Week 1: Part 4
After you’ve decided where to excavate and the size/shape/orientation of your excavation unit, you can’t just start sticking a trowel/shovel/backhoe into it. You’ve got to document the ground surface before you break it. Archaeology is a destructive science. Each layer of uncovered earth (and any artifacts therein) is permanently altered and can’t be put back. Therefore photographs and drawings must be made of surfaces, or levels, before each stage of excavation can begin. That way the destructive process is at least documented for later virtual re-creation in a notebook, journal, or software system.
Drawings can be made using tape measures, line/bubble levels, and plumb bobs. With these three tools, an accurate representation can be drawn by just two people, and with a little practice, one. After a drawings is made, photographs are also taken to have another record of the surface before its disturbed.
Breaking ground is usually done with the archaeologist’s favorite tool, the trowel. The uppermost layer is generally the most difficult to get through because of roots, grasses, and tree roots. However, a sharp trowel edge can cut through all those things. As a rule of thumb, scraping down that first layer (and all succeeding ones) starts from the highest point working toward the lowest point. One must be careful not to dig too far down as they go, a uniform elevation is going to provide the most accurate context for any artifacts found.
Once the uppermost layer of soil is removed, that level is closed, and another begun. A written record is kept of any artifacts or features (natural or human-made) that were found in that level. As for the new level, one must begin again with photographs and measured drawings.