Geology 2 and Rudiments of Geological Mapping

[252SM]
a.a. 2025/2026

2° Year of course - Full year

Frequency Not mandatory

  • 12 CFU
  • 116 hours
  • Lectures and laboratories will be given in Italian language. Further explanations might be given in English to foreign students, when necessary.
  • Trieste
  • Obbligatoria
  • Written and Oral Kindred
  • SSD GEO/03
  • Core subjects
Curricula: PERCORSO COMUNE
Syllabus

The students will acquire the necessary tools to recognize, describe, interpret, and map the tectonic structures at different scales. Specifically, the student will be able to: Recognize, measure, and represent the main tectonic deformation structures, from outcrop to regional scales. Analyze tectonic structures from a geometric, kinematic, and dynamic perspective about the mechanical behavior of rocks. Reconstruct the timing and mechanisms of tectonic structure activation. Understand the role of tectonic structure assemblages in the evolution of crustal domains across different geodynamic settings.

Basic knowledge of fundamental geology concepts acquired during the first year

The course aims to explore the deformational processes affecting rocks and the Earth's crust, examining their causes, mechanisms, and consequences on both microscopic and regional scales. Through an integrated approach, the main geological structures are studied, including faults, folds, foliations, and fractures, with particular attention to their formation, classification, and role in the tectonic evolution of crustal areas. The fundamental principles of deformation are analyzed, distinguishing between brittle and ductile behavior, and the relationships between stress, strain, and rock anisotropies are explored. The course also provides basic knowledge of cartographic representation techniques, geological surveying, and the construction of geological cross-sections.

1) Structural Geology Author A. Fossen Editor: Cambridge University Press 2) Basic Geological Mapping. Fifth Edition. Authors: R. Lisle, P. Brabham, J. Barnes Publisher: Wiley-Blackwell 3) Stereographic Projection Techniques for Geologists and Civil Engineers. Second Edition. Authors: R.J. Lisle and P.R. Leyshon Publisher: Cambridge University Press Course slides, as well as additional teaching materials, will also be provided

The course begins with an overview of structural geology, the branch of geoscience that investigates the deformation of the Earth's crust and the processes responsible for it. Emphasis is placed on structural analysis as a key tool for interpreting the tectonic evolution of rocks. The concept of deformation is explored in detail, highlighting its connection to tectonic processes and examining how forces acting on the crust alter the geometry and arrangement of geological formations over time. The course delves into the analysis of strain in rocks, including its components, measurement techniques, and examples of both homogeneous and heterogeneous deformation. Stress is discussed at various scales, ranging from the mesoscale—where local features like fractures and folds are observed—to the lithospheric scale, which encompasses large tectonic systems. The rheology of rocks is examined in relation to environmental conditions such as pressure, temperature, and fluid presence, showing how these factors control the transition between brittle and ductile behavior. Brittle deformation is addressed through the study of fractures, with a focus on joints and veins, exploring their origin, classification, and role in fluid circulation. Faults and folds are analyzed in depth, with attention to their kinematics, dynamics, and how they relate to regional stress fields. The course then turns to ductile deformation, investigating structures such as foliation and cleavage, their formation mechanisms, and tectonic implications. Lineations are studied as markers of movement direction and sense in deformed rocks. Boudinage is introduced as an example of heterogeneous deformation, supported by case studies involving competent rock layers interbedded with more ductile ones. The final part of the first semester focuses on shear zones and fault rocks, highlighting their microstructural features, stages of evolution, and significance in reconstructing tectonic histories. In the second semester, the course provides the theoretical and practical skills needed to interpret and graphically represent geological structures. Students begin by learning basic graphical methods, such as determining the orientation of planes and lines, constructing lines of intersection between surfaces, and applying the three-point method to define a plane's position in space. Through hands-on exercises, students learn to identify and calculate the true and apparent dip of planes, measure the real and apparent thickness of strata, and graphically depict these elements in geological cross-sections. Stereographic projections are introduced as an essential tool for analyzing the 3D geometry of geological structures. Students are taught how to use the stereonet to project planes and lines, interpret folds and faults, and solve geometric problems such as determining plane intersections, calculating dihedral angles, statistical fold axes, performing axis rotations, and visualizing stress fields. The course also includes fieldwork, where students practice geological surveying techniques. This involves using a geologic compass, mapping outcrops, maintaining a field notebook, and collecting and interpreting structural-geological data.

In-class lectures and exercises, field practice.

First Semester: Oral examination covering the theoretical content presented in lectures. Second Semester: Practical assessments and written examination evaluating both classroom content and field-based learning components.