The Excavation of a Burnt at Autumn Brook, Yate.

A Summary report Draft report for Transactions of the Bristol and Gloucestershire Archaeological Society

for Barratt Homes Bristol

CA Project: 9211 CA Report: 15705

July 2016

Summary publication report for Transactions of the Bristol and Gloucestershire Archaeological Society

The Excavation of a Burnt Mound at Autumn Brook, Yate. A summary report by CHRISTOPHER LEONARD, JONATHAN HART and SARAH COBAIN

CA Project: 9211 CA Report: 15705

Document Control Grid Revision Date Author Checked by Status Reasons for Approved revision by A 21 July M Alexander M Watts Internal Quality assurance MAW 2016 review

This report is confidential to the client. Cotswold Archaeology accepts no responsibility or liability to any third party to whom this report, or any part of it, is made known. Any such party relies upon this report entirely at their own risk. No part of this report may be reproduced by any means without permission.

© Cotswold Archaeology

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The Excavation of a Burnt Mound at Autumn Brook, Yate. A summary report by CHRISTOPHER LEONARD, JONATHAN HART and SARAH COBAIN

INTRODUCTION

During October and November 2013, Cotswold Archaeology undertook an archaeological excavation at Autumn Brook, Yate, South Gloucestershire (centred on NGR: ST 7183 8404; Fig. 1), at the request of Barratt Homes Bristol. The site lies on the north-eastern edge of Yate and comprised four fields situated on land that slopes east to west from 100m to 80m OD. The wider landscape is generally low lying with numerous brooks, and the underlying geology comprises Triassic Mercia Mudstone (BGS 2016).

Archaeological work commenced with a desk-based assessment (CA 2010). This identified no archaeological remains within the site, but a subsequent geophysical survey recorded linear and discrete anomalies (Bartlett 2011). Following this, trial trenching revealed deposits of charcoal and burnt stone associated with a Middle Bronze Age radiocarbon date, which was provisionally interpreted as the remains of a burnt mound (CA 2013). A pit to the immediate south returned an Anglo-Saxon radiocarbon date, whilst boundary ditches correlating to those on the 1838 Yate Parish Tithe Map were also present (ibid.).

Subsequent excavation targeted the probable burnt mound and Anglo-Saxon pit. Two opposing quadrants of the burnt mound were excavated stratigraphically to the natural substrate. The remaining quadrants were not excavated. A post-excavation assessment report was subsequently prepared (CA 2014) recommending further analysis and publication. The following report presents a summary of the results of the excavations and the further analysis of the charcoal undertaken by Sarah Cobain. The assessment report and details of the analysis are stored in the archive at Bristol City Museum and Art Gallery, Accession number BRSMG 2014.42. The assessment report (no. 14149) is available via the Cotswold Archaeology Reports Online library (http://reports.cotswoldarchaeology.co.uk).

EXCAVATION RESULTS

The excavation fully exposed the burnt mound and Anglo-Saxon pit, as as revealing a Roman ditch and other features (Figs 2 and 3). A total of 27 worked flints were recovered.

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The assemblage which was largely composed of , including flakes, blades and bladelets, displayed some characteristics of /Early manufacture, but all were found in later contexts. However, a displayed retouch more typical of Bronze Age , and may be contemporary with its context within the burnt mound.

Middle Bronze Age The burnt mound was found on the western edge of a palaeochannel (2074) that ran sinuously through the excavation area and which continued as a depression to the south- east. No relationship between this channel and the mound was present but burnt stone and charcoal from the burnt mound was found within the channel fills. Alder/hazel and hawthorn/rowan/crab apple could be identified from the charcoal, a sample of which was radiocarbon dated to 1499–1324 cal. BC at 95.4% probability (SUERC 45114; 3153 ± 26 yr BP). A column sample taken through the channel was examined for pollen, but did not contain any identifiable material. Some smaller channels, presumably braids from the main channel, had stratigraphic relationships with the mound. Channel 2044 was sealed by the earliest mound deposit, whilst channel 2068, which followed a similar alignment cut through the lower mound deposit but was sealed by the upper mound deposit (Fig. 2). Both were cut by the Roman ditch, and a post-medieval ditch (not shown).

The burnt mound (2054) comprised an oval spread of burnt stones and charcoal, 20m by 17m in extent and up to 0.4m thick. A wider spread of burnt stones, recorded in the subsoils that sealed the mound, represented material disturbed from the mound below. Excavation revealed that the mound consisted of two distinct layers, both of similar composition, with the lower layer directly overlying the natural substrate. Within the north-western quadrant, these layers were separated by an ashy deposit but no were exposed during the excavation. Finds from the mound were restricted to a Bronze Age scraper and a few small fragments of unidentifiable bone. The charcoal was derived from fuelwood, mainly oak from trunkwood or large branches, with other species in smaller quantities. Cherrywood charcoal from the upper mound layer was radiocarbon dated to 1631–1501 cal. BC at 95.4% probability (SUERC 66199; 3290 ± 29 yr BP).

Five troughs were sealed by the burnt mound deposits. The earliest, troughs 2091 and 2106, were oval pits with vertical sides and flat bases in the north-west quadrant (Fig. 3). Neither was fully exposed, both being partly within the north-east quadrant, but they were up to 0.4m deep. Both were unlined (the natural substrate would have retained water) and filled with burnt stones and charcoal. Charcoal from the trough fills was comparable in composition to

3 that from the mound: a fragment from trough 2091 was radiocarbon dated to 1500–1413 cal. BC at 95.4% probability (SUERC 66200; 3175 ± 25 yr BP). These troughs were sealed by the lower mound deposit that was cut by an intercutting sequence of three further troughs (2052, 2062 and 2072). These were flat-based, sub-rectangular pits filled with burnt stones, and were sealed by the upper mound deposit. A clay layer was found within trough 2062, sealing its lowermost burnt stone. A further possible trough, 2125, was exposed in the south- east quadrant where it had been largely truncated by a Roman ditch. An additional trough, 2047, was located immediately west of the mound.

Six postholes (2111, 2113, 2115, 2117, 2119 and 2121) were found within the south-eastern mound quadrant. They were 0.2–0.4m wide with steep sides and flat bases. Whilst it was not clear whether these postholes were earlier or later than the mound deposits, all were filled with material derived from the mound.

Charcoal from the mound deposits, and within trough 2091 was dominated by oak (Quercus) with smaller quantities of alder/hazel (Alnus glutinosa/Corylus avellana), alder, ash (Fraxinus excelsior), hawthorn/rowan/crab apple (Crataegus monogyna/Sorbus/Malus sylvestris), cherry (Prunus) species and willow/poplar (Salix/Populus). The relative absence of curved growth rings, plus the positive identification mature oak timbers (presence of tyloses) suggests the majority of the fuelwood used was made up of large oak timbers (trunkwood or large branches).

Roman A single ditch, 2040, cut across the burnt mound on a north-west/south-east alignment. It terminated at the palaeochannel and was therefore probably associated with drainage. Its upper fill contained spanning the Roman period, including 1st to 2nd-century AD Savernake grog-tempered ware, local micaceous greywares dating to the 3rd to 4th centuries and East Gaulish samian dating to the mid 2nd to mid 3rd centuries. Further Roman finds came from the palaeochannel and included Roman pottery and a limestone object, probably a polisher.

Middle Anglo-Saxon Pit 404, identified within evaluation trench 4, was dated to the Anglo-Saxon period by a radiocarbon determination of cal. AD 718–889 at 95.4% probability (SUERC 45115; 1209 ± 25 yr BP) from a hazelnut shell fragment. It was cut through the upper palaeochannel fill and was a circular 1.2m wide and 0.15m deep with gently sloping sides and a flat base

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(Fig. 2). Its lower fill was a thin layer of charcoal and this was covered by redeposited clay. To the north, three pits (2027, 2083 and 2086), also cut into the upper palaeochannel fill, were technically undated but were comparable in shape to pit 404 and included similar fill sequences.

The charcoal identified from pits 2027 and 2086 was dominated by oak with smaller quantities of maple, alder, hawthorn/rowan/crab apple, cherry species, blackthorn (Prunus spinosa) and willow/poplar also present.

Undated A small number of features remained undated. Of potential significance were four patches of scorching, of which patches 2100 and 2109 were on the upper palaeochannel fill close to the Anglo-Saxon pits (Fig. 2). Patch 2101 was on the upper fill of palaeochannel 2023 immediately west of the burnt mound, and patch 2102 was an area of scorched substrate just south of the mound (Fig. 3). Two pits close to the mound may be contemporary with the pits ascribed to the Anglo-Saxon period, but given their distance from the pits discussed above, the date of these features must remain conjectural.

DISCUSSION

The discovery of a burnt mound is the first to be made in South Gloucestershire. In some areas of the British Isles, development-led archaeology has shown burnt to be fairly common, with 39 having been found along the narrow corridor of the 216km-long Milford Haven to Brecon gas pipeline (Hart et al. 2014a) and numerous examples found around Birmingham (Hodder, in prep.). In the south-west and west of England the picture is less clear. Only a handful are known from Gloucestershire, including examples at Sandy Lane, Charlton Kings (Leah and Young 2001), Blenheim Farm, Moreton-in-Marsh (Hart and Alexander 2007), The Buckles, Frocester (Darvill 2011, 165) and Dryleaze Farm, Siddington (TVAS 2011), and known remains are similarly sparse in Somerset. Within Devon, two burnt mounds at Town Farm Quarry, Burlescombe were reported on in 2007 as the first discovered in Devon (Gent 2007, 42), since when only a few others have been found (Wilson-North and Carey 2011; Hart et al. 2014b). Whether this apparent paucity reflects a true regional difference or is an accident (or lack) of discovery is not clear.

Burnt mounds most commonly date to the Bronze Age, although and examples have also been recorded. The Middle Bronze Age dates from Autumn Brook are

5 thus consistent with the existing corpus and the mound is comparable in form with most other known examples, in that it included deposits of burnt stones associated with troughs and was located close to a water source. No hearths were found, but these may have lain beneath the unexcavated quadrants, or have been at the areas of scorching noted on the site, or indeed simply have left no identifiable trace.

Since their first discovery, archaeologists have struggled to interpret these features. It is generally agreed that they resulted from a process requiring hot water and/or steam, hence the fact that all are located by streams (often since entirely silted up as in the present instance) or other water sources. Stones were heated on hearths and then placed into the water-filled troughs to heat the water. Interpretation of these features has included use for boiling meat, saunas, washing places, brewing, leather preparation, fulling and dyeing (for a résumé of these see Ripper and Beamish 2011, 199–200 and Kenney 2012, 267–9). Clear evidence to support any of these theories is lacking, but use for or for saunas or washing places are the most commonly propounded interpretations. Experiments have shown that hot water can cook meat effectively. However, this is difficult to reconcile with the current evidence which suggests that burnt mounds were located away from settlement areas; the five examples found at Dryleaze Farm (TVAS 2011) were 1km north of the Bronze Age settlement at Shorncote (near Cirencester, Gloucestershire) (Hearne and Adam 1999). It is possible that meat was cooked and consumed at the mound sites only on special occasions. If so, their location, close to water, may have been more than simply pragmatic since water seems to have formed an essential part of Bronze Age religion, with connotations relating to death and the underworld (Darvill, forthcoming). The paucity of animal bone at most mound sites may not be a significant counter-argument against the cooking theory since, if the bones were cast into an adjacent stream (incidentally or as a religious act), they may simply have dissolved or not have been recovered.

The main contending theories, as washing places or saunas, are largely reliant on the paucity of material culture remains at most mound sites, but also relate to their apparent remoteness from settlement. The postholes found at some mound sites, including Autumn Brook, could have supported light structures analogous to those employed for sweat lodges used during rituals by the Lakota Sioux (Bucko 1998). In this context, it is possible that the sites were used for saunas, and also for cooking meat and for brewing, all of which might form part of a ceremony. Again, the provision of ritual saunas near streams sits happily with the connotations of water in Bronze Age religion and with the extra-domestic setting of the mounds.

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The succession of troughs and mound layers at Autumn Brook, taken with the radiocarbon dates, point to at least two episodes of use, one between 1631–1501 cal. BC, the other between 1500–1324 cal. BC. Evidence for episodic use is apparent at many other burnt mound sites (one site along the Milford Haven to Brecon gas pipeline included at least eight mounds representing a period of use of 1250–1570 years (at 95.4% probability); Hart et al. 2014a, 147).

Charcoal analysis revealed that the majority of the fuelwood was large oak timbers (trunkwood or large branches) from mature trees. Oak would have been an ideal fuel as it is a densely grained wood and burns efficiently (Gale and Cutler 2000, 205). Fuel for burnt mound activities would have been collected locally and the charcoal assemblage suggests that mature oak and alder-carr woodland consisting of alder and willow/poplar were present in the local landscape. Given the location of the site, at the base of a hill together with evidence for palaeochannels crossing the site, it is likely the water table in this area was high and would provide an ideal environment for alder-carr woodland to establish. It is likely that the mature oak woodland, which typically established on drier, well-drained soils, was located on higher ground to the east of the site. The presence of shrubby species such as hawthorn/rowan/crab apple, cherry species and blackthorn are indicative of scrub woodland establishing on the margins of more mature woodland (where woodland clearance has taken place). Despite the large charcoal assemblage obtained, there was no evidence for wide growth rings which may indicating woodland management (coppicing) was taking place.

Mounds would have supported different vegetation growth to their surrounds and this would have facilitated their rediscovery, although this may have become harder after more than a couple of years (Ripper and Beamish 2012, 198). If a ceremonial use for the mound sites is accepted (either for saunas or cooking), then the act of rediscovering the mounds may have formed part of the ceremony, whilst the expanse of stone, transformed red and black and reduced to fragments by fire and water, may have added to the sense of place. If so, the usual interpretation of the mounds, as incidental formations resulting from the discard of heat-shattered stones, is misleading and they may have been deliberately built up to create platforms in otherwise wet areas, becoming monuments enduring for years and even generations. In light of this, it is unclear why few mounds seal buried soils. This could simply be because soft streamside soils have mixed with the mound deposits to the depth of the substrate but an alternative possibility is that softer ground was deliberately reduced in order to foster the formation of what were felt to be significant deposits.

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Of the later remains, the Roman ditch presumably formed part of wider efforts to drain agricultural land during that period, and the Roman finds within the palaeochannel indicate that this still flowed at that time. It is difficult to say much about the Anglo-Saxon pits, other than to observe that the charcoal fills common to all could relate either to a domestic or to a craft activity. It is possible that the scorched areas on site were related to these pits rather than to the mound, but evidence for either is lacking. Woodland clearance was extensive by the Anglo-Saxon period, and it is likely the oak dominating the charcoal samples from the pits was brought in from elsewhere to use as fuel. The other species within the samples are likely to reflect kindling/tinder used, and thereby more likely to be locally collected. If this is the case, there is evidence for scrub woodlands/hedgerows nearby including cherry species, blackthorn and hawthorn/rowan/crab apple trees and wet woodland including alder and willow/poplar.

ACKNOWLEDGEMENTS

The work was carried out at the request of Barratt Homes Bristol and was directed by Christopher Leonard under the management of Richard Young. Post-excavation analysis was undertaken by Christopher Leonard and managed by Mary Alexander. Jon Hart adapted this report for publication. The environmental remains, finds and animal bone were reported on by Sarah Cobain, Jacky Sommerville and Andrew Clarke respectively. Ed McSloy provided guidance on the finds reports. Lucy Martin and Rosanna Price prepared the illustrations. The radiocarbon dating was undertaken by the Scottish Universities Environmental Research Centre (SUERC). The archaeological work was monitored by Paul Driscoll and specialist advice was provided by Vanessa Straker, Science Advisor (South West), Historic England. The archive will be deposited with Bristol City Museum and Art Gallery (accession number: BRSMG2014.42).

REFERENCES

Bartlett, A. 2011 Land at Peg Hill, Yate, South Gloucestershire: Report on Archaeological Geophysical Survey unpublished client report

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BGS (British Geological Survey) 2016 Geology of Britain Viewer http://mapapps.bgs.ac.uk/geologyofbritain/home.html viewed 6 January 2016

Bucko, R. 1998 The Lakota Ritual of the Sweat Lodge. History and Contemporary Practice. Studies in the Anthropology of North American Indians. Lincoln, University of Nebraska Press

CA (Cotswold Archaeology) 2010 Land at Peg Hill, Yate, South Gloucestershire: Archaeological Desk-Based Assessment and Heritage Statement. CA typescript report 10055

CA (Cotswold Archaeology) 2013 Autumn Brook, Peg Hill, Yate, South Gloucestershire: Archaeological Evaluation. CA typescript report 13067

CA (Cotswold Archaeology) 2014 Autumn Brook, Yate, South Gloucestershire: Post- Excavation Assessment and Updated Project Design. CA typescript report 14149

Darvill, T. 2011 Prehistoric Gloucestershire. Forests and Vales and High Blue Hills 2nd ed. Stroud, Amberley

Darvill, T. forthcoming ‘Discussion: The Barrow Cemetery in its Wider Context’, in Havard, T. and Alexander, M. ‘A Bronze Age Cemetery, Pit Alignments, Iron Age Copper Working, and Later Activity at Four Crosses, Llandysilio, Powys’, draft text for the Archaeol. Jnl

EH (English Heritage) 2011 Introduction to Heritage Assets: Burnt Mounds http://www.english-heritage.org.uk/publications/iha-burnt mounds/burntmounds.pdf viewed 6 January 2014

Gale, R. and Cutler, D.F. 2000 Plants in Archaeology; Identification Manual of Artefacts of Plant Origin from Europe and the Mediterranean Otley, Westbury and the Royal Botanic Gardens Kew

Gent, T. 2007 ‘Bronze Age Burnt Mounds and Early Medieval at Town Farm Quarry, Burlescombe’, Proc. Devon Archaeol. Soc. 65, 35–46

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Hart, J. and Alexander, M. 2007 ‘Prehistoric, Romano-British and Medieval Remains at Blenheim Farm, Moreton-in-Marsh, Gloucestershire: Excavations in 2003’, in Watts, M. (ed.) Prehistoric and Medieval Occupation at Moreton-in-Marsh and Bishop’s Cleeve, Gloucestershire. Bristol and Gloucestershire Archaeological Reports No. 5, 1–72

Hart, J., Rackham, J., Griffiths, S. and Challinor, D. 2014a ‘Burnt mounds along the Milford Haven to Brecon gas pipeline, 2006–07’, in Archaeologia Cambrensis 163, 133– 172

Hart, J., Wood, I., Barber, A., Brett, M. and Hardy, A. 2014b ‘Prehistoric Land Use in the Clyst Valley: Excavations at Hayes farm, Clyst Honiton, 1996–2012,’ in Proc. Devon Archaeol. Soc. 72, 1–56

Hearne, C. and Adam, N. 1999 ‘Excavation of an Extensive Late Bronze-Age Settlement at Shorncote Quarry, near Cirencester, 1995–6’, in Trans. BGAS 117, 35–73

Hodder, M. in prep. ‘Burnt mounds and beyond: the later of Birmingham and the Black Country’, in Hurst, J.D. in prep. Westward on the High-hilled Plains: the later prehistory of the west midlands

Kenney, J. 2012 ‘Burnt mounds in north-west Wales: are these ubiquitous features really so dull?’, in Britnell, W.J. and Silvester, R.J. Reflections on the Past. Essays in honour of Frances Lynch Cambrian Archaeological Association, 254–279

Leah, M. and Young, C. 2001 ‘A Bronze-Age burnt Mound at Sandy Lane, Charlton Kings, Gloucestershire: excavations in 1971’, Trans. BGAS 119, 59–82

Ripper, S. and Beamish, M. 2011 ‘Bogs, Bodies and Burnt mounds: Visits to the Soar Wetlands in the Neolithic and Bronze Age’, Proc. Prehist. Soc. 78, 173–206

TVAS (Thames Valley Archaeological Services) 2011 Dryleaze Farm, Siddington, Gloucestershire. Extraction Phases 1 and 2 TVAS typescript report

Wilson-North, R. and Carey, C. 2011 ‘A Burnt Mound on Brendon Common, Exmoor’, Proc. Devon Archaeol. Soc. 69, 9–22

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Figure captions

Fig. 1 Site Location

Fig. 2 Burnt mound and other archaeological features

Fig. 3 Detail of the burnt mound and associated features

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7711 7722 N

8855

South Gloucestershire

SSiteite 1 0 1km

Reproduced from the 2006 Ordnance Survey Explorer map with 8844 the permission of Ordnance Survey on behalf of The Controller of Her Majesty's Stationery Office c Crown copyright EExcavationxcavation Cotswold Archaeology Ltd 100002109 AreaArea Peg Hill

BB4060

4

060

8833 SO 7185

8405

Excavation area/ T5 Evaluation trench

Furrow 2074 Palaeochannel

Bronze Age 2054 excavated/unexcavated 2040 2086 Roman excavated/unexcavated 2083 Anglo-Saxon excavated/unexcavated 2027 2100 Undated excavated/unexcavated 2109

8400 404

0 25m 1:1000 SO T4 2040

2023

2044 2074

trough

2044 2056 2106 trough trough 2047 2047 trough 2106 trough trough 2091

2068 2091

2125 trough 2052 2113 2119 2068 2121 trough 2062 2111 2117 2101 trough 2062 2115 trough 2072 2054 trough 2072 2102 trough 2052 2074

2113 2119 2023 2086 2121

2117 2083 2111 2027 2115 2100 2101 2109

2054 404

Excavation area/ Bronze Age 2102 2040 Evaluation trench excavated/unexcavated

Palaeochannel Roman excavated/unexcavated excavated/unexcavated 0 10m

Stone/mound deposit Undated 1:250 excavated/unexcavated