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New Member
Found these next to the abandoned railroad tracks along the El Dorado Trail in Placerville, CA.
They're really heavy, don't break well when hit with a hammer, and are slightly magnetic (not a strong pull).
They're everywhere along the tracks. We think they were used to build the tracks? We don't think they were thrown from the trains since they would have started grass fires.
Thanks in advance for your help.

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Forum Host
Staff member
Fossilized dinosaur droppings.

Ok, I have a theory, but I'm not sure. You say they're "everywhere"? Are there a lot of them, or just a few of them, but scattered around all over?

It might be slag from welding the rails together, though it doesn't look like our slag usually does. But maybe they use a different method than we do.


Forum Host
Staff member
Anyone work on a rail grinder crew? Could this be the slag from a rail grinder? I'm thinking that's a more likely answer.


Active Member
I'll go with the rail grinder slag if no one else chimes in. The grinding action could cause the steel to become somewhat magnetic. Then again, that is a lot of slag.

If we were on ModelRailroadForums.com we could ask DJ if he's seen the like.

Night Watchman

New Member
I don't know for sure, but I think I would agree with Bret D. It's some kind of slag. Not from a rail grinder, but some kind specialized forging. Maybe for a quick and dirty repair for something that popped up in the middle of nowhere and they didn't have access to loco machine shop. Great video, looks pretty dangerous. It didn't show the slag, though. What I saw in the runoff looked flat and not lumpy to me. I don't know. I'll leave it to those far more knowledgeable than me.
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Looks like a small form of pillow lava, maybe used as ballast.

Or pāhoehoe:


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