PlanetGeo: The Geology Podcast

Chris and Jesse
  • 4.8 (256)
  • Earth Sciences
  • Updated Weekly

A Geology and Earth Science Podcast. Join Chris, an award-winning geology teacher, and Jesse, a geoscience professor, in discussing the amazing features of our planet and their impact on your everyday life. No prior knowledge required. New episodes coming at you every week. Listen, subscribe, share with someone you know!

  1. Jul 30

    How to Find Copper — Dr. Tim Ireland, First Quantum

    There's a photo on Tim Ireland's Google Scholar profile of a toddler standing on the floor of an open pit gold mine in Australia's Northern Territory, wearing a hard hat and — because it was the early 1980s — flip flops. That toddler is now the Principal Geologist for Exploration at **First Quantum Minerals**, one of the world's major copper producers, and in this episode Jesse sits down with him to talk about how mineral exploration actually works. Tim grew up with two geologist fathers, but the path in wasn't as direct as it sounds. He took a gap year as a field technician and mostly hated it. He considered leaving to design jewelry. He turned down a PhD because being told he'd become "one of the world experts on sedimentary rock–hosted zinc" sounded uncomfortably narrow — then spent a few years alone in the desert with a drill rig and 22,000 square kilometers of ground before the university called back with something better. From there we get into the machinery of exploration. Tim describes the job as **reducing search space** — starting with a continent and narrowing until you're willing to spend real money drilling — and why that philosophy holds whether you're chasing porphyry copper in Chile, sediment-hosted copper in the DRC, or orthomagmatic nickel in Finland. We also get into the part they don't teach in a mineral deposits course: three or four people weighing in over email on whether to spend millions on relatively scant information, and why what a company really pays a principal geologist for is a **calibrated gut**. The scientific heart of the episode is what Tim calls the **quality question**. Deposit models are good at telling a geologist whether they're getting warmer. They're not good at telling you whether the thing you're walking toward will ever be a mine — and the industry is full of "technical successes" nobody publishes, where the geologist did the job right and the deposit simply wasn't good enough. We also cover critical minerals and why the West is late (Tim was in the room in Oslo in 2007 when China announced the plan out loud), the 22-year lag from discovery to production, and why he's skeptical of AI prospectivity tools — if there are only ten porphyry deposits on Earth with more than a hundred million tons of contained copper, that's not a training set. It closes with Tim's best day as a geologist: alone in a gorge in the northern Chilean desert, a ten-mile traverse, a spire of rock he probably shouldn't have climbed, and one outcrop that put his hand on a fault he'd only been able to argue about on paper. In this episode - The Google Scholar baby photo — hard hat, flip flops, floor of an open pit - A gap year he didn't enjoy, and the jewelry business that never happened - Why he turned down a PhD on sedimentary zinc — and what he asked for instead - Industry-funded research: "cut-price consultants," or the best training pipeline there is? - Reducing search space: the one philosophy that holds across every deposit type - Spending millions on scant information, and what a calibrated gut is worth - Critical minerals, the 2007 Oslo warning, and who's still in denial - 22 years from discovery to production — and why averages lie - The quality question: why our models can't tell a mine from a "technical success" - AI in exploration: the useful camp, the black-box camp, and why ten deposits isn't a training set - Big company vs. junior — kudos versus shares, and the trade-off nobody spells out - Tim's best day as a geologist, alone in a Chilean gorge About the guest Dr. Tim Ireland is Principal Geologist for Exploration at First Quantum Minerals, a global copper-focused mining company. He trained at the University of Tasmania, with an honors project on the MacArthur River zinc deposit and a PhD on porphyry copper systems in northern Chile. His career has run through Newmont in Turkey, a junior working sediment-hosted copper in the DRC, and thirteen years at First Quantum. Memorable quotes - "If it were mathematical and there was a definite yes/no answer, we wouldn't be needed." - "You still have to do the work. You can't just sit at your desk and think about the model." - "If you've only got ten porphyry deposits in the world with more than a hundred million tons of contained copper, ten's not a great enough training set." - "I'm still kind of hanging out for that day that I walk up a hill and crack the first rock." Download the CampGeo app now at this link. On the app you can get tons of free content, exclusive images, and access to our Geology of National Parks series. You can also learn the basics of geology at the college level in our FREE CampGeo content series - get learning now! Like, Subscribe, and leave us a Rating! —————————————————— Instagram: @planetgeocast Twitter: @planetgeocast Facebook: @planetgeocast Support us: https://planetgeocast.com/support-us Email: planetgeocast@gmail.com Website: https://planetgeocast.com/

  2. Jul 16

    The Rock 50 Light-Years Away

    What if you could tell whether a rock exists on a planet 50 light-years away — without ever leaving Earth? This week Chris and Jesse welcome back friend-of-the-show Dr. Jackie Faherty (American Museum of Natural History) for her fourth appearance to talk about one of the wildest results in exoplanet science yet. The crew digs into a new Nature Astronomy paper on a rocky planet about 30% larger than Earth, orbiting a tiny star, whipping around fast with a scorching ~1,000 Kelvin surface and — surprisingly — no atmosphere. With no gas in the way, the James Webb Space Telescope was able to read the light coming off the planet itself and start distinguishing what the surface might be made of, right down to the debate geologists love: mafic vs. ultramafic, basalt vs. granite. Along the way, Jackie explains what makes JWST so special, why it sees in infrared, and how astronomers actually assign those famous colors to the images (spoiler: it's not random). They get into brown dwarfs and why she thinks one may be hiding in our own galactic neighborhood, the coming firehose of data from Rubin and NASA's Roman telescope, and why Jesse has to eat his old postdoc-era complaints that Webb was a waste of money. It's a mind-bending conversation about living in what feels like a science-fiction era — where a planet's light tells us its secrets. Download the CampGeo app now at this link. On the app you can get tons of free content, exclusive images, and access to our Geology of National Parks series. You can also learn the basics of geology at the college level in our FREE CampGeo content series - get learning now! Like, Subscribe, and leave us a Rating! —————————————————— Instagram: @planetgeocast Twitter: @planetgeocast Facebook: @planetgeocast Support us: https://planetgeocast.com/support-us Email: planetgeocast@gmail.com Website: https://planetgeocast.com/

  3. Jul 2

    The Room Problem (and how Geochronology solves it)

    Granite is everywhere — it makes up much of the continental crust beneath our feet; yet, for over a century geologists were stuck on a deceptively simple question: where does all that magma find room? In this episode, Jesse and Dr. Mike Ackerson pick the granite series back up to tackle the "room problem" — the puzzle of how you wedge a magma body tens of kilometers wide into solid crust. Using California's Tuolumne Intrusive Suite (the fruit fly of igneous petrology) and the landmark Coleman et al. 2004 paper, they show that the way out isn't space at all — it's time. These giant plutons weren't emplaced in one molten flash; they were assembled incrementally over millions of years. Along the way: a whirlwind history of geochronology, why the word "lead" makes clean-lab chemists recoil in horror, and the slow death of the "magma chamber." Download the CampGeo app now at this link. On the app you can get tons of free content, exclusive images, and access to our Geology of National Parks series. You can also learn the basics of geology at the college level in our FREE CampGeo content series - get learning now! Like, Subscribe, and leave us a Rating! —————————————————— Instagram: @planetgeocast Twitter: @planetgeocast Facebook: @planetgeocast Support us: https://planetgeocast.com/support-us Email: planetgeocast@gmail.com Website: https://planetgeocast.com/

  4. Jun 11

    Rocks for the Future - with MIT Prof. Oli Jagoutz

    What does cracking open green-shiny rocks in a German preschool have to do with feeding eight billion people without oil and gas? In this episode, we sit down with Prof. Oli Jagoutz, professor at MIT and director of the Earth Resources Laboratory (ERL), for a wide-ranging conversation that travels from the Himalayas to the wastewater treatment plant — and makes the case that geology might be one of the most societally relevant sciences of the coming decades. Oli traces his winding path into the field: the son of a cosmochemist who dragged him along on mantle-sampling campaigns, a self-described "failed" almost-med-student who spent years climbing, traveling, and working as a nurse before discovering that he could inhale geology once he finally found it. His advice to late bloomers — it's not your age that matters, it's that you've figured out what you actually want. From there the conversation digs into the Kohistan arc, the spectacular tilted-on-its-side cross-section of ancient island-arc crust now exposed in the Himalayas, and what it tells us about how continental crust forms (magmatic differentiation, water, and density sorting). Oli explains why he came to believe the textbook story of the India–Asia collision was wrong — arguing the real collision happened closer to 40 million years ago, not 50 — and why that timing matters for understanding how mountain-building and tropical weathering of calcium- and magnesium-rich rocks may have reshaped global climate. That climate thread becomes the pivot point of the episode. Oli describes walking away from the decades-old "origin of continental crust" question to chase problems with real-world stakes, and lays out the four areas his lab now tackles: carbon sequestration, critical minerals, geothermal energy, and geological hydrogen. Along the way he challenges the standard weathering-CO2 story (betting instead on the organic side — clays protecting buried organic matter), and walks through a genuinely clever carbon-sequestration scheme that uses sulfur-reducing bacteria and industrial waste gypsum to lock up carbon while making money by recovering elemental sulfur — a chemical the world will desperately need for fertilizer in a post-oil economy. The episode closes on practical wisdom for students: master the fundamentals, stay broad, actually go to the talks (not just the beer), use tenure to fund "Neverland science," and recognize that an outsider's perspective — connecting dots others haven't — is often where the best ideas come from. Oli also explains how AI-driven, probabilistic "hygrometry" of whole-rock data is opening a new path for mineral prospectivity, and why he thinks metamorphic petrology — the chemistry of hot fluids reacting with rock underground — is the science of the future for mining, energy, and carbon storage alike. In this episode How a cosmochemist dad and a broken finger started a career in geologyWhy coming to the field "late" can be an advantageThe Kohistan arc and the puzzle of how continental crust is madeRe-dating the India–Asia collision — and why ~40 Ma changes the climate storyWeathering, CO2 drawdown, and the case for the organic carbon pathwayTurning sewage, gypsum, and bacteria into profitable carbon sequestrationSulfur, fertilizer, and the hidden product tree of oil and gasCritical minerals, geothermal, and geological hydrogen at MIT's ERLAI + whole-rock geochemistry for finding copper depositsWhy metamorphic petrology is the way of the futureAdvice for students who want to use geology to solve big problemsOli's "best day as a geologist" Memorable quotes "Don't get discouraged when the community thinks you are wrong. You're probably right.""Just because I haven't worked on it doesn't mean I don't have anything to offer.""If you can't make it a business, it won't work.""Every day I go into the office and think: today I'm gonna find something awesome."Download the CampGeo app now at this link. On the app you can get tons of free content, exclusive images, and access to our Geology of National Parks series. You can also learn the basics of geology at the college level in our FREE CampGeo content series - get learning now! Like, Subscribe, and leave us a Rating! —————————————————— Instagram: @planetgeocast Twitter: @planetgeocast Facebook: @planetgeocast Support us: https://planetgeocast.com/support-us Email: planetgeocast@gmail.com Website: https://planetgeocast.com/

  5. May 28

    The Fundamentals of Geology (Exam)

    This week we take on the FG test — the Fundamentals of Geology exam — the very first step on the road to becoming a professionally licensed geologist. Jesse just sat the exam this past fall (yes, a geology professor going back to take Geology 101), and we get into exactly what that was like: the nerves, the cram sessions, and the very real fear of an embarrassing fail. We break down what's actually on the ASBOG FG exam — 110 multiple-choice questions across eight content domains, from general and field geology to hydrogeology, engineering geology, mineralogy, structure, and economic geology — and which sections scared us the most (looking at you, Darcy's law and soil mechanics). We talk through why university programs prepare students so differently, why the exam exists in the first place, and how we'd study for it if we only had two weeks. Then we put it all to the test: Josh takes on a round of real and AI-generated practice questions live on the mic, and we share our honest take on using tools like Claude to build your own study guide. Whether you're a student staring down the FG exam, a geologist heading back to the field after years away, or just curious how much a PhD really remembers, this one's for you. — A good study guide? Getting reps. Our Camp Geo mobile app is our intro-to-geology companion — grab it from the first link in the show notes. Follow us @PlanetGeoCast on all social media, and reach out anytime through the contact link at planetgeocast.com. We'd love to hear from you. Download the CampGeo app now at this link. On the app you can get tons of free content, exclusive images, and access to our Geology of National Parks series. You can also learn the basics of geology at the college level in our FREE CampGeo content series - get learning now! Like, Subscribe, and leave us a Rating! —————————————————— Instagram: @planetgeocast Twitter: @planetgeocast Facebook: @planetgeocast Support us: https://planetgeocast.com/support-us Email: planetgeocast@gmail.com Website: https://planetgeocast.com/

  6. May 21

    Granite Wars: The Debates That Built a Science

    In this episode, we sit down with Dr. Mike Ackerson (Smithsonian) for the kick-off of a deep-dive series on granites and granitoids. This one goes into the weeds: the 250-year history of how arguing about granite shaped nearly every major idea in the geosciences. We trace the great controversies from the 1700s to today: 🌊 Neptunism vs. Plutonism — Did granite precipitate out of a global ocean, or crystallize from molten rock? How James Hutton's fingers of granite at Glen Tilt helped kill the Neptunist worldview. ⏳ Uniformitarianism & deep time — How Charles Lyell's expansion of geologic time gave his friend Charles Darwin the temporal runway for natural selection. (Yes, the founder of biology was basically a geologist.) 🧪 Magmatists vs. Transformists ("granitizers") — The 20th-century brawl over whether granites are intruded magmas or rocks transformed in place by fluids — and how Bowen, Tuttle, and experimental petrology tipped the scales. 🪨 The Room Problem — Walk across the Sierra Nevada and you cross miles of granite. How do you make space in the crust for that much rock? The 150-year-old puzzle that's still not fully resolved. Plus: the legendary Norman Bowen "horse equilibria" letter, why H.H. Reid said "he who has seen the most rocks wins," and where the most exciting frontiers in granite petrology lie today — low-temperature magma storage, fluids in the crust, and links to geothermal energy and critical mineral ore deposits. This is Part 1 of a series — future episodes will tackle the timescales of granite emplacement, geochronology, and a return to the Room Problem. Want the intro-level foundation first? Download the CampGeo mobile app (first link below) for our textbook-style content on igneous rocks, including a full episode on Bowen's Reaction Series — what is granite, what is basalt, and all the basics. #geology #granite #petrology #geoscience #earthscience #PlanetGeo #magma #JamesHutton #Darwin #science Download the CampGeo app now at this link. On the app you can get tons of free content, exclusive images, and access to our Geology of National Parks series. You can also learn the basics of geology at the college level in our FREE CampGeo content series - get learning now! Like, Subscribe, and leave us a Rating! —————————————————— Instagram: @planetgeocast Twitter: @planetgeocast Facebook: @planetgeocast Support us: https://planetgeocast.com/support-us Email: planetgeocast@gmail.com Website: https://planetgeocast.com/

  7. Apr 30

    The Geologist's License: How the FG and PG Exams Get Built — with Keith Rapp

    In this episode, we sat down with Keith Rapp, senior hydrogeologist, longtime volunteer with ASBOG (the Association of State Boards of Geology), and immediate past president of the organization. We dug into the professional geologist licensure process — what the FG (Fundamentals of Geology) and PG (Practice of Geology) exams actually test, how questions get written and vetted by panels of subject matter experts, why some states require licensure and others don't, and why Keith argues that licensure is fundamentally about protecting public health and safety. Keith walked us through his path from growing up in Duluth with a geomicrobiologist uncle, to a master's in hydrogeology at Baylor, to a career cleaning up contaminated sites using microbes — what he calls hydrogeomicrobiochemistry. We talked about his current work on PFAS bioremediation, the idea of "pushing evolution" by engineering biofilm environments where microbes can adapt to degrade forever chemicals, and the role of zeolites as remediation media. We also got into the practical stuff students and early-career geologists actually want to know: how to study for the FG exam, why test scores point you toward weak domains, what reciprocity between states looks like, the difference between an ASBOG license and an AIPG Certified Professional Geologist (CPG) designation, and why writing skills still matter in a hiring pile. We closed with a conversation about AI in geoscience — where it helps, where it gets you in trouble when your name is on a signed report, and how the profession should think about it going forward. If you're a student preparing for the FG, a working geologist thinking about getting licensed in another state, or just curious about how a professional credentialing system gets built and maintained, this one is for you. The ASBOG annual meeting is in Hershey, PA this October — open to anyone interested in the profession. Download the CampGeo app now at this link. On the app you can get tons of free content, exclusive images, and access to our Geology of National Parks series. You can also learn the basics of geology at the college level in our FREE CampGeo content series - get learning now! Like, Subscribe, and leave us a Rating! —————————————————— Instagram: @planetgeocast Twitter: @planetgeocast Facebook: @planetgeocast Support us: https://planetgeocast.com/support-us Email: planetgeocast@gmail.com Website: https://planetgeocast.com/

  8. Apr 16

    What Makes Supervolcanoes? With Professor Shan de Silva and Dr. Rachel Phillips

    What distinguishes supervolcanoes from regular or non-super volcanoes? How many supervolcanoes are on Earth today? What are the precursors to supervolcano eruptions? In today's deep dive, Dr. Rachel Phillips, from GeoGirl, and I we got to talk to supervolcano researcher, Dr. Shan de Silva, to answer all your supervolcano questions (and more)! Download the CampGeo app now at this link. On the app you can get tons of free content, exclusive images, and access to our Geology of National Parks series. You can also learn the basics of geology at the college level in our FREE CampGeo content series - get learning now! Like, Subscribe, and leave us a Rating! —————————————————— Instagram: @planetgeocast Twitter: @planetgeocast Facebook: @planetgeocast Support us: https://planetgeocast.com/support-us Email: planetgeocast@gmail.com Website: https://planetgeocast.com/

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About

A Geology and Earth Science Podcast. Join Chris, an award-winning geology teacher, and Jesse, a geoscience professor, in discussing the amazing features of our planet and their impact on your everyday life. No prior knowledge required. New episodes coming at you every week. Listen, subscribe, share with someone you know!

Information

  • Creator
    Chris and Jesse
  • Years Active
    2020 - 2026
  • Episodes
    292
  • Rating
    Explicit
  • Copyright
    © 2026 PlanetGeo: The Geology Podcast
  • Show Website
    PlanetGeo: The Geology Podcast

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