Greg Druschel

321 Delehanty Hall

Gregory.Druschel@uvm.edu

GEO 135Introduction to Geochemistry

Course Goals

At the end of this course…

• You will be able to utilize thermodynamic to determine if individual reactions are feasible/important under any given condition

• You will be able to design a sampling protocol, analyze key chemical components, apply thermodynamic or kinetic models, and test hypotheses concerning the mobility of elements in any setting

• You will be able to appreciate both the dynamics and complexity of geochemistry yet utilize what you know to ascertain processes important in the stability, movement, and reactivity of elements in the earth

What is Geochemistry??• Victor Goldschmidt defined the study of

geochemistry as: “the laws governing the distribution of the chemical elements and their isotopes throughout the earth”

• What does that mean?• We are interested in understanding the

different ways in which elements move whether in the core, mantle, crust, oceans, sediments, air, space, or other planets…

b

FeS2 + 3.5 O2 + H2O Fe2+ + 2 SO42- + 2 H+

Fe2+ + O2 + H+ Fe3+OOH + 2 H+

O2 diffusion

Bacteria/ archea Fe oxidizers, S oxidizers

Light photochemical rxns, phototrophic organisms??

CH2O + FeOOH Fe2+ + CO2

CH2O + SO42- HS- + CO2

H+ + SO42- < -- > HSO4

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Field Geochemistry• Scale – Where and when do you take a sample??

Field Notebook

• Need to record all observations, measurements, and sampling locations/times

• Get something weatherproof (Write-in-the rain notebooks work great)