Conservation Continues by Elizabeth Homberger

Here's an example of the type of conservation work we're doing on site:

Before treatment. The image above shows an unstable area of mosaic, with stone tesserae (tiles) at risk of detaching.

After treatment. The image above shows the same area after students have cleaned the tiles and applied an edging of mortar to hold the tesserae in place.

Intro to Conservation 2014 Season

 by 2014 Conservation Supervisor Elizabeth Homberger

The third season of the Rutgers University Upper Sabina Tiberina excavation in Vacone is underway! This year the conservation team includes Conservator Elizabeth Homberger, Conservation Assistant Amanda Klein and six graduate students. Our main priority this season is to clean and stabilize the exposed in-situ architectural details of the villa, including stone mosaic floors and plaster wall paintings.

 We have just two weeks to complete our work, and in the first 2 days started to assess the condition of the mosaics and wall paintings, began cleaning and stabilization of some unstable areas, but unfortunately today we faced a rain storm that kept us inside! 

My Introduction to Archaeological Conservation Process, by Boris Von Faust

After a blog hiatus due to the busy weekend, Boris has provided another guest blog post about work on site:

I am working on my master's degree in world history at Rutgers University Newark. I had never participated in any aspect of archaeological work before, so participating in the Vacone villa excavation project awards me a unique opportunity at firsthand uncovering of ancient history that was impossible to pass by. I came to Vacone ready for the hot weather and looking forward to two weeks of hard, but rewarding scientific work. So far, my involvement with the conservation effort primarily entailed the cleaning of the mosaic floors around the site, in order to prepare these areas for future stabilization and other necessary intervention procedures.

As Annie explained in her blog entry, the cleaning technique involves removal of dirt and clay from the surface of the mosaic by the least intrusive methods possible (minimal amount of clean water, soft sponges and brushes, and wooden skewers and tongue depressors for edgework and detailing.) Soaps, cleaning products, and solvents may damage the  surface of the tessellatum, as can too much wetting and drying of the mosaic, so the conservation specialists must be aware of the delicate nature of the process. It is also important to note any surface deterioration, such as detached tessarae, lacunae, cracks, and to avoid any further damage to the delicate edges of the mosaic. The cleaning procedure may appear easy enough at the first glance, but the scorching Mediterranean sun makes the treatment a much more challenging endeavor.

Above is a photo of student Jack cleaning a mosaic on site.

Aside from removal of deteriorating materials, cleaning enables the conservation specialists to better assess the condition of the mosaic, as well as prepare the area for the stabilization treatment, which ranges from resetting the detached tessarae, edging repair, infilling of lacunae and cracks, grouting of voids between preparatory layers, and injecting fresh mortar to reinforce problematic sections of the mosaic.

Small voids and lacunae are carefully filled with mortar.

During my first week at Vacone, I was also involved in several other aspects of working at the archaeological site, removing soil and sand from the Geo-textile, which was used to conceal the mosaic excavated the year before, as well as some actual excavation work.

 One thing that fascinated me the most was the variety and creativity of the mosaic designs around the villa. Each room has its own unique patters, and in some instances, two distinct patters can be found within the same room. Characteristically of the period, all mosaics are geometric, rather than figurative, varying from bi-chrome to polychrome in color, and feature a variety of patterns.

I've always had a profound respect and admiration for the intense labor and passion of the archaeologists, and now, having witnessed and experienced some of the process, I feel privileged to be a part of this remarkable project.

Guest blog post: Preparing Mosaics for Stabilization by Annie Cannatella

Guest blogger Annie Cannatella has provided a recap of yesterday's work in the trenches:

Before participating in the Rutgers intensive conservation course, I had experience with similar field school excavations.  However, in the past I have done very little Conservation work on site.  I chose to participate in this course to help me grasp a stronger understanding of what conservation work entails because I am interested in going to grad school for conservation and restoration.  We started off today with finishing the cleaning of the mosaics.  Using water, we removed the dirt from the tiles with gentle brushes and sponges being careful not to further damage the mosaic.  In areas that had a thicker covering of dirt we would dampen the surface and use a wooden tongue depressor to scrape away the mud and then return to brush the tiles clean.  After initial cleaning we went back over the mosaic focusing specifically on the cracks this time.  We used bamboo skewers to remove the dirt from inside the cracks.  These are gentle on the tesserae and will not damage the degraded stone. We excavated each of the cracks down to the original mortar preparation layer.  These cracks would be filled with a lime-based mortar to reseal the damaged area.  The dirt had to be removed in order for the mortar to properly attach to the mosaic. Tomorrow I will begin to work on inserting the mortar into the cracks to prevent any further damage to the mosaic.  

Here's a photo from today's work, with Annie inserting mortar in the mosaic cracks to stabilize them.

Le Colline Agroturismo

Student and staff on the project are housed in Le Colline agroturismo, pictured above. The surrounding countryside is beautiful!

Here are some of the other inhabitants.

Over the next few days, conservation students will provide recaps of work in guest blog posts. Until then, here's a photo of Erin cleaning a pretty black and white mosaic.

And a bronze artifact just after cleaning in the lab.

In Situ Conservation Work: Day One

We spent the first day on site preparing mosaics for stabilization in situ. This included not only carefully cleaning layers of dirt and clay off freshly excavated tesserae, being careful not to dislodge any loose pieces, but also assessing last year's work to see if it had survived the winter.

Here is the conservation team working hard on site.

 And a detail of Amanda carefully removing dirt around tesserae that will require stabilization with mortar. Because mortar will not adhere well to dirty surfaces, it is important to spend adequate time cleaning.

Boris and Jack are using tools that are a conservation favorite: bamboo skewers. Even though the mosaic floors were originally built to be walked on and stone is a hard material, age and exposure to various agents of deterioration have made the mosaic fragile. The bamboo skewers and gentle mists of water allow for fine cleaning and detail work in particularly fragile locations.

Once the floor is ready, aged lime mortar will be used to fill gaps and cracks before the mosaic is reburied to ensure preservation.

Intro

The Upper Sabina Tiberina project is located in Vacone, about 40 km north of Rome, close to the Tiber Valley. 

The dig housing is in an agroturismo, Le Colline, pictured here.

The goal of this blog is to introduce the site and document conservation efforts as we work to preserve a 1st century AD Roman Villa.

Check back often as the conservation team adds guest posts and photos!