Aley El-ShazlyGeology DepartmentMarshall University

Four person department; offering BS degrees with emphasis in: Geology Engineering Geology Environmental Geosciences

Average 25 – 30 majors Geochemistry is a 400 level class

required for environmental geoscience emphasis

Geochemistry is 4 credit units with a labOffered every other yearPre-requisites are Physical Geology; Chem I & II.

Enrollment is very low: typically 2 – 3 students!

Most Geochem classes offered w/o a lab!

Environmental issues: their importance to WV!

Marshall fairly well equipped for an undergraduate program of this size!

I- General Electric X-ray diffractometer (XRD-9000 Z-80/ XRD-6VS) & XRF Spectrometer (1960’s model upgraded in 1986).

II- Scanning electron microscope

Capable of: imaging at magnifications

up to 200,000 X. Qualitative analysis for all

elements with atomic number higher than 8

Quantitative analysis of spots in solids as small as 2 m

JSM-5310LV SEM with an Oxford Instruments EDS detector, and ISIS 300 software

III- Varian Liberty 110 Inductively Couples Atomic Emission Spectroscope (ICP-OES)

Capabilities:Useful for analysis of dilute

solutionsElements (mostly metallic) are

detected at the parts per million level (ppm).

IV- Varian Spectra AA 600 Zeeman Graphite Furnace Atomic Absorption Spectrometer (GF-AAS)

Useful for the analysis of dilute aqueous solutions

Concentrations of cations detected at the part per billion (ppb) level .

1960’s GE XRD/XRF Spex Mill + standard equipment for crushing,

grinding, sieving, sawing, and polishing rocks Frantz Isodynamic separator + separatory funnels

+ heavy liquids; Centrifuge Muffle furnaces Wet Chemistry lab w/ pH meter + water chemistry

kits + digital titrators & pipettes + all necessary glassware

ICP-AES ZGF-AAS SEM with EDS + Access to Hach spectrophotometers + Access to TEM and AFM in Biotechnology Center,

and portable spectrophotometers

Introduction: Basic chemical principles. Basics of calculus. Cosmochemistry: Origin of the Solar system; nucleosynthesis; Cosmic abundance

of elements; Meteorites; Differentiation of the Earth, Origin of atmosphere & hydrosphere

 Mineral and Crystal Chemistry: Types of bonding, coordination numbers, crystal structures, polymorphism; Isomorphism, Goldschmidt’s rules for substitution; Camouflage, capture & admission

Distribution and Association of elements: The Periodic Table of elements; Goldschmidt’s classification; Distribution of elements in igneous, sedimentary, and metamorphic rocks; Partition coefficients, Trace elements in igneous petrology

Chemical equilibrium: The Phase rule, Phase diagrams, Reversible and irreversible chemical reactions, Balancing reactions, Law of Mass Action, Le Chatelier’s principle, Solubility products, Common ion effect, Activity, Fugacity

 Thermodynamics: 1st, 2nd, and 3rd laws; Gibbs Free Energy, Enthalpy, Entropy, Heat capacity, thermal expansion, compressibility. Some key relations. Applications.

 Water chemistry: Properties of water; Acids & bases; pH, Dissociation constants, Ionic concentrations, Buffers, pH-pC diagrams;  

 Solution – Mineral equilibria: carbonates; silicates; Chemistry of groundwater; chemistry of seawater, Analysis of water samples, Mixing, Dilution, Evaporation.; Activity - activity diagrams: weathering and mineral stability

 Kinetics: Diffusion; Nucleation; Growth  Oxidation and Reduction: Eh – pH diagrams  Radioactive isotopes: Age dating techniques  Stable Isotopes: Principles, applications  Organic Geochemistry

Topic EquipmentBasic principles and objectives; safety measures Grand tour of the labs

Sample crushing, sieving and separation of minerals Frantz Isodynamic separator

Principles of X-ray Diffractometry; Tutorial for HW 2 & 3

XRD

First MT examAcid digestion & preparation of standard solutions Wet Chemistry Lab

Analysis of aqueous solutions ICP-AESAnalysis of aqueous solutions GF-AASWater chemistry pH meter;

spectrophotometersSecond MT ExamAnalysis of minerals in thin section SEM

Other techniques (XRF, EPMA, ICP-MS). Work on projects

Work on projects/ tutorials for homeworks XRD, SEM, ICP-AES.

Grading: 3 tests: 50% Homeworks: 20% : 8 problem sets

covering Cosmochemistry Periodic table + Crystal chemistry Trace elements in igneous rocks Phase rule & phase diagrams Balancing chemical reactions Thermodynamics Water chemistry

Weekly Labs: 15%. Lab project + term paper: 15%

Major Problems Ran out of time! Organic geochemistry was not

covered in lecture! Students who have not had Mineralogy struggled! Students failed to turn in homeworks on time;

homeworks were very painful! There was little time for tutorials Labs took longer than the 2 hour period allocated SEM and ZGFAAS: how much did they really learn? Usual annoying comments about thermodynamics

in students’ evaluations

Designed a separate 300 level lab class called: “Lab techniques in Geology and Environmental Science”

Class is aimed at familiarizing students with capabilities of equipment in Geology/ CoS.

Lab caters to all Science majors who may make use of our equipment for their capstone projects

Only pre-requisite is Physical Geology and Earth Materials Lab

Lab is worth 2 credit hours; lab period is 3 hours long, meeting once a week.

Lab starts with a theoretical background of equipment to be used for ~ 45 minutes.

Enrollment limited to 6

Topic EquipmentBasic principles and objectives; safety measures Grand tour of the labs

Sample crushing, sieving and separation of minerals Frantz Isodynamic separator

Principles of X-ray Diffractometry XRD

Analysis of aqueous solutions I: Mixing & Dilution; Preparation of standards; analysis for Al, Mn, & Fe.

ICP-AES

Analysis of aqueous solutions II: Standard Addition techniques

ICP-AES

Analysis of aqueous solutions III: Trace amounts GF-AAS

Chemistry of Natural waters: Cations & anions pH meter; spectrophotometers; Hach digital titrator and kits

Bulk chemical analysis of rock samples: major elements ICP-AES

Bulk chemical analysis of rock samples: trace elements ICP-AES

Analysis of minerals in thin section: Principles & imaging SEM

Analysis of minerals in thin section: quantitative analysis SEM

Microthermometry of fluid inclusions Linkam StageOther techniques (XRF, EPMA, ICP-MS). Lecture only

I- Grading: Weekly lab reports: 85% Final Exam: 15%

VN-33_ Plag2

Distance (microns)

0 200 400 600 800 10000.0

0.2

0.4

0.6

0.8

Distance (microns)

0 100 200 300 400 500 6000.0

0.2

0.4

0.6

0.8XAnXAbXOr

Cpx

Hb

0.3 mm

Students are asked to obtain: A BSEI w/ mafic and felsic minerals; identify all

minerals in your picture with the help of the EDS. A Secondary electron image of the same area. An X-ray image of a zoned plagioclase feldspar A linescan of the same zoned plagioclase

feldspar crystal. A quantitative analysis of one mineral: Hb/Bt vs.

Pl/Or Stoichiometry of the Pl, Or, Bt, or Hb A 2 page report on this sample with all the

results that you obtained. 

III- Student Comments: Would prefer a project over a final exam! All would opt for a project of major element

analysis using the ICP-AES! All enjoyed the SEM work the most! Most enjoyed major element analysis of

rocks and the use of GCDkit or Petrograph!

IV- Pitfalls to avoid Objectives: make sure that they are clearly stated

for each lab Using your (current) research samples: do not

attempt to get meaningful data through the student lab

Sample Preparation: provide the students with pre-prepared (and preferably pre-analyzed) samples

Data manipulation/ interpretation: factor the time needed for that; ….. provide sufficient PC support

Projects: Have those ready for students, chances are most won’t be able to come up with ones in the course of the semester

IV- Outstanding Problems Very time-consuming: Need to prepare and

analyze solutions ahead of time; best if you had a technician/ TA.

Students must be supervised at all times; if they work in pairs, that triples your contact hours!

Students w/o a background in Mineralogy struggle with mineral separation/ SEM lab/ stoichiometry/ XRD lab.

A good comprehensive textbook? Thermodynamics! Calculus! Lack of background in Mineralogy is a

serious problem Two – year rotation? Low enrollments? How can we measure our true success?

Thank You!