SM/0009 - STRATIGRAPHY OF SEDIMENTARY BASINS
Academic Year 2021/2022
Free text for the University
LUCIANO LECCA (Tit.)
ALFREDO LOI (Tit.)
- Teaching style
- Lingua Insegnamento
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- Provide the bases of Sequence Stratigraphy.
- Understand mechanisms stacking of sedimentary facies and their architecture in space and time.
- Description and Identification of the main sedimentary facies of terrigenous platform.
- Survey stratigraphic sections and build a curve of sea level changes.
- Develop skills of critical analysis of the discipline.
The aim of this course is to make students self in field measurements and in the interpretation of facies in terms of sedimentary environments. Understanding the peculiarities of the role of the geologist in understanding and interpretation of the geological evolution of an area.
-Competence: sedimentary basin, its filling formations, relations with tectonics, case study of the oligomiocene Sardinian Rift.
- Knowledge and understanding:
sedimentary basin and its filling by sedimentary successions, relationships with tectonic structures and subsidence; relationship between geodynamics and paleogeographic evolution. Oligo-Miocene geodynamic and paleo-geographic evolution of the Western Mediterranean and the genesis of the Sardinian Rift.
Sedimentary and volcanic and sequences deposited in the basins of the Rift Sardo. Stratigraphic relationships between the filling formations, their sedimentological characteristics and chronostratigraphic schemes.
- Knowledge and understanding skills applied: reading and drawing of sections of sedimentary basins; recognition in outcrop of the most important sedimentary formations of the Rift Sardo; stratigraphy of the Rift Sardo formations in the Geological Map of Italy and in the stratigraphic columns derived from the wells drilled in Campidano and in the geological sections.
-Making judgments: evolution of a basin; paleo-evolution of the Sardinian Oligo-Miocene Rift.
-Communication skills in the stratigraphy of the basins and of the Sardinian Rift in particular.
Courses Geology and Sedimentary Geology of the Bachelor degree in Geology or Earth Sciences.
Knowledge and understanding of sedimentary geology, elements of Tectonics and of Geodynamics.
Module I (Sequence Stratigraphy)
- Sedimentary structures and main terrigenous and mixed sedimentary environments. Law of Lyell.
- Law of Gressly and facies analysis.
- Sedimentological and stratigraphical models of the main depositional environments.
- Stacking of sedimentary facies and influence of autocyclic and allocyclic factors.
- Sedimentary Cycles, causes and stratigraphic responses (Milankovitch Cycles).
- Elements of Sequence Stratigraphy (available space, accommodation potential, Walther's Law, Wheeler's Law or base level ...)
- Depositional Genetic Sequences at high, medium and low frequencies.
- Boundaries of Genetic Sequences, flooding surface, maximun flooding surface and ravinement surface.
- Asymmetry of marine and continental Sequences, the concept of volumetric partition of sedimentary environments.
- Wheeler diagram.
- Fisher diagram.
- "Global" Sequences (sequences of first, second and third order).
- The Vail sequences.
- System tract, facies tract and sequence boundaries.
- Relative and absolute sea level changes.
- Backstripping procedure and eustatic curve establishment.
- Techniques of measurement in field sections and sequence analysis.
(Sedimentary basins and Stratigraphy of Sardinia Oligo-Miocene Rift)
5 cfu of lectures (40 hours), 1 cfu of field observations, two excursions(12 hours).
1-The sedimentary basins as product of the plate tectonics.
Wide-ranging part of sedimentary basins controlled by the global geodynamics. Elements on the genesis of the sedimentary basins, calls on global tectonics, lithospheric margins, continental margins basins. Filling cycles of sedimentary basins.
2-Subsidence, taphrogeny and extensional sedimentary basins
Subsidence, isostasy. Genesis of extensional basins. Extensional tectonics and types of basins structures.
3-Relations between sedimentary processes and tectonic stages
Semi graben. relationships between the halfgraben stages and filling. Sequences pre, and post rift since a limited area by faults. filling models of halfgraben, marine transgression in a halfgraben. Rifting of intra-arc.
4-Paleogeographic evolution of Sardinian and Corsican block
Orogenic and paleogeographic evolution from the Mesozoic to the Western Mediterranean area today. The main chains of the Western Mediterranean. Genesis of the Western Mediterranean and the Rift Sardo oligo-Miocene and main geodynamic interpretations.
5-Architecture of Sardinian rift and infilling sequences
Regional structure of the Oligo-Miocene Sardinian rift basins, grabens and half grabens, cross sections. Rift ages. Rift sequences. Volcanic sequences: andesites and ignimbrites. Sedimentary sequences (formations): Ussana conglomerates F., Ales marls F., Gesturi sandstones F.( Villanovatulo), Villagreca and Isili limestones F., Marmilla F., Gesturi marls F., Fangario clays F., Pirri sandstones F., Cagliari limestones F., the Messinian of Sinis, marine Pliocene re-flooding, Samassi F., Pliocene-Quaternary complex. Regional cross-sections.
6-Lithostratigraphy of for oil exploration wells in Sardinia: Oristano 1, Oristano 2, Villasor-Campidano, Marcella southern Sulcis shelf.
Two excursions (1 cfu) of field observation of the main formations of the southern Sardinian rift, with field notes.
The course consists of lectures and practical exercises on stratigraphic sections. There are four daily field trips in the Iglesiente area, where the outcrops allow the application of the methodology acquired in the classroom. This field work is part of the course.
In the case of pandemic emergency COVID-19, lectures could be given also via web streaming. For the same reason, indoor and outdoor practicals could be set on online/streaming platforms.
Lecturing in classroom is accompanied by power point projections to help students for visualize landscapes and concepts. Minimum of 60% class attendance. Language of teaching: Italian, but principal English expressions will be used. Two excursions (1 cfu) of field observation of the main formations of the southern Sardinian Rift, with field notes. Participation in two excursions is required, because there is no way to repeat them off course.
Verification of learning
Continuous control of the learning. The final exam consists in the evaluation of field work and oral examination. The evaluation is expressed through attribution of a final grade.
Evaluation in progress: active participation in lessons, questions, execution of drawings and a report.
The final exam will be written and oral. The written exam consists of six questions with short open answers; no text available; for each question you will have available a total of 15 minutes, beginning 10 plus 5 for review. Questions will be dictated one at a time. The oral will be held in the following days (depends on the number of students). The final vote will be assigned based on the written exam, the oral test and the presence and active participation in lectures and excursions. During oral will be delivered and discussed a short report on an outcrop analyzed during the two fieldtrips. If oral was not satisfactory, the final vote could decrease compared to the written.
The exams will be: three in January-February, two in June-July, one in September.
Exams Registration: from online services for students.
Einsele: Cycles and event in stratigrapy. Ricken and Seilacher (eds), Springer-Verlag.
Homewood, Mauriaud e Lafont: Best practices in sequence Stratigraphy. ELF Editions
Cojan I. e Renard M.: Sédimentologie. Dunod Edition.
The material for the study consists of: text and figures of the lessons (about 150 pages).
Our University provides support to students with specific learning disorders (DSA). If you are interested, you can find more information on the website: http://corsi.unica.it/scienzegeologiche/info-dsa/
Working students (part time students) are invited to agree with the teacher personalized activities to make up for absences from lessons caused by work activities.
Educational material available to students:
- CD containing copies of the figures used in class and in on field activities.
- Extracts of various texts and research papers.
- Collection of rocks.
To understand the issues and for the exam is recommended:
1 - attend as much as possible, because each lecture constitutes a unique synthesis that to be summarized from a text requires careful reading of tens of pages; please note that our policy recommends a minimum of 60% class attendance; the two field trips with the report are compulsory.
2 - The mere presence in the classroom is not enough, you need to participate, ask questions, take notes and make diagrams, at least write the new terms; later integrate your notes with figures and texts presented in class, provided by the teacher as pdf.
3- We recommend the study and discussion in groups, consult the teacher for the necessary clarifications; regularly study before the next class; for the study is recommended to use the printed PDF because the study at the monitor is less consistent.