This is about how a group of archaeologists dug some trenches. It began with a Flinders University field trip to Magpie Creek ruin, Sturt Gorge, South Australia and the aim of excavating the site to see what we could learn about it. We needed to dig six trenches. Digging a trench might sound easy; however, you need to know where to dig, how wide to dig, how deep to dig, and when to stop digging. First we consulted with Bob, our expert on where to dig holes. Bob selected six places within and outside the ruin where we were likely to uncover artefacts. Our trench sizes ranged from 1 x 1.5 metres to roughly 2 x 2 metres. That was a manageable size for a small team of three or four of us to dig, sieve, and record the changes in context, and the artefacts uncovered. First, we moved away the loose rocks on the surface, then we measured our trench and ran a string along the perimeter so we knew the boundary of the trench.
Then came the digging. It started with a trowel. We poked with point, dragged and scraped along with the side of the trowel to remove the deposit. The idea is to remove the material quickly, but not to break up any artefacts, and to notice changes in the deposit, or context. These changes included changes to the composition, density and colour of the deposit that were indications that a change happened at that point.
Each time the context changed the details of the size, composition, PH and colour were recorded, together with details of any artefacts uncovered. Levels and the surface area of the new context were measured and recorded, and then this new context was excavated. This continued until the original, undisturbed soil surface or other structure was reached.
Once the undisturbed natural soil, or a new feature, was reached we had hit the bottom. At square ‘A’ shown in the image above, most of the excavation involved removing a built up deposit that had resulted from the collapse of the walls. Once the deposit was removed a brick floor was uncovered inside the building, together with an adjoining floor composed of plaster and soil. This was the only area of the building that had a brick floor. The use of this substantial floor material is an indication that it was an important area within the building. Below this it was a very short distance to the natural soil. When the excavation was completed the site records were updated, and then we back filled the trenches and tidied up the site.