Archaeology Update for the Week of January 9
Happy New Year, everyone! All of us working on the Headwaters Big Dig hope that you had a wonderful holiday and are looking forward to a great 2019! I was excited this year because I got some nice socks from Santa! You know you’re a boring grown-up when you actually honestly say “Hey, alright! Socks!” A-a-a-anyway…
A soggy start to 2019… bummer…
We mentioned last time we’d be taking a few weeks off for the holidays – which we did – but we weren’t able to actually get back to our test units until yesterday. Several sweeps of heavy rains came through the area during the down time, including a particularly heavy downpour right after the New Year (which happened to be our originally-planned start). For the most part, we’ve visited the site to make sure everything is still at least somewhat intact, pumped out any water that’s made its way into the blocks, and just pushed things off until yesterday. But we ARE BACK and looking forward to resuming our regular updates from this point forward.Here are some of our field crew working away in Block A today. You can see the remnants of that big rock jumble we’d recorded as a burned rock midden (Feature 55) just above the bottom of the block. We are getting into older deposits now. I wonder if any of these guys got new socks… I bet they didn’t.
The break gave us a chance to see how we’re doing schedule-wise, and we’re a tad behind. But planning these projects is tough.
One of the trickiest – and potentially most consequential – aspects of large archaeological excavations like these comes in the early planning stages when we gauge the excavation schedule. There are a lot of variables that factor into planning our field schedule from weather, to the number of people, to how quickly we can dig, to how long it will take to write down our notes. Sometimes a project proceeds exactly according to plan and sometimes (in fact, pretty-much always) it doesn’t. With several field crews digging away, it can be hard to gauge things on the fly. We took the break to slow down a bit and see how things are going. We can see we are a bit behind schedule and this is mostly because of all of the rains (one of those variables mentioned above). Time that would have been spent digging is instead spent bailing out water or setting up and taking down shelters (or just scraping mud cakes off our tools!). In addition, even though we knew the site was culturally-rich, we didn’t necessarily predict just how artifact- and feature-rich it would be. All of these finds add up to more time to study them properly.
Before the first shovel hits the ground, we break down all of the work that is needed out at the site; What kinds of equipment we’ll need; How much of different kinds of supplies are going to be necessary; How long will the fieldwork take; How long will it take for the government agencies to look through our findings; etc. Some aspects of a project are pretty predictable (for instance the Texas Historical Commission legally has 30 days to review and comment on reports that they receive). Others are simply our best estimates given our knowledge of the work and the specific conditions on a given project. Math comes in pretty handy to try to tackle a mountain like this…
We often break the excavations down to figure out how much time it would take for one person to dig everything, then divide that by the number of people doing the work. If a 1 x 1 test unit were typically dug through 10, 10-centimeter levels, that would work out to one cubic meter of soil excavated. To dig 90 cubic meters of soil (as is required here), it would be the equivalent of 90 test units. If one person were to dig through one 10-centimeter level per day (0.1 cubic meters; that’s a little slow but it’s easy to work with here), then it would take that one person 900 days to finish (90 cubic meters/ 0.1 cubic meters per day = 900 days). I don’t think that one person would like digging at the site every day for the next two-and-a-half years! That’s two socks boxes from Santa (maybe even three!)!
So, you add more people to your plan (as we’ve done in reality). Having six people digging at the site cuts that down to 7.5 months. But that assumes everyone is digging at that same rate. What if they aren’t? You may begin to see the challenges in planning these projects…
- What if you don’t have six excavators all the time?
- What if the site is more complex and takes more time to properly excavate?
- What if we added more people?
- Do you work an 8-hour day or a 10-hour day?
And that doesn’t even factor in artifact densities (how many artifacts are within a given unit of space in the ground). What if your planned density of 500 artifacts per cubic meter turns out to be 5,000 artifacts per cubic meter!?! Give it a try yourself! I’ve set up this basic excavation planning model. The left side lays out what I’ve described above. The right side is where you can adjust some of the color-coded variables to begin to see how your plan can change dramatically. Click this link to open a live spreadsheet and make your own copy (Choose “File”>”Copy”).Ultimately, archaeologists aren’t Superman (or -woman)… No, no, no… I promise, we aren’t. We don’t have X-Ray vision where we can look into the ground and see EXACTLY what’s down there. We also can’t predict the future. We don’t know if it’s going to be perfect conditions at the site the whole time or if it’s going to be unusually wet. We do our best to factor in as much information as we can to plan these projects out. This includes looking at information we know about this particular site (such as the estimated artifact density) as well as information we’ve learned through experience working on projects like these in regions like these (such as the rate we expect a person can dig per day). We do, however, have to adjust as those curveballs come flying in, including those in the shape of rain clouds.
In our case, we are indeed behind schedule, but we are adjusting to try to work a bit faster and finish up as soon as possible. Wish us luck!
What’s going on later this week?
With the new year, we all think a little bit about our calendars and years passing by. We thought it might be a good time to look at that topic in this week’s Live Update on YouTube Live. We’ll be talking about about Dating in the World of Archaeology. And not “dating” like you’d expect closer to Valentine’s Day, but actually figuring out how old something is at the site. We’ll talk about some of the methods that archaeologists have to estimate and even definitively identify how old different parts of archaeological sites are. We’ll cover the rough approximations we can get from relative dating to precise, scientifically-defined exact dates (or at least date ranges) that come from absolute dating such as radiocarbon dating and dendrochronology. Come check us out tomorrow morning at 10 AM!
And coming up this Saturday (1/12/2019) at 10am, Kurt Korfmacher, the architectural historian from AmaTerra Environmental, Inc. who worked on the historic buildings at the Headwaters site, will be giving a tour and presentation about the site’s development and use in the last 100 years (or so) when it was the site of the City of New Braunfels’ first municipal water supply and when it even housed a giant pond for raising fish hatchlings! If you’d like to attend, sign up here.Pebbles embedded into cement railing cap on top of one of the historic buildings at the Headwaters Site that spell out “1934”.