Long Term and Short Term Experiments

1. Author of the presentation- Prof. Bruce Bradley Organisation- University of Exeter- Archaeology Date- 8 October 2012 WP-5 Long Term and Short Term Experiments

2. Long Term Experiments allow us to ask site formation questions- Structure building, maintenance, use, decay and destruction Example: Iron Age Houses in Flames: Testing house reconstructions at LEJRE 2007

3. Example: The Experimental Earthwork Project

4. Understanding how earthworks change- Martin Bell • Earthworks account for a large proportion of Britain's surviving archaeological monuments • Little is known about how they change over time, how their appearance is altered and how their contents decay. • The Experimental Earthwork Project was founded 52 years ago • Two earthworks were built, one at Overton Down near Avebury in 1960, and one at Wareham in Dorset in 1963, to aid our understanding of monuments on acid heathland. • The project was designed to take 128 years - the earthworks were to be excavated after two, four, eight, 16, 32, 64 and 128 years • Artefacts were deposited in both earthworks. • It was assumed organic material would disappear long before metal decay-products inhibited the microorganisms of decomposition. The earthworks experiment, however, has shown that textiles often take longer to decay than was thought. • Forensic archaeologists in particular are now looking closely at how the different types of material have decayed over the past five decades, to help them and the police understand what happens to clothing and other items (for instance, leather) associated with present-day buried murder victims. • As for the bones in the earthworks, at Wareham all but one cremated piece had vanished after 33 years. At Overton, although much of the bone remains well-preserved, fungal activity suggests some may not last very much longer • At Overton, the appearance of the earthwork changed dramatically each year at first, with chalk eroding from the ditch and the bank. After ten years, however, the whole monument had been stabilised by vegetation, and erosion largely ceased. This suggests that, on chalk, all but the largest prehistoric earthworks would have looked striking and 'fresh' for only about a decade. In 20 years, they would have faded into the landscape, and would already have looked like old features • During the period when Overton was eroding, annual winter/summer banding was recorded in the silts washed into the ditch. This was an entirely new discovery, and may establish whether prehistoric ritual activity was seasonal. Ritual deposits are often found in ditches, and analysis of silt banding may provide clues as to the time of year they were buried. • Archaeologists tend to assume that the buried soil in a monument becomes 'fossilized' at the time of burial, and that the seeds, pollen, molluscs and other such evidence in the soil represent a clear record of the ancient environment. • At Overton, the buried soil has been completely reworked by earthworms, suggesting the stratification of environmental evidence may sometimes be unreliable. At Wareham, by contrast, very little reworking has taken place, and each turf in a stack at the core of the mound can still be distinguished. • One of the big problems for archaeology is that our timescale of knowledge is so short in relation to the time we seek to comprehend. The ambitious timescale of the earthworks project seeks to bridge the gap between the research preoccupations of successive generations. It also highlights the more central role which experimental archaeology ought to play in helping us understand how the archaeological record has formed. • Dr Martin Bell, of the University of Reading, is the Director of the Experimental Earthwork Project for the 1990s.

5. Long-term Experiments are used to evaluate artefact storage and preservation: Example- The Marstrand Project, Norway Under water reburial of artefacts as a means of preservation. http://www9.vgregion.se/vastarvet/svk/reburial/news/news.htm

6. Long Term Experiments are used to determine the uses of space, specifically in structures: Example: STORIES FROM THE EARTHEN FLOOR OF THE IRON AGE HOUSE Period: Late Iron Age (c. 400-1050 AD) Project title: KringhusochHärd: Kulturlagrenskemisomdokumentöverforntidsmänniskansnäringsfång Researcher: BjörnHjulström, Stockholm Universitet, Sverige The aim of this experiment was to gain insight into the activities in the Iron Age houses through analysis of soil samples from the floors of the Iron Age houses. The reconstructed Iron Age houses at Lejre Experimental Centre were well suited to this type of experiment as the houses are in actual use every summer. The experiment at Lejre forms a part of a larger project that includes analyses of soil samples from archaeological excavations of Iron Age houses in Sweden. Long Term Experiments can be ‘hard’ science based: Discussion: Prof. Martin Bell, M. (2009) Experimental archaeology: changing science agendas and perceptual perspectives. In: Allen, M. J., Sharples, N. and O'Connor, T. (eds.) Land and People: Papers in Memory of John G. Evans. Oxbow, Oxford, pp. 31-45. ISBN 9781842173732

7. One off Long Term experiments

8. Short Term Experiments: Primarily for hypothesis testing and discovery. Examples forthcoming: