Appendix Ji The effect of deep ploughing on archaeological deposits. Hayton, East Yorkshire - a case study. Peter Halkon

Transcription

1 Appendix Ji The effect of deep ploughing on archaeological deposits. Hayton, East Yorkshire - a case study. Peter Halkon The University of Hull Department of History, 2001 Oxford Archaeology May 2002 (revised December 2002)

2 THE EFFECT OF DEEP PLOUGHING ON ARCHAEOLOGICAL DEPOSITS. HAYTON, EAST YORKSHIRE A CASE STUDY. Peter Halkon THE UNIVERSITY OF HULL Department of History November 2001

3 The effect of deep ploughing on archaeological deposits. Hayton, East Yorkshire - a case study Introduction Peter Halkon (University of Hull) Information included in this report is drawn from a detailed investigation of the Foulness Valley, East Yorkshire, initiated by the writer in 1980 and run jointly with Martin Millett since One of the great successes of the project has been the close relationship that has been built up with the farmers and landowners in the area of study, made easier by the writer s own farming background. The aim here is not to castigate farmers for ploughing archaeological sites, but to contribute towards current proposals for the provision of subsidies to mitigate the effects of cultivation on the buried past. The farmers on whose land we have worked, especially those at Hayton, display a genuine interest in the archaeology on their farms and have been happy to discuss issues involved here. The report is structured as follows: 1. Outline of the Foulness valley project 2. Background to fieldwork at Hayton 3. Case study 1 - the Burnby Lane site 4. Case study 2 the Roman roadside settlement 5. Conclusion and recommendations 1. Outline of the Foulness Valley project 1.1 Phase one: This consisted of an exploration of an 8x8km block around Holme-on-Spalding Moor, by fieldwalking a representative sample of each km square on c. 55 farms. Sites were then selected for research/training excavation (Halkon and Millett 1999). Discoveries included over 130 scatters and concentrations of Roman material presumed to be foci of settlement and industry, 30 pottery kiln sites and an extensive Iron Age iron industry. At Moore s Farm, Welhambridge, one of the largest prehistoric heaps of iron slag in Britain, dating from c 300BC was excavated (Halkon 1997; Halkon and Millett 1999). Other discoveries included the Iron Age Hasholme log boat, (Millett and McGrail 1987). All this was tied in with a programme of aerial survey, study of soil maps and palaeo-environmental investigation. During our first excavations at Bursea House (Halkon and Millett 1999), we noticed the contrast between the condition of features protected by a grassy bank and the immediately adjacent ploughed field. The excavation of on an Iron Age enclosure containing a roundhouse at Bursea Grange, Holme-on-Spalding Moor, 1

4 (Halkon and Millett 1999) also revealed evidence for heavy erosion of the archaeological deposits caused by subsoiling of the sandy soils (see Figure 1). Figure 1. Excavations at Bursea Grange, Holme-on-Spalding Moor. Note the parallel grooves filled with dark soil left by the subsoiler. The dark curved feature in the centre is the foundation trench or eaves drip of a roundhouse. 1.2 Phase two: This phase investigated a Roman roadside settlement at Shiptonthorpe (Millett 1991). A full report on this is in final stages of preparation (Millett forthcoming). Fieldwalking was combined with soil chemistry and geophysical surveys (Taylor 1995) the latter revealing the clear plan of the road flanked by a series of plots used for housing, stock and a cemetery. During the following programme of research excavation, ( ), a section was cut across the Roman road and a complete plot next to it was excavated. This was found to contain a sequence of timber buildings and a waterhole, the latter containing evidence for structured deposition including well-preserved shoes, animal bones and pieces of wooden writing tablet. As at Bursea Grange, the excavation at Shiptonthorpe highlighted the damage caused by subsoiling. 2

5 2. Background to fieldwork at Hayton 2.1 Location, soils and land-use Hayton is situated 3km south-west of Pocklington, on gently undulating land at the foot of the western escarpment of the Yorkshire Wolds, at the eastern edge of the Vale of York. The present village is transected by the A1079, now the main road between York and Hull, which follows the approximate route of the Roman road between Brough on Humber and York (Margary 2e). The main soil type around Hayton is the Landbeach Series, which consists of light loamy gleyic brown calcareous earths, overlying glacio-fluvial gravels (King and Bradley 1987, 41). These are described by the Soil Survey of England and Wales as being generally well drained, good general purpose soils, and because of this are heavily cultivated. The main crops grown are wheat, barley, oilseed rape, potatoes and sugar beet (Middleton 1999). Because the soils can be stony within the plough zone in places, de-stoning is carried out, especially in preparation for potatoes, with obvious implications for archaeological deposits. Subsoiling is also regularly undertaken in order to overcome compaction (Bradley and King 1987), presenting a further threat. 2.2 Earlier archaeological work Although a few stray finds of Roman pottery were recorded in the 1950s, the main impetus for archaeological study in the Hayton area began with the discovery of an auxiliary fort from the air by St Joseph in It is clear from subsequent aerial photography and research that the fort was revealed as deeper modern ploughing removed the last vestiges of rig and furrow. The fort, which was excavated by Stephen Johnson for the Department of the Environment in the following year (Johnson 1978), was shown to be Flavian in date, though evidence for both Iron Age and Anglo-Saxon activity was found in the immediate vicinity. Johnson also investigated road-works during the dualling of the A1079 Trunk road, which suggested the presence of considerable Roman activity especially in the Grove Farm, Bridge Farm area, along the Roman road which runs just to the north of the modern route. Some fieldwalking was carried out during the 1980s by the writer, and by Bryan Sitch, with ERAS, following up metal detector finds brought into Hull Museums whilst he was working there (Sitch 1999). By this time Hayton had become especially popular with metal detector users and large numbers of Roman coins are recorded from various sites in the village (McLinden 1990). 3

6 3. Case Study 1 The Burnby Lane site In March 1993, destoning in preparation for planting potatoes led to the third phase of our research in the Foulness valley. A farmer observed large quantities of tile, mortar, worked stone and some Roman pottery brought to the surface of a field on his neighbour s land at Burnby Lane, Hayton (see Figure 2). He reported this to the writer, who identified the tile as coming from a hypocaust and organised a detailed gridded fieldwalking survey (Halkon 1993). The biggest concentration of ploughed up material was found on the gravel ridge by the lane, which runs parallel to Hayton Beck. Subsequent discussion with the landowner revealed that a Grimme Tornado destoner had been used here to break up clods of earth in areas of heavy land near the beck, to prevent them clogging up the potato harvester, making it easier to pick potatoes from the conveyor. Figure 2. The field at Burnby Lane, Hayton, in March 1993 soon after the discovery of the site. Note the mortar, tile and stone from the bath-house on the surface of the field. (Inset) a tile from the hypocaust pilae as found. Mortar is still adhering to it. Since the discovery of the ploughed-up hypocaust, we have examined a 3x3km landscape-block around Hayton, through further fieldwalking, geophysical and aerial survey, focussing research and training excavation on the Burnby Lane site. Here we have uncovered a series of Roman buildings with a bathhouse and excavated the Iron Age enclosure revealed in a geophysical survey. The full report is in the process of production and interim statements have been published on each season s fieldwork (Halkon and Millett 1996; Halkon, and Millett and Taylor 1997 and 1998; Halkon et al 2000). 4

7 In 1995 (Millett and Halkon 1996), trenches were opened over the main geophysical anomalies and in the area of the densest concentration of tile and other debris brought to the surface during destoning. It quickly became apparent that the destoner had penetrated deeply into archaeological features and the regularly spaced parallel grooves left by the machine were clearly visible in trowelled surfaces. (Figures 3-5) Figure 3. An area of the 1995 excavation after ploughsoil stripping and trowelling, showing the effect of a destoner on buried features. Figure 4. The 1996 excavation showing a further area of destoning damage. 5

8 Figure 5. A detail of the hypocaust during the 1996 excavation. Note (right) the only pila left upstanding. The tile shown in Figure 2 (inset) is almost certainly from this stack. 4. Case study 2 The Roman roadside settlement 4.1 Background The discovery of Roman material by Johnson during the dualling of the A1079, metal detector activity and earlier fieldwalking has been referred to above. The roadside settlement is situated on a prominent ridge of slightly stony, sandy loam in the Landbeach soil series, overlying chalk and flint gravel, rising to 30m OD. The Roman road itself appears to have been placed to take advantage of the this higher ground, as it runs along the ridge from the direction of Shiptonthorpe, and is clearly visible as crop mark on a series of aerial photographs taken by the writer since A large very dark loamy soil mark, most apparent after the field is freshly ploughed and contrasting with the lighter gravel soil on the ridge itself, indicates the most intensive area of settlement, which lies in a hollow to the south west of the gravel ridge. To the north and west the field drops away towards Hayton Beck and the soil changes to clay. 6

9 A further opportunity to investigate the site on the ground came in 1994, when the farmer asked the writer to carry out watching briefs during the construction of farm building extensions. Eventually a programme of detailed fieldwalking in 10m squares was carried out over most of the roadside settlement by students from Hull and Leeds universities and members of the East Riding Archaeological Society. Geophysical and geochemical surveys have also been undertaken. The writer also co-ordinated watching briefs and some salvage excavation during the construction of turkey sheds, providing the opportunity to view the subsurface archaeological deposits and showing that dark soil mark has been caused through a substantial build-up of deposits relating to the Roman roadside settlement. 4.2 The roadside settlement and plough damage It became clearly apparent from the aerial survey, fieldwalking and from recording the sections of the various service trenches to the turkey sheds, that considerable damage had been done to subsurface features by cultivation - the most intense inflicted by destoning prior to potato planting in 1994/5. The machine used was a Grimme Tornado. The following section examines the effect of cultivation revealed by the various methods of investigation. a) Aerial photography In 1990 the writer observed and photographed positive and negative crop marks to the north of the A1079, which had been unobserved previously (see Figure 6). 7

10 Figure 6 Crop marks of the Roman roadside settlement at Hayton, July The parch-marks are likely to be caused by sub-surface stone and gravel. Note particularly the H shaped feature, which is likely to be a large building. Figure 7 Crop marks of the Roman roadside settlement at Hayton, July The buried features revealed as parch marks are noticeably more blurred here than in Between the time the two photographs were taken the field was destoned once in preparation for the planting of potatoes. 8

11 These comprise a series of enclosures, boundaries and other ditched features, and maculae likely to be wells and pits. Of particular note, however, are the parch marks created by the presence of stone walls and gravel features in the subsoil. Most prominent amongst these is a roughly H shaped feature aligned on the Roman road which may be the remains of a large courtyard building. Because of the loamy/silt soil matrix, these features are generally only observed in very dry seasons. The features described appeared again in the very dry summer of 1996 and were photographed by the writer (see Figure 7). The difference between the photographs is very evident. The negative features or parch marks are much more blurred in Figure 7 than in Figure 6, especially the crop marks generated by the possible H shaped building. The most likely reason for this is the spreading of the buried stones by the destoner in a similar fashion to the site at Burnby Lane, Hayton. b) Field walking Since 1995, fieldwalking has been undertaken in 10m grids at each side of the A1079, over most of the area of the Roman roadside settlement, with each square being walked systematically. The results of field walking are shown in Figure 8. The settlement spreads over three modern fields Bridge Farm 1 (furthest from the farmhouse), Bridge Farm 2 (nearest to the farmhouse) and Grove Farm, each having slightly different soil/topographical characteristics. The soil is shallower in the north-eastern part of Bridge Farm 1, where it slopes up to the gravel ridge and deeper towards the A1079 and Bridge Farm itself in Field 2. At Grove Farm, to the south of the main road, the dark soil mark continues, until the gravel rise, where the soil becomes lighter and thinner again. Soil depth is likely to have some bearing on subsoil preservation, with sherd size being smaller where the soil is shallow as pieces of pottery have been incorporated into the plough soil for longer and subjected to more erosion. Where deep ploughing/destoning has taken place, one would expect larger sherds with fresh fractures. The sherds themselves were not measured, but a guide to their size can be gauged from calculating the average weight per sherd in each field. This is illustrated in the table below for each of the three fields. Average sherd weight (g) Total no Total weight (Roman pottery) Grove Farm Bridge Farm Bridge Farm

12 10 Figure 8 Distribution of fieldwalking finds from the Roman roadside settlement at Hayton. All Roman Pottery 1 dot = 1 sherd Samian pottery 1 dot = 1sherd Huntcliff pottery 1dot = 1sherd Meters N Hayton Roman roadside settlement Field walking pottery distribution Crop marks in red Roman road Roman road Roman road

13 Electricity cable trench It would appear from the results of the fieldwalking survey that sherds from Bridge Farm Field 2 are much larger than in either of the other fields. The best explanation for this is that material from previously undisturbed stratigraphy is now being brought to the surface through deeper ploughing and destoning in preparation for the planting of potatoes. The farmers themselves noticed that more pottery was now visible in Field 2 than in previous years. Field walking had taken place on both fields at Bridge farm after potatoes had been grown in the field, on Grove Farm in stubble after cereals. This factor may also partly account for the discrepancy in sherd size. c) Watching briefs The construction of the Turkey sheds in 1996 and the installation of the services associated with them provided an opportunity to examine the stratigraphy of the site. Although the original intention was to carry cables to the Turkey sheds on posts, the Yorkshire Electricity Board and BT decided at short notice to bury their cables. Narrow trenches, (see Figure 9) each c50cm wide and c. 1m deep were machine-dug across the field from the main road towards the sheds. A further trench was excavated to take a water main. (See Figure 9). Thanks to the interest and generosity of the farmer, it was possible to draw the section along the water (Figure 10) and telephone trenches (Figure 11), though time was limited. It was not possible to do a section drawing of the electricity trench, but the position of the main features was noted. Telephone line trench Roman Road cropmark features A 1079 Water main Trench B N Water main Trench A 0 50 m Figure 9 Location plan showing service trenches and generalised crop marks. 11

14 Figure 10 Generalised section drawing of the water trench. Top two sections are SW face, Trench A. Bottom two sections are NW face, Trench A. (See Appendix 1 Figure 12, for detailed section drawing and context description). 12

15 Figure 11 Generalised section drawing of the South face of the telephone line trench. 13

16 The depth of stratigraphy revealed in these trenches is surprising, but it is clear from Figures 10 and 11, that the upper layers have been lost as a result of ploughing and destoning to a depth of over 50cms in places. 5. Conclusions It is not the intention here to discuss detailed site development, nor the inferences that can or cannot be drawn from ploughsoil assemblages (e.g. Haselgrove 1985) or excavated evidence. Both case studies show that considerable damage has been done to sub-surface archaeological features, as a result of deep ploughing and particularly destoning prior to potato planting. Although medieval rig and furrow revealed on both sites shows that there had already been considerable destruction to Roman layers, at least the archaeological features under the ridges had been relatively well preserved. Current farming practices now mean that the protective rig deposits are being rapidly removed. The large quantity of late Roman calcite-gritted Huntcliff ware dating from cad340 onwards (Monaghan 1997; Corder 1989) recovered during fieldwalking (Figure 8) suggests that much of the upper stratigraphy of the Roman roadside settlement has been lost. The quantity of samian implies that material is being removed from earlier contexts as well. Further damage could be avoided by preventing the planting of potatoes in an 80m strip over the Roman roadside settlement. The farmer here has already expressed some interest in this idea, but the amount of compensation provided currently through such schemes as Countryside Stewardship, make this not viable financially. The cultivation of cereals, rape, linseed and other crops, which do not require such deep ploughing, is a further solution, as it would seem very draconian, given the current state of farming, to prevent the production of any crop here. Most farmers in the writer s experience fully realise the importance of the archaeology in their charge, displaying great interest; it is to be hoped that they will be given greater incentives to ensure the long term preservation of the past under their ploughsoil. 14

17 References Halkon, P. and Millett, M Rural Settlement and industry: Studies in the Iron Age and Roman Archaeology of lowland East Yorkshire, Yorkshire Archaeological Report 4. Leeds: Yorkshire Archaeological Society Roman Antiquities Section and East Riding Archaeological Society. Halkon, P. and Millett, M Fieldwork and Excavation at Hayton, East Yorkshire, Universities of Durham and Newcastle-upon-Tyne Archaeological Reports 19, Halkon, P From elephants to hypocausts - more fieldwork in the SE Vale of York CBA Forum Annual newsletter of CBA Yorkshire. Halkon, P., Millett M., Easthaugh E., Taylor J. and Freeman, P The landscape Archaeology of Hayton. The University of Hull. Halkon, P., Millett, M. and Taylor, J Fieldwork and Excavation at Hayton, East Yorkshire, Universities of Durham and Newcastle-upon-Tyne Archaeological Reports 20, Halkon, P., Millett, M. and Taylor, J Fieldwork and Excavation at Hayton, East Yorkshire, Universities of Durham and Newcastle-upon-Tyne Archaeological Reports 21, Haselgrove, C Inference from Ploughsoil artefact Assemblages in C. Haselgrove, M. Millett, and I. Smith, eds, Archaeology from the Ploughsoil studies in the collection and interpretation of field survey data. Dept. of Prehistory and Archaeology, University of Sheffield. Johnson, S Excavations at Hayton Roman Fort. Britannia 9, King, S.J. and Bradley, R. I., 1987 Soils of the Market Weighton District. Memoirs of the Soil Survey of England and Wales. Harpenden. McLinden, J.A Roman coins from Hayton East Yorkshire. Yorkshire Archaeological Journal 62, Middleton, R Landuse in the Vale of York, in R. Van De Noort and S. Ellis, eds. Wetland Heritage of the Vale of York, Humber Wetlands Project, University of Hull, Millett, M. and. McGrail, S The Archaeology of the Hasholme logboat, Archaeological Journal, 144, Millett, M. forthcoming Shiptonthorpe, East Yorkshire: Archaeological studies of a Romano- British roadside settlement. Yorkshire Archaeological Society Roman Antiquities Section monograph. Monaghan, J Roman Pottery from York The Archaeology of York The pottery 16/8 YAT/CBA, 908. Sitch, B.1999 Recent Research on Roman Coins from the East Riding, in P. Halkon, ed. Further Light on the Parisi. Recent Research in Iron Age and Roman East Yorkshire, ERAS, ERART, University of Hull,

18 Taylor, J., 1995 Surveying small towns: the Romano-British roadside settlement at Shiptonthorpe, East Yorkshire, in A. E. Brown (ed.) Roman small towns in eastern England and beyond: Oxford: Oxbow books Corder P Excavation of fourth century pottery kilns at Crambeck, in Wilson P.R. Crambeck Roman Pottery Industry Roman Antiquities Section, YAS, 22. Acknowledgements Fieldwork was carried out by: The Department of Archaeology University of Durham The Department of Archaeology University of Southampton University of Hull University of Leeds East Riding Archaeological Society many volunteers Maps, sections, cover design and aspects of layout by John Marshall All photographs by P. Halkon Field walking plots prepared by P. Halkon. The programme for plotting fieldwalking data was devised by R. Middleton. Crop marks in Figure 8 plotted by Alison Clarke Thanks to Wetlands Archaeology and Environments Research Centre at the University of Hull for their assistance. Thanks to the Smith and Nicholson families for farming advice and allowing the archaeological projects to go ahead in the first place. 16

19 Appendix 1 Figure 12 Detailed section drawing and plan of SW face of water main trench from Bridge Farm. 17

20 Bridge farm water main trench 1996 contexts Context Water Trench A Location Metres from 0 Description Finds No. in Triangle interpretation Stratigraphic relationship 1 whole Brown loam with gravel plough soil above all Brown sandy loam with brown loam patches medieval plough soil above 3 below Chalk pea grit layer 1-5cm deep above 4 below Chalk and l/stone rubble (some burnt) 5-12cm deep demolition layer above 6,7,8 below Yellow sand lens above 8 below 4, below Brown laminated layer some burnt clay floors? above 8 below Sand lens above 10 below Black layer above 14, below Dark layer above 27, 10 below 3,4, Sandy clay layer above 14,12 below 4, 7 3,4,9a Narrow burnt clay layer in 10 in Brown sandy loam 2 fill of gully above 13 below Cut of gully 30cm deep 90cm wide cut of gully cuts 9,20,23,26, Yellow sand layer - 5 make-up layer? above 10, elow Black layer demolition or occupation layer above 16 below Thin yellow sand layer above 17, below Thin yellow sand layer Thin black layer over floor? above 19 below Compact pinkish white chalk 10 floor layer above 20 below Black layer above 21 below Yellow chalky sand 1 above 22 below Thin black layer at E end of trench above 71 below Brown gravel above below cut by Yellow sand layer above 25 below 9, Thin gravel layer floor above 26 below 24, 14 cut by Brown loam layer containing much pottery etc 4 above 74 below Rough irregular limestone blocks up to 4 Courses deep at least wall of building above below 9 abuts Dirty sand above 27 18

21 below Curved lens of red marl above 27 below Sandy loam layer above 28 below Layer of red marl/loam with stone inclusions floor above 30 below Red marl = 31 above Brown loam above 34 below Black layer in laminar make up floor layer above 30 below Thin gravel band Below Compacted gravel layer 6 floor Below Sandy loam Above 38 Below Yellow sand layer Above Below 30, Brown loam Above 40 Below Gravel lens Above 38 Below Red marl foundation or collapse layer Above 39 Below Clay layer Above 41 Below Clay and sand layer 11 Above Below Limestone and yellow clay wall Above Below Brown loam layer (includes Ebor ware and Infant burial 7 Above 46 Below Brown gravel surface Above Below Yellow clay 14 Above 45 Below 39, Dark red clay Above 47 Below 39, Thin black layer Above 49 Below Marl layer with patches of brown loam 12 Above 49 Below Brown loam layer darker towards E Above 47 Below 50, Brown loam with sandy clay patches Medieval plough soil Above 41 Below Yellow sand layer Above 54 Below Brown sandy clay with flints Above Below Brown gravel Above 70 Below Burnt clay layer Above 70 Below Brown silt bottom of the ditch Above 13 Below Gravel floor Above Below Cut early ditch Above Below 13 19