GEOLOGY FOR CULTURAL HERITAGE STUDIES

The course will provide basic knowledge of Mineralogy and Petrography to enable the student recognizing the most common minerals and rocks. Minerals and rocks will be contextualized on the basis of the environments and formation processes and on their use in a Cultural Heritage framework. The main chemical-physical characteristics of rocks and minerals and their main forms of weathering and deterioration will be examined in relation to their use in architecture and art and to the exposure to pollution and weather. The course will introduce the main methodologies for the study, identification and chemical-physical characterization of rocks and minerals. Some of the geochemical investigation methodologies useful for tracing, dating and characterizing stone materials for Cultural Heritage will also be presented.

The student will learn to recognize the main rocks used in historical and artistic context. The student will be able to determine the main forms of weathering and deterioration related to the rocks of interest. At the end of the course, the student will gain a basic geological language that will enable her/him to communicate with other experts in cultural heritage. More specifically, the student will acquire a basic knowledge of the main lithogenic and geomorphological processes which will help her/him in choosing possible actions for the conservation, safeguard and restoration of cultural heritage.

Inorganic chemistry, physics

• Internal structure and dynamics of the Earth. The Earth system and its subsystems. Introduction to plate tectonics.
• Distribution and abundance of elements in the Earth’s crust.
• Classification of minerals, with particular attention to silicates, oxides and hydroxides of iron and aluminum, carbonates of calcium and magnesium, and calcium sulfates.
• Mineralogy:
- Concepts of crystalline and amorphous states, crystal habit, crystal growth. Polymorphism and isomorphism.
- Concepts of crystal chemistry: crystal lattice, lattice spacing, types of packing, coordination polyhedra, Pauling’s rules, atomic substitutions and solid solutions, types of bonding.
- Morphological crystallography and crystal classification: identification of groups and systems, introduction to classes. Crystallographic axes. Elements and operators of point symmetry. Miller indices. Introduction to primitive and multiple lattices and to space groups.
- Macroscopic description of minerals. Physical and optical properties of minerals (hardness, tenacity, fracture, cleavage, isotropy and anisotropy, pleochroism, birefringence). Observations with the petrographic microscope.
- Systematic mineralogy and Strunz classification with particular focus on silicates.
• Petrography:
- Definition and classification of rocks. Lithogenetic processes (magmatic, sedimentary, and metamorphic). The rock cycle.
- Igneous rocks: physical and chemical characteristics of magmas. Classification schemes for igneous rocks (Streckeisen and TAS diagrams).
- Sedimentary rocks: depositional environments, composition, and classification. Distinctive criteria and terminology used for sedimentary rock classification.
- Metamorphic rocks: main metamorphic environments and types of metamorphism. Protolith and metamorphic grade.
- Macroscopic observation of rocks, including textural analysis and qualitative/quantitative mineralogical analysis.
• Main natural stone materials used in works of art and architecture. Major geological resources related to cultural heritage in Italy.
• Main forms of deterioration of stone materials: chemical, physical, and biological.
• Binding materials and bricks: cement, lime, mortars, concrete, gypsum, etc.
• Introduction to isotopic geochemistry applied to cultural heritage studies: main radiometric dating methods, isotopic ratios.

Capire la terra (J.P. Grotzinger, T.H. Jordan)
Mineralogia e petrografia (C. Klein, A. R. Philpotts)
Scientific papers and notes provided by the lecturer.

A written exam consisting of:
- Ten multiple-choice questions on general topics covered in the course (60/100)
- Morphological crystallography: identification of the crystal group and system of a simple solid, with discussion of key elements for recognition (20/100)
- Macroscopic textural analysisof a rock sample, with discussion of possible mineralogical composition and key features for classification (20/100)
The student may request an oral integration of the exam.

written

Grades are given out of thirtieths; see the learning "assessment method" for the weight assigned to each element.

The course includes both lectures and practical laboratory exercises (rock identification, optical properties of crystals, physical properties of rocks and minerals). A field excursion is also planned to deepen some of the concepts discussed during the course.

This subject deals with topics related to the macro-area "Climate change and energy" and contributes to the achievement of one or more goals of U. N. Agenda for Sustainable Development