PřF:G9811 Geochem. exogen. proc. - Course Information

G9811 Geochemistry of exogenous processes

Extent and Intensity

2/1/0. 5 credit(s). Type of Completion: zk (examination).
In-person direct teaching

Teacher(s)

Mgr. Pavel Pracný, Ph.D. (lecturer)
Mgr. et Mgr. Veronika Synková (assistant)

Guaranteed by

Mgr. Pavel Pracný, Ph.D.
Department of Geological Sciences – Earth Sciences Section – Faculty of Science
Contact Person: Ing. Jana Pechmannová
Supplier department: Department of Geological Sciences – Earth Sciences Section – Faculty of Science

Timetable

Mon 11:00–12:50 Gs,-1011, Mon 13:00–13:50 Gs,-1011

Prerequisites (in Czech)

! G9810 Geochem. exogen. proc. && ( (!(PROGRAM(B-GE)||PROGRAM(N-GE)||PROGRAM(D-GE4)||PROGRAM(D-GE)||PROGRAM(C-CV))) || (NOW( G0101 Occupational healt and safety )&&NOW( C7777 Handling chemical substances )))

Course Enrolment Limitations

The course is also offered to the students of the fields other than those the course is directly associated with.
The capacity limit for the course is 28 student(s).
Current registration and enrolment status: enrolled: 10/28, only registered: 0/28, only registered with preference (fields directly associated with the programme): 0/28

fields of study / plans the course is directly associated with

there are 32 fields of study the course is directly associated with, display

Course objectives

Main objectives can be summarized as advanced understanding of the geochemical processes proceeding under conditions of earth surface, especially:
- physical/chemical/thermodynamic/kinetic aspects of rock weathering
- diffuse model of rock-water interaction
- reaction model - the transition state theory
- nucleation and crystal growth
- geochemistry of clay minerals
- equilibrium models of Al-pH and Al-Si-pH systems
- diagrams of predominant stability in the systems of Na-Al-Si-H2O, K-Al-Si-H2O, and Ca-Al-Si-H2O
- dynamic model of weathering in open system under different climatic conditions

Learning outcomes

Student will be able to:

a) distinguish which weathering processes take place in individual environments.
b) explain basic theories in the background of water-rock interactions (diffusion model, transition state theory, nucleation and crystal growth ...).

c) create the equilibrium model of Al-pH, Al-Si-pH.

d) compare the data in the stability charts.

e) make a dynamic model of weathering in an open system with the involving of climatic changes.

f) summarize geochemical processes acting on the selected site.

Syllabus

• Rocks stability at surface conditions: Non-stability of igneous and metamorphic rocks. Rock system evolution. Entropy and Gibb's energy. Goldish's scheme.
• Rock weathering: Physical and chemical weathering. Aluminosilicate weathering. Reversibility and irreversibility of processes. The model of diffusion through surface layer. The model of surface reaction. The role of atmosphere and waters. The buffering of waters by CO2. Biogeochemical processes.
• The kinetics of rock-water interaction: Experiments. Box-models. Mass reservoirs, fluxes. Rate equations, rate constants. Steady state, equilibrium. Arhenius' equation. Pre-exponential factor. Activation energy.
• Transition State Theory: Elementary processes. Theory of activated complex. Modeling, computation. Potential barrier. Thermodynamic approach. Rate of interaction. Chemical affinity.
• Saturation state: Thermodynamics of dissolution. Saturation index. Supersaturation, equilibrium and under-saturation of solutions.
• Nucleation theory: Thermodynamics of surfaces. Interfacial surface energy. Polymerization, condensation. Homogenous and heterogeneous nucleation. Clusters, nuclea, and critical nucleus. Potential barrier. Supersaturation influence.
• Crystal growth: Growth mechanisms. Ostwald's step rule, re-crystallization. The formation of secondary mineral phases. Dioctaedral gibbsite layer. Trioctaedral brucite layer. Amorphous SiO2 gels, quartz stability.
• Clay minerals: 1:1 layer minerals: kaolinite, halloysite. Stability and solubility. 2:1 layer minerals: smectite (pyrophyllite, montmorillonite, beidellite), vermiculite. 2:1:1 layer minerals: chlorites.
• Models of secondary phase formation: Al-pH system, equilibrium boundary, solution and mineral stabilities. Al-Si-H2O system, kaolinite, gibbsite, and pyrophyllite stability.
• Diagrams of predominant stability: Na-Al-Si-H2O, K-Al-Si-H2O, Ca-Al-Si-H2O systems. Construction. Stability fields. Equilibrium lines. Reaction path and system evolution.
• Dynamic model of rock weathering: Influence of climatic condition. Annual precipitation. Drainage. Soil water composition and concentrations.

Literature

recommended literature
• BAUER, Andreas and Bruce D. VELDE. Geochemistry at the earth's surface : movement of chemical elements. Berlin: Springer, 2014, 315 stran. ISBN 9783642313585. info
• STUMM, Werner and James J. MORGAN. Aquatic chemistry : chemical equilibria and rates in natural waters. New York: John Wiley & Sons, 1995, xvi, 1022. ISBN 0-471-51184-6-. info
• APPELO, C.A.J. and D. POSTMA. Geochemistry, Groundwater and Polution. 1st ed. Rotterdam/Brookfield: A.A.Balkema, 1994, 519 pp. ISBN 905410 106 7. info
• DREVER, James I. The Geochemistry of Natural Waters. Prentice Hall, 1997, 450 pp. ISBN 0-13-272790-0. info

not specified
• Chemical weathering rates of silicate minerals. Edited by Art F. White - Susan Louise Brantley. Washington, D.C.: Mineralogical Society of America, 1995, xv, 583. ISBN 0939950383. info
• PFEIFFER, Hubert, Thomas KLUPSCH and Werner HAUBENREISSER. Microscopic theory of crystal growth. Berlin: Akademie-Verlag, 1989, 400 s. ISBN 3055006844. info

Teaching methods

Lectures, reading, seminars

Assessment methods

2 written tests, final test.

Language of instruction

Czech

Further comments (probably available only in Czech)

Study Materials
The course is taught once in two years.
Information on the per-term frequency of the course: Bude otevřen v podzimním semestru 2024/2025.

Listed among pre-requisites of other courses

• GS021 Environmental geology
  (G9811 || NOW(G9811) || G9811k || NOW(G9811k)) && (GA921 || NOW(GA921) || GA921k || NOW(GA921k))  

• Enrolment Statistics (recent)
  
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