Wonder

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