sandstone

Devil’s Punchbowl: sandstone formations warped by San Andreas Fault

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North of Los Angeles lies a striking sandstone outcrop known as the Devil’s Punchbowl. I’d seen it before from the air— it’s right where the Transverse Ranges of Southern California give way to the Mojave Desert, directly adjacent to the San Andreas Fault. But it was not until this year that I finally had a … Read more

Time-traveling through 1.7 billion years of geology at the Grand Canyon

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We visited the Grand Canyon in Arizona this spring and hiked all the way to the bottom! Starting with the Kaibab Formation at the top, which formed around 270 million years ago during the Permian period, and moving down to the Vishnu Schist at the canyon floor, which formed 1.7 billion years ago during the … Read more