maturity in understanding the theoretical notions underlying the course.

1. Mylonites and their kinematic indicators. 
2. The sheath-folds. The low-strain domains.
3. Fault rocks and their correlations as a function of depth of formation.
4. Tectono-metamorphic evolution of the Mandanici Unit.
5. Pencil-structures and L-tectonites.
6. The crenulation cleavage.
7. The rheology of plastic deformation.
8. Collisional environments.
9. Mylonites within the Mandanici Unit.
10. The stereographic projections.
11. Lineations and foliations.
12. The tectonite concept and the evolution of the Flinn diagram.
13. Tectono-stratigraphic setting of the Calabrian-Peloritanian Orogen.
14. Kinematic indicators;
15. The stratigraphic structure of the Aspromonte Massif.
16. The crustal anatexis and migmatites.
17. Migmatitic layering.
18.  Strain rate vs. recovery.
19.  The sheath folds.
20.  The interference structures.
21.  Kinematics and evolution of mylonitic structures.
22.  The concept of vorticity and the kinematic vorticity number.
23.  Pure shear vs. simple shear.
24.  Tectono-stratigraphic setting of the Peloritanian Mountains: The Mandanici unit.
25.  Main, secondary, and accessory minerals and their role in reconstructing blasto-deformational relationships.
26. Geothermal-barometric techniques: a comparison.
27. Spatiotemporal relationships between the emplacement of granitoid bodies and the metamorphic basement.