Field School Week 2: Mapping and Context

Students learn mapping as their first major field research skill.  We begin with mapping because this is the first skill from which all other archaeological tools derive: the ability to know where something is in relation to other things.  An archaeologist must be able to control their data collection, locating things in space and time on the landscape.  You can think of this in one way as the X, Y, and Z coordinates where a thing was found.  We call that information an artifacts provenience, and because we know how things relate to each other in space (and thus time), we can say things like “These two artifacts were buried at the same time, roughly 1855” or “That button was manufactured in 1863 and it was in a layer of sediment deposited when this foundation was laid, so this building was built sometime in or after that year.”  If someone brings me a button or bottle that they have removed from a site, they have lost most of this information and that greatly reduces the information we can learn about daily life at the site through that object.

So knowing where things are is key.  Building from that, an archaeologist needs to be able to put things they see on or in the ground into the absolute space of maps, using systems like UTM, Township and Range, or Latitude and Longitude.  These skills matter because it takes a great deal of work to be able to look at a foundation on the ground today and definitively say, this is the foundation of this structure indicated on this 1849 map.  Figuring that out can be very hard.  Just ask Sean and the other research team members.

The students eventually learn to work with an EDM/Total Station, GPS, and sometimes other technologies like LiDAR.  When we teach mapping, however, we really start with basics because we want the students to understand the processes behind the button pushing for digital data.  The students start learning basics: the significance of triangles and trigonometry; triangulation by measurements, triangulation by bearing, and bearing-and-distance mapping; determining scales; and drawing by hand.

We spent time during the first and second weeks making maps of campus buildings. One team stretched tape measures to build a triangle of three base points, then measured distances from those points to all the key building corners.  The second team used magnetic compasses to take bearing readings off magnetic north from a single point, then measure the distance.  Then both teams plotted their buildings onto hand-drawn maps at the same scale.  This was the result:

Not bad for a first try!

Optical Transit Instrument

This is an optical transit, similar to the model used by Michigan Tech Industrial Archaeology students when they learn the basics of surveying and map making. Creative Commons image courtesy of Land Surveying Services, Inc.

Later, when we went into the field to the South Cliff Stamp Mill, we pulled tape measures to lay in base points and started making our map of the building remains.  We also started learning how to use an optical transit.  This is pretty easy to learn until you depress or incline the angle of your telescope, so I’ll spare you all the math.  Using the optical equipment certainly prepared the students to appreciate the EDM and GPS units!

Stadia measurements.

This schematic diagram shows computations of distance using stadia measures, when the transit is level. Creative Commons image courtesy of the Food and Agriculture Organization of the United Nations.

Students plot a map of the South Cliff Stamp Mill

Kaeleigh, Jordan, Rob, and Connor plot points on a scaled map of the South Cliff Stamp Mill. And yes, that is snow on the ground at the end of May in the Keweenaw.

Connor Will reads geospatial data using the Total Station/EDM.

Tim Goddard teaching Connor Will how to use the Total Station/EDM to collect geospatial data.

As the work progressed, the students generated a scaled drawing of the mill’s main features in the field. Working from this drawing, they were able to then select areas for shovel test pits.  We wanted to assess the potential of the South Cliff Stamp Mill for archaeological excavation.

The third week, Tim Goddard was able to spend some time with us in the field, teaching about the EDM/Total Station as a tool for collecting geospatial data.  The students learned quickly and they reshot many of the South Cliff points again, so we will be able to compare the digital with our “analog” data. The EDM data will allow us to easily add the new information about the South Cliff Stamp Mill into the CliffMAP GIS.

Kaeleigh levels the survey rod prism.

Kaeleigh Herstad levels the prism to record machine anchor bolts in the South Cliff Stamp Mill.

We were generally pleased with the results and look forward to showing our open house visitors the stamp mill site and explaining what we have learned about it during the week we spent studying it.  We’ve only had a quick and preliminary view, but it looks very  promising for more research. This mill also has an interesting story as a place of technological experimentation and it gave us tantalizing clues!

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About Timothy James Scarlett

Associate Professor of Archaeology at Michigan Technological University.

5 responses to “Field School Week 2: Mapping and Context”

  1. Bubba Jo McGee says :

    Very interesting, a good civil engineer also needs to know how to map!

    • Timothy James Scarlett says :

      Thanks Bubba. We give the students a good knowledge, but this is only one skill. We are not teaching them to be surveyors and archaeologists aren’t experts at survey (they can’t testify in court about property boundaries, for example). I would hope that a any civil engineer would know how to map! This is such a basic skill for these occupations, I would hope that the Civils would have personal understanding of the jobs done by surveyors on their projects!

  2. Mary Hill says :

    Hello Tim and crew. Unfortunately, my family won’t be able to make it up for the tour this year. Good luck and please post lots of pictures…especially of the Clifton dig sites, since you know I am still looking for the Warren family home site.

    • Timothy James Scarlett says :

      Hi Mary- We will post lots of pictures! I’ve caught up to be about a week behind on postings, but now I’m ready to start talking about the excavations. I plan to start posting these during my “days off” after today’s open house.

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