How deep do you dig?

After the capital of the colony was moved to Williamsburg in 1698, the James Fort area became farmland. This is fortunate for archaeologists because the area did not evolve into a functioning city. It's unfortunate because the plows disturbed the strata of the soil, digging down and turning it over. Another unfortunate, but interesting feature of James Fort is the fact that it was used as a Confederate fort during the Civil War. The Confederate soldiers moved the earth into mounds, as a basic defense facing the James River. During this process, they shifted tons of artifacts. It can be hard to pin down a specific date for a discovery if the context is ruined.

That's why the wells were such great finds. Everything was in context. The layers were undisturbed, with the oldest artifacts further down. If you find something that you can date, you can know for certain that everything below it is older than that date, and everything above it is younger. There are other sections of the fort area that are undisturbed, but for the most part, the plow zone and Confederate earthworks are accounted for. The archaeologists are sure to take into consideration the fact that the artifacts found in these layers are out of context. However improbable, it is possible that a Civil War soldier had a 17th century artifact from somewhere and buried it during the 19th century.

Underneath the miscellaneous upper layers (like the old gravel road and church rubble we are currently digging through), the Civil War fort, and the plow zone is the fort period layer. This level is undisturbed, with no bits of brick or gravel. The archaeologists don't know quite how deep this layer is until they find it and until they dig further down and hit the native horizon, where prehistoric artifacts can be found. This fort period layer is what the archaeologists are Jamsestown are looking for. This layer is closely examined for features and artifacts as the soil is scraped away with trowels. We stop digging when we find features (areas of the earth that are visibly or physically different, evidence of the remains of a post hole, grave, foundation, etc.) or reach the native horizon.

The basics

So here's what this field school is about. I'm attending an archaeology field school at Historic Jamestowne in Virginia. We're excavating James Fort, the first permanent English settlement in the Americas. It's kind of a big deal. We're currently digging in one of the last unexplored spots in James Fort.

We start with shovels, and dig away the top level of grass and dirt. All of the digging is done across the square, not straight down. It's basically scraping away layers of dirt. When we get to the second layer, we usually start screening. We put the dirt in buckets and dump it on these mesh screens over wheelbarrows. Then we don some gloves and shuffle through the dirt, pressing it through the screen. The artifacts stay behind. About 3 layers down (if the grass is A, then this level is D), we start troweling. They spray a little water on the unit to keep the dust down, then get on our knees and scrape away the soil with a trowel. The dirt is scooped up and screened. I might go more into technique in another post. We dig from 8 in the morning until 4:30, with breaks every two hours or so.

We find artifacts all the time. I would say that the vast majority of what I've found are nails. I can't tell the age off-hand yet, but the archaeologists can. They can estimate the age by the style of nail. Square-headed nails are from a certain era, machine-made nails are from such and such period. I hope to be able to tell the difference by the end of the six weeks.

I've found a pipe stem or two, some bits of pottery, glass of various ages, and, of course, plastic. Nothing spectacular, but I'm not complaining. Other people have found more ornate artifacts. The site is full of artifacts. The staff archaeologists have said that they're used to finding 100 things per bucket. I'm finding maybe 10 per, but hopefully there will be more. The thing is, this is the first archaeology experience most of the students have so we really don't know that this is a small yield. We were squealing over nails at first, but now they are commonplace.

While most of our time is spent in the field, we all spend one day a week in the lab. There we wash and sort artifacts. I might like it more than the field, because everything is already dug up. Sorting is hard work, though. As time goes by, I'll get better at telling things apart, but it's kind of daunting right now. There are tiny pieces that you have to use a microscope to identify. Basically, we take a bag of artifacts, wash it, and put it on a rack to dry. We take the dry ones and sort them by hand, with piles for bones, glass, ceramics, etc. I think these piles are further sorted later down the line into more specific groups. The copper pile is sorted into copper scrap, aglets, rivets, tacks, etc. They use a tiny brush to paint a tiny number on everything later on. I think I'll be doing that next week.

This is week two of six and I'm looking to buy a camera, so look for more posts soon.