Wednesday, December 7, 2011

Building Up Site Plans

Illustrating the layout of the site
I'm working on site plans at the moment.  These maps show the distribution of archaeological features, excavations and test pits across the site.  Hopefully there will be enough topographic information included that you can place those features into their local landscape.  They should give you a sense of the setting of the site and what archaeological investigations have taken place there.

Each little square in the grid is 1 x 1 m, and each heavier square is 10 x 10m


A tent ring and two 2x2m units
I'm working in Adobe Illustrator to combine information from a lot of different sources into one (hopefully) concise and cohesive map of each site.  I'm copying and shrinking the feature maps that I was tracing a few weeks ago and dropping them into their correct positions relative to each other and the landscape.  The landscape information comes from site plans collected in the field this summer or in previous years.  By law, in Nunavut, you can't excavate a site in the same year that you find it.  That means that the sites we were digging this year were found, mapped, and recorded in previous field seasons, so I almost always have some good map data to start with.

On this layer I'm adding some radial information. I have the angles and distances recorded to each test pit from the southwest corner of the tent ring we excavated.
The greenish square is a scan of the paper map we drew in the field.   It includes the distribution of archaeological features as well as the frost cracks, which were useful in tying the site into the air photo to help fill in the overall shape of the elevated beach terrace that the site was sitting on.


Luckily we have some hi-res air photos of the area
When I don't have detailed site plans to work from, I like to build my maps off of air photos.  I record enough landmarks in the field to tie the site into aerial photographs.  Then, working from the air photos, I trace out the landscape features that are prominent and would be easily recognizable by someone unfamiliar with the site.  In the map I'm working on today there is a prominent system of frost-cracks, criss-crossing the site.  Those cracks show up on the ground and air photos and anyone holding the finished map should be able to orient themselves on the ground by following the cracks.

This is a view of the site from the lower left (southwest) corner of the map.  You can orient yourself using the pattern of linear frost cracks.  This terrace is a raised beach ridge and the high tide line has dropped about 30 meters and moved 700 metres north since the site was initially occupied.
Photo Credits: Tim Rast

4 comments:

  1. I'm curious about the reasoning behind why you can't excavate a site the same you found it. Not that I have ever found and excavated a site in the same year (I have done some pretty extensive testing of newly found sites though). And usually I do pick a site to excavate for a particular reason (ie question it could answer). But in the high arctic I can envision a scenario where one would never have a chance to return to a particular site. Wouldn't it make sense to excavate it - or at least test it thoroughly? Patrick

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  2. It's partly a result of the permitting and consultation process and partly in place to protect sites from being rushed through by developers or overly enthusiastic researchers. All research done on a site has to be approved by the territorial permitting agency and the nearest community. That approval process takes several weeks/months and happens only once a year. If a previously unknown site is threatened, it is sometimes possible to speed that process up so that it can be salvaged, but it's not the norm. Since all excavation strategies need to be approved and the only time to get that approval is in the spring, there's no real way to find and dig a site in a single field season.

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  3. In the case of CRM work, I kind of appreciate the delay. I think it's good for the sites. It gives the archaeologist an opportunity to pause and develop a mitigation strategy over the winter and then have that plan get a stamp of approval from the government and communities. You don't feel alone when making the case for the value of archaeological resources with the client and you can always pass the blame onto the gov't for having to do slow, careful work.

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  4. I too appreciate 'delay'. Really - why excavate a site unless you need to and why not do it right? Good on you Canada! Patrick

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