29 June 2008

Pennies from, er...

...definitely not heaven, anyway. I found them whilst digging dirt out for paving stones.

I strongly suspect that I'm responsible for the extreme pits in the most mangled one. I tried cleaning it up in CLR, and I'm guessing that the metals in the penny were so strongly bound to the stuff the CLR was eating that it just ate them all. The one in the best shape seems to have been coated in red paint, for no obvious reason. Presumably the paint protected it and kept it from accumulating as much junk. The other one I was more careful cleaning. It did get CLR treatment, but very briefly. Also 2% hydrogen peroxide (on all of them).

I have no idea how long they were buried. The legible dates are 1980 and 1983, so at most 25 years. I thought that the most deteriorated one said 1984 shortly after I pulled it out of the CLR, but it's now completely illegible past the '19', so it's quite possible I imagined it. It's also possible that the pennies were dropped at separate times, but as they were fairly close together in the digging, it seems likely that they were dropped at the same time.

By digging in the backyard, I've realized that the reason that artifacts get buried has less to do with more soil being blown in and more to do with the yearly freeze/melt cycle. There are probably places where loess is also important, but in my backyard, an item will simply sit on the earth while it's dry. Then the winter snows come. When the ground thaws, it is soft and wet, so items tend to sink. Heavier items seem to sink more than lighter items. Or maybe weight distributed over surface area is more important. *shrugs* At any rate, that paving stone I found in the same general area had sunk maybe 2-3 inches below the soil surface (roughly 5 years since I put it in). The pennies were about 4 inches down, which suggests a longer time period.

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