00452 - Geochemistry

Learning outcomes

 The main targets of this course are to provide the following abilities:

1)  to gain the basic knowledge about geochemistry and its applications in different geological and environmental fields;

2) to gain the basic knowledge about thebehaviour of the elements in the superficial environment;

3) to gain  analytical laboratory experiences;

4) to gain the ability to analyse the chemical composition of natural waters in order to assess origin, interactions with the hosting rocks, mixing, dilution etc.

Course contents

Origin and evolution of stars. Cosmochemistry. Nucleosynthesis and the origin of the elements.

Meteorites. Chemical and mineralogical composition, age, classification and genetic hypotheses.

Origin and evolution of the solar system an of the Earthlike planets. Origin of the Earth: condensation vs homogeneous/heterogeneous accretion. Contribution of geochemistry. Internal structure of the Earth. Core-Mantle segregation. Primary geochemical differentiation.  Geochemical classification of the elements: lithophile, siderophile and chalcophile. Genesis and evolution of the continental crust.

Essentials of magma genesis and evolution. Major, minor and trace elements. Goldschmidt's rules of substitution. Clarke and Clarke of concentration. Definition of geochemical availability of the elements.

Superficial processes - Introduction to sedimentary processes. Mechanical disgregation and chemical alteration of minerals and rocks. Dissolution, oxydation, hydratation and hydrolisis. Essentials of thermodynamics. The three principles of themodynamics. Gibbs's free energy. Free energy and chemical equilibrium: applications. Mineral stability and Eh/pH diagrams. Chemical speciation in aqueous solutions: applications. Ionic strength and activity.

Hydrosphere - Chemical composition of seawater. Evaporation and precipitation of salts. Evaporitic sequences, theoretical modelling and field observations. Chemical composition and classification of continental waters. L.L. square classification diagram. Saturation and variability diagrams. Mixing models for waters and related computations.

Atmosphere - Chemical composition and structure. Chemical processes and nuclear reactions in the atmosphere. Ozone and 14C production. History of the atmosphere.

Geochemical cycles . Carbon, nitrogen and sodium.

Isotope geochemistry - Geochemistry of unstable isotopes. The radioactive decay. Radiometric dating, principles and applications. Geochemistry of stable isotopes. Principles of isotope fractionation. Formulations of the isotopic compositions and related applications.

Essentials of some methods of instrumental analytical chemistry: AAS (Atomic Absorption Spectroscopy); ICP (Inductively Coupled Plasma Atomic Emission Spectroscopy); LC (Liquid Chromatography).

Readings/Bibliography

Konrad B. Krauskopf - Introduction to Geochemistry - McGraw-Hill Ed.

Gunter Faure - Principles and Applications of Geochemistry - Prentice Hall Ed.

Brian Mason - Principles of Geochemistry - John Wiley and Sons Ed.

C.A.J. Appelo and D. Postma - Geochemistry, groundwater and pollution - A.A. Balkema Publishers Ed.

James I. Drever - The Geochemistry of Natural Waters - Prentice Hall Ed.

Teaching methods

Lectures.

Laboratory exercises.

Assessment methods

oral examination

Office hours

See the website of Enrico Dinelli