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Big Announcement: Roadside Geology Comes to Audio — Plus an Introduction to Sedimentary Rocks The glove-compartment classic is now in your headphones. In this episode, we announce a partnership between Camp Courses (the team behind the CampGeo app) and the Geological Society of America to produce audio-visual editions of Roadside Geology of Colorado and Colorado Rocks! — available right now in the CampGeo mobile app. These aren’t ordinary audiobooks. Geology books live and die by their maps, cross-sections, and outcrop photos, and CampGeo’s patented approach syncs the full narration with those images on your phone — so you can see the geology while you hear it. For us, this one is personal: the Roadside Geology series is how we learned to read a landscape, riding shotgun on rock-collecting trips from Colorado to New England. GSA now owns the entire Mountain Press geology library, and these two titles are the first brought to audio. If listeners find them useful, more will follow — so check them out and tell us what you think. This launch is timed with the GSA Connects conference in Denver. 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: [email protected] Website: https://planetgeocast.com/

Chris's college mineralogy lab final was 20 specimens, and one of them was a quartz crystal his professor had dipped in graphite. The luster was off, the color was off, and Chris got it wrong even though every other property said quartz. That one exam question shows why mineral ID is hard and why you need a system. This episode lays out that system. We finish the minerals chapter of the Camp Geo audio textbook with polymorphs, which are minerals with the same chemical composition but different crystal structures. The classic example is graphite and diamond. Both are pure carbon, but in diamond each carbon atom bonds to four others instead of three. That denser arrangement is stable at high pressure, which makes polymorphs useful clues to where a rock formed. Along the way we get into synthetic diamonds, companies that turn ashes into gems (Jesse will pass on that one), and a white dwarf star that Chris describes as a 2,500-mile-wide diamond, nicknamed "Lucy" after the Beatles song. Then Chris walks through the mineral ID flowchart he's refined over decades of teaching. Start with luster, because metallic or non-metallic decides your next step. Metallic minerals go straight to streak, and non-metallic minerals go to hardness. Chris brackets hardness on the Mohs scale with things you already carry: a fingernail (2.5), a copper penny (3.5), a knife or glass plate (5.5), and feldspar (6) and quartz (7) if you can find them. From there it's cleavage vs. fracture (the key test for telling feldspar from quartz) and why chemical bonding controls both. Then streak, where shiny silver specular hematite from Michigan's Upper Peninsula leaves a reddish-brown powder. Last come specific gravity, color, crystal form, and a few specialty properties like magnetism and fluorescence. Color gets a public trial, because amethyst, rose quartz, and milky quartz are all the same mineral. That leads to a rescue story: Chris hauled a rose quartz specimen down a scree slope and everyone else thought it was junk. He still has it and says he was right. Then the quiz, which Chris aces. In this episode The graphite-dipped quartz that cost Chris a question on his mineralogy finalPolymorphs: same composition, different crystal structureGraphite vs. diamond, and why four bonds beat three at high pressureSynthetic diamonds, memorial diamonds, and a diamond-core white dwarfWhy mineral ID needs a structured workflowLuster first: metallic vs. non-metallic decides your next testThe Mohs hardness scale and the fingernail–penny–knife–glass bracketWhat controls hardness: the weakest link in the chemical-bond chainCleavage vs. fracture, and how to tell feldspar from quartz in the fieldStreak: silver hematite, reddish-brown powderSpecific gravity, the "heft test," and how density separates zircons in the labWhy color is the least reliable property (amethyst, rose, and milky quartz)Crystal form: diagnostic when crystals have room to grow, which is rareMagnetism, fluorescence, and willemite under a black lightThe quiz: Chris goes 2 for 2Up next: sedimentary rocksDownload 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: [email protected] Website: https://planetgeocast.com/

There are roughly 7,000 known minerals on Earth. You need to know about ten of them. In the third installment of the Camp Geo Intro to Minerals series, Chris and Jesse finish the minerals chapter by working through the rock-forming minerals — the short list that makes up the overwhelming majority of the rocks in Earth's crust — and by explaining where minerals actually come from in the first place. Before the top-ten list, they step outside the silicates. Just as the silica tetrahedron defines the silicate family, other mineral groups are defined by their own dominant anion: the carbonates (CO₃²⁻, home to calcite, arguably the second most important mineral group on the planet), the sulfates (gypsum, which Jesse grew up seeing mined in Michigan), and the phosphates (apatite — the stuff your teeth are made of, and a mineral Jesse's lab dates routinely). Along the way, Jesse clarifies a point from Part 1: an anion can be a single charged atom or a charged molecule like CO₃ or SiO₄. Then, the four environments in which minerals grow — igneous (crystallizing from cooling magma or lava), metamorphic (solid-state recrystallization under heat and pressure), hydrothermal (precipitating from hot circulating water, as at Yellowstone and, far more commonly, at mid-ocean ridges), and sedimentary (salts left behind as cool saline water evaporates, think Bonneville Salt Flats). Chris flags the one that trips students up most: hydrothermal and sedimentary both precipitate minerals from water, but only one of them involves heat. This detour also produces the episode's best story: the day the two of them drove up a sketchy dirt road to the Gore Mountain garnet quarry in upstate New York without permission, watched a black Chrysler 300 come roaring up behind them, and left with about two tons of volleyball-sized garnets in the back of Chris's F-250. Finally, the countdown: feldspar, quartz, the micas, the olivines, the pyroxenes, the amphiboles (hornblende, for intro purposes), the clay minerals, calcite, dolomite, and halite plus gypsum. Seven of the ten are silicates, and Chris and Jesse tie each one back to its tetrahedral structure from Part 2 — framework, sheet, single chain, double chain, single tetrahedron. They cover the tricks for telling calcite from dolomite (a drop of HCl fizzes like Alka-Seltzer on one and like flat pop on the other), why mica rarely survives in sedimentary rocks, why clay minerals are basically what feldspar turns into when it hits a stream, and Chris's field-tested (and decidedly not medically endorsed) use of crushed limestone as heartburn relief. The episode closes with Jesse's quiz question for Chris, which Chris promptly declares "has potential" but needs reworking. 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: [email protected] Website: https://planetgeocast.com/

Ask an intro geology class what the most abundant element in the crust is and, year after year, the answer comes back "carbon." It doesn't make the top eight. That gap between what feels right and what the planet is actually made of is where this lesson lives. Chapter 2 of the Camp Geo audio textbook starts with the layered Earth — crust, mantle, and core — and why Chris's peanut M&M (with a caramel injection for the liquid outer core) beats Jesse's apple. Then the chemistry of each layer: an iron core, a silicon-oxygen-magnesium mantle, and a crust that's wrapped around the planet like tissue paper on a bowling ball and dominated by silicon, oxygen, and aluminum. Because silicon and oxygen run the show, one building block runs the mineral world: the silica tetrahedron, a pyramid with silicon in the middle and four oxygens at the corners. Chris and Jesse walk through the five ways those pyramids link up — single tetrahedron, single chain, double chain, sheet, and framework — with bead curtains, books of mica from a Black Hills collecting trip, and quartz as the fully-connected end member. Jesse gets rambly about charge balance; Chris reins him in. Chris goes two for two on the quiz and critiques the question-writing anyway. In this episode Crust, mantle, core — chemical layers, and why the peanut M&M winsWhat each layer is made of, and how thin the crust really isThe most abundant crustal elements (spoiler: not carbon)The silica tetrahedron and why the 3:1 oxygen-to-silicon ratio forces sharingThe five silicate structures, simplest to most connectedMicas, pegmatite "books," and the muscovite on Chris's bookshelfWhy quartz is SiO2 and needs nothing elseThe quiz: Chris goes 2 for 2Download 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: [email protected] Website: https://planetgeocast.com/

Ask a room full of intro geology students whether a snowflake is a mineral and almost every hand says no. Ask why, and someone will tell you it's because no two snowflakes are alike. Chris Bolhuis has been asking that question for 25 years — he asked it of a young Jesse Reimink sitting in his high school classroom — and the answer is the whole point of this lesson. It's been a while since we've released an episode on the Planet Geo feed, and there's more coming (plus a few projects we can't wait to announce). In the meantime, we're sharing the intro chapter of our Camp Geo audio textbook — the first lesson of the Physical Geology course you'd take in your first semester as a geology major. Several podcast platforms now display chapter artwork, which is close to how the Camp Geo mobile app works, so this is also a bit of an experiment: tell us how it lands. Chris and Jesse start where geology starts: the five criteria something has to meet to be a mineral. It has to be solid, naturally occurring, inorganic, have a definite chemical composition, and have a definite crystalline structure. The first three are easy (though "inorganic" is on shaky ground as mineralogists warm to biominerals — this rule may not survive the decade). The last two are where students get hung up, so they slow down: quartz is always SiO2, halite is always NaCl, and swap potassium in for sodium and you've got a different mineral entirely. Then a quick tour of the chemistry you half-remember from high school. Chris blows an atom up to the size of a 30-seat classroom — the nucleus is the tip of a pencil dangling from the ceiling, and everything else in the room is electron cloud. Jesse walks through protons, neutrons, and electrons, and why the loosely held electrons are what drive bonding. Ionic bonds transfer electrons (sodium hands one to chlorine, and a cation and anion snap together); covalent bonds share them. Chris's "paw-sitive" mnemonic and Jesse's parenting advice about covalent bonding are both, by mutual agreement, terrible. They both work. The episode closes with the analogy that ties it all together: a five-gallon bucket of tennis balls dumped on the floor. There's one best way to stack them. Add a bucket of marbles and the best way to stack changes — a different composition forces a different structure. Because there is a definite chemical composition, there is a definite crystalline structure. Elements make minerals, minerals make rocks, rocks make the planet. And then Jesse quizzes Chris. Chris goes one for two and files a formal complaint about question number two. In this episode Why we're releasing Camp Geo content on the Planet Geo feed (and what's coming)The five criteria for a mineral — solid, naturally occurring, inorganic, definite chemical composition, definite crystalline structureWhy "inorganic" may get dropped from the definition as biominerals gain acceptanceQuartz vs. halite vs. the potassium version — what "definite composition" really meansIs a snowflake a mineral? Working through all five criteria (yes, and you're a snowflake too)The classroom-sized atom and the pencil-tip nucleusProtons, neutrons, electrons — and why electrons do all the bonding workIonic bonding: sodium, chlorine, cations, anions, and "paw-sitive"Covalent bonding: sharing electrons instead of stealing themThe tennis-ball-and-marble analogy for crystal structureDefinite composition → definite structure → minerals → rocksThe quiz: Chris goes 1 for 2 and disputes the scoringAbout the series Camp Geo is Chris and Jesse's audio textbook version of an introductory Physical Geology course, built for the Camp Geo mobile app, where each lesson comes with a stack of images to follow along with. This is Chapter 1. Chris Bolhuis is a nationally recognized earth science teacher in Michigan; Dr. Jesse Reimink is his former student and now a professor in the Department of Geosciences at Penn State. 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: [email protected] Website: https://planetgeocast.com/

What happens when a finance guy who's never heard of lithium takes a job in a small North Carolina town because it's near where his favorite author lived?Joe Lowry is the founder of Global Lithium LLC, host of the Global Lithium Podcast (239 episodes and counting), and author of the new memoir Lithium Confidential: Confessions of a Corporate Misfit. He spent 35 years in the industry — including years in Japan and China — and for a stretch in the 1990s he personally controlled essentially all of the lithium supply going into the world's first commercial lithium-ion batteries.This is a longer, less traditional episode for us, and it's worth every minute. Joe walks through the entire lithium cycle from rock to cathode, explains why the industry started as a hydrogen bomb program, and gives an unusually blunt read on where the industry is headed — including his line that there's no Smackover lithium without direct lithium extraction, and why he thinks the first real success there lands around 2029.There's also plenty here for students and early-career geologists: Joe's argument that you should learn the industry, not just deploy your geology skills, and his advice on what actually makes a career durable.Some things we get into:Why lithium was in Post-it Notes, blue jeans, and grease long before batteriesThe full flow sheet: spodumene → calcine → lithium sulfate → carbonate → hydroxide, and why the "midstream" means cathode, not chemicalsHard rock vs. Atacama brine vs. sedimentary (Thacker Pass) vs. Smackover oilfield brineWhy grade matters: 600 ppm Smackover vs. sub-100 ppm produced water (sorry, Marcellus)How the market went from 300,000 tonnes LCE in 2020 to nearly 2 million todayThe 2022 spike to $80,000/t and what happened afterWhy Joe called BS on the high-nickel/hydroxide narrative and was right about LFPSodium-ion: real use cases, or a CATL press release every time lithium ticks up?What "crappy brine" means, and the fraud problem in African spodumeneCommodity or specialty chemical? Why fungibility is the whole argumentGetting fired as the best thing that ever happened to himTimestamps 00:00 – Intro01:30 – Welcome, and the strange experience of being recognized by voice03:10 – How Joe got into lithium: oil, corporate raiders, a gold mine, and a small town near Asheville06:00 – Lithium before batteries: glass, grease, and the dye in Post-it Notes08:30 – Japan, China, and being the only person who thought batteries would matter12:30 – What the "midstream" actually is, and why battery plants without cathode plants don't solve anything13:30 – The hydrogen bomb origin story: DOE, Lithium Corp of America, Foote Mineral14:20 – Hard rock processing, start to finish15:45 – Enter brine: Silver Peak, then the Atacama17:20 – Sodium sulfate, the glass industry, and putting the blue in blue jeans18:50 – SQM arrives and the price goes from $2/lb to 68 cents21:20 – Greenbushes: a tantalum mine that happened to have lithium23:00 – China's assets, lepidolite, and how CATL became a third of the market25:20 – 300,000 tonnes to 2 million: "what's grown that fast that's not software?"26:40 – Thacker Pass: wrong flow sheet, right rock, and a $2.3B DOE loan29:40 – "Soft rock," the McDermitt caldera, and Tom Benson30:20 – The Smackover, bromine wells, and why you can't build ponds in Arkansas31:30 – DLE: what counts, what's actually working, and what's still a declared victory33:15 – What makes a brine "crappy"33:40 – Grades, produced water, and why Pennsylvania shouldn't get too excited34:20 – Arkansas is all-in; Exxon is slow-walking it37:50 – Garbage spodumene, African supply, and lithium that showed up in China with no lithium in it38:50 – The four-minute mile: why 2029 is the year to watch40:40 – Recycling and the circular economy reality check42:50 – Is it still the lithium decade?43:20 – China controls processing — and depends on everyone else for supply44:40 – LFP vs. NMC/NCA, and the call Joe got right46:30 – What's actually in your iPhone48:00 – Sodium-ion: niches, not a replacement50:00 – BESS, aging grids, and a prediction Joe made in 201051:55 – Advice for students and young geologists entering lithium53:40 – On AI, and bulletproofing what you do54:00 – Starting the Global Lithium Podcast: Tim Ferriss, a LinkedIn post, and a studio in Buenos Aires55:20 – Downloaded in every country on Earth except Bhutan57:10 – The Korean listeners who finally explained themselves1:00:10 – The real value of a podcast is what's said before and after the record button1:02:30 – Australia 34%, US 30%, and why resource economies listen1:05:10 – Which lithium conference should a student actually go to?1:09:00 – Writing Lithium Confidential: five life goals from January 1, 1982, and a granddaughter1:11:30 – Why the book has exactly 100 chapters1:16:20 – Commodity or specialty chemical? The fungibility argument1:18:20 – Specs, secret sauce, and selling the same product twice1:20:00 – The freedom that comes with getting fired1:20:25 – Joe's best day in the lithium business1:23:30 – Best deposits he's ever visited: Pilgangoora's vision, Liontown's buildLinks Lithium Confidential: Confessions of a Corporate Misfit — available in print and Kindlegloballithium.netThe Global Lithium Podcast — wherever you get podcastsJoe on LinkedIn: Joe Lowry | On X/Twitter: @GlobalLithium (note the handle — not the Australian company)CampGeo mobile app — pegmatites, mineral basics, and all our back catalogplanetgeocast.com | @planetgeocastDownload 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: [email protected] Website: https://planetgeocast.com/

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: [email protected] Website: https://planetgeocast.com/

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: [email protected] Website: https://planetgeocast.com/

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: [email protected] Website: https://planetgeocast.com/

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: [email protected] Website: https://planetgeocast.com/

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: [email protected] Website: https://planetgeocast.com/

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: [email protected] Website: https://planetgeocast.com/

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: [email protected] Website: https://planetgeocast.com/

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: [email protected] Website: https://planetgeocast.com/

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: [email protected] Website: https://planetgeocast.com/