ULAS
University of Leicester Archaeological Services

A Bronze Age burnt mound, Willington, South Derbyshire

A burnt mound of probable later Bronze Age date was identified and excavated following a watching brief at Willington Quarry Extension, South Derbyshire in July 1999. This is the second burnt mound to have been found in the quarry.

A deposit of fire-cracked stones and charcoal was identified in an area where glacially deposited natural clayey sands and gravels gave way to the silts and peats of ancient marshy ground. Limited work with a JCB machine exposed further areas of fire-cracked stone and charcoal, waterlogged timbers in apparent structural form, and other non-structural timbers within the peats and silts. These deposits were identified as the infills of palaeochannels or former water courses, of at least two separate phases. Machining was halted where the timbers survived, the site was covered with tarpaulins to protect the waterlogged areas, and hand excavation of selected areas was carried out.

From the results of our work and initial analyses, the following story is clear. The burning took place on the outer meander bank of an active stream, which itself cut through distinct dark crumbly peats interspersed with thin layers of creamy white coloured silts, that had formed soon after the last glaciations around 9000 years ago.

The bend in the shallow stream was sharp, turning from the north to the east within six metres, although it is not clear in which direction the channel was flowing at the time.

Interspersed within the organic channel deposits were numerous small branches and twigs, many showing chop marks. A number of timbers converged at a single upright although they were not joined together in any way. One timber was exceptionally long (4.85m) and lay across the channel. The timbers may have been introduced to consolidate the silting channel and a similar phenomenon has been found adjacent to a burnt mound at Waycar Pasture in Nottinghamshire. Around the timbers at the base of the channel was a small number of fire-cracked stones and charcoal. A number of distinct layers were identified within the filling of the channel, including a twiggy, woody layer and a thin layer of dense leaf litter, which may help assess how long the silting of the channel took.

As this site was revisited and clearly enlarged while the nearby stream was fast choking with silts, the location of the activity was clearly important.

A second cluster of timbers to the south-east included two tree stools which had been partly disturbed by later stream courses, and a timber which was charred at one end, and also bore tool marks.

The channel fills also contained bone fragments of ox or horse at least one of which may have been butchered. Part of an adult male human femur was also discovered between the fills of a Bronze Age and Roman channel.

The Trough

Cutting the upper levels of the ancient river channels was a rectangular pit which would have served as a water bearing trough, with a capacity of approximately 400 litres (88 gallons). Measuring over two metres in length and over one and a quarter metres wide, it had been lined with 25 timbers of alder or birch with four upright ash timbers driven into the corners. In places charcoal had been packed behind the timbers.

As shown here, all timbers showed some signs of tooling marks formed by cuts from metal blades - probably socketed axes or palstaves (see below). Such tools were used between 1500 and 1000 years BC.

Once the trough had been abandoned, the end nearest the bank had filled with layers of gritty fire-cracked stone and charcoal, which filled almost half the trough. This fill contained the only find from the trough, a flint blade fragment showing some signs of heating. Bark had survived on the trough timbers where they had been covered by the burnt stone, but not elsewhere. A central area of the base appeared blackened but had not been significantly burnt.

The trough was partly surrounded by a crescentic-shaped spread of fire-cracked stone and charcoal, while several other spreads of burnt stone and charcoal were recorded in the area, and appeared to lie on the western edge of the channel.

The following sequence of events can be suggested from the examination of the site. Stones were collected from the gravels, heated in a fire and then shovelled into the adjacent water bearing trough. This would have served to heat the water. After use, or on re-use, the trough was emptied, and the broken fire-cracked stones cast about, building, over time, a mound.

What the trough was for, and why it was of such large proportions are difficult questions to answer. However, during experimental work in Ireland with a slightly larger trough, with a 100 gallon capacity, after heating rocks in an adjacent hearth, the trough was boiling in 35 minutes.

As the stones cooled, more were shovelled into the trough to maintain the heat. With the aim of cooking a 4.5kg leg of mutton, the experimenters kept their trough boiling for 3hr 40mins - 20 minutes to the pound and 20 minutes over! This left the trough two-thirds full of stone at the end of the process - not dissimilar to the state of the Willington trough when we found it.

The functions of burnt mounds remain unclear - some but not all were probably used for cooking. The lack of food debris remaining has led archaeologists to devise other interpretations such as steam bathing, the fulling of cloth, or the soaking of osiers for basketry. At other recently excavated burnt mounds, limited quantities of associated animal bone and other food waste affirm that cooking formed at least part of the proceedings.

This is the fifth burnt mound to be found by ULAS in the East Midlands in recent years, and is part of a growing corpus that has expanded the distribution and recorded detail of these enigmatic monuments in mainland Britain. The location of the sites in marshy ground, while at variance with contemporary ideas of cleanliness, suggests that the marshy area itself may have held an appeal, providing special resources within a special location. As this site was revisited and clearly enlarged while the nearby stream was fast choking with silts, the location of the activity was clearly important.

Initial interpretations of the pollen, plant remains and insects from the trough and contemporary channel suggest that the burnt mound lay within at least a small area of tree clearance with some associated grazing land. It is possible that the people who came down to the river’s edge, lived on the nearby gravel terraces. Excavation of some of these areas in the early 1970s revealed Iron Age settlements, that may well have had their origins in the Bronze Age.

We would like to thank RMC Aggregates for their funding of this project