16 July 2013

Landscape Geophysics

It is the time of year when all of the fields are full of that annoying stuff called crops, so my options for survey are limited. I've been spending the time writing my book and being sociable for a change. Here is a small extract, musings on the subject of Landscape Geophysics.

Landscape archaeology is the study of not just one site, but the way in which peoples used and modified the environment around them. It uses a multitude of techniques, such as remote sensing, geophysics, environmental archaeology, excavation and bioarchaeology. This gives a broad picture of land use rather than focusing on one particular site. The usual course of events in archaeology usually involves three steps.

1) Exploration. Finding a site by methods such as remote sensing, metal detecting or looking for pottery scatters.
2) Survey. Study of the site by fieldwalking, geophysics and earthwork survey.
3) Excavation. Answering specific questions about the site by targeting excavations to answer them.

The problem I have found is with the third part. It takes an awful lot of time and effort to excavate and publish a site, even if the excavated areas are quite small. There are pros and cons to excavation. A site that would take a couple of weeks to geophys might take about 200 years to fully excavate if the same area was covered (not that you would want to). Of course, excavation can provide a huge amount of information about dating, phasing and the use of the site, whereas geophysics will only give you a basic layout. The pay-off comes when you survey a site and move on to the next. Rather than digging that site for the next 20 years, you could survey hundreds of sites in that time, building up basic information on a huge area. This enables the study of a landscape that the time restrictions of excavation would not allow, and this is the method I have chosen to study the Roman road network.  

Roman roads and their associated settlements show up well using geophysics. It is a landscape that is being ploughed away. It will not be there forever. By studying as wide an area as possible, not only will the limited information that geophysics provides be available long after the site is destroyed, but it offers the chance to save such sites using schemes such as Higher Level Stewardship. The study of the road network itself gives a better understanding of what the Romans were trying to achieve in their occupation, giving the basic layout of their entire infrastructure. It is archaeology on a large scale. Where you lose the finer detail, you gain a much broader picture of what is going on. That is what I like to call Landscape Geophysics.

I am not for a moment suggesting that excavation is bad. I am saying that the two methods are complementary, and a greater balance between the two would benefit archaeology as a whole.