UCL Earth Sciences


GEOL0017 Isotope Geology

This module introduces the student to theoretical and practical aspects of radiometric geochronology and stable isotope geology.

Coordinator: Prof Pieter Vermeesch

Module details
TitleIsotope Geology
UG CodeGEOL0017
CoordinatorProf Pieter Vermeesch
Other ContributorsDr Susan Little
Credit15 credits
Written Exam70% (3 hours unseen written exam)



Maths & Stats Content and Requirementbasic math (arithmetic, rearranging equations)
Total Number of Hours of Student Work188 hours
Hours of Lectures/Seminars20 hours
Hours of Practicals/Problem Classes20 hours
Hours of Tutorials0
Days of Fieldwork0

The following topics will be introduced, discussed and analysed:

  • Nucleogenesis, isotopes, radioactivity, mass spectrometers, isotope dilution 
  • The age of the Earth, the geologic time scale, relative and absolute dating, 14C dating 
  • The age equation, the Rb-Sr, Sm-Nd, Re-Os and Lu-Hf methods, isochrons 
  • The U-Pb and Pb-Pb methods, concordia 
  • K-Ar and 40Ar/39Ar dating 
  • Thermochronology with the U-Th-He and fission track methods 
  • U-series disequilibrium dating 
  • Basic error propagation
  • Extinct nuclides 
  • Mantle isotope geochemistry: element compatibility and how it affects isotopes (Nd, Hf, Pb, Sr, Nd) and crustal evolution 
  • Principals of stable isotopes: notation, isotope fractionation, kinetic and equilibrium fractionation, stellar isotope production 
  • High temperature oxygen isotopes: sun, meteorites, mantle (igneous and metamorphic) 
  • Low temperature oxygen and hydrogen isotopes: ocean, temperature, glaciation 
  • Carbon isotopes: carbon cycle, plants, fossil fuels 
  • The long-term carbon cycle: The carbonate system, and palaeo-CO2 records (B isotopes); Palaeo-weathering and the long-term C cycle (Sr, Os, Pb, Li isotopes) 
  • S isotopes: biogenic fractionation, sulphur cycle, rise of oxygen (MIF and MDF S isotopes) and isotope evolution of marine sulphate 
  • Ocean circulation: 14C, Nd, Pa isotopes Low-temperature U series: alpha decay, coral dating (+14C), ocean productivity 
  • Transition metal isotopes: oceans and critical zone


To enable the students to: 

  • understand and interpret published isotope data
  • understand Earth processes through isotope geochemistry
  • identify suitable isotope ratios for their own geochemical applications


    • Introduce the physical and chemical processes that determine the isotopic composition of Earth materials, including nucleosynthesis, radioactivity and fractionation processes
    • Provide a basic understanding of mass spectrometry
    • Derive the basic mathematical underpinnings of the radiometric age equation, isochrons and the U-Pb concordia diagram
    • Provide a rigorous background in error propagation
    • Provide a broad overview of the natural processes that can lead to mass-dependent fractionation of stable isotopes
    • Explain how stable isotopes measurements can be used to understand said natural processes, both in the solid Earth and its fluid envelopes.

      Practical and transferable outcomes:

      • Understanding of the cycling of matter and the flows of energy into, between and within the solid Earth, hydrosphere, atmosphere and biosphere.
      • The chemistry, physics, biology and mathematics that underpin our understanding of Earth structure, materials and processes.
      • Geological time, including the principles of stratigraphy, radiometric dating.
      • The multidisciplinarity and interdisciplinarity of geochemical approaches
      • The range of spatial and temporal scales geochemistry covers
      • Appreciating issues of sample selection, accuracy, precision and uncertainty during collection, recording and analysis of data
      • Preparing, processing, interpreting and presenting data, using appropriate qualitative and quantitative techniques and packages
      •  Solving numerical problems using computer and non-computer-based techniques