Wonder

A few weeks before Holly set sail for Greenland with The Explorers Club and Adventure Canada’s 2026 Young Explorers Program, she and Anthony sat down with Dr Julie Hollis for a pre-expedition brief on everything Greenlandic geology!

Julie spent years mapping Greenland’s rocks and leading geology at Greenland’s Ministry of Mineral Resources, and she tells us that Greenland really is the one place she calls home. Together with Julie we read Greenland’s deep memory: from some of the oldest rocks on Earth near Nuuk, to the deep roots of a nearly two-billion-year-old volcanic arc along the south coast, to why Greenland’s resources are suddenly on the world stage. Plus, we hear the outrageous story of the one geologist to be sat on by a polar bear... 🐻‍❄️

So - tune in to hear about the Greenlandic geology Holly's about to sail through. And we've now also released Holly's mini-film, shot live from the field, all on her scientific notes from the edge of the ice... Go check that out next!

Where Anthony sees crystals and Holly sees a rock, Dr Eric Vandenberg sees atoms, and specifically, Eric counts the neutrons. Eric is a postdoc at the Adelaide University and part of the ARC Training Centre for Critical Resources for the Future, and he shrinks the solid Earth down to the subatomic scale to answer some of geology's biggest questions: how the first continents formed, how plate tectonics got started, and how the rarest metal deposits on the planet came to be.

⚛️ What even is an isotope? Same element, different number of neutrons. But some isotopes are "radiogenic" and quietly decay over geological time (hello, beta and alpha decay), and why anything heavier than lead is inherently unstable.

⏳ The gold standard for dating rocks: why uranium and thorium love hiding inside zircon crystals, why lead doesn't, and how that mismatch lets geologists measure the exact age of a rock - this is geochronology in a nutshell.

🪨 The Pilbara: older than almost anything left on Earth. A craton stretching from 3.6 to 2.8 billion years old, closer in age to the formation of the planet than to today, and one of the best-preserved windows we have into Earth's earliest crust.

🌋 Earth vs Venus: why Earth is the only planet in the solar system with true plate tectonics, what a "stagnant lid" planet like Venus looks like instead, and the decades-old scientific debate over exactly when Earth made the switch.

⛏️ From ancient cratons to critical minerals: How isotope geochemistry traces the journey of gold, copper, nickel and platinum from sulfides deep in the mantle into the porphyry and IOCG deposits we mine today, without needing the impossibly hot magmas of the early Earth.

A huge thank you to the Centre for Critical Resources for the Future for supporting this episode.

🔗 Find us at thegeoco.com.au 📸 Instagram & TikTok: @thegeoco 📰 Sign up to our newsletter: thegeoco.substack.com

GeoCo connects to you from the traditional country of the Kaurna people of the Adelaide Plains, South Australia. We pay our respects to their Elders past, present, and emerging.

Volcanologist Dr Hayden Dalton (University of Melbourne) joins Holly & Anthony with the science he's bringing to a fascinating human question: exactly how many hominin species were alive at the same time, in the same place, and were they really competing for the same resources?

Or... has the apparent overlap in existing timelines been an artifact of imprecise dating? Hayden reveals that scientists can now bracket ash layers to within about 800 years on rocks over a million years old, roughly a tenfold jump in precision from a couple of decades ago, and that new resolution is what makes it possible to test whether the overlap theory holds up (or not!). What an epic leap in science tech?!! Hayden walks us through the mystery of ancient 'trackways', that at over a million years old, preserves two different hominins' footprints in the same ash - proof, at least in that moment, that more than one species walked the same ground... You'll have to listen to find out what Hayden's age-dating reveals.Lastly, we pivot 360 to to Hayden's first volcanic love - kimberlites...

Make sure you're following Wonder wherever you get your podcasts - and chuck that notifications bell on!

Find us on Instagram @thegeoco

Thanks to the ⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠Geological Society of Australia⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠ for making this episode of Wonder possible!

GeoCo comes to you from the traditional country of the Kaurna people of the Adelaide Plains, South Australia. We pay our respects to their Elders past, present, and emerging.

Pushing the frontiers of knowledge about our planet has never been so much fun! We've explored less of the ocean floor than we have the surface of Mars, so Dr Ron Hackney, director of ANZIC (the Australian New Zealand International Scientific Drilling Consortium), brought the ocean floor to us. Across three remarkable objects: a core from the fault that ruptured the 2011 Tōhoku earthquake; a set of microscopic radiolarian fossils; and the world-famous "day the dinosaurs died" core from the Gulf of Mexico; we trace what scientific ocean drilling can tell us about earthquakes, mass extinction, and life clinging on kilometres beneath the seafloor.

We also hear how Ron went from an Antarctica-obsessed undergraduate to leading Australia and New Zealand's role in international ocean drilling.

Thanks to the Geological Society of Australia for facilitating this episode, and so many Wonder episodes over the past couple of years.🔗 Find us at thegeoco.com.au 📸 Instagram & TikTok: @thegeoco 📰 Sign up to our newsletter: thegeoco.substack.comGeoCo connects to you from the traditional country of the Kaurna people of the Adelaide Plains, South Australia. We pay our respects to their Elders past, present, and emerging.

We've directly observed less than 0.001% of the seafloor — so what's really going on down there? In this episode, Dr Stefan Löhr (ARC Future Fellow at the Adelaide University, and researcher with the Centre for Critical Resources for the Future) makes the case that the ocean floor is anything but a passive dumping ground for eroded continents. This will reshape the way you view the ocean - who knew it was so dynamic!

We trace marine weathering from a decades-old mystery in seawater chemistry, through the strange true nature of "clay" (and why geologists bite rocks to classify it), into the surprisingly unresolved question of whether land plants permanently changed how fast the Earth weathers. Finally we digress to discuss a rare earth element deposit in South Australia that shouldn't exist by the textbook rules, sitting on limestone that has essentially zero rare earths of its own. Turns out the answer is written in an ancient lagoon, a pH gradient, and a very long river.

Supported by the ARC Centre for Critical Resources for the Future.

🔗 Find us at thegeoco.com.au📸 Instagram & TikTok: @thegeoco📰 Sign up to our newsletter: thegeoco.substack.com

GeoCo connects to you from the traditional country of the Kaurna people of the Adelaide Plains, South Australia. We pay our respects to their Elders past, present, and emerging.

Critical Chromium: From Field Samples to Space Technology: How Do We Secure Supply?

Exploring for critical chromium, from the ground up (to space!)

Aerospace alloys, industrial protective coatings, stainless steel - chromium is literally everywhere in critical technology and in our kitchens, yet global supplies are stretched. So how do you hunt for chromium deposits? In this episode we journey through the world of chromium and find the answer takes us from dusty fieldwork in Odisha, India, to satellites reading rocks from orbit.

We explore the chromium: from the mantle rocks of India collected during some incredible fieldwork, to the Mars rover-equivalent technology used to analyze it, to space-based remote sensing that helps us locate new deposits.

And we're doing it alongside Anwesha Nasreen, research student from Adelaide University, who ventured into Odisha to collect foundational field samples, and Dr Raphael Baumgartner from CSIRO, who's using space-age analytical techniques to understand how chromium hides in plain sight.

This is the story of how modern exploration works: starting with boots on the ground, moving to cutting-edge labs, and finishing with eyes in the sky. It's a great story of fieldwork, mentorship, and the systematic science that connects ground to orbit.

This episode:

🛡️ Infrastructure critical: Chromium has so many important uses, everything from aerospace to the coatings that protect critical infrastructure

🔬 Chromium as an oxide mineral in magmatic systems (bound with oxygen, locked in ancient rocks)

🌍 The deep mantle connection: Platinum group elements love chromite the mineral, and both are rare and precious

✈️ Anwesha's fieldwork adventures: Bollywood soundtrack included

🧪 Lab analysis meets space tech: Scanning electron microscopes, laser ablation, geochemistry we explore the same tech that powers Mars rovers being used here on Earth

📡 Reading rocks from satellites: Remote sensing to map chromium-rich goethite and iron oxides from space

✨ Real mentorship in real science: How researchers like Anwesha learn through genuine discovery

Funded by the Australian Government, the India-Australia Critical Minerals Research Partnership ran from January 2023 to 30 June 2026, advancing sustainable and environmentally responsible critical minerals development for the benefit of both nations.

We acknowledge the Kaurna people of the Adelaide Plains, on whose country the Wonder podcast is made.

🔗 Find us:

📺 @theGeoCo on YouTube

📻 Wonder on Spotify

🐦 @theGeoCo on TikTok

📸 @theGeoCo on Instagram

📬 Geoco News on Substack: thegeoco.substack.com

— Holly, Anthony & the CSIRO Minerals team

💎 Carbonatites: To REE or Not to REE?

Earth's strangest magma is carbonate-rich, comes from the mantle, and there's only ONE erupting on the planet right now. It's called a carbonatite, a rare igneous rock that hosts the world's largest rare earth element resources. But here's the plot twist: only about 10% of the ~600 carbonatites that have been found are actually rich in rare earths. So how do we find the REE-bearing ones? Dr Shirley Hu and Dr Louise Schoneveld from CSIRO are using geochemistry and samples from India to understand carbonatite systems, including the ones that don't contain REE. Because sometimes, science learns as much from what isn't there as what is. Featuring actual rocks, one active volcano, and the exploration mystery that's reshaping how we hunt for critical minerals.

Funded by the Australian Government, the India-Australia Critical Minerals Research Partnership ran from January 2023 to 30 June 2026, advancing sustainable and environmentally responsible critical minerals development for the benefit of both nations.

🔗 Find us:

• 📺 @theGeoCo on YouTube
• 📻 Wonder on Spotify
• 🐦 @theGeoCo on TikTok
• 📸 @theGeoCo on Instagram
• 📬 Geoco News on Substack: thegeoco.substack.com

✨ The Weirdest Critical Metal You've Never Heard Of: Indium, Mine Waste & the Hunt for Hidden SuppliesYou've touched it hundreds of times. It's in your phone screen, your laptop, your solar panels, your TV. But unless you're a obsessed with periodic table trivia, you probably have no idea what it is.Meet indium. Its a critical metal so rare, yet so essential. But here's the catch: there's basically no such thing as an indium mine.Today we're talking to the wonderful Dr Olivia Mejas-Gonzales, a research fellow at the Centre in Critical Resources for the Future, who did her entire PhD on this obscure element.

Olivia - you're going to love her. She's a dynamic Chilean and a curious scientist who's not afraid of getting her hands dirty. Olivia shares some of her experience working underground at El Teniente, one of the world's great copper mines; including the challenges she faced - and overcame - being the only female on site at the time. Amazing!And Indium? Well for Olivia that story involves mine waste, surprising mineral discoveries, mysterious supergene enrichment zones, and some super cool synchrotron research. Plus, she's got a teaser about using biology to extract critical metals from waste rock. Trust us, you'll want to hear more.🎯 This episode:🌍 Why indium is critical (answer: every screen you own)💻 The supply chain paradox: we need it desperately, we barely mine it🪨 Why indium is almost nothing in the Earth's crust⛏️ How indium hides as a byproduct of zinc extraction, mostly in China🔬 Olivia's PhD adventure: finding indium in mine waste environments🪣 Supergene enrichment: when waste rock dumps hide geological surprises🔄 The living angle: can organisms dissolve and extract critical metals?🧪 Synchrotron science and the power of asking unconventional questionsAnd one of the standout quotes from Olivia:"I'm just curious without fear to fail. It doesn't matter if I fail because I know I will try again."Kinda one of the standout quotes from our whole Wonder series to be real!🔗 Find us:📺 @theGeoCo on YouTube📻 Wonder on Spotify🐦 @theGeoCo on TikTok📸 @theGeoCo on Instagram📬 Geoco News on Substack: thegeoco.substack.comThis episode was produced in partnership with the ARC Training Centre in Critical Resources, which brings together industry, four of Australia's leading universities, and state and federal governments to address the challenge of securing our future resources.🙏 We acknowledge the Kaurna people of the Adelaide Plains, on whose country the Wonder podcast is made.Thank you to Podbooth studios, Adelaide where we record our podcast.— Holly and Anthony

Electric vehicles are the future. But here's the problem: India's lithium demand is skyrocketing, but the local supply is nearly zero. Enter pegmatites: fancy, crystal-studded rocks hiding in the Rajasthan desert that might just hold the key to India's battery revolution.Today we're back with Dr Louise Schoneveld and Dr Mario Iglesias-Martinez from CSIRO to tell the complete story of the CSIRO's Australia-India research partnership on critical metals, centering here on lithium exploration. And boy we cover it all. From fieldwork in India's desert landscape to the analytical work happening in Western Australian laboratories, it's a tale involving unexpected geological encounters, shepherd guides, sparkly purple minerals, and the kind of detective work that makes the journey from field to lab the best kind of science.From pegmatite formation theory (yes, there's a debate, of course!) to the geochemistry that helps you sort the lithium-rich rocks from lithium-poor ones, this episode digs into what happens when you find a promising rock in Rajasthan and bring it home to Australia for detailed analysis, and its all part of a larger collaboration to tackle a global supply chain challenge.🎯 This episode:💎 Why pegmatites are fancy granites with bigger crystals (and what makes them really fancy)🔋 India's lithium challenge: massive demand, almost no domestic supply🏜️ Exploring Rajasthan: a region previously mined for tin and tungsten, now reimagined for lithium🪨 Two competing theories of pegmatite formation, and why it matters which one is right👀 The Clevelandite moment: how a feldspar on a roadside sparked a breakthrough🧪 Geochemistry in the field: reading element ratios to find the fertile pegmatites🤝 Fieldwork as collaboration: Indian Institute of Technology researchers and good science📍 For a bit of background - these are the main lithium and related minerals we talk about on the episode: - Lepidolite (bright purple lithium-bearing mica; stunning) - Spodumene (chunky lithium silicate with crystals measuring centimetres) - Clevelandite (the sodic feldspar that started it all)Funded by the Australian Government, the India-Australia Critical Minerals Research Partnership ran from January 2023 to 30 June 2026, advancing sustainable and environmentally responsible critical minerals development for the benefit of both nations.🔗 Find us:📺 @theGeoCo on YouTube📻 Wonder on Spotify🐦 @theGeoCo on TikTok📸 @theGeoCo on Instagram📬 Geoco News on Substack: thegeoco.substack.com🙏 We acknowledge the Kaurna people of the Adelaide Plains, on whose country the Wonder podcast is made.— Holly, Anthony & the CSIRO team

When you connect wirelessly to anything, you have CSIRO to thank - they are the ones who invented Wi-Fi. But beyond the banknotes and wireless tech, Australia's national science agency is working on something equally important: methods to find the critical minerals that will power the future.

Funded by the Australian Government, the India-Australia Critical Minerals Research Partnership ran from January 2023 to 30 June 2026, advancing sustainable and environmentally responsible critical minerals development for the benefit of both nations.

As part of a special partnership between CSIRO and Wonder podcast, we sit down with Dr Louise Schoneveld and Dr Eric Romaneido from CSIRO's Mineral Resources Group and discuss this important multi-year research collaboration that they have been part of.

From the dense forests of Meghalaya to the ancient weathered rocks of Odisha, this is the story of how science travels, how geology shapes exploration, and how Australia and India are building resilience in global supply chains. It's a love letter to fieldwork and the diverse, brilliant minds making modern minerals exploration smarter.

In this episode:

🔍 Why critical minerals matter (and why you should care)

⚒️ CSIRO's greatest hits and their mineral resources mission

🗺️ Exploring the three distinct geological region across India where the research fieldwork was undertaken: jungles, deserts, and weathered coasts

🌏 The Australia-India partnership tackling sustainable mineral development

👥 All about the diverse team running the program, spanning postdocs, students, and research scientists from Australian and Indian institutions.

🔗 Find us: @theGeoCo on YouTube 📻 Wonder on Spotify @theGeoCo on TikTok and Instagram Geoco News on Substack: thegeoco.substack.com

We acknowledge the Kaurna people of the Adelaide Plains, on whose country the Wonder podcast is made.

— Anthony, Holly & the CSIRO Australia-India Partnership team