Show Notes
In this exciting episode of our series on Gettysburg's geology, we dive deep into the Gettysburg Basin to uncover how the rocks beneath the famous battlefield shaped the events of history. From the famous McPherson's Ridge to the subtle hills that played crucial roles, discover how changes in rock types have left their mark. Join us as we zoom in on sedimentary rocks, explore the reddish Gettysburg Formation, the Heidelsburg member, and reveal some truly fossil-iferous finds. Rock on with us ...
More from PlanetGeo: The Geology Podcast
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, ...
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 differen...
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 define...
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...
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 w...