GeOCHemISTea

Is the next generation of mineral discoveries really hiding at extreme depths, or have we overlooked opportunities much closer to the surface?
In this episode, Sam sits down with returning guest Mark Arundell, geoscientist and geochemical consultant, to challenge one of exploration's most widely accepted assumptions: that bigger discoveries require deeper drilling. Together they explore the "fallacy of the deep," discuss why statistics matter when interpreting exploration success, and examine how integrating geology, geochemistry, geophysics, and modern analytical techniques can unlock value from legacy datasets. They also share insights from consulting, near-miss exploration, and why asking better questions often leads to better discoveries.
In this episode:
Why the "deeper is better" narrative became so influential
Average vs. median discovery depths and why the difference matters
The untapped potential of the first 100 metres
Using modern multi-element geochemistry to reinterpret historic data
How legacy drill core and pulps can create new exploration opportunities
The psychology of exploration and why expensive targets often seem more attractive
When deep drilling is justified—and when it is not
Practical advice for designing smarter exploration programs
As always, we bridge our intro and geochem sections with Tea Time, where Mark shares a memorable airport security story and Sam offers one of her favorite travel hacks.

For Episode 51, the tables are turned as Imdex Chief Geologist and Technologist Dave Lawie takes over hosting duties and puts Sam in the hot seat.
Fresh from the SME Current Trends in Mining Finance conference in New York City, Dave and Sam discuss the growing disconnect between how mining projects are evaluated financially and how they actually behave technically. From resource models and geometallurgy to critical minerals, permitting, and project risk, they explore why geology, mineralogy, metallurgy, and geochemistry remain central to project success.
The conversation also looks at Sam's path into geochemistry, the origins of GeOCHemISTea, and the role mentorship has played throughout her career.
How Sam found her way into geochemistry
Why technical risk is often overlooked in mining finance
The realities of critical mineral recovery
Geometallurgy, mineralogy, and project valuation
Where AI may (and may not) help the industry
Why mining needs better conversations between technical and financial teams
A candid discussion about the assumptions, risks, and opportunities that sit between a discovery and a successful mine.
SME Current Trends in Mining Finance Conference
Imdex
LKI Consulting

For our 50th episode of GeOCHemISTea, we’re doing something a little different... a panel discussion that brings together two very different perspectives on one deceptively simple problem: levelling geochemical data.
Joined by a government survey geochemist, Pedro Acosta-Gongora, and a mathematical geologist, Tom Carmichael, this conversation digs into what levelling really means in practice, why it’s become standard in regional datasets, and where it can quietly distort the geological signal. From legacy data and batch effects to the tension between clean maps and real-world noise, this episode explores the intersection of applied geochemistry and data science.
If you’ve ever worked with multiple datasets and wondered “can I actually trust this?...” this panel is for you.
For this episode we read:
Exploratory data analysis of geochemical exploration data (Arne and Garrett, 2026)
Data Leveling of Multi-Map Geochemical Exploration Data Using Compositional Data Analysis: A Case Study from the Baiyinchagan-Maodeng Area, Inner Mongolia, China (Tang et al., 2025)
Levelling of multi-generational and spatialyy isolated geochemical surveys (Main and Champion, 2022)
G-BASE data conditioning procedures fro stream sediment and soil chemical analyses (Lister and Johnson, 2005)

In this episode of GeOCHemISTea, Sam sits down with Gabe Bowen to explore the world of forensic isotope geochemistry and the power of isoscapes.
From identifying where someone has lived, to reconstructing movement through hair and teeth, isotopes are becoming a powerful investigative tool—bridging geochemistry, ecology, and forensic science.
They break down:
What forensic isotope geochemistry actually is (and what it isn’t)
How isoscapes turn isotope data into geographic maps
Why hydrogen, oxygen, strontium, and sulfur matter
How hair, teeth, and bone record different parts of a life story
The role of geochemistry in solving cold cases and tracking animal movement
And yes... there’s a detour into true crime, salmon migration, and what isotopes might reveal about your last vacation.
This episode highlights how geochemistry extends far beyond rocks and into real-world problems with immediate impact.
🎧 If you’ve ever wondered how geochemistry can help answer the question “Where did this come from?”... this one’s for you.

For this episode we read:
Human tissue oxygen and strontium isotope values in North America: A data compilation and assessment for forensic geolocation (Verostick et al., 2025) BITS: A Bayesian Isotope Turnover and Sampling model for strontium isotopes in proboscideans and its potential utility in movement ecology (Yang et al., 2023)
Isoscapes: Understanding movement, pattern, and process on Earth through isotope mapping (West et al., 2010)
Multi-isotopes in human hair: A tool to initiate cross-border collaboration in international cold-cases (Batalle et al., 2022)

This episode of GeOCHemISTea explores cobalt cycling, critical metals, and why geochemists need to think beyond bulk chemistry to understand how elements behave in surface environments. Sam is joined by Owen Missen, lecturer in environmental geology at the University of Tasmania and researcher with CODES, whose work focuses on the environmental geochemistry and mineralogy of elements like cobalt and tellurium.
The conversation explores why cobalt matters in modern technology, how nanoscale particles are changing the way we think about metal mobility, and what this means for environmental risk around mine waste and legacy sites. Owen also shares insights from Tasmania’s mining legacy, including the Mount Lyell–Macquarie Harbour system, and reflects on why understanding metals at the right scale matters for better mining and environmental decisions.
For this episode we read:
Natural cobalt–manganese oxide nanoparticles: speciation, detection and implications for cobalt cycling (Missen et al., 2024)