SGBK20004U Stable Isotopes

Volume 2024/2025

Stable isotopes can be thought of as "the DNA of inorganic materials". They inform us about where materials come from and how they formed.

Stable isotopes provide novel insights to chemical processes across a wide range of fields within the geosciences, including paleoclimate, agriculture, ecology, hydrology, petrology, oceanography, planetary science and paleontology.

This course provides the theoretical background for understanding stable isotope fractionation in natural systems, how isotopes are measured and examples of applications within bio- and geosciences, where isotope analyses are currently used. Stable isotope compositions are used in provenance studies for 'barcoding' inorganic materials, constraining global biogeochemical cycles and chemical reactions and pathways in nature. The course concerns mass-dependent isotope fractionation (e.g.,13C/12C and 18O/16O isotopes),  non-mass dependent isotope processes (e.g.,17O and 33S) and nuclear volume effects (e.g. Tl and U isotopes), and clumped isotope molecular effects (e.g. 47CO2). It also introduces instrumentation for isotope analyses and measures for data quality. Applications of stable isotope systems will be selected following the students specific interests in order to investigate important biogeochemical, environmental, and geologic processes today and in the past. For example, we will explore some of the non-traditional isotope systems (e.g., Li, B, Si, Ca, Fe, Mo, U stable isotopes) and address these tools to scientific problems ranging from the microscopic to the planetary scale.

Learning Outcome


  • A theoretical background in stable isotope behaviors in natural systems, including mass-dependent, non-mass dependent isotope fractionation processes, as well as clumped isotope effects.
  • Practical applications of stable isotopes to solve problems in bio- and geosciences, including non-traditional isotope systems.
  • Analytical techniques (mass spectrometry, optically-based) isotope instruments, quality assurance and control measures for appropriate corrections for stable isotope data.



  • Demonstrate understanding of the governing parameters that can lead to stable isotope fractionation
  • Assessing data quality
  • Evaluate methods applicable for specific problems
  • Solving numerical problems using computer and non-computer-based techniques
  • Assessing data quality
  • Extract key information from primary scientific literature



  • Ability to explain how stable isotopes measurements can be used to understand natural processes in Earth's surface environment.
  • Be familiar with some of the methods used to measure stable isotopes
  • Appreciating issues of sample selection, accuracy, precision and uncertainty during collection, recording and data analysis
  • Assessment of data quality of stable isotope data

See Absalon for a list of course literature.

Academic qualifications equivalent to a BSc degree is recommended.
Weekly lectures, case stories and exercises. Students will read book chapters, primary scientific literature and present a scientific paper for the class.
  • Category
  • Hours
  • Lectures
  • 24
  • Class Instruction
  • 16
  • Preparation
  • 107
  • Exercises
  • 32
  • Project work
  • 26
  • Exam
  • 1
  • Total
  • 206

Feedback to exercises and the student project is given verbally in class. Written feedback to the essay is given before the oral exam. 

7,5 ECTS
Type of assessment
Oral examination, 30 min
Continuous assessment
Type of assessment details
Each student writes one essay (ca. 5 pages) about an isotope system and its application. The student choose an essay topic with approval from one of the teachers and work on the topic during the course. The essay can be handed in anytime and 14 days before the oral exam at the latest.

Oral exam include questions to the curriculum. The exam is 30 min (plus 30 minuttes of preparation time).

Final grade is given by a combination of the oral and written exam, where the oral exam counts 75% and the essay counts 25%.
Exam registration requirements

Approved essay.

All aids allowed
Marking scale
7-point grading scale
Censorship form
No external censorship
One internal examiner

Identical to the ordinary exam.

If an essay has been submitted, then this also counts during the re-exam. If an essay has not been submitted, then a new essay topic is chosen with one of the teacher's approval approximately 4 weeks prior to the oral exam and must be handed in no later than two weeks before the re-exam.

Criteria for exam assesment

See Learning Outcome.