Modern Analytical Methods in Radiogenic Isotope Geochemistry:

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Modern Analytical Methods in Radiogenic Isotope
Geochemistry A Semester Long Applied Course
Jeff Vervoort Washington State University
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Motivation Finding a mechanism to train a group
of students to use the laboratory safely and
intelligently so that the students Understand
what they are doing. Gain the skills and
knowledge so that they can do further independent
geochemical work (e.g., thesis research, etc.)
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Context Audience This course is designed for
beginning graduate students and advanced
undergraduates. The pre-requisites for the
course are Introductory Geochemistry and
(ideally) radiogenic isotope geochemistry. Skills
and concepts that students must have mastered A
basic understanding of chemistry and geochemistry
is required. An understanding of the principles
of radiogenic isotope geochemistry would be
advantageous.
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Structure of the Course Structure This is a
laboratory based course with lectures scheduled
to provide background for the laboratory
work. By necessity, the course is front-end
loaded, with heavy scheduling of lecture and lab
sessions at the beginning and a much lighter
(scheduled) load at the end of the semester (but
replaced with independent project).
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Goals Understand the principles behind
different geochemical methods (e.g., sample
preparation solution chemistry mass
spectrometry). Know the quality of the data
(precision, accuracy). This is important for the
correct interpretation of the data (not all data
are created equal). Gain the skills and
knowledge so that the students can do further
independent geochemical work (e.g., thesis
research, etc.). Think critically (question
everything!).
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Course Structure Laboratory
Lecture Laboratory work drives the lectures
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Projects Group Project Class works on one
project collectively (e.g., Rb-Sr and Sm-Nd
isotope geochemistry) Individual
Project Students work on independent projects
of their choosing
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Lecture Introduction to the elements Geochemical
behavior of the elements Sample preparation Ion
chromatography Rb-Sr and Sm-Nd chromatography Use
of isotopic tracers principles of isotope
dilution Determination of analytical
blanks Fundamentals of mass spectrometry TIMS
MC-ICPMSmass bias interference corrections Data
reduction Assessment of data (Precision,
accuracy, quality) Interpretation of
data Presentation of results (e.g., epsilon
values etc.)
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Laboratory Introduction to the laboratory
(including safety training) Fundamental
laboratory techniques (mixing acids,
pipetting) Titration of acids Cleaning
protocol Sample dissolution and treatment Ion
chromatography e.g., Rb-Sr, Sm-Nd, Lu-Hf, Pb,
etc. Collection of blanks Preparation of samples
for mass spectrometry Mass spectrometry
standards unknowns blanks Data reduction
(mass bias interference corrections, etc.)
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all lab and lecture topics are presented in the
context of the group class projects
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Group Project Class works on one project
collectively (e.g., Rb-Sr and Sm-Nd isotope
geochemistry) end product Submit short
report on results (reduce, present, and
interpret isotope data)
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Laboratory Introduction to the laboratory
(including safety training) Fundamental
laboratory techniques (mixing acids,
pipetting) Titration of acids Cleaning
protocol Sample dissolution and treatment Ion
chromatography e.g., Rb-Sr, Sm-Nd, Lu-Hf, Pb,
etc. Collection of blanks Preparation of samples
for mass spectrometry Mass spectrometry
standards unknowns blanks Data reduction
(mass bias interference corrections, etc.)
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Lecture Introduction to the elements Geochemical
behavior of the elements Sample preparation Ion
chromatography Rb-Sr and Sm-Nd chromatography Use
of isotopic tracers principles of isotope
dilution Determination of analytical
blanks Fundamentals of mass spectrometry TIMS
MC-ICPMSmass bias interference corrections Data
reduction Assessment of data (Precision,
accuracy, quality) Interpretation of
data Presentation of results (e.g., epsilon
values etc.)
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Independent Project Proposal Students
submit a proposal for their project Research
Plan Details of the analytical
methods Analytical work Students in
charge of their own schedule End Products
Written Detailed methods section Oral
Presentation of research and results
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What has worked (students) This IS problem
based learning Students have learned to think
critically Hands-on techniques are an effective
way to teach geochemical fundamentals
(relevance) Many unexpected (and very
intriguing) results Results have led to further
work and impressive end products (presentations
at meetings providing the basis for thesis work
and further research)
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Independent Projects Examples Sr-Nd
isotopes in the Talkeetna Arc Hf-Nd
isotopes in the Aleutian Arc Sr-Nd-Pb-Hf
isotopes in mantle xenoliths Sr-Nd-Pb
isotopes of Canary island volcanics HFSE
chemical separation protocol Ca isotope
chemistry and analysis Sr isotopes in
stream and soil water Sr isotopes in
paleosols LA-ICPMS zircon dating of lower
crustal xenoliths
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What has worked (Instructor) Moves the
instructor in new and unexpected directions
(letting the genie out of the bottle) Find out
interesting things along the way
(serendipity) Can be used to set up new
techniques in the lab
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• What has not worked
• Diverse interests in this course
• students want different aspects from this
  course
• hard to focus on the scientific literature in
  depth
• Only works (in my class) with small numbers.
• Very time consuming.

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Challenges/Problems Diverse interests in this
course students want different aspects from
this course hard to focus on the scientific
literature in depth Time consuming This kind
of course can only accommodate a few
students Scheduling (irregular hours irregular
times throughout the semester) Need to start
with a common (group) project so that students
can help each other (avoids chaos) Project
results may not be interesting
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Applicability This course grew out of my needs
at WSU, but has applicability to other
departments and situations --applicable to
other analytical techniques --senior thesis
work --promoting undergraduate research
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