Bedrock: Earth's Earliest History

What types of volcanoes were erupting 3.8 billion years ago? Today, we meet a new type of rock and a new type of volcano, far more powerful and dangerous than those we've met so far. The old volcano is long dead, but the scars it left behind can still be seen across the Greenland landscape. Along the way, we'll learn how different types of lavas are made, why a few rocks can float in water, and learn about a field trip Dylan took to Iceland in 2010. Extra Credit: Eat a grilled cheese sandwich, blow a bubble in gum, or make campfire.

What was Earth's mantle like 3.8 billion years ago, and how do we know? The mantle is a realm that humans have never visited, and examining it is only harder in the ancient past. Fortunately, the mantle sometimes gifts us with beautiful green rocks from the deep, souvenirs of an unknown underworld. Today, we learn how the mantle has changed over time, and its surprising connections to outer space. On the way, we'll meet the father of geochemistry, revisit old asteroid friends, and learn why you should always flour your berries before making a cake.Extra Credit: Bake some blueberry muffins.Donate to support the show- anything is appreciated!

What is the world's oldest slice of mantle, and how did it reach the surface? Today, we'll meet the first tangible piece of the world below the crust, a world humans still have not visited. Along the way, we'll meet an old mineral friend from Season 1, a researcher named Friend, and learn how diamonds can be a geologist's best friend when looking for slices of the mantle.Extra Credit: Clean your bathtub, or call an old friend.Donate to support the show- anything is appreciated!

In 1971, two geologists traveled to the edge of Greenland's ice sheet. What they found were the oldest rocks known at the time, 3.8-3.7 billion years old. Shockingly, they were in decent condition, sparking a half-century of geology stories. Today we'll begin our tour of Isua, the final destination of Season 2. Along the way, we'll meet a Holocaust survivor who landed on top of the world, visit an iron mine surrounded by glaciers, and start to meet the highest-quality rocks of this season.Extra Credit: Eat some candy, some shrimp, or some Indian food.Donate to support the show- anything is appreciated!

Two months ago, I made an audience survey focusing on one topic: how would you like to support the show? Many folks answered, and here's what you said about donations, Patreon, ads, and merch. If you want to give your own opinion, take the survey here, put a comment below, or send a message to bedrock.mailbox@gmail.com.If you'd like to give a donation, you can click here- any amount is appreciated!

Nearly 30 years ago, one paper claimed to find the oldest evidence for life on Earth. How does that evidence hold up in 2025? Are these fossils or duds? Don’t panic, we’ll answer these questions to life, the universe, and everything in due time. Along the way, we’ll meet the most abundant mineral in the human body, an important fertilizer, and finish a trilogy of intense debates over a small Greenland isle. Extra Credit: Read The Hitchhiker’s Guide to the Galaxy, eat cake with sprinkles, and make sure to floss afterwards.Donate to support the show- anything is appreciated!Click here for the audience survey!Click here to read Dylan's Nature paper!

In 1991, a mysterious, striped red and gray rock was discovered on a cold Greenland isle. Years later, this rock would rock the scientific world with multiple debates about the early oceans and life. What exactly is this rock, and why do we care? Stay tuned, and on the way, we’ll learn how scientists can officially argue with each other.Extra Credit: Eat something with peanut butter and chocolate, pet a large and a small dog, or make sure your vaccines are up to date!Donate to support the show- anything is appreciated!Click here for the audience survey!Click here to read Dylan's Nature paper!

How old is the oldest slice of Earth's seafloor? The answer is more contentious than you would think. Today, we visit one of the most debated locations in the show: a small island off the Greenland shore named Akilia. Everything about these rocks has been contested, and we'll meet three scientists who form cornerstones of the debates.Extra Credit: Watch something on an old CRT TV, or count tree rings in a stump.

Earth’s crust is shattered into dozens of moving plates, but many other worlds operate very differently. What are some alternatives to plate tectonics?Today, we’ll compare tectonics on Earth with tectonics on other planets, through the lens of 3.9 billion-year-old rocks from Greenland. On the way, we’ll visit the westernmost town in the USA, visit one of our cosmic neighbors, and learn about the Occam’s Razor of geology.Extra Credit: find today’s planet in the night sky, drop a pebble every day this week and see if anything changes, or read “The Long Rain” by Ray Bradbury.Donate to support the show- anything is appreciated!Click here for the audience survey!Click here to read Dylan's Nature paper!

This season's final arc is set in Greenland. Let's start with the most common rocks in the region: what are they and what stories do they tell about the world 3.9 billion years ago?Along the way, we'll weave a tapestry of stone, boil some rocks, and learn a bit about Dylan's birthstone. Extra credit: try the Play-Doh experiment from this episode, or make some stone soup.Click here for the audience survey!Donate to support the show- anything is appreciated!

We're back! After nearly a year, Dylan has updates about his life and the future of the show. Please take the audience survey in the link below to let Dylan know how you'd like to support the show! Also, please check out the donate button if you like what you've heard so far.Click here for the audience survey!Donate to support the show- anything is appreciated!

Hi folks,If you’re a long-term listener, you know this show often takes long, multi-week breaks. This break has been much longer than normal, and will likely continue for a few months. What’s going on?Right now, I have one goal on my mind: to find a new, permanent job.My three-year contract at Grand Valley State University will end in April. I knew this going in, and it’s public information, so don’t worry about any dirt being spilled. In the past three months I have applied for dozens of jobs, and that number will double before year’s end.Each application takes time. I also have a full teaching schedule and I’m supervising undergraduate research. In short, there’s simply no time to make the show right now.I don’t know where I’ll be in six months, and that’s honestly a very stressful situation. But things are looking up- I’ve had a few interviews, and jobs are still being posted.When I find a permanent position, hopefully by early 2025, I will let you all know and finally return to Bedrock, both the show and in my own life. In the meantime, thank you as always for your patience and enthusiasm. If you’ve finished the show, you can recommend it to a science-curious friend. You can always drop a line at bedrock.mailbox@gmail.com, it always makes my day.See you next time, whenever that may be.

Hi folks! I've just been invited by my university to join a field trip to Iceland next week, one of the best spots in the world to study geology. This means there will be a slight hiccup in our programming. Episode 38 will drop early next week, while Episode 39 will hopefully drop the first week of August. If I have time and space, I might try some experimental episodes from Iceland itself, field diaries and interviews, but no promises yet. As always, thanks for your patience and support!

Why are some ancient rocks well-preserved, while others are extremely messed up? Today, we'll take a side quest from our Greenland arc to learn more about metamorphosis, which changes rocks beneath our feet. On the way, we'll transform toast into cookies, take an elevator ride deep into the crust, and meet an ancient rock with a babyface. Extra credit: make some toast, or go looking for butterflies.

What is the oldest *major* slice of rock, one that's relatively well-preserved, one that's fueled a half-century of research? The episode's name kinda gives it away, but stay tuned as we meet the last location of Season 2: a series of rocks near Greenland's capital. Along the way, we'll meet the different groups of people who have settled on this remote island, and a geologist from the other side of the world. I'll also take a brief detour into why I unfortunately can't talk about every single ancient rock out there. Extra Credit: Find a choir to sing in, or play some ping-pong.

How did the Man in the Moon form? What does the Moon's Far Side look like? Today, we'll learn about the most visible remnant of the ancient world- the pattern of dark lunar rocks that stares down on us each night. On the way, we'll hitch a ride with a flying fax machine, play a game with crystals in magma, and learn why bananas are slightly radioactive (and why that doesn't really matter). Extra Credit: Try to send me a fax, or just eat a banana.

When did the Moon's craters form? Can they tell us any stories about the ancient Solar System? Today, we'll learn some early explanations for lunar features, meet a "lunatic asylum" of planetary geologists, and learn how the larger planets might have bullied their smaller neighbors. Extra Credit: Watch Apollo 13, or The Right Stuff.

What are the oldest disputed fossils on Earth? Why are they disputed?Today, we wrap up our tour of Nuvvuagittuq in northern Quebec, 3.8 billion years ago, March 3rd on the Earth Calendar. In 2017, microscopic rusty threads were discovered inside these rocks, thinner than a human hair. Were they bacteria, or something else entirely? Stay tuned to find out! Extra Credit: Learn how to make a chemical garden, or find a piece of chert, flint, jasper, agate, or onyx.Common Descent Interview: https://youtu.be/amQ9rntfKV0?feature=shared

Where does humanity get most of its' iron, and what do these rocks tell us about the ancient Earth? Today, we'll learn about banded iron formations, the backbone of the modern steel industry an important stop in the search for early life and oxygen, and a rock that is impossible to make today. It's rare to find a rock as important to both economics and research. Along the way, we'll take a breath of fresh air, meet orange pond scum in a forest stream, and find a dagger carved from a meteorite. Extra Credit: Find as many steel objects as possible around you, or search for bog iron in a local swamp.

What are Earth's oldest volcanic rocks, and how did they form? Today, we'll explore the seafloor 3.8 billion years ago through dark basalt rocks in Nuvvuagittuq, northern Quebec. Along the way, we'll earn a green belt in geology, rest our heads on volcanic pillows and journey to the deepest spot in the modern ocean.Extra Credit: Try to find dark black basalt in a building or countertop near you.