The gap nobody can explain

I love a place that hides its best secret in plain sight, and the Grand Canyon does it better than almost anywhere. Those walls are basically a timeline, layer after layer going back nearly two billion years. Except for one bit.

Between the dark rock at the very bottom and the sandstone sitting above it, there's a gap. Up to 1.2 billion years of rock is just missing, either worn away completely or never laid down in the first place, and geologists still don't fully agree on which. It's called the Great Unconformity, and it means roughly a third of the whole planet's history isn't recorded anywhere in the one place that's supposed to show you all of it.

I painted it in watercolour and ink, all those layered reds and oranges. There's a poster with a letter home a postcard,if you'd like one.

Shop the poster here: Grand Canyon, Arizona · Travel Poster