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.