GEOLOGIA STRATIGRAFICA

The main goal of course is to provide students with the basic principles of Stratigraphic Geology, which aims to describe, order and classify rock sequences and correlate them in time and space.

Therefore, at the end of the course the student will:

a) acquire the fundamental Principles of Stratigraphic Geology, including the mechanisms to define the original setting in which a rock body has formed;

b) know how to describe and classify rock sequences according on the basic stratigraphic units;

c) understand the meaning and apply the methodologies of the stratigraphic correlation;

d) know the main methods of dating a rocky succession and the principles which they are based on;

e) know how to reconstruct the geological history of an area, also in relation to the sea level variations, defining the relative chronology for sedimentary events and tectonic phases;

f) be able to reconstruct stratigraphic columns from schematic geological profiles (also on a different scale) and perform correlations among them;

g) know how to produce an "age-depht" diagram, including the meaning of "sedimentation rate" and "sedimentation gap";

h) recognize stratigraphic units in geological maps.

REQUIRED PRACTICES

• Acquired the concepts of the Course of “Physical Geology” (Geologia Fisica) (first semester, first year of L-34 degree in Geological Sciences);
• Being familiar with the reading of topographic maps and knowing how to perfectly perform a topographical profile.

FREQUENCY LESSONS: OBLIGATORY

The course is organized as follows:

-traditional lectures, carried out using a participative approach in order to obtain the maximum involvement of the students;

- practical exercises. Such exercises are supervised in order to be sure that all the students will learn during the class-time how to apply the most important concepts and methods to be used in the field of Stratigraphic Geology;

- periodic tests, aimed to verify the level of understanding of the topic of the course and the problem-solving capacity of the students;

-excursion in the field with practical application of methodologies learnt during lectures.

If the teaching is given in mixed or remote modalities, the necessary changes may be introduced with respect to what previously stated, in order to respect the program envisaged and reported in the syllabus.

Exams can also be carried out in remote modality, should the conditions require it.

Stratigraphic Geology, frontal lessons: 6CFU (42 hours)

PART I: Introduction

Definition and Purposes of Stratigraphic Geology. Rocky successions and stratigraphic record. History of Geology.

PART II: The Basics of Stratigraphic Geology.

Steno’s Principles and exceptions. Concept of "normal" and "overturned", "high" and "low" in geology. Concept of "Stratum" and "Strata orientation". Polarity of strata. Relationship between strata orientation and morphology of the slopes.

PART III: Successions and Stratigraphic Classification

Basic Stratigraphic Units: Lithostratigraphic, Biostratigraphic, Cronostratigraphic. Stratigraphic Codes and the International Stratigraphy Commission. The concept of "stratotype". Definition of "stratigraphic limit". Vertical and horizontal passages. Temporal meaning of stratigraphic limits. The concept of "Stratigraphic Correlation". Condensed and comprehensive sequences: concept of sedimentation rate. Continuous and discontinuous successions: types of unconformities. Stratigraphic lacune and temporal hiatus. Concept of "transgression" and "regression". Sea level variations.

PART IV: The facies

Definition of facies. Horizontal and vertical facies variations. Unconformity Bounded Stratigraphic units” and relationships with sea level variations. The principle of Walther. Main depositional geometries.

PART V: Methods of dating a rocky succession

Unstable isotopes, radioactive decay and radiometric dating. Concept of "half live". Relative dating methods: Smith's principle, "index" fossils, and the concept of "homotaxy". Geological Time. Age of Earth and first subdivisions of the Geological Time. The Geological Time Scale. Paleomagnetism and Magnetostratigraphic Units. Concept of Global Stratotype Section and Point (GSSP)".

Stratigraphic Geology, Laboratory: 3CFU (36 hours)

Realization of stratigraphic logs at different scales. Symbols of the main lithologies. Calculation of thickness and orientation of the strata. Stratigraphic correlations. Curve of relative sea level variation. Calculation of sedimentation rates. Identification of stratigraphic gaps. Construction of "age-depth" diagrams. Reconstruction of the geological history of an area and relative chronology of geological events.

Testi:

1. P. Doyle, M. Bennett, A. Baxter: The key to Earth History – an introduction to Stratigraphy, Ed. Wiley
2. G. Nichols: Sedimentology & Stratigraphy, Ed. Blackwell Science
3. A. Ferrari: Unità stratigrafiche e correlazioni, Pitagora Editrice Bologna.
4. S. Raffi-E. Serpagli: Introduzione alla Paleontologia, Utet Torino (pagg. 3-20; 419-505).
5. B. Simpson: Lettura delle Carte Geologiche. Edizione italiana a cura di G. Cusimano e P. Di Stefano. Dario Flaccovio Editore.
6. Lecture notes provided by the teacher during the course

Websites:.

1. http://www.ucmp.berkeley.edu/exhibit/geology.html
2. http://www.msnucleus.org/membership/html/jh/earth/stratigraphy/index.html