We have been working hard over the past three days and we have finally reached the lower limits of the cultural deposit at AlDf-30. While the crew has been steadily troweling away at the final units, Gabe and I have been busy mapping the basal levels of the deposit and drawing the site profiles (records of the soil stratification in the deposit). As discussed earlier, we’ve been using the iDraw app to create many of the drawings and maps for the deposit.
By working on a graph paper-like background, which I described in an earlier post, you can create extremely accurate section profiles with iDraw. To draw each soil layer interface we use the pen tool and plot each data point across each level sequentially. The pen tool allows for curves to be created simply by holding and sliding the stylus on a plotted point, which permits the creation natural contours. Labeling the map only takes a few moments and complex colours, fills, and shapes can be easily added. The end result is a vector-based map created in the field which is near publishable quality. A few minutes of clean-up with any desktop illustration package and these maps can be inserted directly into a report or publication.
Our mapping on the iPads has resulted in a few observations. First, we have found that the Jot brand styli aren’t suited for fieldwork. Dust and debris often coat the screen protectors and this gets caught between the Jot’s plastic disc and the screen, resulting in some fairly severe scratches on our iPad screen covers. We have found that a (much cheaper) Pogo stylus with a foam tip is far superior; it is both more accurate and leaves no scratches even when the iPads are dusty. Second, we are happy to report that the iPads, with their protective cases, work very well in the rain. Water droplets don’t impede visibility and don’t appear to inhibit the capacitive touch screen in any way. While our protective cases are water resistant, in heavy downpours we put the iPads in plastic bags and simply draw through the plastic. This works so well that yesterday we mapped a significant portion of the AlDf-30 feature through a plastic bag.
Now that AlDf-30 is finished, we will be moving on to other sites in the harbour. Just two more sites to test and the field season will be complete. In fact, this is the first time in the history of the project where we will have met all the goals of a specific season – I’ve had a good crew and we’ve had very lucky weather. Gabe in particular has had a great result for his thesis. We spent nearly four weeks carefully digging the house deposit and we have uncovered at least three superimposed structures, all of which he’ll interpret over the course of his dissertation.