PlanetGeo: The Geology Podcast
- Episodes
- 301
- Released
- every two weeks
- Latest episode
- Nov 12, 2026
About the podcast
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!
Episodes 301
Clastic Sediments - Geology 101: Sediments Part 3
Quick reminder up top: the Camp Geo mobile app now has both the Roadside Geology of Colorado audiobook and Colorado Rocks, the shorter, lower-jargon intro. If you’re headed to Colorado, grab one and tell us …
Show notes
Quick reminder up top: the Camp Geo mobile app now has both the Roadside Geology of Colorado audiobook and Colorado Rocks, the shorter, lower-jargon intro. If you’re headed to Colorado, grab one and tell us what you think.
Then it’s Episode 3 of our sedimentary rocks series from the Camp Geo audio textbook. With the four steps of making a sedimentary rock behind us, Chris and Jesse get to the rocks themselves, starting with the clastic (or detrital) rocks: the ones built from pieces of older rocks, about two-thirds of all sedimentary rocks. One ground rule first: “sand” and “clay” are grain sizes, not substances. And a rock’s name only matters for what it tells you about where it formed.
Smallest and most abundant first: shale. Feldspar, the most common mineral in the crust, weathers into clay, and clay flakes are so small they only settle in truly still water: the deep ocean, a flood plain, a delta, the middle of a big lake. Shale is fissile, splitting along its stacked flakes (without the layering it’s a mudstone), and it’s impermeable, which is why Chris, whose house sits in clay, calls it his nemesis. The field test is to grind a little between your teeth. Shale is chalky and smooth; siltstone, one step coarser, is gritty. Shale is also easy to spot at 70 miles an hour. It’s a wimp, so it forms the slopes between the Grand Canyon’s cliffs and the valleys between Pennsylvania’s ridges.
Then the rock both hosts have driven thousands of miles to collect: sandstone. The mix of sand grains tells you how far the sediment traveled. Quartz sandstone (90% quartz) has come a long way. Arkose (25–50% feldspar) is close to a granite source or from a dry climate. Lithic sandstone, full of rock fragments, is closest of all. And there’s graywacke, a dark, clay-rich sandstone whose name is fading from use, though not from Chris’s vocabulary.
The quiz brings it home at the beach: Florida’s white sand is nearly pure quartz that traveled far, Japan’s gray sand is rock fragments from the volcano next door, and California’s cliff-fed beaches would make an arkose. Next time: conglomerates and breccias.
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!
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Website: https://planetgeocast.com/Sedimentary Maturity - Geology 101: Sediments Part 2
Show NotesQuick news up top: alongside the Roadside Geology of Colorado audiobook, the Camp Geo mobile app now also has Colorado Rocks, a shorter, lower-jargon intro to the same landscapes. If Roadside Geology …
Show notes
Show Notes
Quick news up top: alongside the Roadside Geology of Colorado audiobook, the Camp Geo mobile app now also has Colorado Rocks, a shorter, lower-jargon intro to the same landscapes. If Roadside Geology is the deep dive, Colorado Rocks is the one to start with. Both are live in the app now, and since this is a trial run for a whole series of state titles, tell us how it lands. Find us @PlanetGeoCast, through the contact link at planetgeocast.com, or through the contact link in the Camp Geo app menu.
Then it's back to Chapter 2 of the Camp Geo audio textbook. Last episode ended with weathering, the breakdown of rock. This episode is everything that happens next: the sediment gets moved, it gets dumped somewhere, and it gets turned into rock. That's erosion, deposition, and lithification, and it's the heart of why sedimentary rocks are so useful, because every step leaves a fingerprint you can read back out of the rock millions of years later.
Chris starts by drawing a line he admits he blurs himself after all these years of teaching: weathering breaks the rock, erosion moves it. The movers are wind, streams, glaciers, and longshore currents (which, yes, have ended up in court over who stole whose beach). Chris's Michigan students always vote for glaciers as the most important agent of erosion, and you can see why when the whole skin of the state is glacial. But it isn't close. Streams move more sediment than everything else combined.
Water is also picky in a way glaciers aren't. A glacier will carry a house-sized boulder as easily as a sand grain, but moving water can only lift what its energy allows. That's why high mountain streams in Pennsylvania are full of boulders and the Mississippi is full of mud, and it's why one glance at the clast size in a sedimentary rock tells you the energy of the environment it was deposited in. Big pieces mean fast water. Dust-sized pieces mean water so still that nothing kept them in suspension, which usually means the deep ocean.
Jesse then explains sediment maturity, which Chris reframes as a measure of how far the stuff traveled. Near the source, clasts are angular and all mixed sizes, a poorly sorted sediment. Far downstream they're rounded, uniform in size, and increasingly just one mineral, quartz, because everything else has broken down along the way. Chris's version: hand anyone a jar of Skittles and say "sort it," and they know exactly what to do. A well-sorted rock is one pile of Skittles. So if you see sharp-edged boulders sitting next to tiny grains in a road cut, that sediment did not go far.
Finally, lithification, the two-step process that turns beach sand into sandstone. Compaction happens as more sediment piles on top, squeezing out water and air and shrinking the pore space. For some rocks that's the whole story: shale, the most abundant clastic rock, is only compacted, which is why it's soft, crumbly, and forms slopes instead of cliffs. Chris calls it a wimpy rock, and it's the easiest one to spot doing "roadside geology at 70 miles an hour" out a bus window, a phrase Jesse first heard as a high schooler on Chris's field course, delivered over the walkie-talkie while Chris drove one-handed. The second step is cementation: quartz can dissolve and re-bond to itself under pressure, but more often fluid moving through the pore spaces precipitates silica, calcium carbonate, or iron oxide between the grains and glues them together. That last one is why the sandstones of the Painted Desert are so red, and it takes surprisingly little iron to stain an entire rock. (It's also the brown streak on your sidewalk, unless, as Jesse points out, you live in Pennsylvania.) Chris wraps it with a Dixie cup demonstration you can do at home: two cups of packed sand, one flushed with fresh water, one with salt water. A week later, one is a handful of loose sand and the other is a cup-shaped rock.
Then the quiz, which Chris talks himself through like a seasoned test-taker before landing the answer. Next time: the clastic sedimentary rocks themselves.
In this episode
- New on Camp Geo: Colorado Rocks, the shorter intro companion to Roadside Geology of Colorado
- Where Episode 1 left off: weathering, mechanical and chemical
- Weathering vs. erosion, and why even Chris has to be deliberate about the difference
- The agents of erosion: wind, streams, glaciers, longshore currents
- Longshore current lawsuits over stolen sand
- Why Michigan students always say glaciers, and why streams win anyway
- Water discriminates by energy; glaciers don't
- Mountain boulders vs. Mississippi mud: reading depositional energy from clast size
- Why the finest particles only settle in very still water
- Sediment maturity: rounding and sorting as a record of transport distance
- Mineral sorting: how a mixed sand becomes pure quartz downstream
- The Skittles test for sorting
- Lithification step one: compaction
- Shale, the "wimpy rock" that's only compacted
- Roadside geology at 70 miles an hour (and one-handed bus driving)
- Lithification step two: cementation by silica, calcite, or iron oxide
- Why the Southwest is red, and the brown streaks on your sidewalk
- The Dixie cup rock: fresh water vs. salt water
- The quiz: what best describes what happens to particles as they're transported?
- Up next: clastic sedimentary rocks
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!
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Website: https://planetgeocast.com/Intro to Sediments - Geology 101: Sediments Part 1
First, some news. The Roadside Geology of Colorado is now an audiobook on the Camp Geo mobile app, produced in partnership with the Geological Society of America. If you've ever driven across the country …
Show notes
First, some news. The Roadside Geology of Colorado is now an audiobook on the Camp Geo mobile app, produced in partnership with the Geological Society of America. If you've ever driven across the country with a stack of Roadside Geology books riding shotgun (Chris and Jesse have, many times), this is that experience in your ears, with the images that go with it. It's the first title in what we hope becomes a whole series, so try it out, tell your friends, and let us know which state you'd like us to do next. Find us @PlanetGeoCast, through the contact link at planetgeocast.com, or through the contact link in the Camp Geo app menu.
Then we open Chapter 2 of the Camp Geo audio textbook: sedimentary rocks. They make up only about 7% of Earth's crust, but they cover roughly 75% of its surface, which means wherever you're sitting right now, odds are good there's a sedimentary rock under you, and odds are even better that it's a shale or a sandstone. Those thin layers hold nearly every fossil ever found, the record of ancient climates, oceans, and landscapes, the order of events in Earth's history, and almost all of our petroleum and natural gas. They're also the first thing a Mars rover goes looking for, because sediment averages a huge area of a planet into one sample.
Chris and Jesse lay out the three categories, in order of abundance. Clastic (or detrital) rocks are compacted and cemented fragments of other rocks, carried in by streams, glaciers, and wind, which leads to a brief detour into the very online geology debate over whether wind can actually lift sand. Biochemical (Chris prefers bioclastic) rocks are built from organisms that pulled ions out of seawater to make shells, from whole shells welded together down to microscopic calcium carbonate. Chemical rocks precipitate straight out of evaporating salty water, like the Bonneville Salt Flats, with no life required. They're small in volume but often big economically.
The episode closes with the question underneath all of it: where does sediment come from in the first place? That's weathering, and there are two kinds. Mechanical weathering breaks rock into smaller pieces, with ice wedging (water expands about 9% when it freezes) doing the heavy lifting in cold mountain country and transport downstream doing the rounding. Chemical weathering dissolves rock, because all rainwater is slightly acidic from dissolved carbon dioxide, and Jesse explains hydrolysis and why it matters that feldspar, the most abundant mineral in the crust, breaks down into clay minerals, which become shale, the most abundant sedimentary rock on the surface. Then the quiz, which Chris gets right and immediately declares himself unstumpable.
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!
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Website: https://planetgeocast.com/Introducing: Audiobook version of the Roadside Geology of Colorado
Big Announcement: Roadside Geology Comes to Audio — Plus an Introduction to Sedimentary RocksThe glove-compartment classic is now in your headphones. In this episode, we announce a partnership between Camp …
Show notes
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!
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Instagram: @planetgeocast
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Website: https://planetgeocast.com/How to Identify a Mineral. Geology 101: Minerals Part 4
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 …
Show notes
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 final
- Polymorphs: same composition, different crystal structure
- Graphite vs. diamond, and why four bonds beat three at high pressure
- Synthetic diamonds, memorial diamonds, and a diamond-core white dwarf
- Why mineral ID needs a structured workflow
- Luster first: metallic vs. non-metallic decides your next test
- The Mohs hardness scale and the fingernail–penny–knife–glass bracket
- What controls hardness: the weakest link in the chemical-bond chain
- Cleavage vs. fracture, and how to tell feldspar from quartz in the field
- Streak: silver hematite, reddish-brown powder
- Specific gravity, the "heft test," and how density separates zircons in the lab
- Why color is the least reliable property (amethyst, rose, and milky quartz)
- Crystal form: diagnostic when crystals have room to grow, which is rare
- Magnetism, fluorescence, and willemite under a black light
- The quiz: Chris goes 2 for 2
- Up next: sedimentary rocks
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!
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The Rock-Forming Minerals. Geology 101: Minerals Part 3
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 …
Show notes
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!
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Instagram: @planetgeocast
Twitter: @planetgeocast
Facebook: @planetgeocast
Support us: https://planetgeocast.com/support-us
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Website: https://planetgeocast.com/Chapters
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The Silicates. Geology 101: Minerals Part 2
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 …
Show notes
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 wins
- What each layer is made of, and how thin the crust really is
- The most abundant crustal elements (spoiler: not carbon)
- The silica tetrahedron and why the 3:1 oxygen-to-silicon ratio forces sharing
- The five silicate structures, simplest to most connected
- Micas, pegmatite "books," and the muscovite on Chris's bookshelf
- Why quartz is SiO2 and needs nothing else
- The quiz: Chris goes 2 for 2
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/Chapters
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What is a Mineral? Geology 101: Minerals Part 1
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 …
Show notes
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 structure
- Why "inorganic" may get dropped from the definition as biominerals gain acceptance
- Quartz vs. halite vs. the potassium version — what "definite composition" really means
- Is a snowflake a mineral? Working through all five criteria (yes, and you're a snowflake too)
- The classroom-sized atom and the pencil-tip nucleus
- Protons, neutrons, electrons — and why electrons do all the bonding work
- Ionic bonding: sodium, chlorine, cations, anions, and "paw-sitive"
- Covalent bonding: sharing electrons instead of stealing them
- The tennis-ball-and-marble analogy for crystal structure
- Definite composition → definite structure → minerals → rocks
- The quiz: Chris goes 1 for 2 and disputes the scoring
About 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!
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Instagram: @planetgeocast
Twitter: @planetgeocast
Facebook: @planetgeocast
Support us: https://planetgeocast.com/support-us
Email: [email protected]
Website: https://planetgeocast.com/Chapters
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Lithium 101 with Joe Lowry: Brines, Pegmatites, DLE, and the Smackover
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 …
Show notes
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 batteries
- The full flow sheet: spodumene → calcine → lithium sulfate → carbonate → hydroxide, and why the "midstream" means cathode, not chemicals
- Hard rock vs. Atacama brine vs. sedimentary (Thacker Pass) vs. Smackover oilfield brine
- Why 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 today
- The 2022 spike to $80,000/t and what happened after
- Why Joe called BS on the high-nickel/hydroxide narrative and was right about LFP
- Sodium-ion: real use cases, or a CATL press release every time lithium ticks up?
- What "crappy brine" means, and the fraud problem in African spodumene
- Commodity or specialty chemical? Why fungibility is the whole argument
- Getting fired as the best thing that ever happened to him
Timestamps
- 00:00 – Intro
- 01:30 – Welcome, and the strange experience of being recognized by voice
- 03:10 – How Joe got into lithium: oil, corporate raiders, a gold mine, and a small town near Asheville
- 06:00 – Lithium before batteries: glass, grease, and the dye in Post-it Notes
- 08:30 – Japan, China, and being the only person who thought batteries would matter
- 12:30 – What the "midstream" actually is, and why battery plants without cathode plants don't solve anything
- 13:30 – The hydrogen bomb origin story: DOE, Lithium Corp of America, Foote Mineral
- 14:20 – Hard rock processing, start to finish
- 15:45 – Enter brine: Silver Peak, then the Atacama
- 17:20 – Sodium sulfate, the glass industry, and putting the blue in blue jeans
- 18:50 – SQM arrives and the price goes from $2/lb to 68 cents
- 21:20 – Greenbushes: a tantalum mine that happened to have lithium
- 23:00 – China's assets, lepidolite, and how CATL became a third of the market
- 25:20 – 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 loan
- 29:40 – "Soft rock," the McDermitt caldera, and Tom Benson
- 30:20 – The Smackover, bromine wells, and why you can't build ponds in Arkansas
- 31:30 – DLE: what counts, what's actually working, and what's still a declared victory
- 33:15 – What makes a brine "crappy"
- 33:40 – Grades, produced water, and why Pennsylvania shouldn't get too excited
- 34:20 – Arkansas is all-in; Exxon is slow-walking it
- 37:50 – Garbage spodumene, African supply, and lithium that showed up in China with no lithium in it
- 38:50 – The four-minute mile: why 2029 is the year to watch
- 40:40 – Recycling and the circular economy reality check
- 42:50 – Is it still the lithium decade?
- 43:20 – China controls processing — and depends on everyone else for supply
- 44:40 – LFP vs. NMC/NCA, and the call Joe got right
- 46:30 – What's actually in your iPhone
- 48:00 – Sodium-ion: niches, not a replacement
- 50:00 – BESS, aging grids, and a prediction Joe made in 2010
- 51:55 – Advice for students and young geologists entering lithium
- 53:40 – On AI, and bulletproofing what you do
- 54:00 – Starting the Global Lithium Podcast: Tim Ferriss, a LinkedIn post, and a studio in Buenos Aires
- 55:20 – Downloaded in every country on Earth except Bhutan
- 57:10 – The Korean listeners who finally explained themselves
- 1:00:10 – The real value of a podcast is what's said before and after the record button
- 1:02:30 – Australia 34%, US 30%, and why resource economies listen
- 1:05:10 – Which lithium conference should a student actually go to?
- 1:09:00 – Writing Lithium Confidential: five life goals from January 1, 1982, and a granddaughter
- 1:11:30 – Why the book has exactly 100 chapters
- 1:16:20 – Commodity or specialty chemical? The fungibility argument
- 1:18:20 – Specs, secret sauce, and selling the same product twice
- 1:20:00 – The freedom that comes with getting fired
- 1:20:25 – Joe's best day in the lithium business
- 1:23:30 – Best deposits he's ever visited: Pilgangoora's vision, Liontown's build
Links
- Lithium Confidential: Confessions of a Corporate Misfit — available in print and Kindle
- globallithium.net
- The Global Lithium Podcast — wherever you get podcasts
- Joe 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 catalog
- planetgeocast.com | @planetgeocast
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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 …
Show notes
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!
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Loading chapters …
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 …
Show notes
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!
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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 …
Show notes
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!
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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 …
Show notes
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 geology
- Why coming to the field "late" can be an advantage
- The Kohistan arc and the puzzle of how continental crust is made
- Re-dating the India–Asia collision — and why ~40 Ma changes the climate story
- Weathering, CO2 drawdown, and the case for the organic carbon pathway
- Turning sewage, gypsum, and bacteria into profitable carbon sequestration
- Sulfur, fertilizer, and the hidden product tree of oil and gas
- Critical minerals, geothermal, and geological hydrogen at MIT's ERL
- AI + whole-rock geochemistry for finding copper deposits
- Why metamorphic petrology is the way of the future
- Advice for students who want to use geology to solve big problems
- Oli'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!
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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 …
Show notes
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!
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Website: https://planetgeocast.com/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 …
Show notes
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.
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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 …
Show notes
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!
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Website: https://planetgeocast.com/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 …
Show notes
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!
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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 …
Show notes
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!
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Website: https://planetgeocast.com/What is a Professional Geologist? An Intro to Licensure
Jesse and Dr. Joshua Davis introduce a new series on professional geology licensure, prompted by listener questions, exam study use of their podcast, and continuing-education approvals. Jesse shares starting …
Show notes
Jesse and Dr. Joshua Davis introduce a new series on professional geology licensure, prompted by listener questions, exam study use of their podcast, and continuing-education approvals. Jesse shares starting the U.S. process by taking the FG (Fundamentals of Geology) exam and explains the typical U.S. pathway in 31 states: FG exam, geologist-in-training status, years of work experience under a licensed geologist (with some state-dependent education carve-outs), then the PG exam and references. Josh contrasts Canada and the UK, noting the UK’s Chartered Geologist is less central, while Canadian systems are province-based and may restrict the “geologist” title; Quebec lacks an academic carve-out and requires supervised experience plus an exam. They discuss rationales for licensure—public protection, minimum geology competency amid changing degree names, professional trust, insurance coverage, employability, and continuing education.
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!
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Website: https://planetgeocast.com/Visualizing the Deep Earth - CEO and Founder Christie Capper
Today Jesse talks with Christie Capper, founder and CEO of Deep Earth, which aims to visualize the subsurface by digitizing and unifying scattered underground data into accessible 3D maps. Christie describes …
Show notes
Today Jesse talks with Christie Capper, founder and CEO of Deep Earth, which aims to visualize the subsurface by digitizing and unifying scattered underground data into accessible 3D maps. Christie describes her path from a toy-inventor upbringing to studying economics and mechanical engineering (robotics) at Claremont and Columbia, then working at SpaceX, interning at the UN and Boeing, moving into early-stage VC in Europe, and joining a fusion startup. Work in carbon removal and geothermal led her to subsurface problems; mining research highlighted boom-bust cycles and long development timelines, motivating a broader focus on faster-feedback markets like water, geothermal, utilities, and construction. She discusses pre-seed funding, network-driven early hires, first paying customers, lessons on pricing and execution, and how investor rejection sharpened the company’s focus.
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!
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Chris is back!! Today we answer the simple question - Why do we see a predictable geologic and topographic progression as we drive from flat plains into mountains? We use examples from Michigan to Tennessee …
Show notes
Chris is back!!
Today we answer the simple question - Why do we see a predictable geologic and topographic progression as we drive from flat plains into mountains?
We use examples from Michigan to Tennessee, the Canadian Rockies, Glacier, the Bighorns, Colorado, and the Appalachians to walk through a common sequence: we start on broad areas of mostly flat-lying sedimentary rocks (sandstones, shales, limestones) deposited in shallow seas, rivers, intertidal settings, and deserts; as we approach the range, we cross subtle, long-wavelength, low-amplitude folds that are often hard to notice without measurements; then we enter the fold-and-thrust belt where anticlines, synclines, and large thrust faults stack sedimentary packages and create dramatic ridges, valleys, and cliff faces (thin-skinned deformation).
We explain how the growing mountain load flexes the plate to form a foreland basin that fills with sediment eroded off the range, typically thickening and coarsening toward the mountains. Farther inboard, we describe how erosion and unloading help exhume deep, high-grade metamorphic “roots” in metamorphic core complexes (gneiss, schist, and other intensely metamorphosed rocks), and how overthickened crust can later relax and extend, aiding exhumation.
We also discuss how some mountain belts preserve suture-related features like ophiolite complexes, while others show subduction-related batholiths (e.g., Sierra Nevada, Idaho Batholith), and we note modern analogs such as the Persian Gulf foreland basin.
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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!
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Website: https://planetgeocast.com/Geology Meets Deep Tech - Danielle Bennett
On this episode of Planet Geo, we welcome Danielle Bennett—a startup operator with a venture capital background (and not a geoscientist by training) who’s been talking with tons of geologists, hydrogeologists …
Show notes
On this episode of Planet Geo, we welcome Danielle Bennett—a startup operator with a venture capital background (and not a geoscientist by training) who’s been talking with tons of geologists, hydrogeologists, and engineers while helping build a geoscience-adjacent mapping company at Deep Earth Tech. Danielle shares how growing up with entrepreneur parents (who ran a groundwater-focused engineering firm) shaped her path, why she started a social-impact company in college, and how she moved from corporate finance to FinTech and then into venture capital for about six years.
They dig into what she’s learned from working with the geoscience community—friendly, non-confrontational, and highly opinionated—and why geoscientists may be slower to found startups (a strong perfection/excellence culture and highly localized expertise).
Danielle breaks down “deep tech” in practical terms (asset-heavy and/or science-and-engineering-driven tech), why capital is moving earlier into deep tech, and how VCs are increasingly pulling innovations from universities and incubators. The conversation also gets into which geoscience-adjacent areas feel investable (like shallow geothermal heating/cooling, critical minerals, and renewables) and why groundwater can be harder to fund due to public-agency buying cycles and complex bureaucracy.
Danielle closes by defining key funding terms—bootstrapping, debt financing, private equity, and venture capital—plus what VCs look for (why now, why this team, and scale) and common red flags (unclear messaging, weak grasp of numbers, and unjustified mega-rounds).
We hope you enjoy this excellent interview!
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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!
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Website: https://planetgeocast.com/Here Be Dragons - Exploring the Unknown with NASA Ames Chief Scientist for Innovation Dr. John Stock
In this riveting episode, we catch up with Dr. Jonathan Stock, Chief Scientist for Innovation at NASA's Intelligent Systems Division. We dive deep into the realms of geosciences and discuss how innovation …
Show notes
In this riveting episode, we catch up with Dr. Jonathan Stock, Chief Scientist for Innovation at NASA's Intelligent Systems Division. We dive deep into the realms of geosciences and discuss how innovation can transform our understanding of the Earth and beyond. From quantum gravity gradiometers to AI-driven geophysical mapping, Dr. Stock reveals the tech that could redefine geospatial exploration. We also ponder why geosciences lag behind other fields in entrepreneurship and innovation and how cross-disciplinary collaborations could be the game-changers we need. Join us as we weave through tales of awe-inspiring geological discoveries and the frontier spirit that keeps the field exciting.
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!
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Instagram: @planetgeocast
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Website: https://planetgeocast.com/Banded Iron Formations - A Deep Dive
In this episode, we bring you a riveting Q&A session with GeoGirl Dr. Rachel Phillips and Dr. Joshua Davies, both experts in geology who explore the mysterious world of banded iron formations (BIFs). We dive …
Show notes
In this episode, we bring you a riveting Q&A session with GeoGirl Dr. Rachel Phillips and Dr. Joshua Davies, both experts in geology who explore the mysterious world of banded iron formations (BIFs). We dive deep into what BIFs are, when they formed, and their significance. Josh unpacks the debated origins of these rocks, discussing how they may be the most hotly contested rocks in the geological world due to our limited understanding of their formation process, despite their voluminous presence on Earth. We touch on how BIF layers represent cycles influenced by Milankovitch cycles, and whether microbial activity plays a role in their formation. Josh explains that while BIFs peters out around 1.8 billion years ago, there are unique conditions and debates on secondary processes that impact our current understanding. We humorously explore modern analogs, like weird anoxic lakes, and laugh about how our Earth would need a huge meteorite impact to revert to BIF-forming conditions—a scenario we're not quite rooting for! Finally, we ponder the possibility of extraterrestrial BIFs, symbolizing our endless curiosity about space and deep time. This one’s a dense, iron-packed dive for sure—just like BIFs!
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!
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Support us: https://planetgeocast.com/support-us
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Website: https://planetgeocast.com/Venezuela’s Black Gold
In this episode, we are kicking off a new series on Geology News. We delve into why Venezuela is rich in oil, the complex tectonic interactions, and the geological formations that make it a hotspot for heavy …
Show notes
In this episode, we are kicking off a new series on Geology News. We delve into why Venezuela is rich in oil, the complex tectonic interactions, and the geological formations that make it a hotspot for heavy, sour crude oil. We also take a humorous stroll down memory lane, reminiscing about our hard rock geology days and the unintuitive yet captivating world of sedimentary rocks. Join us as we explore why Venezuelan oil isn't just black gold but a treasure trove of geological intrigue.
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!
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Instagram: @planetgeocast
Twitter: @planetgeocast
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Support us: https://planetgeocast.com/support-us
Email: [email protected]
Website: https://planetgeocast.com/Rocks, Risks, and Riches: Strategies and Stories with CEO Doug Heller
To kick off Season 6 of the Planet Geo Podcast, we invited Doug Heller, a Penn State alum and geoscience finance guru, to explore investment risk in the geosciences. Doug shares thrilling stories about turning …
Show notes
To kick off Season 6 of the Planet Geo Podcast, we invited Doug Heller, a Penn State alum and geoscience finance guru, to explore investment risk in the geosciences.
Doug shares thrilling stories about turning modest funds into substantial investments and offers invaluable advice for budding geologists and students. The episode delves into Doug's journey from exploring oil in the Gulf of Mexico to managing a complex bankruptcy case, and running Sun Specialty Products.
Doug sheds light on how to think about and manage risk, and provides tips for those interested in geoscience careers, the critical minerals sector, and much more. Join in for a fascinating conversation about the crossroads of geology and finance, complete with insightful risk analysis and career guidance for the next generation of geoscientists.
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!
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Instagram: @planetgeocast
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Facebook: @planetgeocast
Support us: https://planetgeocast.com/support-us
Email: [email protected]
Website: https://planetgeocast.com/Petrification - Rerelease
In this episode of Planet Geo, we dive deep into the fascinating phenomenon of petrification as we wrap up our season five re-release holiday series. From the beauty of petrified wood to its rare yet …
Show notes
In this episode of Planet Geo, we dive deep into the fascinating phenomenon of petrification as we wrap up our season five re-release holiday series. From the beauty of petrified wood to its rare yet awe-inspiring occurrence, we explore how this natural wonder forms. We also tease exciting updates for season six, including segments with Dr. Rachel Phillips and interviews with top geoscientists. Strap in geologists and rock enthusiasts, because we're about to make some solid gains in your understanding of mother nature's mineralization marvels. And don't forget, the Camp Geo mobile app and our website have a treasure trove of geology content waiting for 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!
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Instagram: @planetgeocast
Twitter: @planetgeocast
Facebook: @planetgeocast
Support us: https://planetgeocast.com/support-us
Email: [email protected]
Website: https://planetgeocast.com/How to Identify Rocks - Rerelease
Welcome back to Planet Geo, the podcast where we delve into the wonders of our planet's geology, how it works, and why it matters. In this episode, part three of our holiday re-release series, we’re …
Show notes
Welcome back to Planet Geo, the podcast where we delve into the wonders of our planet's geology, how it works, and why it matters. In this episode, part three of our holiday re-release series, we’re breaking down the basics of rock identification and collection techniques. Chris and I tackle the popular question: how do you identify rocks? We provide a general strategy perfect for budding rock hounds and outdoor enthusiasts. Plus, stay tuned for new episodes and exciting modifications coming to Planet Geo’s sixth year, including deep dives with Dr. Rachel Phillips and geology news segments with Dr. Josh Davies. Follow us on social media and check out our Camp Geo mobile app for tons of free, cool content!
Today's discussion dives into the nitty-gritty of rock identification. We walk through our methods, distinguishing between sedimentary, metamorphic, and igneous rocks, and share handy tips like carrying a magnifying lens, a little acid bottle, and a hammer to reveal a rock’s true identity.
We also chat about reliable resources like the Roadside Geology series to help you understand the geology of specific areas. We emphasize the importance of breaking rocks open to see fresh surfaces and narrow down your identification process methodically. Remember, even seasoned geologists take samples back to the lab for further analysis! Finally, we talk about the value of curiosity and the learning process. Whether it’s being the 'annoying student' who asks all the questions or participating in practical exercises like visiting a gravel pit, there’s a lot to gain from hands-on experience. We encourage you to do some research before your next trip and embrace the joy of discovery. If you have more questions or need help, hit us up at Planet Geo Cast on Gmail or on social media. Happy rock hunting and may your geological inquiries always 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!
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Instagram: @planetgeocast
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Support us: https://planetgeocast.com/support-us
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Website: https://planetgeocast.com/Rockhounding 101 (ReRelease)
In this episode, we dive into the thrilling hobby of rock hounding, sharing our personal adventures and offering a Rocks and Minerals holiday re-release theme. We'll guide you through the basics of rock …
Show notes
In this episode, we dive into the thrilling hobby of rock hounding, sharing our personal adventures and offering a Rocks and Minerals holiday re-release theme. We'll guide you through the basics of rock hounding, including crucial tips, resources, and a few funny anecdotes about our own experiences in gravel pits, quarries, and even snake-infested areas. Also, don't forget to follow us on social media, download the Camp Geo mobile app, and give us your feedback as we transition into the new year with more listener-focused content. So grab your gear, let's get digging, and marvel at the natural beauty of our planet!
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!
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Instagram: @planetgeocast
Twitter: @planetgeocast
Facebook: @planetgeocast
Support us: https://planetgeocast.com/support-us
Email: [email protected]
Website: https://planetgeocast.com/The Moon-Forming Impact - Q&A with Dr. Rachel Phillips aka GeoGirl
In this episode, we're back with the fabulous Dr. Rachel Phillips, also known as Geo Girl on YouTube, diving into part two of our intriguing Q&A session. This time, we cover listener questions about early …
Show notes
In this episode, we're back with the fabulous Dr. Rachel Phillips, also known as Geo Girl on YouTube, diving into part two of our intriguing Q&A session. This time, we cover listener questions about early Earth geology, the moon-forming impact, geochemistry, and much more. Spoiler alert: we journey into the cosmic and tectonic weeds, so grab your scientific hats as we ponder if the moon-forming whammy kickstarted plate tectonics and its broader implications on our planet! The center of our discussion revolves around a burning question: Did the moon-forming impact trigger plate tectonics? From vigorous debates on early Earth’s behavior to the staggering differences between Earth and its 'toxic twin' Venus, we leave no stone unturned—or unmelted. Dr. Phillips and Jesse examine the evidence, debunk some age-old myths (bye-bye, late heavy bombardment), and think about how a cataclysmic impact billions of years ago might have reset our planetary clock. Oh, and don't get us started on whether Earth or moon rocks are older—trust us, it's complicated. As we approach the end of our cosmic conversation, we speculate about how such colossal impacts might have played a role in developing early life on Earth. Did these monumental collisions cook up the perfect conditions for life's early proliferation, or did they serve as the ultimate reset button? Join us on this epic journey through time, magma oceans, and cratered landscapes. And hey, if you have more burning questions or just want to say hello, hit us up on all the social medias at Planet Geo Cast or visit our website planetgeocast.com. Cheers to more geological deep dives in the future!
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!
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Instagram: @planetgeocast
Twitter: @planetgeocast
Facebook: @planetgeocast
Support us: https://planetgeocast.com/support-us
Email: [email protected]
Website: https://planetgeocast.com/
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