Remote sensing technologies are becoming increasingly important to how we do archaeology — and it’s not hard to understand why. Being able to see what’s beneath the surface of the ground without needing to dig is an archaeologist’s dream! Most of the remote sensing methods that have been discussed in this blog have been geophysical techniques, such as the detection of subtle variations in the magnetic properties of the soil.
In my June column in the Columbus Dispatch, I discuss a recent paper by archaeologists Christopher Roos of Southern Methodist University and Kevin Nolan of Ball State University, which was published in the January 2012 issue of the Journal of Archaeological Science.
Their paper, entitled “Phosphates, plowzones, and plazas: a minimally invasive approach to settlement structure of plowed village sites,” describes how varying levels of phosphorus in the soil can pinpoint ancient middens, distinguished by high phosphorus concentrations, and plazas, which have much lower concentrations.
As a test case, Roos and Nolan examined phosphorus levels in the soil of the Reinhardt site in Pickaway County, Ohio, a Late Prehistoric village that dates to around A.D. 1300. They were able to identify a U-shaped ring of high phosphorus concentrations, which corresponded to the village midden. The area enclosed by this ring had low phosphorus concentrations, which is exactly what you would expect for a plaza. Plazas were the ceremonial heart of Late Prehistoric villages and would have been kept clean for the performance of special rituals.
Roos and Nolan point out that “it is remarkable that, although Reinhardt was the locus of human activities over more than a millennium from the Middle Woodland to the Late Prehistoric Periods, and has been mechanically cultivated for more than a century, the pattern of middens surrounding the plaza space at the Late Prehistoric village occupation is still discernible in the phosphorus concentrations.”
Roos and Nolan focus their discussion on the benefits of remote sensing over excavations, which they argue are becoming “increasingly unfeasible and undesirable,” because they are “expensive, time-consuming, and may run counter to conservation ethics.”
It’s important to make clear, however, that remote sensing investigations will never be a substitute for archaeological excavations. In fact, one of the most important applications of remote sensing is to identify likely targets for focused excavation. This saves time and effort lost in fruitless digging and, as Roos and Nolan point out, reduces “the amount of destructive sampling needed to generate relevant data.”
For information about how various remote sensing technologies have been used at OHS sites, check out this previous blog post’: Remote sensing discoveries at OHS sites