GeOCHemISTea

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 geometa...

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...

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 act...

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 a...

Simon Bolster joins GeOCHemISTea to unpack what actually makes near-surface geochemistry work in mineral exploration: understanding regolith and landforms before you ever “put dirt in bags.” With four decades in gold exploration, Simon argues that many programs fail not because geochemistry is “bad,” but because sampling and analytical choices do not match the terrain,the cover, or the project sta...

In this episode of GeOCHemISTea, host Sam Scher engages in a thought-provoking conversation with Professor Mohsen Yahyaei, a mineral processing engineer and director at the Julius Kruttschnitt Mineral Research Center. They explore the impact of geographical differences on mental health, particularly how varying daylight hours can affect mood and productivity. The discussion transitions into the im...

In this episode of GeOCHemISTea , Sam talks with Mike Stock , Professor at Trinity College Dublin, about magma systems from eruption to emplacement. Drawing on work in the Galápagos and Ireland, Mike explores how the same geochemical and petrological processes govern both volcanic activity and ore formation. The conversation focuses on breaking down silos between volcanology and economic geology—h...

This month on GeOCHemISTea, Sam sits down with Scott Halley to talk about extracting meaningful mineralogy from standard four-acid assay data. Scott walks through how the classic MINSQ approach evolved into modern linear-programming methods that handle solid solutions, honor thermodynamics, and produce fast, first-pass mineralogy models. They also dig into ambiguity in geologic interpretation, “co...

Alecos Demetriades, applied geochemist and Chair of the IUGS Commission on Global Geochemical Baselines (2024–2028), joins GeOCHemISTea to unpack the Global Geochemical Reference Network (GGRN): why a 160×160 km grid matters, how harmonized sampling/analysis underpins trustworthy baselines, and what QA/QC must look like before interpretation. We touch on FOREGS, leveling national datasets to globa...

This month on GeOCHemISTea, we welcome back Simon Griffiths, Principal Consultant at Third Planet Exploration Services, to unpack the geochemical exploration strategies for low-sulfidation epithermal systems. From vein textures to vanadium-rich roscoelite halos, Simon walks us through practical strategies for geochemical targeting and alteration mapping. He shares insights into sampling, spectral...

In this episode of GeOCHemISTea, we're joined by Hugh De Souza to explore the evolution of gold analysis; from 4,000-year-old fire assay traditions to disruptive technologies like photon assay. With over 40 years at research and industry analytical labs and deep experience in mineralogy, geochemistry, and lab innovation, Hugh shares his unconventional path into analytical geochemistry, breaks...

This month on GeOCHemISTea, we are talking about one of exploration geochemistry’s most foundational, and rapidly evolving, methods: stream sediment sampling. Sam is joined by geochemical consultant and educator Mary Doherty, lead author of a 2023 review on stream sediment geochemistry, published in Geochemistry: Exploration, Environment, Analysis . Mary shares a career’s worth of field, lab, and...

In this episode of GeOCHemISTea, we're diving deep, literally, with Andy Campbell, oceanographer, geochemist, and former senior leader at the U.S. Nuclear Regulatory Commission. Andy takes us back to his PhD days at Scripps Institution of Oceanography, where he conducted some of the earliest geochemical research on seafloor hydrothermal systems in the Guaymas Basin. His work on manganese cycli...

In this episode of GeOCHemISTea , Sam sits down with geochemist and geothermal expert Stuart Simmons to discuss the unpredictable paths that shape a career in geoscience. From early work in epithermal gold systems to pioneering research in geothermal energy, Stuart shares how professional pivots, academic curiosity, and a chance encounter at a pub in New Zealand all influenced his decades-long con...

Join us this month on GeOCHemISTea as we sit down with Brittany Hupp, Assistant Professor at George Mason University in the Department of Atmospheric, Oceanic, and Earth Sciences. Brittany specializes in micropaleontology, sedimentology, and low-temperature geochemistry, exploring ancient climates and ocean conditions to better understand modern environmental challenges. In this episode, Brittany...

This month GeOCHemISTea talks with Oscar Benavente, an environmental geochemist at SRK Consulting, about using satellite imagery to monitor mine drainage and environmental change. They dive into how Google Earth Engine, Python, and machine learning are transforming geochemical monitoring—mapping water bodies, tracking sulfide oxidation, and improving mine site remediation. Oscar shares insights fr...

Historical geochemical datasets can be challenging with variable methods, missing metadata, and shifting detection limits, but they’re also an invaluable resource for mineral exploration and mining. In this episode, we break down what qualifies as historical data, common pitfalls to watch for, and best practices for integrating legacy datasets into interpretation workflows. We also explore the new...

In this episode we talk with Mark Arundell, Principal Geologist at IMEx Consulting, to delve into the past, present, and future of geochemical sampling. With over 30 years of international experience, Mark shares insights into avoiding suboptimal sampling, the importance of understanding regolith, and how smarter techniques can lead to better outcomes in mineral exploration. Whether you're new to...

In this episode of GeOCHemISTea we dive into the origins of orogenic gold deposits with Rich Goldfarb, exploring the science behind fluids, isotopes, and formation processes. From debunking magmatic theories to highlighting the facts of metamorphic origins, Rich shares the real tea (and quite a number of shenanigans) on how to make an orogenic gold deposit . Join us for a conversation that’s equal...

In this episode of GeOCHemISTea , host Sam Scher sits down with Steve Tambanis, Managing Director at STX Consulting and Director at RealTime Priority Limited, to explore the challenges and innovations in field-based geochemical analysis using portable XRF (pXRF) and laser-induced breakdown spectroscopy (LIBS). Steve shares his journey from traditional exploration geology to pioneering real-time as...

Let's learn about upscaling LA-ICP-MS pyrite results to whole rock geochemistry data using PCA. On the way we'll hear about the life and times of an early career geochemist and some of the ins and outs of being a geochemical consultant. For this episode we read: Using whole rock and in situ pyrite chemistry to evaluate authigenic and hydrothermal controls on trace element variability in a Zn miner...

For this episode we read: Archean Lode Gold Deposits in Ontario (Colvine et al., 1984) aka the Greenstone Bible. We talk about Simon's transition from working from large mining companies to opening his own consultancy for all those considering this as part of their future. Our tea... have you ever been late to your flight, anxious on the shores of Lake Victoria, Tanzania? As for the heart of t...

This is our second episode on GeOCHemISTea where we have branched out from geochemistry into a sister geoscience - spectral geology. For this episode take a look at another of the spectral ecosystem's end-members: hyperspectral core imaging. Join us as we talk about hyperspectral imaging, the data load, and some interesting applications to porphyry geoscience. For this episode we read: Hypersp...

Herein we present a general microanalytical technique rant, at least three soap boxes (my favorite being "I want to also rant about bulk chemistry techniques and why if these techniques are “so routine” that we still have some labs that suck at understanding (or respecting) how to do basic chemistry well"), and the story of how a geologist with a graduate degree in geochemistry found the...

This is our first episode on GeOCHemISTea where we have branched out from geochemistry into a sister geoscience - spectral geology. For this episode we start from one of the spectral ecosystem's end-members: remote sensing, or satellites and airborne. Join us as we talk about the newest developments in sensor tech and data processing, while still paying proper attention to the role of remote s...