Monday, August 15, 2016

Final Steps Before Closing the Units

Hey guys, Paul here again. After two successful days at the Fort St. Joseph Archaeology Open House, followed by two days of rest, the students spent the remainder of the week preparing to close up their excavation units.  This work consisted of cleaning up the floors and walls, cutting away roots and making sure the soil layers and color changes were clearly evident by carefully scraping the thinnest layer of dirt from each.  Drew and I even used a spray bottle of water to moisten the soil and make the rocks in our unit show their colors.  After both black and white film and digital color photos had been taken, we packed up for the evening.  The following day was spent painstakingly mapping the floor of our units onto a grid.  We measured the precise location of each stone and important feature for future reference.  We also mapped or “profiled” the walls of the unit, again, taking time to accurately portray the soil layers and changes, and anything still embedded in the walls. 
Coring Tool
            Friday was spent taking core soil samples at key locations in the unit.  Drew and I chose three spots that were interesting due to the soil differences apparent in the floor.  To take the sample, a coring tool, a partially open cu is pushed in 30 cm increments into the ground, rotated, and then pulled back out.  We can then look at the stratigraphy of the sample and get an idea of how the soil is layered under our unit. 
In the photo to the right, you can see the hole in the floor of our unit left by the coring tool. 
We chose that location specifically to see how much further the red oxidized soil went down.  From the sample we took, it appears to go down about 10 cm more.  Further below that, in the same sample site, we found what seemed to be a void, or empty space.  Maybe an animal burrow, or a vacancy caused by the de-watering operation?  In both of the other spots chosen to take samples from, we found chunks of charcoal at just over a meter below the ground level.  I found that surprising, and wonder what it could mean.  All this was annotated, and added to the rest of the documentation for our unit. 

            We will be writing up our final summaries, and then filling the units back in.  I will be a little sad to have to cover up the fire hearth, and I will wonder if we learned everything we could while working on it.
- Paul

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