Bedrock: Earth's Earliest History

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 man…

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…

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, s…

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…

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 l…

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.…

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 s…

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 tec…

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'…

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! A…

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 o…

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 progr…

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 o…

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 las…

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 …

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 geol…

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, mi…

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 impor…

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…

What's the next step after the oldest rock on Earth?

Today, we'll move the story forward 200 million years and 1,000 miles.

The time: 3.8 billion years ago... or maybe much older (March 3 on the Eart…