Geochemistry
Objectives
The goal of the discipline is to lead the students to understand the mechanisms of the geological processes as a Geochemical process, from magma generation to magma evolution, from distribution and association of chemical elements during the geological processes to mineral accumulation (mineral deposits) and mineral and rock alteration
General characterization
Code
10669
Credits
3.0
Responsible teacher
Joaquim António dos Reis Silva Simão, Nuno Gonçalo Figueiredo de Freitas Leal
Hours
Weekly - 3
Total - 50
Teaching language
Português
Prerequisites
Previous knowledge on:
- Mineralogy
- General Geology
- Igneous and Metamorphic Petrology
and
- General Chemistry.
Bibliography
Mason, Brian & Moore, Carleton B. (1982) - Principles of Geochemistry. John Wiley & Sons. 4th Ed., 344 p.
Rodrigues, B. & Bravo, M.S., (1983) - Interpretação de Diagramas de Fases de Interesse Geológico. FCT/UNL, 163 p.
Cherdyntsev, V.V. (1961) - Abundance of Chemical Elements. The University of Chicago Press, 304 p.
Krauskopf, Konrad B. (1989) - Introduction to Geochemistry. McGraw-Hill International Edition.2nd Ed., 617 p.
Rankama, K & Sahama, T.G. 1950. Geochemistry. The University of Chicago Press. Chigo & London,. 912 p.
Teaching method
Theoretical presentations, with content discussion.
Practical exercises. Student’s presentations of thematic works (chemical elements in the context of Geochemistry, Types of Mineral Deposits, Mineral Deposits in Portugal, minerals with economic importance).
Evaluation method
Continuous evaluation:
6 mini-examination tests (6 X 5%), at the beginning of classes
1 Group work
Oral presentation (10%) + Report (20%)
1 examination test (30%)
Participation (10%)
(Attendance, punctuality, participation in classes and online)
or
Final examination
FREQUENCY CONDITION:
Presence in 2/3 of the theoretical-practical classes.
Subject matter
Introduction: Geochemistry, concept, objectives. The Earth and its relationship with the Universe; meteorites. Origin and abundance of the elements in the Universe and in the Earth. Composition and structure of the Earth. The Periodic Table and the geochemical classification of the elements. Alkaline, calk-alkaline elements, halogens, Rare Earth elements, inert gases. The geochemical classification of Goldschmidt. Siderophile, chalcophile, lithophile and atmophile elements. Abundance, distribution and mobility of the elements. Abundance and distribution of the elements in the Earth and in the crust of the Earth and during the geochemical processes in igneous, sedimentary and metamorphic rocks. Major, minor and trace elements. The Geochemical Cycle. Geochemical environment, primary and secondary environments. Igneous processes, magma generation, partial melting, fractional crystallization, Distribution and mobility of the elements during igneous processes. Sedimentary processes, sedimentary environment. Chemical, physical and biological processes. Weathering, changes in rock composition, sequence of mineral alteration. Weathering agents, effects on carbonates and silicates. Metamorphism and metamorphic reactions. Chemical changes during the metamorphic reactions. Rock alteration as a geochemical process. Alteration of igneous, sedimentary and metamorphic rocks. The role of chemical and mineralogical rock composition during the alteration processes. Climate and pollution during the alteration processes. Environmental Geochemistry. Atmosfphere, hydrosphere and lythosphere. Pollution as a geochemical process, effects on rocks, animals and plants. Geochemistry in mineral exploration/Basic principles. Mineral survey. Dispersion and mineral geochemical mobility. Geochemical distribution pattern, interpretation. Geochemical anomaly, interpretation.
Geochemical field prospecting. How to make a field prospecting. Field equipment and laboratory. Chemical analysis laboratory, existing techniques,advantages and disadvantages of each.