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.

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 Earth Calendar).

The place: Nuvvuagittuq (noo-voo-ah-git-took), Quebec, Canada, in the lands of the Inuit.

In this episode, we'll learn how this seaside outcrop was found and the ongoing debate about its' exact age. Depending on who you talk to, these are either the second-oldest rocks on Earth, or almost as old as the Earth itself.

If the sun was dimmer 4 billion years ago, how did the Earth stay warm?

Today, we learn how just a small percent of Earth's atmosphere goes a long way in controlling global climate, both today and in the ancient past. Along the way, we'll visit an imaginary frozen Earth without any sun, a hazy giant moon of Saturn, and learn exactly what the greenhouse effect is.

Extra credit: Visit a greenhouse, or find a cleaning product with ammonia.

How has the Sun changed over the past 4 billion years?

While the Sun may seem unalterable, it has brightened dramatically over Earth's history, with major implications for our world. Today, we'll meet a team of women who catalogued thousands of stars in the 1800s, play in a galactic ball pit, and puzzle over a cosmic paradox alongside Carl Sagan.

Extra Credit: Watch Cosmos (1980)

Is there any place today that resembles the Earth 4 billion years ago?

Surprisingly, the answer is yes... ish. Today, we'll learn a secret recipe for continents, one that made the very oldest rocks on Earth and is still making the island of Iceland today.

Along the way, we'll freeze a magma chamber solid, meet some politically contentious metals, and cross a real bridge from one tectonic plate to another.

Hi folks,

Thanks for your patience- it's been a busy month for me. The next episode will be up on December 4, followed by a more regular schedule for the following weeks. In the meantime, I've updated Episodes 25 and 26, streamlining them to better flow into the next episode.

This update also gives a brief explanation for why Bedrock has such large gaps. In short, the podcast is just one part of a busy academic and personal life, and there are times when it has to take a backseat.

Your continued support means so much to me, especially during busier times. Thank you once again for listening, telling your friends, and reviewing the show. You'll hear more from me next month!

All the best,

Dylan

What did the oldest rock look like 4 billion years ago, before it was pressure-cooked?

Today, we'll answer that question by melting chocolate chip ice cream, meeting one of granite's less famous cousins, and returning to our old friends: zircon crystals.

Extra credit: Eat some ice cream, go on a skiing trip, or both!

How old is the oldest rock, where was it found, and what type of rock is it?

To answer that question, we'll journey into Canada's Northwest Territories, deep underground to the breaking point of rocks, and we'll run into a shrimpy friend from Episode 10.

Welcome to Season 2 of Bedrock!

This episode introduces Season 2's subject: the Eoarchean (ee-oh-ar-key-an) chapter of Earth's history. The Eoarchean lasted from 4 to 3.6 billion years ago, from February 15 to March 19 on the Earth Calendar. In future episodes, we'll meet Earth's oldest rocks, the Man in the Moon, and a faint young sun.

Since this is our first big chapter break, we'll also learn how and why geologists split time into these chapters, including one of Canada's greatest scientists: Sir William E Logan.

Get caught up to speed on Season 1, a time known as The Hadean.

The Hadean covers Earth's earliest days from 4.6 to 4 billion years ago, January 1 to Feb 14 on the Earth Calendar. This is a time of many firsts, including the formation of the Earth, Moon, oceans, islands, and perhaps life.

Check out previous episodes for more details, like the women who mapped the Earth's inner core (6) and seafloor (11), the largest object to strike our planet (8), and our earliest ancestor (23).