Conservation at Chedworth Roman Villa

At the minute I am living in a town in Gloucestershire, called Sherborne. It's a very small town with a few houses, a primary school and a shop. It is located in the Cotswolds, a part of the UK known for its rolling hills, scenic views and wildlife. Wikipedia defines it as an "area of outstanding natural beauty." No joke!

The field next to our house in Sherborne

I am here working as a conservator at Chedworth Roman villa, a National Trust site. The villa was originally excavated in 1864 and the crumbled walls of a large Roman villa were found. The villa originally contained bedrooms, dining rooms, baths, underfloor heating, floor mosaics, and possibly a tower. At the time of the original excavation, the mosaics in the east and west bathhouses were 'restored' and loose tiles, known as tesserae, were set in concrete. Over the years, these have taken on a hue different to the ones not set in concrete as moisture cannot drain out through the concrete and mineral deposits have been left behind. Other mosaics in the corridor of the villa were re-buried and eventually covered with tarmac, but records of their existence remained.

Mosaic stabilized with geotextile strips

This past summer the mosaics were re-excavated and, due to their good condition, plans have been made to create a pavilion over all the mosaics along the walls of the original villa. This new pavilion will protect the newly excavated mosaics and will better represent the layout of the original villa.

Our job has been to stabilize the mosaics to ensure they survive the pavilion construction process. We've been using B-72, a material I had used before to consolidate fragile fossils, and strips of geotextile to secure loose tiles to stable tiles nearby. Once the pavilion is complete, the mosaics will be displayed in the exact condition they were excavated so that visitors can appreciate their patterns while also getting a feel for what 1500+ years have done to the mosaics: tesserae are missing or out of place, one mosaic has Victorian-era post-holes dug through it, and in several instances the ground has begun to undulate under the mosaics, causing them to buckle.

The work has been interesting and since we are a bit ahead of schedule there's plenty of time to answer visitors' questions about what we are doing and even take a few field trips to the nearby roman sites at Cirencester and Bath.

Chedworth Roman villa and Victorian museum

For more on the mosaic conservation project, check out the blog at: http://ntchedworthromanvilla.wordpress.com/

Tintern Abbey

On a recent (and my very first) trip to Wales, I spotted a sign for Tinern Abbey and couldn't resist taking the detour to see it. Tintern Abbey is located on the bank of the river Wye, which forms the border between Wales and England. The Abbey was founded in 1131 and fell into disrepair in 1536.

William Wordsworth's poem often referred to as Tintern Abbey, but actually entitled Lines Composed a Few Miles Above Tintern Abbey on Revisiting the Banks of the River Wye, written in 1798, celebrates the beauty of the Wye. The poem has been a favorite of mine for years. Here is an excerpt:

Therefore let the moon

Shine on thee in thy solitary walk;

And let the misty mountain-winds be free

To blow against thee: and, in after years,

When these wild ecstasies shall be matured

Into a sober pleasure; when thy mind

Shall be a mansion for all lovely forms,
Thy memory be as a dwelling-place
For all sweet sounds and harmonies; oh! then,
If solitude, or fear, or pain, or grief,
Should be thy portion, with what healing thoughts
Of tender joy wilt thou remember me,
And these my exhortations! Nor, perchance --
If I should be where I no more can hear
Thy voice, nor catch from thy wild eyes these gleams
Of past existence -- wilt thou then forget
That on the banks of this delightful stream
We stood together.

Taro Reading

Yesterday I handed in my Master’s Thesis on the use of Archaeogenetic techniques in studies of crop domestication and dispersal in Oceania,which includes a case study I conducted (with plenty of guidance and support from my supervisor Dr. Harriet Hunt, for which I am very grateful!) on the genetics of taro.

To get a feel for what its about, here’s the abstract:

To date, 27 polymorphic microsatellite markers have been developed for assessing the diversity of cultivated taro, Colocasia esculenta L. Schott, populations in Southeast Asia and Oceania, for the purposes of enhancing cultivation, particularly in regards to disease resistance. This study evaluates the efficacy of these markers for archaeogenetic studies on the domestication, development, and dispersal of taro in Oceania.

Here, microsatellite markers are used to evaluate genetic diversity and reproductive strategy in a wild-type C. esculenta population from Queensland, Australia. Microsatellite polymorphisms revealed that genetic diversity and reproductive strategy varied across the population due to variations in microclimates.

The ability of microsatellite markers to detect polymorphisms and meaningful genetic variation across the Australian taro patch studied, as well as between the Australia population and a set of samples from Papua New Guinea, demonstrate the capability of microsatellite markers to reveal information about diversity and relatedness in archaeogenetic studies. The findings here suggest that microsatellite markers have the potential to address outstanding questions about the domestication and dispersal of taro in Oceania and, in turn, about early agriculture in the region.

Cultivated taro from the Maui Nui Botanical Gardens, Hawaii. Morphological variation (which reflects some, but not all, genetic variation) can be seen in the purple/red petioles on the left and the green ones on the right. Image provided by Forest & Kim Starr via a Creative Commons Attribution 3.0 License.

Microsatellite polymorphism at a single locus in two heterozygous individuals.

We’re hoping to turn it into an article for publication, so stay tuned for updates on that!

 

The Jurassic Coast

The southern coast of England is famous for its fossils. The exposed cliffs contain fossils not only from the Jurassic, but also from the Triassic and Cretaceous, spanning about 180 million years. Some of England's most famous fossils have been found here (including the first complete Ichthyosaur) and new ones are continuously exposed by erosion of the cliffs by waves. The picture above was taken on a walk along the coast to Chapman's Pool, the first inlet seen in the photo.

Stonehenge!

Above: a view from inside the henge. On the evening of the first day of our feidltrip to Wessex, we visited Stonehenge with an archaeologist who had worked on the Stonehenge Environs Project and could get access for us to the entire monument - including the area inside the henge!

Stonehenge was constructed over the course of the 4th and 3rd millenia BC. Two types of stone were used in the monument, bluestones (dolerite) for the shorter uprights and brown-ish sarsen stones (sandstone) for the larger uprights and lintels. The difference in these two stones is now obscured by lichen growing on the stones, but would have been pronounced at the time of construction.

Stonehenge is part of a larger Bronze Age monumental landscape, including barrow mounds, a 3km-long cursus, Woodhenge, and Durrington Walls. See the past few entries for more on the Stonehenge landscape.

Woodhenge and Aerial Survey in the Stonehenge Landscape

On the first day of the MPhil field trip to Wessex, we stopped at Woodhenge. While the space is only marked by knee-high concrete pillars, this stop on the trip gave us an opportunity to discuss many of the choices involved in heritage preservation and management. The concrete posts are minimal, they represent the position and estimated size of the original posts, but make no suggestion of their height or whether they had a purpose such as supporting a roof. A plaque on the site illustrated the various suggestion for the original appearance of Woodhenge. While building a more elaborate structure on the site might be more visually appealing, it also might be misleading, as much is unknown about what Woodhenge actually looked like.

Woodhenge was originally detected in aerial photographs of the Stonehenge landscape in 1925. Aerial photography has been an invaluable tool for the remote sensing of archaeological sites for nearly a century, aiding in excavation planning and identifying traces of sub-surface archaeological features. 

Aerial photographs are particularly useful in detecting buried structures that may subtly effect the topography, growth of vegetation, coloration, and deposition of snow. Often these differences are occur on too large of a scale to be recognized as a feature to a surveyor on foot.

A second type of aerial remote sensing now commonly used in archaeology, LIDAR, or Light Detection And Ranging, is an active remote sensing technique that has a variety of applications from atmospheric observation to ocean floor mapping to environmental monitoring. A laser pulse is emitted from a scanner on an airplane and the time it takes the laser to bounce off an object below and come back is recorded. From this, the distance between the object and the plane is determined.

   

Aerial Survey of the Stonehenge Landscape, UK

An aerial study of the Stonehenge area, using both aerial photographs and LIDAR, was completed as a joint project between the UK government’s Environment Agency and English Heritage. The results of this study were published in 2005 by R.H. Bewley, S.P. Crutchley, and C.A. Shell in Antiquity in an article entitled ‘New Light on an Ancient Landscape: Lidar Survey in the Stonehenge World Heritage Site.'

English Heritage hoped that the LIDAR survey could provide information about which features of the landscape were still visible above the surface and which had been leveled to the extent that no visible trace remained. It was believed that all features that had not been completely leveled by ploughing had been identified, since the Stonehenge area is one of the most studied archaeological landscapes in Europe. The authors did not expect the LIDAR survey to find new sites. The survey did however identify new features and sites in the landscape and demonstrated that some sites, which had been categorized as having ‘no visible surface expression,’ were indeed still expressed above the surface.

Field systems near the Winterbourne Stoke Barrow group at Stonehenge with underlying lidar data illuminated from the north. From Bewley et al, 2005. © English Heritage - Original data from The Environment Agency

Such sites include new field system enclosures through illumination of LIDAR images from the North (seen in blue in both pictures). These had not been identified in aerial photographs because the banks are oriented parallel to the sun’s path, so that they rarely produce shadows. Additionally, the LIDAR survey found features obscured by the vegetation of the Fargo Plantation at the west end of the Cursus (pictured below), including some field system boundaries and the course of a WWII rail line not preserved outside the wooded area. The images here show previously identified features in orange and new ones in blue.

 

In addition to exceeding expectations and identifying new features in the Stonehenge landscape, the information gathered from this survey had practical applications for the management of the Stonehenge area. The survey was taken into account for plans to build a new visitors center. The LIDAR survey informed the decision on where to put the new center so as to avoid areas where archaeological features are expressed. 

LIDAR image of the west end of the Cursus and the wooded Fargo Plantation, illuminated from the northeast. From Bewley et al, 2005 © English Heritage - Original data from The Environment Agency

White Horse of the Chalk Downlands

This white horse in Wiltshire, England was created by removing the top layers of soils over an underlying chalk geology. While such features are difficult to date, it is estimated that the white horses of the chalk downlands, 24 still (somewhat) visible, were created in the Iron Age. Many more recent hill features have been created in the area, including a new horse near the town of Devizes in 2000.

MPhil Wessex Field Trip Day 1

This past weekend the MPhil class took a field trip to Wessex, led by several of our professors. Having worked on several of the sites we visited, they gave us an incredible tour.

On Friday we visited the Danesbury Iron Age Hillfort and the accompanying museum, Woodhenge, several barrows in the Stonehenge landscpe, the Stonehenge Cursus, and Stonehenge itself. I was struck by the proximity of all of these features to one another - structures from a variety of time periods were all located within a three hour drive of Cambridge and less than an hour of each other.

The Stonehenge landscape, in particular, was densely filled with features from prehistory. Walking through the landscape, with our path blocked by certain features and redirect towards others, reminded me of Tim Ingold's discussion of the taskscape in The temporality of the landscape.

The landscape as a whole must likewise be understood as a taskscape in its embodied from: a pattern of activities ‘collapsed’ into an array of features. - Ingold

A view of the surrounding landscape from Stonehenge. At least 5 barrow mounds can be seen in the distance. I took this photo on a trip in January, so the ground is frost-covered.

The French Alps & historic Briançon

The Alps were formed by the collision of the African and Eurasian plates in the last 30 million years and form part of the same chain of mountains as the Himalayas. When the winter snow-cover melts, prehistoric remains are abundant, ranging from Triassic fossils to the early Bronze-age ice-mummy, Ötzi.

Briançon (pictured below), the highest city in the EU, is 4350 feet above sea level. Occupied since (at least) the Roman era, the heart of the town is a medieval fortification protected as a UNESCO world heritage site.

Higher Education Field Academy

Now that winter is gone and frozen ground is no longer a concern, Access Cambridge Archaeology, a not-for-profit organization run from the Archaeology Department here at Cambridge, has begun the spring season of its Higher Education Field Academy (HEFA). HEFA organizes for high school students from around southeast England to take part in archaeological excavations. I have signed up to be a volunteer test-pit excavator.

The first dig of the year happened at Little Hallingsbury, about an hour's drive from Cambridge. I had three students in my group. Even though the usual excavation crew on HEFA dig is 4 students, our group was very motivated and got down to 80 cm below surface in our 1 meter by 1 meter test pit in two days. The top 20 or so centimeters contained artifacts from a variety of time periods, including a pull-tab coca cola can. This mixing indicates that the top layer of soil may be soil moved during the construction of a building, such as the near-by cricket pavilion.

Our test pit after the turf has been removed. Had too much fun the rest of the day to remember to take any more pictures...

In lowers layers we found small portions of Medieval and Roman pottery, which ceramics expert Paul Blinkhorn identified for us. One piece of pottery however needed no identification; broken into 3 sherds, we found a small gray dished labeled "HAMPSTER," with the makers insignia stamped on the bottom. The perfect archaeological object: the dish told us both its maker and its function!

The first HEFA dig of the season was a great success with many teams coming back with interesting finds. After two days excavating test pits, HEFA participants spent a third day in Cambridge compiling data from their finds with information from previous years and touring the colleges. For more pictures from HEFA digs, see their website!

Salisbury Cathedral

The Salisbury Cathedral was completed in 1258 and its spire is the tallest in the UK. The cathedral houses one of the four original copies of the Magna Carta and the newest addition to the cathedral is a font, added in 2008; water wells up in the center and flows out of the four corners, creating a smooth, reflective surface (see below).

Montmartre

At the top of butte Montmartre is the Basilica Sacre Coeur, a cathedral completed in 1914. The basilica is located at the highest point in Paris, from which much of the city can be seen. This summit can be reached on the metro or by a scenic tram ride.

On the walk down are shops, galleries, cafes, and ample opportunities to buy paintings and other souvenirs. The Espace Dali Montmartre, a museum of Salvador Dali's art work, is located on a side street and, when I visited, had an exhibition of sculpture and jewelry by Dali.

At the bottom of the hill is the Moulin Rouge.

Île de la Cité

An island in the river Seine, the Île de la Cité is the center of the city of Paris and has been important throughout its history. The island was once inhabited by the Parisii, a tribe of Gauls in the Iron Age, from which the city gets its name. The Île de la Cité has often been a place of refuge during time of siege and is home to the Notre Dame cathedral, built in 1163. Above is my favorite, although not the traditional view, of the cathedral.

For more on the Gauls and a great discussion of their legacy in France today, see Michael Dietler's Our Ancestor's the Gauls: archaeology, ethnic nationalism, and the manipulation of Celtic identity in modern Europe.

Tower Bridge & vicinity

The Tower Bridge, often mistaken (by those of us not from the UK) for the London Bridge, was constructed between 1886 and 1894. The bridge gets its name from the Tower of London, nearby, which was founded in 1066 and since has been used as a prison, armory, royal mint, and is currently a museum and home of the Crown Jewels. Even older than the Bridge or the Tower, remnants of the Roman-era London Wall, built in the 2nd or 3rd century AD, still stand near Tower Hill.