
Don't Panic Geocast
John Leeman and Shannon Dulin discuss geoscience and technology weekly for your enjoyment! Features include guests, fun paper Friday selections, product reviews, and banter about recent developments. Shannon is a field geologist who tolerates technology and John is a self-proclaimed nerd that tolerates geologists.
Latest episodes

Feb 10, 2023 • 43min
Episode 357 - "Looks like the iron throne"
Giant crystal in caves sounds more like a plot twist than a geological phenomena, but this week we learn how the Naica Mine crystals were formed!
Fun Paper Friday
Head, D., and T. Vanorio. "Effects of changes in rock microstructures on permeability: 3‐D printing investigation." Geophysical Research Letters 43.14 (2016): 7494-7502.
Standford News Article
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Shannon Dulin
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Feb 3, 2023 • 39min
Episode 356 - "They'll find me laying in a graben"
This week we talk about basin and range topography, horsts, grabens, and more! Also how similar is your mouth bacteria to someone you kissed?
John McPhee Book
USGS Basin and Range Report
Fun Paper Friday
Kort, Remco, et al. "Shaping the oral microbiota through intimate kissing." Microbiome 2.1 (2014): 1-8.
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Shannon Dulin
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Jan 27, 2023 • 53min
Episode 355 - "Best First Week of Class Ever"
This week John and Shannon discuss some mysterious rocks whose extraterrestrial origin is still debated and if growing a beard is a good defense against a punch.
Arstechnica article on Hypatia Stone
Fun Paper Friday
Beseris, E. A., S. E. Naleway, and D. R. Carrier. "Impact protection potential of mammalian hair: Testing the pugilism hypothesis for the evolution of human facial hair." Integrative organismal biology 2.1 (2020): obaa005.
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Shannon Dulin
@ShannonDulin

Jan 21, 2023 • 33min
Episode 354 - "That's Gneiss"
New York City is a sprawling metropolis, but the design of the city is heavily influenced by the geology of this tortured patch of rock. This week we talk about it and what rocks you'll see as you stroll the city streets.
Manhattan Schist
Inwood Marble
Fordham Gneiss
Fun Paper Friday
Cameras left behind by explorers over 80 years ago found and may unlock secrets of glacial movement
Article
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Shannon Dulin
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Jan 13, 2023 • 1h 14min
Episode 353 - "We Didn't Do So Well"
Shannon's Resolutions
Streamline Digital Workflows
Read a lot! (and use goodreads)
Take a sabbatical
John's Resolutions
Read 24 Books
Cut carbs and meal prep lunch
Take quarterly vacations
Systemize, delegate, react
Fun Paper Friday
Do you have a funny walk? It could be healthy!
Gaesser, Glenn A., David C. Poole, and Siddhartha S. Angadi. "Quantifying the benefits of inefficient walking: Monty Python inspired laboratory based experimental study." bmj 379 (2022).
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Shannon Dulin
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Dec 23, 2022 • 51min
Episode 352 - "Why are things so heavy in the future?"
Shannon went to a workshop on determining the provenance of sediments using heavy elements, optical microscopes, and Raman spectra!
Raman Spectroscopy
Fun Paper Friday
Do dogs lie when they mark?
McGuire, B., et al. "Urine marking in male domestic dogs: honest or dishonest?." Journal of Zoology 306.3 (2018): 163-170.
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Shannon Dulin
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Dec 16, 2022 • 1h 13min
Episode 351 - "Our Favorite Things"
2022 flew past, so this week John and Shannon review their favorite things, experiences, classes, and more of 2022. Everything from bee keeping to kitchen appliances to multimeters to books!
John's Favorite Things 2022
Hantek 2D72
GEARS Workshop
Collapsing Wagon
Milwaukee Packouts and Ratchet Wrenches
Soda Stream
Confluence
Shannon's Favorite Things 2022
Goodreads and the Three Body Problem Triology
Camping in the Mohave Desert
Regents Teaching Award
Samsuing Tab S8
Bee Keeping Workshop
17 Inches of snow before field camp
Fun Paper Friday
Did dinos use their tails as a whip and weapon? These scientists think they have the answer.
Conti, Simone, et al. "Multibody analysis and soft tissue strength refute supersonic dinosaur tail." Scientific Reports 12.1 (2022): 1-9.
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Shannon Dulin
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Dec 2, 2022 • 48min
Episode 350 - "Borehole to Hell"
How deep have we actually drilled into the Earth? Turns out, not very far, just 12,262 metres (40,230 ft) or about 0.3% of the way to the center of the Earth. We talk about the challenges of this feat and about potty training cows.
Kola Superdeep Borehole
Fun Paper Friday
Cows are a source of many environmental concerns, but what if we could potty train them?
Science News Article
Dirksen, Neele, et al. "Learned control of urinary reflexes in cattle to help reduce greenhouse gas emissions." Current Biology 31.17 (2021): R1033-R1034.
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Shannon Dulin
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Nov 18, 2022 • 57min
Episode 349 - "That Sounds Heavy" Tech Replacement
It's hard to decide when it is finally time to let go. When do you recycle that old tech and replace it? It may still work, but is it the thing holding you back, or do you just want something new and don't really need it? This week Shannon and John grappled with this exact question and talked each other into and out of some potential technology purchases
Fun Paper Friday
Everyone knows that physics can solve any problem if you simplify it enough, but biologists are fed up! This week John Doyle tells us to be more like engineers and embrace complexity in our models.
Doyle, John. "Beyond the spherical cow." Nature 411.6834 (2001): 151-152.
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Shannon Dulin
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Nov 6, 2022 • 43min
Episode 348 - "Hot Juicy Magma"
Forms in fractures of rocks already in place, so it an INTRUSIVE feature
Form at right angles to the direction of extension in the area - nature’s frac jobs
Can be super thin or super thick, but generally are self-consistent
Can have multiple periods of injection or even multiple compositions of injection over time
Can get en echelon patterns, rings, and cones (last two common with caldera volcanism)
Magmatic are the most well known and form when magma flows into a crack and cools into a sheet.
The igneous rock is generally more weathering resistant so we get cool weathering features
Can be rhyolitic, but mostly basaltic
Rate of cooling determines grainsize (slow = big) and big near the center
Can have columnar jointing
Big phenocrysts orient with flow direction - cool! AMS studies show this.
These are awesome when you get them radially around a volcano!
Horizontal dikes are called sills
Clastic dikes are formed by sediments episode 177
Can be formed with fluid pressure
Cracks in permafrost that fill in
Fun Paper Friday
One plus one equals two, right? Sure, but you won't get published saying it that way.
Siegfried, John J. "A first lesson in econometrics." Journal of Political Economy 78.6 (1970): 1378-1379.
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Shannon Dulin
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