Every geoscientist is capable of understanding and applying geochemical data, however, at GeocHemiSTea we understand that there is an incredible amount of nuance and accumulated knowledge. We are here to break down the impediments towards geoscientists learning more about this exciting field! Are you a student wanting to break into the field? Listen to each episode to see how reknown geochemists got to where they are today. Are you intrigued by integrating geochemistry, but don't know how? Stay tuned! Lastly are you looking for some Tea/good gossip? We got it.
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)
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 stage. The conversation moves from regolith terrain assessment andmapping as the real starting point, to why “lowest detection limit” is not a substitute for good planning. Simon also breaks down industry “silver bullets” (MMI, calcrete, ultrafines) and why blanket adoption creates false confidence. Finally, he explains how DetectOre upgrades gold from ppb-scale field chemistry into something actionable and fast, by leaching and concentrating gold onto a collector device that can be read by pXRF, enabling real-time decision-making while rigs are still turning. For this episode we read: Valuing time and how some of the latest technologies arecompressing time to fast track and de-risk new discoveries and mines (Bolster, 2025)
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 importance of integrating geological and processing data to optimize mineral extraction processes, emphasizing the need for collaboration between geologists and processing engineers to enhance decision-making and reduce waste in mining operations. As the conversation unfolds, Mohsen shares his journey from mining exploration to mineral processing, highlighting the significance of automation and AI in modern mining practices. He advocates for a holistic approach to mining that considers the entire lifecycle of minerals, from extraction to recycling, and stresses the importance of leveraging existing geological data to improve processing efficiency. The episode concludes with a forward-looking perspective on the future of mining, envisioning a fully integrated system that not only maximizes resource extraction but also prioritizes environmental sustainability and circular economy principles.
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—highlighting shared tools, concepts, and models that are often studied in isolation. The episode closes with a discussion on batholiths and crustal-scale magma systems, offering a fresh perspective on how modern volcanology can inform interpretations of ancient intrusions and mineralized systems, making it relevant for volcanologists and economic geologists alike. For this episode we read: Integrated Petrological and Geophysical Constraints on Magma System Architecture in the Western Galápagos Archipelago: Insights From Wolf Volcano (Stock et al., 2018) Late-stage volatile saturation as a potential trigger for explosive volcanic eruptions (Stock et al., 2016) Cryptic evolved melts beneath monotonous basaltic shield volcanoes in the Galápagos Archipelago (Stock et al., 2020)
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, “cognitive entrenchment” in porphyry systems, and how linking calculated mineralogy to rock physics is helping bridge the gap between geochemistry and geophysics. For this episode we read: MINSQ - a least squares spreadsheet method for calculating mineral proportions from whole rock major element analyses (Herrmann and Berry, 2002)
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 global references, and practical ways exploration and mining teams can access, use, and contribute to these datasets. Plus: tea stories during Tea Time and why passing knowledge to the next generation keeps this global effort moving. For this episode we read: International Union of Geological Sciences Manual of Standard Methods for Establishing the Global Geochemical Reference Network
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 workflows, and how roscoelite at Porgera became one of the most reliable vectors to high-grade gold. Plus a wild tale about how an ICP machine was used to crack down on gold theft in the mine lab. For this episode we read: Geology of the Porgera Gold Deposit, Papua New Guinea (Hay et al., 2020)
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 down the physics behind modern methods, and reflects on what the future holds for gold assay. Whether you're a field geo or into analytical chemistry, this one's for you.
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 leadership experience, from carrying samples for her USGS geologist father as a child to building geochem training programs for Newmont and ALS, and recently teaching at the Colorado School of Mines. We talk about key developments in stream sediment methods, from fine fraction and BLEG to HMC and indicator mineral chemistry, as well as how to choose the right tool for the job. The episode also covers the practicalities of QA/QC, field planning, and how geomorphology and hydrology shape interpretation. Mary emphasizes the importance of training, knowledge-sharing, and the growing integration of mineralogical data, and machine learning into modern workflows. Whether you are designing your first drainage survey or revisiting legacy data, this episode is a reminder that good geochemistry begins with solid fundamentals and that the future of exploration is already here. For this episode we read: Stream sediment geochemistry in mineral exploration: a review of fine-fraction, clay-fraction, bulk leach gold, heavy mineral concentrate and indicator mineral chemistry (Doherty et al., 2023)
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 cycling, water column anomalies, and hydrothermal plume modeling not only helped lay the foundation for modern vent geochemistry, it also offered early insight into how ore deposits might form in sediment-hosted marine environments. But the real tea? Andy was part of the shakedown cruise for the Titanic dives... yes, that Titanic... on the iconic Alvin submersible. He shares first-hand stories about extreme ocean storms, lost samples, deep-sea discoveries, and how a science cruise turned into an unexpected government career path. From manganese-rich vent clouds to nuclear safety policy, this episode explores the many ways geochemists contribute far beyond the lab. For this episode we read: Water column anomalies associated with hydrothermal activity in the Guaymas Basin, Gulf of California (Campbell and Gieskes, 1984) Manganese geochemistry in the Guaymas Basin, Gulf of California (Campbell et al., 1988)
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 contribution to both industry and research. The conversation also dives into the geochemistry of geothermal systems, the evolution of isotope studies, and the promise of enhanced geothermal systems (EGS). Whether you're early in your career or decades in, this episode is a reminder of the importance of staying open to unexpected opportunities... and the power of combining geoscience with real-world application.For this episode we read: Formation of a Large Cold Groundwater Mantle Helium Anomaly and High Temperature Geothermal Resources in Response to Bimodal Magmatism Near Roosevelt Hot Springs and Utah FORGE, Milford Valley, Southwest Utah (Simmons and Kirby, 2024)
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 shares her unconventional path into geosciences—from a dairy farm in rural Ohio to oceanic research cruises—and offers practical advice for aspiring geochemists seeking interdisciplinary careers. She introduces listeners to the Paleocene-Eocene Thermal Maximum (PETM), a pivotal ancient global warming event used as a critical analog to current climate change. Brittany explains how geochemical proxies, such as stable isotopes and trace elements in microfossils (foraminifera), illuminate past temperature shifts, ocean acidification, and hydrological changes. Tune in for captivating stories from life at sea, including the social dynamics aboard research vessels, and discover how paleoclimatology provides valuable insights into Earth's climate sensitivity and future scenarios. Grab your tea... it's time to spill! For this episode we read: The Paleocene-Eocene Thermal Maximum: A Perturbation of Carbon Cycle, Climate, and Biosphere with Implications for the Future (McInerney and Wing, 2011) Diagenetic Attenuation of Carbon Isotope Excursion Recorded by Planktic Foraminifers During the Paleocene-Eocene Thermal Maximum (Kozdon et al., 2018) Development of a novel empirical framework for interpreting geological carbon isotope excursions, with implications for the rate of carbon injections across the PETM (Turner and Ridgwell, 2016) Individual foraminiferal analyses: a review of current and emerging geochemical techniques (Fehrenbacher et al., 2024)
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 from his career spanning geothermal exploration, environmental geochemistry, and consulting. They also discuss the importance of fieldwork, communicating complex science effectively, and the surprising connections between planetary and mining geochemistry. Tune in for a lively conversation filled with geochemistry, remote sensing, and some unexpected tangents—including volcanic adventures, music, and the tight-knit world of geochemists. For this episode we read: Monitoring of mine drainage related processes through satellite imagery - Dynamic Mapping of Sulfide Oxidation (Benavente, 2024) Dynamic Mapping of Water Bodies using Google Earth Engine (Benavente, 2024)
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 newest geochemical data from field-portable and scanning technologies, examining how they complement and contrast with traditional datasets. For this episode we read: Advances in ICP-MS technology and the application of multi-element geochemistry to exploration (Sader and Ryan, 2019) Advances in exploration geochemistry, 2007 to 2017 and beyond (Winterburn et al., 2019) Evaluation of partial digestions for soils to detect a deeply buried VMS Cu-Zn prospect in boreal forests (van Geffen et al., 2014) Major advances in exploration geochemistry, 1998-2007 (Cohen et al., 2010)
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 geochemistry or a seasoned professional, this conversation is packed with practical advice and thought-provoking discussions on improving exploration geochemistry strategies. For this episode we read: Why 80 mesh? (Garrett, 2019) Metallogeny and mineral exploration - some personal reminiscences (Sillitoe, 2024) Seeing through alluvial gold - fine fraction stream sediment sampling in the Sofala Area, Central New South Wales (Arundell and Gatehouse, 2004)
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 parts science and intrigue. For this episode we read: Orogenic gold: is a genetic association with magmatism realistic? (Goldfarb and Pitcairn, 2022)
