8/10/2019 Walpole AEA2014 Poster

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Integrated human palaeoecology and palaeoeconomy of a prehistoric coastal wetland margin, Walpole, Somerset, UK Matt Law1,2, Arthur Hollinrake1, Nancy Hollinrake1, Emma Smith1, Poppy Hodkinson2, Richard Madgwick2, Dave Norcott3, Ellen Simmons4, and David

Smith5 1 C&N Hollinrake Ltd 2 Cardiff University 3 Wessex Archaeology 4 University of Sheffield 5 University of Birmingham

http://www.hollinrake.org.uk. matt.law@hollinrake.org.uk

Neolithic 

At this point, the Lias outcrop would have stood as hill in a low-lying landscape that would have varied between freshwater

and saltmarsh . The clay overlying the Lias bedrock contained the butchered remains of a domestic pig. Samples from this

deposit contain calcareous granules secreted by earthworms, suggesting a dry land soil existed here, as well as numerous

shells of the land snails Cepaea sp., Discus rotundatus, Clausilia bidentata and Pomatias elegans, which suggest a shaded,

possibly wooded, environment, certainly with tree trunks and loose, broken ground. In a pool off the northern edge of the

outcrop, a landing structure was made of brushwood with mooring posts fashioned from beaver-gnawed wood.

Immediately to the north of the outcrop a sequence encompassing a blue-grey clay overlain by a peat layer and another

blue-grey clay were analysed for insect remains (Ellis 2012). The lowest part of this sequence suggested an aquatic

environment dominated by Helophorus spp. with Octhebius spp., with Limnobaris sp. from waterside vegetation, and slow

moving water choked with vegetation suggested by the presence of Coelostoma orbiculare (Ellis 2012). The peat sample

contained Colymbetus fuscus suggestive of areas of deeper water and Coccadula rufa,  likely to indicate the presence of

bulrushes (Ellis 2012). The upper clay contained predominantly waterside and aquatic species, although a moorland

environment nearby is suggested by the presence of Plateumaris discolor , which primarily lives on the roots of cotton grass

(Eriophorum spp.) (Ellis 2012).

A reedy brackish channel or lagoon developed on the south of the Lias outcrop, with beetles such as Bembidion minimum,

B. laterale, Dyschirius salinus and Octhebius marinus, which are saltmarsh species, present in as well as Bembidion varium

and Platystethus cornutus which are associated with reeds. Individual sclerites of beetle species associated with woodland

and pasture were also present (Shotter 2011). The beetle  Anthicus gracilis, a species associated with decaying wetland

vegetation was also present. This latter species has been extinct in the UK, probably since the iron age (Shotter 2011). Three

fragments of cattle bone and one of pig bone were recovered from the buried lagoon deposit. Samples from the south of

the outcrop at this time are generally dominated by vast numbers of the snail Ecrobia ventrosa, which lives in brackish

water with relatively low salinity, away from direct tidal influence, accompanied by large numbers of Potamogeton sp.

(pondweed) fruits, ostracods foraminifera (Haynesina germanica, Elphidium williamsoni and Ammonia beccarii var.

limnetes, which are associated with low saltmarsh to mudflat habitats), bryozoans (all Conopeum seurati , a lagoon

specialist), and occasionally other molluscs (Macoma balthica, Peringia ulvae, Scrobicularia plana - all intertidal or brackish

water species). Gross disturbance, interpreted as cattle trample, was recorded in a monolith sample, and numerous

hoofprints were also recorded during excavation.

IntroductionWalpole Landfill Site lies on the Somerset L evels in the south west of England. Archaeological monitoring and excavation ahea d of landfill

cell construction since 2000 has revealed a complicated prehistoric landscape with 18 preserved wooden structures of neolithic and

bronze age date crossing a coastal wetland landscape around the margins of an outcrop of Lias limestone which remained dry land, at

times a small island, until the early iron age (Hollinrake and Hollinrake 2006; Law and Hollinrake 2014). This poster presents interim

results about the changing environment on the Lias outcrop at Walpole landfill site as a result of the programme of works undertaken by

C&N Hollinrake Ltd on behalf of Viridor. Phasing is provisional, and is primarily based on stratigraphy and assessment of prehistoricpottery.

Iron Age At the south of the outcrop, a saltmarsh environment was developing. Samples of the buried surface from this date contain E. ventrosa and Potamogeton fruits, alongside animal bone fragments and

flints. Pig and cattle bones were hand collected during excavation. Slightly later samples from the buried surface yielded sterile residues, except for one that contained a small number of Potamogeton 

fruits and fragments of animal bone. Calcined cattle bones were collected from this deposit during excavation. The presence of calcined bone in the iron age is likely to reflect a continuation of thepractice of disposing of domestic refuse in hearths before secondary deposition away from the (as yet undiscovered!) habitation areas. To the west of the sub-circular ditch, a large circular grain

storage pit c.1 metre in diameter and 0.75 metres deep was dug through the Lias bedrock. The lowest fill of this contained visible matted plant material on excavation, and was found to contain seeds

of nettles, brambles, dock, goosefoot and henbane, suggesting dry land with nitrogen rich soils in the vicinity. The same fill also included a small assemblage of snails such as Discus rotundatus,

 Aegopinella pura and Clausilia bidentata and a slug plate of the Limacidae family, which together suggest a shaded environment with tree trunks, as well as earthworm granules including one of the

Lumbrica rubellus type - a species which prefers rotting leaf litter. Poorly preserved water beetles ( Agabus, Ochthebius and Helophorus spp.), all suggestive of slow moving water, were also present in

this fill.

From the late iron age, one monolith sample of the buried surface was described as representing alluvium with stasis and drying. The animal bone from this deposit tends to be cattle and pig, although

sheep/ goat appear for the first time in the Walpole assemblage in the late iron age. Alluvium was deposited relatively quickly during the late iron age and early Romano-British periods, although there

appear to have been two periods of stasis during which there was possible incipient reed growth with burning. A network of ditches across the Lias outcrop carried brackish water. A sample of one ditch

fill contained E. ventrosa as well as Potamogeton fruits and a bramble seed, suggesting dry ground nearby.

Chalcolithic and Bronze Age

The lagoon appears to have persisted to the south west of the

outcrop. Further north, the Lias outcrop appears to have

remained dry, possibly an island, with samples containing charred

seeds, fragments of cattle and pig bones, and flints. At some point

early in the bronze age, a sub-circular ditch, with an exterior

diameter of 8 metres, was dug on the outcrop surface. The ditch

had no entrance, and no sign of a structure was found in the

internal area, so its function is not yet understood. The ditch

apparently carried brackish water, as its lowest fill contained

shells of E.ventrosa, along with charcoal, flint and fragments of

Beaker pottery.

Pig and cattle bones were recovered from the lagoon deposit

during excavation. Much of the animal bone from Bronze Age

contexts was calcined, perhaps suggesting refuse disposal in

hearths. The enigmatic sub-circular ditch was filled by a clay

containing flint and what appear to be fragments of chalk.

Another late bronze age ditch fill contained a single ‘woodworm’

 Anobium punctatum which can be associated either with dead

timber in woodland or prepared timber in settlement and a single

Sitona spp. ‘clover weevil’. 

Acknowledgements

The fieldwork and post-excavation work were directed by Arthur Hollinrake and Matt Law, and the project managed by Nancy Hollinrake. Emma Smith contributed the GIS. ML wrote the text of the poster, drawing on assessment reports by Poppy Hodkinson and Richard Madgwick (animal bone), Dave

Norcott (geoarchaeology), Ellen Simmons (plant macrofossils), and David Smith (insects); and ML contributed original analyses of molluscs, foraminifera, bryozoans and earthworms. The archaeological work at Walpole landfill site is kindly supported by Viridor Ltd.

References

Ellis, H., 2012. Insect analysis from Walpole. Unpublished BA Dissertation, University of Birmingham.

Hollinrake, C., and Hollinrake, N., 2006. Neolithic structures and aurochs bones at Walpole landfill site, Somerset: archaeological works in 2005 -6, Archaeology in the Severn Estuary , 17. pp. 143-159.

Law, M., and Hollinrake, N., 2014. The Walpole landfill site: wet, muddy & rewarding. British Archaeology , 138. pp. 28-33.

Shotter, L., 2011. Title not known. Unpublished BA Dissertation, University of Birmingham.

Map showing Walpole island, with heights of

bedrock below ground surface, and a

representative profile through the overlying

sediments (vertical scale is exaggerated). Map

contains Ordnance Survey data © Crown

copyright and database right 2014  

Above: the early Bronze Age ditch