Well, I changed my mind, sorry. (Or sooorry as the Canadians on my dig would say, heh heh.) There’s less than a week left of the excavation (already!), so instead of talking about Neandertal behavior, I want to tell you what we actually do day to day here – while I’m still actually here. How, exactly, do archeologists do their work? I promise we’ll get to Neandertal behavior, probably next post.
This is my very first ever archeological dig. I have just finished my first year of grad school and it was not quite what I expected. Silly me, I assumed I would be learning, you know, excavation techniques: the proper use of trowels, where to start digging, stuff like that. Aside from my osteology class (the study of human bones), my first year has been lots and lots of theory. Reading way more than a human possibly can in the time given, and writing papers. So you can imagine how absolutely thrilled I am to finally be getting my hands dirty! Not metaphorically, either.
There are basically three jobs to be done during the excavation: digging, sieving, and sorting. For the most part, the students rotate between these three jobs and the specialists (like my professor) stick to one of these jobs to supervise.
DIGGING (fouilles in French)
Aside from seeking the Ark of the Covenant and performing whiptricks, digging is what you expect archeologists to do. The funny thing is, of course, that it is such a small fraction of the actual work of archeology. But it is on these summer excavations that we finally get to do it. The amount of digging you do each day and the speed at which you go varies depending on the era you are excavating and your goals. In our case – prehistoric era and academic research – this means we go very, very, VERY slowly and deliberately. For this summer’s project, we are digging a one by one meter square. This square is sub-divided into four squares that are 50 by 50 centimeters. But since we are looking for Neandertal remains that are so rare and old, we are sub-dividing that even further, into sub-sub-squares of 25 by 25 centimeters. Each excavator digs one sub-sub-square only two centimeters deep, then stops. Any artifact – which means any bone or lithic – that is two centimeters or larger is left in situ (in place), and when all four sub-sub-squares have been dug two centimeters, they are photographed and each artifact’s size and orientation is measured very precisely. Every bit of dirt dug with these small tools is swept with a little brush into a little plastic cup, which is then emptied into a bucket. All the dirt and rocks are measured by volume and recorded. Crazy painstaking work, right? Obviously we intend to miss NOTHING. If there are any Neandertal remains at all – even the tiniest fragment, we will find it.
Artifacts are then bagged individually with their own identifying tag, and buckets of sediment and rocks are taken to the sieving station for the next step in the process. So far we have found a lot of animal bones and the layer we are in now includes LOTS of lithics, which is pretty exciting. Sorry, I should say that lithics are stone tools or stones that are the result of humans making stone tools – so flakes that are not used, but come off when a larger point or knife is made, or the hammer stones (stone tool used to make a stone tool) or cores (raw material from which stone tools are made). It is easy to recognize a lithic. They have very smooth surfaces, the edges can be very sharp, and they are always made of a very hard stone, like flint. Regular rocks are very different. Trust me, you don’t need any training to recognize lithics.
My first day of digging I thought I would die. The dirt was hard AS A ROCK, my hands hurt, I was uncomfortable, and it was hot. But it got a lot better after that. We had quite a bit of rain so the ground softened. And once we got down further it was a goldmine of exciting stuff, like a woolly rhino foot bone! I just spent the day digging on Saturday (we have a lot to do in only three weeks, so we only get Sundays off) and there were so many lithics and animal bones it was extra slow going, but of course cool too. I loved being the first one to uncover several human-made tools since they were left there over 30,000 years ago. (We haven’t dug up any human remains yet, but we have four days left, so it could still happen.) Hunched down uncomfortably next to my little square, carefully picking away at dirt around a piece of limestone, I imagined my square as a tiny landscape, with mountains and valleys and itty-bitty cities of lithics. I was the giant invisible god, erasing time by coaxing the loosened dirt down through the valley and into my plastic chalice.
SIEVING (tamisage in French)
Sieving has got to be one of the most fun jobs, but also the most exhausting. We have two sieves, one with four-millimeter openings and one with two. The four-millimeter goes on top of the two-millimeter and the bucket of dirt is poured in, first dry, so over a plastic garbage can that wobbles back and forth, and next wet. The wet sieving is the best! You are basically creating and playing in the softest, gooiest mud you could ever wish for. The two sieves are put on top of garbage cans and we spray water from a hose over them, washing away all the dirt until only rocks and bones are left. That’s what makes the wet sediment left behind so silky smooth. So next time you are making mud pies, I recommend sieving first!
What makes this work exhausting is that you are moving boxes, buckets and bags of rocks all day, including up and down a small hill. I am a muddy, filthy shell of my former self at the end of a day of sieving. Sure is a satisfying feeling though! Beats reading theory anyway. Besides sieving the buckets that come from the dig, we are also sieving bags of sediment dug up by Leveque and his team, the original excavator who found the first Neandertal here in the 1970s, (more on this history in an upcoming post). These bags have been waiting on a shelf for over 30 years and it is all the sediment that comes from close to where the Neandertal was found. Unlike many of his day, Leveque did an excellent job keeping track of and labeling and KEEPING everything he excavated (in the past so much was just thrown out). So we are hopeful that we will have plenty of material to analyze. Sieving the Leveque stuff is the most fun, because it is full of beautiful, complete stone tools and large animal bones. Nowadays you would never have such large artifacts just sitting in a bag, since anything larger than two centimeters is measured and cataloged separately.
SORTING (trier in French)
Sorting is the last step in the excavation process (after that is the analysis and the scientific papers), and it means what it sounds like: sitting at a table with a tray what has been sieved and sorting everything into categories: limestone, flint, iron oxide, animal bone fragments, burned animal bone fragments (by humans either to cook the meat attached or as fuel – there are a lot these!), microfauna (tiny rodent bones and teeth – love finding them!) and “other” rocks. Small bits of limestone and tiny bone fragments look very similar, as you might imagine, and at first I was not convinced that I could ever learn the difference. But I did. Bone fragments have a regular structure. This means you can see patterns of lines or holes, whereas limestone is random. It can be harder to see when it’s very small or burned. One trick is to knock the piece against your teeth, and apparently bones and stones sound different. But that doesn’t work for me. I just can’t hear the difference. What works perfectly for me is the tongue test. Touch the unknown fragment to your tongue. If it sticks, it’s a bone. If it doesn’t, it’s a stone. Now sometimes limestone, which is porous, will kind of stick, but it’s not quite the same. Bone really grabs on, and sometimes you have to peel it off your tongue. When that happens sometimes I’ll say, with a lisp, “Okay I get it, you’re a bone!” We laugh. Archeology humor. Limestone, on the other hand, never grabs on that hard and leaves a gross powder on your tongue. Bone leaves your tongue “clean.” I’m pretty excited to have learned this.
So these are the jobs we do every day. Oftentimes they are tedious, exhausting, or mind-numbingly boring (sorting two-millimeter bags, hello?). Sometimes they feel very cool and sciencey. Sometimes they feel absolutely pointless. And sometimes you get to play in the mud, or pretend you are a giant uncovering a tiny landscape lost to time.