The most common images of archaeologists working are pictures of excavation in the field (although, much of archaeology actually happens in the lab and at the computer). Archaeologists work in a variety of conditions, from freezing cold wet sites, to sweltering hot areas full of biting bugs. Field work is definitely not glamorous, and it is very hard work, but it also fun and exciting!

Excavation is the process of digging in the ground to uncover artifacts and features (see blog post #2). Have you ever noticed that archaeologists often dig square holes? We call the holes units, and they are square, not because it looks awesome (although, come on, it does look awesome!), but because we are scientists and we measure and record everything. One of the things we measure is the volume of artifacts in specific amounts of soil so that we can compare artifact volumes between various units and sites. It is much easier and accurate to figure out the volume if we are taking dirt from square units. We can control how much soil we are removing much more easily if we use straight lines.

Most often, we measure using the metric system because we are scientists. The metric system is not only easier to use than inches and feet, it also makes it easier to share our work with other scientists who use the metric system.

Archaeologists dig different types and sizes of holes, including round shovel probes, but a common dimension for an excavation unit is a 1 meter by 1 meter (1x1m) square. Sometimes you might see an archaeologist working in a trench measuring 1x4m. That would be 4 units in a row. Or you might see a 2x2m block,and that would be 4 units making a big square shape. Sometimes a large number of contiguous units are excavated covering an entire site.

We dig discrete levels in our units that are typically 5 or 10 cm deep. We keep track of how deep we are digging with a line level on a string and a metric tape measure. We record everything we find in each level. This includes artifacts, features, soil composition, rocks, roots, animal burrows, and anything else we notice. The number of levels we dig for each excavation unit varies depending on the site. Sometimes a finished unit will be fairly shallow, maybe 30cm down. Sometimes it will be deep, up to 1 meter in depth.

Archaeologists use many types of tools to excavate. Of course, the poster child of archaeology is the humble (and sharp) trowel. Every archaeologist that I know has their own special flat pointing trowel made for use in masonry.

Trowelling is a skill that archaeologists hone, and good archaeologists can remove dirt very quickly, carefully, and accurately with their trusty trowels. Archaeologists also use many other tools, like square trowels, brushes of all sorts and sizes, bamboo skewers, dental picks, and numerous other gadgets, to painstakingly remove soil a bit at a time. We must be very careful to not damage artifacts and features, and to leave everything in place (we call it in situ) until it can be mapped and photographed. In contract archaeology (called Cultural Resources Management, or CRM), archaeologists often use shovels. In CRM, jobs must be done very quickly, so dirt has to be removed much faster than in academic archaeology. CRM archaeologists are still very careful and skilled, but because of the limited time they have to complete jobs for their clients, they must work very fast.

As archaeologists excavate, they remove a lot of dirt. Find out what happens to all that dirt in an upcoming post!