Appendix Jiii Effects of past and present ploughing on the prehistoric monuments: the Wyke Down, , , case study.

C A I French

© C A I French, 2001

Oxford Archaeology May 2002 (revised December 2002) Effects of past and present ploughing on the prehistoric monuments:

the Wyke Down, Cranborne Chase, Dorset, case study

C A I French

(6/12/2001)

Introduction

Palaeoenvironmental and geoarchaeological fieldwork focusing on the later Neolithic-earlier

Bronze Age periods in the Wyke Down area of Cranborne Chase in Dorset (Figs. 1-3) is in the process of gathering new data with which to re-examine the landscape models put forward by Barrett et al. (1991a and b) and Barrett (1994) for . In the process, this project has revealed data relevant to the past and present erosion of prehistoric monuments which is ostensibly associated with past and present arable agriculture.

To date a selection of prehistoric scheduled monuments on Wyke and Bottlebush Downs

(Fig. 2) have been sample investigated to retrieve archaeological and palaeoenvironmental data. This has been combined with geomorphological survey of the Allen valley. Results

Introduction

Four barrows of the Wyke Down group (SAM 299 c, f, g & i) and a length of the

Dorset on Bottlebush Down (SAM 310) have now been investigated through a combination of hand augering, topographical and geophysical surveys and sample excavation.

The Wyke Down barrow group

The main part of the Wyke Down barrow cemetery was evaluated by topographical and magnetometer surveys of about 1 hectare in extent (Figs. 4-6). These clearly show barrow

44 (bottom left) and 47 (top left) upstanding with evident internal features, but the remainder are ostensibly ploughed out with only ring-ditches surviving as earthfast features.

The conventional topographical, magnetometer and resistivity surveys of barrows 34,

36, 41 and 44 pin-pointed with great accuracy the position of the ring-ditches, the extent of the surviving mounds, and areas of antiquarian and plough disturbance (Figs.

7-14) (GSB 1998, 1999 & 2001).

Barrow 41

Barrow 41 was much destroyed and denuded, and to a large extent this had already occurred in the past. Today the monument survives as a small, low (c 80cm high), turf mound in the centre of the area enclosed by a ring-ditch (Fig. 7). The ring-ditch is about 3.5m wide, 1.6m deep, with an internal diameter of about 19m and an external diameter of about 26m. The inner third of ring-ditch backfill was composed of densely- packed, clean chalk rubble which would appear to be a deliberate backfill deposit. One could speculate that this chalk substrate material had acted as either a cap to the turf core, or as a circular bank on the inner edge of the ring-ditch, which had been deliberately put back into the ditch after a short period. Thus this barrow has probably previously been two slightly modified versions of a disc barrow.

There is a difference of about 25cm between the level of the chalk on the outer edge of the ring-ditch and the chalk subsoil beneath the surviving mound (Table 1). The mound itself has become elongated along the east-west direction of the property boundary between the

Shaftesbury Estate to the north and Martin Green’s land to the south (Figs. 7 & 8).

Barrow 34

Barrow 34 was exhibited a more complicated and diverse sequence than barrow 41.

Despite the presence of the large antiquarian trench on its northern side (which may be early

20th century in date, and is regrettably unrecorded), the mound of this barrow appears to be substantially intact and standing to a height of about 1.6m above the present day surface

(Figs. 7-9 & 11).

Sample excavation revealed that the site was comprised of at least two superimposed barrow monuments associated with first an inner and then an outer ring-ditch. First, a small

(c 2 x 3m), sub-rectangular chalk cairn was erected on a thin (<10cm), truncated old land surface. This cairn would appear to mark the centre of the subsequent mounds and was covered by one or two layers of turf. The inner ring-ditch (of about 18m internal diameter) was then dug (or deepened), and the chalk subsoil upcast from this was used to make a primary chalk mound of about 16m diameter placed over the primary chalk and turf cairn.

The surface of this chalk mound was initially left bare and underwent a period of weathering sufficient to discolour the upper 5-8cm of the chalk, and saw the accumulation of large quantities of worked flint, probably worked in situ. Then, a more substantial turf mound was created with its outer edge vertical sided and retained by a slight wooden revetment of stakes (slender fence post size, <10cm), with each stake placed about 40cm apart, presumably retaining a woven wattle-work fence, located about 1m in from the inner edge of the ring-ditch. The inner ring-ditch had become completely infilled by the time the outer, slighter, ring-ditch was dug (with a c 23m internal diameter, c 24.5m external diameter). The mixed upcast of turves, soil and chalk rubble produced by the digging of this ditch was thrown-up against the outside of the wattle fence around the first barrow, which was now leaning outwards, thus increasing the diameter of the barrow mound by about 3m and creating a gently sloping outer edge to the barrow, but still leaving a wide berm (2.5-3m).

Apart from the antiquarian disturbance of the north-central part of the barrow mound, ploughing over different time periods has differentially affected its northern and southern sides (Figs. 7-9). The mound survives to a maximum height of 1.6m above the modern ground surface. On its northern side, the mound rises abruptly from the flat level of the present day ploughsoil where it has been ploughed for a 45 year period. In contrast, the southern side, which has not been ploughed for the past 15 years and is under established grassland, exhibits a more gentle sloping aspect between the edge of the surviving mound and the inner edge of the outer ring-ditch. This mound talus slope exhibits a 56cm thickness over a distance 6m (Table 1). Barrow 36

Sample excavation of barrow 36 revealed a thin rendsina soil profile (c 12-15cm thick) overlain by a thick turf core and substantial dumped chalk mound, as was indicated by the auger survey. The mound was about 25m across north-south and 23m across east-west, and has the best height survival at 2.45m. Essentially, the mound has become sub-square in plan (Figs. 12, 14-16). The single ring-ditch was about 2.5 m in width and 1.3m in depth.

Significantly, the berm area between the inner edge of the ring-ditch and the outer edge of the surviving mound exhibited three steps in the upper level of the chalk subsoil. The first step was of 10cm between the outer and inner edges of the ring-ditch, then about 1.5m in from the inner edge of the ring-ditch there was a second step of 15cm and then another metre in there was a step of 27cm at the outer edge of the surviving mound. This gives a total figure of 52cm of truncation over a width of about 5m in the level of the chalk subsoil on the east side of the mound (Fig. 17; Table 1). The field in which this barrow sits is known to have been ploughed for 45 years (P Rymer and M Green, pers comm.), and has apparently caused the significant denudation and re-shaping of this mound.

Barrow 44

Sample excavation of barrow 44 revealed very much the same picture as for barrow 36, but the mound and buried soil were less well preserved (Figs. 13, 14 & 18). The mound exhibits a diameter of about 27m across east-west and 18m across north-south, and has effectively become sub-rectangular in plan. The single ring-ditch was about 3.2m in width and 1.35m deep. This barrow mound survives to a maximum height of 1.33m and has suffered severe rabbit warrening and possibly an antiquarian trench being placed in its northwestern quadrant. As for barrow 36, it too exhibits three steps in the level of the chalk between the inner edge of the ring-ditch and the outer edge of the surviving edge of the barrow mound. In this case, there are steps of 7, 18 and 53cm giving a total figure of 78cm of denudation (Fig. 18;

Table 1).

The Dorset Cursus

Four sample sections were excavated through the northern and southern cursus ditch and bank on the c 1km stretch leading to the Bottlebush Down terminal (Figs. 15, 16,

19 & 20). Unlike those sections previously excavated by Richard Bradley (Barrett et al. 1991: figs. 2.12 & 2.13), these new sections revealed fills that were mainly dominated by clean chalk rubble. Moreover, the surviving bank was much denuded in height (i.e. less than 30cm) and appeared to have been ploughed in pre-Roman times.

From the 2001 field investigation it looks as if the Bottlebush Down length of both cursus banks was deliberately slighted back into the ditch shortly after the monument was constructed. This is in contrast to the other fill sequences observed further to the south in the same monument on Wyke Down and in Firtree Field by Bradley (ibid.) where the homogeneous organic silt loam and fine chalk rubble fills suggested a natural infilling over a lengthy time period. These observations in the northern sector of what is believed to be the first major length of Dorset Cursus would suggest a complete change in its importance and function in the landscape within the later Neolithic. In addition, it may imply a complete re-aligning of the fields and boundaries in this part of the downland landscape. As an important addenda to this work, the sample excavations enabled the assessment of the preservation of this important linear field monument. Although only part of the southern bank/ditch of the cursus is scheduled in this stretch from the terminal northwards, the whole length is quite poorly preserved. Modern ploughing, post-17th century AD estate boundaries and scrub woodland development have all played a hand in the destruction of the northern and southern banks. In addition, there were several ard marks preserved beneath the Roman Ackling Dyke and the cursus northern bank in one assessment trench which may also indicate some later prehistoric slighting and denudation of what was left of the cursus bank in places (Fig. 19). A major observation of this field season was that both cursus banks in the c 1km length investigated were severely slighted, probably in the late Neolithic period and again in preparation for the construction of the Roman Ackling Dyke in the 1st century AD. Indeed, where the southern cursus bank appears to be very prominent and well preserved and it is therefore scheduled, there is the same slighted bank, accentuated by the later creation of a property boundary, and plough downcutting creating a false contour on its eastern side (Fig. 20). Table 1: Observed amounts of truncation at four barrows of the Wyke Down group.

Truncation stage: Barrow site: 41 34 36 44

Surviving mound height 0.8m 1.58m 2.45m 1.33m

Truncation step across ring-ditch - - 10cm 7cm

Truncation step on berm - on north: 15cm 18cm c 30cm; on south: gentle slope over 6m

Truncation on outer edge c 25cm (as above) 27cm 53cm of mound

Total truncation c 25cm c 30cm 52cm 78cm

Conclusions

Ploughing in both prehistoric and recent times has resulted in varying degrees of destruction of upstanding scheduled monuments in the Wyke and Bottlebush Down areas of Cranborne Chase. These conclusions are fully attested by topographical and geophysical surveys and test excavations (French et al 2000).

Both the northern and southern banks of the Dorset cursus have been affected by the deliberate back-filling of the ditch with bank material as well as pre-Roman ploughing.

The cursus banks occasionally survive to a thickness of about 25-30cm where they are protected either by other monuments or later field boundaries. Where they are unprotected and have been ploughed for at least the past 45 years, no earthwork survives, there is only a dissipated linear scar visible in the field today.

The Wyke Down barrow group consists of only seven upstanding barrow mounds out of a total of at least 29 ring-ditch sites. The ploughed out barrow mounds are just visible in the field under the right light conditions as very slight rises in the field, but are not otherwise detectable.

Ploughing since the latter 1950s of the scheduled and upstanding barrows has resulted in the sculpting of the mounds resulting in ovoid to sub-rectangular to sub-square shapes to the once circular mounds.

In addition, this same ploughing has created truncation steps around at least four barrows, with up to c 25-78cm of chalk subsoil having been scoured away over about

45 years. This has particularly affected the ring-ditch, berm and outer edges of the mounds, and is particularly marked in barrows 36 and 44.

In one case at barrow 36, the conversion of former arable land to pasture for the last 16 years has dramatically slowed this truncation process on its southern side. It has resulted in a less abrupt and more gently sloping talus edge to the surviving barrow mound, which better reflects the natural collapse and erosion of the mound over time. 1. Figure 1: Location map of the study area in southern England (H Lewis). Figure 2: Location map of the research area showing the Wyke Down barrow group, the auger transects and the relict stream channel areas (scale 1:25,000; after the Ordnance Survey of England and Wales) (H Lewis). Figure 3: Terrain map illustrating the drift geology and prehistoric sites (red = henge; blue = ploughed out barrow or ring-ditch; blue lines = Dorset cursus; yellow = upstanding barrow). Figure 4: Location map of the topographical and geophysical survey areas of the Wyke Down barrow group (GSB Prospection). Figure 5: The contour plan of barrows 44 to 47 of the main part of the Wyke Down barrow group (P White). Figure 6: The magnetometer survey of barrows 44 to 47 of the main part of the Wyke Down group showing a much greater number of ploughed out barrows and ring-ditches (GSB Prospection). Figure 7: The contour survey of barrows 34 and 41 (P White). Figure 8: Mesh terrain model of barrow 41 (foreground) to barrow 34 (P White). The field on the right hand side of the property boundary has been pasture since 1985, and the field to the left has been ploughed since 1958. Figure 9: The contour plan of barrow 34 with the location of the sample trenches and auger transects (P White). Figure 10: The contour plan of barrow 41 with the location of the sample trenches and auger transects (P White). 2. Figure 11: The magnetometer survey of barrows 41 (Area A) and 34 (Area B) (GSB Prospection). Figure 12: The topographical survey of barrow 36 (P White). Figure 13: The topographical survey of barrow 44 (P White). Figure14: The combined magnetometer and resistivity surveys of barrows 36 and 44 (GSB Prospection). Figure15: Oblique aerial view from the northwest of the Wyke Down barrow group, Wyke Down henge and part of the Dorset cursus (M Green).

Figure 16: Oblique aerial view from the north of barrow 36 (centre) and part of the Dorset cursus (M Green). Figure17: Evaluation trench across the ring-ditch, berm and eastern edge of the mound of barrow 36, showing the three truncation steps in the level of the chalk subsoil. 14. Figure18: Evaluation trench across the berm and the southern edge of the mound of barrow 44, showing the two truncation steps in the level of the chalk subsoil. Figure 19: The ploughed out northern bank of the Dorset cursus (right) and the agger of the Roman Ackling Dyke with ploughmarks beneath.

Figure 20: The ploughed southern bank of the Dorset cursus on Bottlebush Down. Acknowledgements

The results of this project have been made possible through the co-operation of Mr P Rymer of the Shaftesbury Estate and Martin Green. Funding for the fieldwork is gratefully acknowledged from the Arts and Humanities Research Board and the McDonald Institute for Archaeological Research.

References

Barrett, J, 1994, Fragments from Antiquity : An archaeology of social life in Britain, 2900-1200BC, Blackwell, Oxford.

Barrett, J, Bradley, R and Green, M, 1991(a), Landscape, monuments and society: The prehistory of Cranborne Chase, Cambridge.

Barrett, J, Bradley, R and Hall, M, 1991(b), Papers on the Prehistoric Archaeology of Cranborne Chase, Oxbow Monograph 11, Oxford.

French, C, Lewis, H, Allen, M, Scaife, R, 2000, Palaeoenvironmental and archaeological investigations on Wyke Down and in the upper Allen valley, Cranborne Chase, Dorset: Interim summary report for 1998-9, Proceedings of the Dorset Natural History and Archaeological Society 122, 53-71.

GSB Prospection, 1998, Wyke Down, Gussage St Michael, Dorset, Geophysical Survey Report 98/65, Bradford.

GSB Prospection, 1999, Wyke Down II, Gussage St Michael, Dorset, Geophysical Survey Report 99/99, Bradford.

GSB Prospection, 2001, Bottlebush Down, Sixpenny Handley, Dorset, Geophysical Survey Report 2001/87, Bradford.