GeOCHemISTea

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!

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:

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:

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.

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 assays, recounting how he and his team set out to develop a portable field laboratory for immediate sample analysis in remote settings. Together, they dive into the highs and lows of calibrating and optimizing pXRF and LIBS, discussing the meticulous sample preparation and calibration required to achieve accuracy and reliability, even in challenging field conditions.

From overcoming unexpected hurdles, like creating custom calibration pellets to ensure consistent LIBS results, to exploring the practical limits and advantages of each technology, this episode sheds light on the adaptability required to make these devices work effectively in geochemical exploration. Sam and Steve also touch on the importance of engaging with vendors for technical support and the value of sharing field-tested insights with other users to advance best practices. Whether you're an experienced geochemist or new to the field, Steve's experiences offer invaluable guidance for anyone interested in applying portable assay technologies to improve exploration outcomes.

For this episode we read:

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.

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.

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 sensing in the mining value chain.

At GeOCHemISTea we love it when someone is so passionate about their geochemistry topic that they reach out and request(!!) to be on the show. An honor, Ben!

So what ground did we cover... manifest your own destiny (or was that the US in the 1800s?). Ben has been a geochemist, a geophysicist, and a data scientist; there's lots of nuggets in there for young geos who are looking for the how-to... so how did Ben become a geochemist?

Our topic of interest this month was to talk about methodology selection to solve geochemical, geometallurgical, and dare I say geophysical situations that arise during the course of exploration and mining programs... and dare I say... Ben has a lot of opinions, advice and ideas on the matter!

We always talk about fluids in geochemistry. How the ore metals are moving and how they are depositing - we think in pressure-temperature-redox space.

However, when we get our geology, structure and geochemistry in 3D... and then we start to rotate a model for the first time... it is the most rewarding moment because we see the fluid pathway and why our metals have deposited.

Nothing, perhaps, in exploration geochemistry is more rewarding then spinning a 3D model. I've paraphrased myself from this interview here, but I hope everyone listening finds a friend in Julia because all geochemistry is 3D and deserves to be seen as we discuss!

For this episode we read:

There are geochemists and isotope geochemists... this episode we're speaking with the latter and this discussion could not be more interesting! Seriously. I found myself at different points so riveted (by that I mean thinking too hard) that I forgot I was supposed to be asking more questions.

As usual, my favorite part of the episode is Tea Time, but for a different reason. As an undergraduate, Libby asked a question to established researchers that were giving a talk to her university 8000+ of miles from their lab en route to do some fieldwork at the Platreef (Bushveld Complex, South Africa) that became a huge contribution to science and ore deposits research, as well as the focus for her MSc and PhD research. So cool.

Critical metals are merely lists built based on geopolitics and supply chain, but are nonetheless essential for advanced technology and particularly the 'green' energy transition.

Our interview spans softball critical metal questions to talking about the dredged material containing sulfate-reducing bacteria that is generating pyrite on the bottom of a canal in the Chesapeake watershed through to more typical acid mine drainage. All the while we retain focus on the recovery of critical metals from unconventional sources to supplement domestic supplies.

For this interview we read:

This episode returns to our roots... to our very first episode with Simon where we talked about the geochemistry of Carlin deposits, except this time we're talking about high sulfidation epithermal systems.

We're talking scale, exploration methodologies, geochemistry, and even a light amount of geophysics, all with a stiffly brewed cup of tea.

For this episode we read two papers:

This is a different conversation from those we’ve had before because we took two extremely different topics in hydrogeochemistry and pXRF on drillcore and looked at how these different techniques and scales come together in a junior exploration program.

A favorite thing Dave likes to say is "we do all sorts of things to the rocks... to try and understand them...." But then Dave often likes to tell geologists and especially mining engineers that "rocks don't give a shit to what we think of them. They're just rocks. They're just gonna sit there and be like, all right, whatever guys. I'm a rock."

And as for why you won't see Dave penning a book on his career... "because it with be complete utter bullshit." That's hindsight bias for you.

What are we observing versus what are we supposed to see, in other words, how (and how much) is dogma directing our interpretations? We explore this concept this month when we delve into Duncan McLeish's PhD work on the transport and deposition of gold at the Brucejack Deposit (Canada). 

In a world where aqueous complexation has long been considered the only viable means of transporting gold to depositional sites in hydrothermal ore-forming systems, Duncan et al. found that rejecting dogma was of the utmost importance. For example, a major weakness of the Au transport in solution hypothesis is that it cannot readily explain the formation of ultrahigh-grade gold veins when transporting Au at ppb levels.

...so how do “bonanza” veins contain weight-percent levels of gold in some epithermal and orogenic deposits?

...what are colloids and flocculation?

...why is this research both exciting and important? 

All this and more in this episode! Put on your thinking caps, it's time to listen to some applied chemistry, economic geology and a little bit of philosophy. 

Did you know that in addition to being one of our industry's geochemical powerhouses, JC is also an artist? But also as we continue along in the episode we'll see that he's perhaps a staunch businessman. 

"...and the moment you run into this will tell you a lot about how you feel as a person, to learn something you might have been wrong about." -Tom Carmichael 

Tom is the Chief Data Scientist at Datarock and we spent a long time at the beginning of this episode talking about the fields of mathematical and computational geology, particularly from the perspective of someone at the university level that is interested in getting into these fields. The rest of the show is about Tom losing his membership to the AGU and a lot of Q&A on the concept of spatial autocorrelation - and importantly how it applies to geochemical data.