?Prof Cris Lana from the Department of Earth Sciences in the Faculty of Science at Stellenbosch 中国体育彩票 delivered his inaugural lecture on Tuesday 23 September 2025. The title of his lecture was “'Unlocking Earth's past: stories written in isotopes".
Lana spoke to the Corporate Communication and Marketing Division about how isotopes – different forms of the same chemical element with slightly different weights – shed light on the timing and processes that shaped Earth's history.
Tell us more about your research and why you became interested in this specific field.
My research focuses on isotope geochemistry – the study of tiny variations in the atoms that make up elements, and how these differences can help us understand the timing and processes that shaped Earth's history.
I use innovative methods such as lithium, boron, carbon, strontium, neodymium and hafnium isotopes, U-Pb geochronology (a way of dating the age of rocks and minerals by checking how much uranium has turned into lead over time), as well as trace-element mapping.
I became interested in this field because my passion is to understand how our planet evolved. Also, isotopes allow us to measure geological time precisely and to trace the chemical conditions of ancient oceans, magmas, and environments.
Early in my career, I was fascinated by how tiny mineral grains could record billions of years of Earth's evolution. That curiosity grew into a passion for developing new analytical tools to push the limits of what we can learn from rocks, fossils, and even fluids trapped deep underground.
How would you describe the relevance of your work?
My work is relevant on several levels. Scientifically, it provides precise timelines and environmental reconstructions that are critical for understanding continental breakup, climate change, ocean chemistry, and mass extinction events.
Technically, it contributes to the development of open-source software, reference materials, and advanced analytical methods, which benefit the broader geoscience community.
In terms of society, this research has applications in natural resource exploration, environmental monitoring, and education. The applications range from helping locate critical minerals to reconstructing past climate conditions.
Ultimately, the relevance of my work lies in bridging fundamental science with applied solutions, and at the same time training the next generation of researchers in cutting-edge isotope techniques.
What are some of the things that isotopes can tell us about Earth's history?
Isotopes are powerful tools for uncovering Earth's history because they act like clocks as well as fingerprints. Radiogenic isotopes (isotopes that are formed when unstable atoms decay over time), such as uranium-lead (U-Pb) or rubidium-strontium (Rb-Sr), allow us to measure geological time and date events like mountain building, continental breakup, mass extinctions, or fossil burial.
Stable isotopes, like oxygen, carbon, and strontium, record past climates, ocean chemistry, and global carbon cycles, while others trace redox conditions (whether an environment encourages atoms to gain or lose electrons) or the origins of magmas and differences or variations in the composition, temperature, or properties of the Earth's mantle. They can help to track animal migration and even reveal the movements and diets of ancient organisms. Together, isotopes let us reconstruct when key events happened and the environments in which they unfolded.
Can you give examples of how your research is applied in real-world contexts?
By dating rocks and tracing fluid histories with isotopes, we can identify the timing and conditions of ore deposit formation. This helps mining companies target areas rich in critical minerals, such as lithium, rare earth elements, or precious metals.
Stable isotopes of oxygen, carbon, and strontium in fossils and sediments allow us to reconstruct past climates and ocean chemistry. These records provide analogues for today's climate change, showing how ecosystems responded to warming, sea-level rise, and ocean anoxia (when an ocean has very little or no oxygen) in the past. My work on pre-salt carbonates in Brazil, for example, uses isotopes to date and characterise rocks that form reservoirs for oil and gas. Understanding their age, fluid circulation, and chemistry improves reservoir models and guides exploration.
Beyond geology, isotopes trace the origins of materials. Strontium and calcium isotopes in bones and teeth reveal where animals (or humans) lived and what they ate. This has applications in archaeology, wildlife conservation, and even food authentication (e.g. proving where wine or honey was produced).
Looking into your crystal ball, what developments do you see in isotope studies?
I see isotope studies moving into an era of higher precision, broader application, and greater accessibility. Technological advances in instruments, such as multi-collector ICP-MS with collision/reaction cells and increasingly smaller laser ablation spots (small areas on a material's surface that are vaporised with a laser), will enable us to analyse tiny domains within minerals, fossils, and even environmental particles with unprecedented accuracy.
I also see isotopes applied far beyond traditional geology: from tracing climate change impacts in soils and waters, to monitoring pollution, food authenticity, and human health.
Another big shift will be the integration of isotopes with big data and open-source tools, enabling global databases and AI-driven pattern recognition across time and space.
The higher education environment can be challenging. What keeps you motivated when things get tough?
People keep me motivated. Supervising students and watching them turn questions into papers and even becoming academics – these are things that keep me going.
I love collaborating with colleagues across continents and building tools (like data-reduction and mapping software) that make other isotope labs faster and more reproducible.
I also draw energy from the real-world relevance of the work. When isotope data helps to constrain the timing of continental breakup, improve reservoir models, or inform environmental questions, it reminds me that our efforts matter.
Tell us something exciting about yourself that people would not expect.
Something unexpected? I'm very predictable. I think about science all the time. Even when running, hiking, cooking, or travelling, I find myself making connections back to rocks, fossils, or isotopes. Friends and family joke that I see the world through a geologist's eyes.
How do you spend your free time?
I enjoy catching up on sleep, which is the best way for me to recharge. I also like reading, both for inspiration and relaxation. And I enjoy going out, whether it's exploring new places, sharing meals with friends, or simply stepping outside to enjoy nature, something that is wonderfully easy to do in South Africa.
- Photo: Prof Cris Lana at the inaugural lecture: Photo: Ignus Dreyer
?
?
