1989:096 - Monvoy, Waterford

NMI Burial Excavation Records

County: Waterford Site name: Monvoy

Sites and Monuments Record No.: N/A Licence number:

Author: Marek Zvelebil, Edwin Moth and Jane Peterson, Dept. of Archaeology and Prehistory, University of Sheffield.

Site type: Rhyolite quarry

ITM: E 656938m, N 603055m

Latitude, Longitude (decimal degrees): 52.176365, -7.167512

(See Appendix 2.)IntroductionThe site consists of a large field enclosed by roads on all sides. A ridge of volcanic rock, containing mostly rhyolites of different crystalline structure, runs across this and adjacent fields in a north-west-south-east direction. In some locations, fine-grained rhyolite veins come to the surface of the ground. Clusters of rhyolite artefacts and some flint tools were found associated with the rhyolite ridge. Monvey BL300 then, is one among a number of similar find locations in the area, which together form a continuous distributional surface of low lithic density with clusters of finds peaking in a number of locations on a north-east-facing slope of the ridge.The decision to excavate at BL 300, (Monvey) was taken because a discrete, high-density cluster in the eastern part of the field was clearly associated with a fine-grained, rhyolite outcrop at the location. Nature of the finds suggested that we were dealing with a prehistoric quarry of an unusual lithic material, where the primary breakdown of the rock and primary processing of artefacts into flakes, blades and prefabricated forms went on. Last, but not least, we received every encouragement to proceed with the excavation from the owner of the site, Mr Richard Power, whose early recognition of the finds on his field as stone tools alerted us to the existence of the site in the first place. After the initial fieldwalking, the site was excavated in two seasons, in July and August 1986 (Excavations 1986, 35), and in August 1989. The objectives of the excavation were to define the scatter around the main outcrop, to record the variation in artefact density, to reconstruct the technology of rhyolite tool manufacture, and to locate any features which might have remained preserved under the surface. It would also have been interesting to uncover the working face of the quarry. This was, however, made impossible without the aid of a JCB by the recent dumping of large boulders, tree stumps and other material over the hollowed surface which is presumed to have been the working face, In addition, the raw material might have been also quarried in pits around the main outcrop, and this has become a subject of investigations carried out in 1989.The excavationExcavations in August 1989 continued the test excavation programme begun in 1986. One by one metre units on a basic grid layout were excavated across the top, mid and bottom break of the slope, running perpendicular to the 1986 transect, in a west-east direction from the quarry. In addition, a trench 8m by 1m was excavated along the western edge of the central quarry area, incorporating the artefact-rich profile which was cleaned in 1986.The soil from the excavated units was dry-screened, except for the units at the northern end of the trench, where ploughzone only was removed.The general stratigraphy of the site was as follows. Layer 1 consisted of the plough soil, an organic yellow-brown sandy loam. Layer 2 was consistently a sandy silt with the average stone size of 60mm in diameter and abundance of c. 5% (discounting the artefacts). In a unit at the bottom of the slope an iron pan was contained within Layer 2. Layer 3 consisted of a finer sandy silt with the average stone size of c. 6mm and abundance of c. 5%. This layer did not occur in every profile, and became more sandy in the western and mid-slope part of the site. In other parts of the site, Layer 2 directly overlay weathered bedrock. The depth of these deposits varied with the location of the slope, the bedrock being reached between 0.2m and 1.5m.Four areas, ranging from 1 to 3 square metres each, were excavated at 40m intervals along the transect running along the bottom of the slope. Starting from the western end of the transect (furthest from the quarry), the first unit came down to bedrock immediately un4er the ploughzone which was no more than 0.3m deep and contained just a few fragments of chert and basalt. The next area contained a few rhyolite artefacts in the ploughzone. Underneath was a plough-disturbed sandy silt, 0.lSm deep, with no further cultural material. The next two units contained the same sandy silt layer at a deeper level. Within this layer, a feature 0.06m-0.12m deep and 0.2m-0.25m wide was found, filled with a fine grey silt and containing a few small and medium-sized stones (0. l5m-0.2m), powdery white and yellow-orange mottles and some charcoal flecks. It also contained a hinge fractured flake, the only artefact found. The meaning of this feature is uncertain. The unit closest to the quarry had a high density of artefacts, but no features were found.Along the mid-slope transect, two areas were opened. One contained a sandier soil than the lower units, with a low density of rhyolite artefacts. Further down, the soil changed to a much finer sand containing medium-sized glacial erratics. The other was located on a rise of ground and confirmed this as another rhyolite outcrop, but no signs of quarrying on the face of the bedrock were discovered.Five units were opened along the top of the slope. Three contained a few lithics, mainly in the ploughzone, and one none at all. Soil in these units was a sandy silt with weathered rhyolite blocks, turning into a weathered rhyolite bedrock at a depth of 0.35m-0.7m. The last unit was located on an outcrop and came down to a weathered rhyolite bedrock without finds or signs of quarrying activity.Three units were excavated on the top of the main outcrop, just above the presumed quarry face, to test for signs of quarrying activity. In two units, bedrock occurred at a depth of 0.6m-0.7m, and contained a high density of dumped loose rhyolite slabs and artefacts. The third unit was located on the eastern edge of the disturbed south end of the outcrop. A layer of compact orange soil (possibly a slump?) covered the bedrock to a depth of 0.3m. There were no signs of hewing, cutting, or heat-shattering or other marks on the bedrock itself which would indicate quarrying activity.Finally, a trench was opened along the western edge of the central quarry area. This was a metre-wide excavation running north-south within the grid system. Two one-metre units were taken down to the bedrock, which was reached at a depth of about 1.5m. The ploughzone layer varied in depth between 0.25m and 0.5m and had a high density of artefacts and rhyolite debris. Beneath this a layer of silty clay approximately 0.3m-0.4m deep contained rhyolite finds gradually decreasing in density with depth. Underneath was a compact clayey layer about 0.1m deep containing only a few artefacts. This overlay a layer of gravel about 0.lm deep with no finds. Last was a sand and gravel layer on the rhyolite bedrock about 0.4m in depth. No signs of quarrying from the bedrock itself was found.The overall stratigraphy of the site is conditioned by its location on the north-eastern slope of the rhyolite ridge and by the agricultural activities that have taken place. The slope has an undulating surface, with outcrop locations, or elevations where the bedrock comes close to the surface, separated by concave areas of greater soil depth. Despite the potential for soil erosion and slippage, the examination of soil profiles by the project geomorphologists (Drs Marklin and Ferguson) leads to the conclusion that most of the soil formation took place in situ. It is more likely that greater disturbance took place by the repeated ploughing of the locality, and by the dumping of material in and around the outcrop area. In view of these observations, the high density of finds in the ploughzone, their relative paucity below the ploughzone, and the absence of cultural features all point towards the in situ destruction of the fossil occupational surface by farming activities.Analysis of findsTo date, about 30,000 artefacts have been found in 40m sq. of excavations. Clearly, the site is one with a high density of artefacts. Although the analysis is still in progress, the marked variation in the distribution of finds is apparent, showing a dramatic drop-off in the density of finds as one moves further away from the source. It seems that the area 40m-60m from the face of the outcrop was the richest in terms of the number of artefacts. Beyond this zone, the density of finds drops from thousands per m sq. of deposit to double digits or even single figures.Stone artefacts are almost exclusively made of rhyolite. The examination of the assemblage from the quarry as well as of surface collections from the neighbouring fields demonstrate that the quarry was used over a long period of time. Neolithic leafpoints, Bronze Age tanged arrowheads, and possible Mesolithic Bann flakes were identified. Except for a bifacially worked axe preform, other artefact categories made in rhyolite are analogous to those made from flint pebbles elsewhere in the region, such as blades, scrapers, etc. So it would appear that from the point of view of technology, rhyolite was utilised as a resource much in the same way as flint was, and that this was true throughout the Stone Age. From the point of view of distribution, however, there is a marked difference in that rhyolite tools have a very localised distribution, which is confined to an area within about 3km of the quarry. Beyond this zone, rhyolite artefacts are extremely rare. Two tentative explanations may be advanced: either rhyolite was mined and rendered into preforms at the site for trade/exchange outside the region; or rhyolite was not regarded as a material superior to the pebble flint to the extent that its distribution beyond the immediate vicinity was desirable. The second suggestion seems surprising, in that rhyolite does appear to have a greater potential for the manufacture of large tools or blades then does the local pebble flint.In terms of the lithic reduction sequence, nearly every pit assemblage is dominated by shatter and flake/blade categories. Cores and rejuvenation flakes also occur in each pit context. The number of retouched pieces is very small.In terms of the lithic reduction, the artefacts fall mainly into the early stages of the process as can be expected of a quarry site. At present, it is difficult to say whether there are differences in the pattern of lithic reduction in different areas of the site, although the initial impression had been that the material was further reduced as one moved away from the outcrop (Henson, pers. comm.). Further work by Jane Peterson, the project lithic specialist, is expected to shed some light on this question.ConclusionThis was obviously a quarry area of some importance, used over a long period of time. In view of this, the absence of clear cultural features, such as hearths, pits or habitation remains, is surprising, even if the post-depositional destruction of the site through modern disturbance is taken into account. One would expect some sort of residential base to be in the vicinity, perhaps in the adjacent location BL 320, which in reality forms a continuous lithic distribution surface with our site. Alternatively, a number of other locations near to local streams in the area may have been suitable for a settlement.The lack of wider distribution of rhyolite artefacts within the region remains a puzzle. At present, it would appear that the local groups used rhyolite locally, incidentally and over a long period of time. The highly localised use of rhyolite raises a number of interesting questions: (1) how intensive was, in fact rhyolite production, bearing in mind the high waste to finished product ratio of its reduction process; (2) who was in control of the rhyolite source – perhaps a group not resident in the region; (3) was rhyolite obtained for export, and if so, what was its destination; (4) why did the local people ignore the advantages of this raw material for making large and medium-sized tools?The central quarry area has not been excavated so far. Yet this is where the actual quarrying activity probably occurred. The removal of the modern deposits dumped on this area and the excavation of surfaces buried underneath would be the next logical step in the examination of the site. (See Appendix 2 for report on the recovery of environmental and economic material from the site.)