Found a surprising detail about the stones in my local creek

I was reading a county survey from 1978 and learned the rounded granite cobbles in Miller Creek are actually glacial erratics, carried over 50 miles from the Sierra Nevada. Has anyone else found unexpected origins for common local rocks?

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3 Comments

patriciah996mo ago

Check out old railroad maps too. They sometimes brought in ballast rock from far away, so you might find those stones mixed in with the local stuff.

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uma_nguyen246mo ago

That's a smart tip from @patriciah99, I never would have thought to check railroad ballast for different rocks.

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pathenderson6mo ago

Actually have to disagree with @patriciah99 on this one. Most railroad companies just used whatever local rock was cheapest and closest to the tracks. The idea they shipped in special stone from far away doesn't hold up for most lines, especially smaller ones. You might find a weird piece now and then, but it's not a reliable way to hunt. Wouldn't you just end up with a bucket of the same local granite everyone else has?

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