Honestly... I don't know which is more interesting... the content of the mesothermal gold chat or the tea.

Almost 17 years after the work was originally presented, we dive into Jeff's honors project - a study on gold mineralization at the Callie Deposit, Dead Bullock Soak, NT, Australia. The evolution of the research to present day is fascinating for all the fans who have asked for some orogenic gold love on the show!

A big thanks to Heidi Pass, Michelle Carery, Dave Lawie, Pim van Geffen, Putra Sadikin, Mike Whitbread, Des Pascoe, & Steve Sugden for rolling with this as we tried for our Holiday special to embody the Dickens-esq theme of Geochemistry: Past, Present & Future.

Everyone on the show this month was part of the ioGlobal team, a global applied geochemistry consultancy for the mineral exploration and mining industries, the likes of which has not been seen since the company was bought in the early 2010s.

Part charming family reunion, part educational, and many parts geochemistry. Happy holidays to everyone from GeOCHemISTea <3

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:

https://www.seequent.com/technical-tuesday-linking-lithology-and-geochemistry-with-iogas-and-leapfrog-geo-workflows/

https://www.seequent.com/connect-your-exploration-teams-with-the-power-of-a-fast-and-agile-workflow/

https://www.seequent.com/mapping-metal-deposits-in-canada/

https://www.seequent.com/data-is-a-solid-investment-for-junior-exploration-companies-2/

https://www.seequent.com/modelling-large-and-complex-data-in-the-integra-gold-rush-challenge/

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.

For this episode we read:

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.

Critical metal geochemistry in groundwaters influenced by dredged material (Goodman et al., 2023)

Rare earth element recovery in hard-rock acid mine drainage and mine waste: A case study in Idaho Springs, Colorado (Goodman et al., 2023)

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:

Alturas: A Unique Discovery Within a Mature District Through Integrating Sound Geological Practices, Multidisciplinary Expertise and Leading Technology (Astorga et al., 2017)

Multi-Scale integrated application of Spectral Geology and Remote Sensing for Mineral Exploration (Zhou et al., 2017)

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.

If you've never been to Nevada, no worries... we're going there together, now.

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.

Join us as we discuss Nassim Nicholas Taleb's philosophical book "Fooled by Randomness" and try and apply it to the wide world of geochemistry... with drinks.

For this episode we read the Datarock blog post Fusing core imagery and chemistry to model stratigraphy.

Perhaps more interesting that the foundation of Datarock is built on Aussie rules football is some of the advice that Brenton Crawford, one of the the company's founders has to impart: that we can get distracted by what we 'need' from a university in order to get the geoscience job we want. He goes on to counsel that getting involved in a community of your choosing, albeit geochemistry, data science, or some other sector, can be a better investment of your time and energy. Importantly, if you have interested in transitioning to data science, remember that your knowledge of the geosciences is infinitely more important than an additional degree in data science - your ability to make an impact on your team is greater simply because you understand the nuances of the data you are working with.

As for working with image data and integrating it with geochemistry... you'll have to have a listen.

For this episode we read: Geochemical Modeling of Water-Rock Interactions in Mining Environments (Alpers and Nordstrom, 1997).

For those who've asked "how do I become an environmental geochemist?" ...Tom has some advice for you. And for those that have questions about the business of consulting... his tea has some hard numbers. Best, though, is when we examine geochemical modeling philosophy and the Alpers and Nordstrom quote that models are "not reality, nor [are they] reliable, correct or valid representation[s] of reality."

After this show, I think we need to interview some more environmental geochemists!