Monday, July 25, 2016

Week III

In my third week at Gabii I spent three days in the field excavating, one day in our finds lab and one day working with our topography team aka "topo". As not everyone is given the opportunity to work with topo for the sake of time, I will be outlining my experience in this blog post.

Our topography team at Gabii is responsible for recording our SUs through visual representations. Essentially, through measuring the elevation of an SU and creating polygons to represent SU shapes, we can form maps true to site. The total station is the stationary component of measuring the SU an elevation points; it fires a laser to the prism, which reflects the light back to the total station. This enables the station to record where the prism is in three dimensions. The prism is moved throughout the day around given SUs documenting points for which the team will connect-the-dots.

Tyler taking the SU points of a cut with the prism.

Before starting the day in topo, Tyler and Emmanuele set up the total stations owned by the University of Michigan. This process involves lining up the total station and prism at fixed points in space. Aligning the total station and prism on site is the most crucial step because it will allow the team to represent SUs in relation to each other. Since we take SU points every day, we need to ensure our data accurately represents the distance and elevation of every previous SU in space, and aligning the total station and prism at fixed points guarantees this phenomenon within a small margin of error.
Emmanuele supervising the alignment of the total station to the prism.

The first step in recording involves a photo model by Matt Naglak. From one physical location, Matt will take photographs of several different angles of an SU before moving to a different aspect entirely. In doing this, Matt is able to create a three dimensional photograph of an SU to be viewed virtually. Ultimately, the photographs can be stitched together to recreate a visual representation of a given area at a specific point in time.

Outlining the SUs with points from the prism completes the process in order to give our photo models significance in space. When Matt's photo models are joined with points from the prism, the data can be entered into a gaming system called Unity. This allows archaeologists to virtually explore the site of Gabii freely back in North America. Additionally, the interface allows for the user to excavate SUs virtually with excavation descriptions to better understand the stratigraphy.


While most of us still don't fully understand the physics behind topography, I think the Gabii workforce would agree that topo's work is not only very cool, but will be incredibly useful for future scholars of the site.

Saturday, July 16, 2016

Week II

This week at Gabii revolved around excavating the interesting walled room with the steps I discussed in my previous post. We continually rotated between pickaxing, shovel tossing, and sieving our wheelbarrow for finds before trading our tools in for subtler excavation instruments.

As the volunteers in our room excavated closer to the presumed level of the floor, the soil became incredibly compact with rocks and huge chunks of tile. We tried to trowel one of the longer walls in hope of an emerging floor surface. Luckily we struck a firm, flat surface and dubbed it as the floor that we could follow with our trowels. Arduously, our team worked on peeling back the floor surface for the rest of the week, but not without a few surprises.

After alternating between the trowel and the mini pickaxe for the thousandth time midweek, I started to see a curved feature in the floor. In my previous area, seeing circular cuts or obscure linear deposits would be normal fare, but not in such clear constructions in the Imperial Era. As we peeled back the compact soil covering our floor, we discovered a circular depression right in the middle of the concrete! Neither supervisor nor volunteer knew what to make of it, but our area knew we had stumbled upon something even more significant than the steps.

Erica Canavan utilizing the miniature pickaxe and trowel to define the stair feature.
Continuing to scrape soil from the right side of the room, the perspective of our team drastically changed. Our level surface was exchanged for a rough layer with huge inclusions jutting out in the floor. What's more, the separation between both surfaces revealed a narrow cut bordered by local stones.

By the end of the week my team was ready to finish excavating. We had been working diligently for two weeks and finally wanted to see the fruits of our labor with a quick brush of the walls and floors. Of course, nothing in this room was accomplished easily and Friday was no exception. Planted firmly on the last foot of unexcavated floor surface were two sturdy basalt rocks. Basalt at Gabii is distinctly dark grey/black and notably used as road pavers.

While most of the rocks on site are more friable than tiles found in the same SU, basalt will remain undented in spite of our efforts. Time and pressure has been shown to gradually weather the rocks in a few hundred years, which makes them great for road building. Lifting the stones is the only way to get them to budge, but similar to lead objects, the basalt volume and density do not correlate with the estimated weight of the rocks.

A visual representation of the two basalt stones our SU team removed (still in situ).
With all of this information in mind, my team had been staring down these two massive rocks for a solid seven days, eager to liberate them from our SU. Four individuals guided the basalt stones into a wheelbarrow and dumped them into their spoil heap resting place.


Although we were all happy to ultimately see the full floor and give it a final brush, the basalt stones removal was a major turning point for my team's morale. Seeing those rocks get tossed aside onto our soil waste pile reaffirmed that our physical and mental strengths in a particularly complex and rigorous SU. Our teamwork and efforts of the past two weeks were validated so poignantly, signifying turning point for our time at Gabii and archaeological career paths. Naturally, we celebrated with gelato that night.

Monday, July 11, 2016

Week I

On the site of Gabii roughly forty volunteers and forty staff members annually combine their efforts into uncovering and analyzing stratigraphy and the materials produced from excavation.

Last year, I volunteered for a Latial area of Gabii whose small stratigraphic units (SUs) were differentiated by slight changes in color, composition, and compaction. Identifying SUs delicate were of the utmost importance and we were instructed to save every potsherd the size of our thumbnails, or larger. Aside from a few extreme cases, all of the pottery we uncovered was impasto, hand-built, low-fired vessels with thick walls, and most of it barely made the threshold of "thumbnail-sized". Under the expertise of Dr. Marilyn Evans, our team was able to sieve and take soil samples* of every stratigraphic unit. At the end of last season, we hit a sterile layer of bedrock thereby putting the area to rest from further excavation.

This year, my area of excavation could not be more different. After the backhoes had removed much of the topsoil resulting from contemporary plowing activities, we could already see walls constructed of stone and mortar. We reached the limits of the area's second SU from more than a day's worth of pickaxing and shoveling!

Erica Canavan picking away the layer of topsoil.

In soil, we found all sorts of tile and red, thin pottery sherds that could have been highly important if deposited about 1,200 years earlier in my previous area. Poignantly put, digging in the Late Imperial Era after a pre-Iron Age settlement is an entirely different kind of archaeology. Although our finds matter, there is quite literally so much anthropological material coming from our SU, as a team we could not hope to excavate the entire thing in five weeks with the same methodology as I used last year.

Upon brushing the walls, we discovered that two of the walls were constructed in a later phase than the initial boundary. The new wall alignment was crooked and appeared to be a slipshod building style in comparison to its neat counterparts. Perhaps the building materials were a poorer quality as the later phase walls hardly resisted the modern farming activities.

Darcy Tuttle tossing soil in front of the two stone steps.

The deeper we excavated, the more enigmatic this room became; six inches of the walls were exposed without an exit or entrance in sight. Could ghosts have built this room? After troweling against the walls, I noticed a change in soil compaction which turned out to be a large flat rock parallel to the soil surface. Upon further investigation, we had discovered our first stone step! The second was discovered below it shortly after, but we had to wrap up the week before finding a proper floor surface. As of this moment, only one thing is confirmed: much like their modern counterparts, the Ancient Gabiines could not walk through walls. Stay tuned to see if we uncover a full flight of stairs or other fascinating building techniques!


*At Gabii, soil sampling consists of pouring a given amount of soil into a strainer submerged in flowing water. The strainer catches pottery, rocks, bones, and other larger items while seeds, charcoal, and small items are skimmed from the top into a fine strainer. The silt sinks to the bottom, thus separating dirt from anthropological materials.

Photos courtesy of the Gabii Project Media Coordinator.