The Use and Reuse of Stone Circles

by Richard Bradley

  The new work at Hillhead changes the pattern to a significant extent. Although the deposits of quartz in its interior were probably meant to create an aesthetic effect, it can hardly apply to the scatter of lithic artefacts which was found outside the monument and continued over a large part of the hillside above the stone circle. Although quartz occurs naturally here, there was also some worked flint. The date of this material poses problems, but the results of excavation suggest that it accumulated after the monument had been built, for there were very few artefacts in the buried soil beneath the ring cairn. Even so, the density of finds from the forestry trenches is at least as high as it was on the lower ground investigated by fieldwalking. The distribution of artefacts across the hillside took no account of a recently excavated roundhouse which is dated to the Late Bronze Age (Moyra Simon pers. comm.).

  The unusual character of the monument at Hillhead supplies a possible answer. It is uncommonly large and massively built and yet it is in an area that even today has little agricultural potential. On the other hand, it is situated in a pass beside the route that leads between Cromar and the next basin to the east, the Howe of Cushnie. It is also on the watershed of the two main rivers in the region, the Dee and the Don. Perhaps the site was used by at least two different communities. That might account for its unusual diameter, the provision of a large internal court, and for the amount of high quality worked quartz and flint found in the area around it. By contrast, Tomnaverie and Waulkmill were much smaller and both were located inside the Howe of Cromar and on the edges of a broader zone that was more suitable for settlement. They may have been used by a smaller number of people, and quite possibly by the local inhabitants. The Blue Cairn remains a problem as little is known about its immediate surroundings.

  Figure 9.5. Two pairs of stone monuments, which may have been used in sequence. Information from Kilbride-Jones 1935 and 1936 and Welfare 2011.

  That suggests an important amendment to the territorial scheme proposed in the 1970s and 80s. The two smallest monuments might have been associated with people who lived nearby, whilst the largest of all these sites was located on the boundary between two different regions. It may have been visited by people from both areas.

  There is another problem to consider. How can the ‘territorial’ scheme be reconciled with the argument in Chapter 7 that individual monuments were formally closed by the erection of a recumbent stone circle? It was the case at Hillhead where a setting of stones seems to have blocked the entrance to a rubble enclosure. There is evidence from Tomnaverie that the placing of the monoliths had been planned from the time when the cairn was first constructed. That idea has an important implication. If certain ring cairns were closed after a period of use, were new ones built to take their places? If so, the territorial scheme proposed by Barnatt and Burl would be misleading for what they could be observing is a sequence of monuments that were built and decommissioned at comparatively brief intervals. At present it is impossible to consider this question in any detail, but the radiocarbon dates from Tomnaverie suggest that it was built before the monument at Hillhead. It is an open question whether their periods of use overlapped. In fact there are two recumbent stone circles which do seem to have been replaced by new structures built alongside them. That was almost certainly the case at Loanhead of Daviot where both monuments are associated with diagnostic pottery (Kilbride-Jones 1935; 1936), and the same could have happened at Clune Wood where a ring cairn with a central court was constructed right next to a similar feature enclosed by a setting of monoliths (Fig. 9.5; Welfare 2011, 153).

  Such observations sound a warning at placing too much emphasis on surface evidence. Since the days of Alexander Keiller and Fred Coles archaeologists have been adept at recognising large-scale patterning among Scottish stone circles. John Barnatt and Aubrey Burl have followed in that tradition and their work has produced valuable results. If their surveys identify general trends among these monuments, the results of excavation play another part. They emphasise the sheer diversity of structures which are grouped into the same category. The same point is made by Adam Welfare (2011).

  It is equally true of individual monuments which changed their character over time, but it is rarely possible to trace their histories in any detail. One of the rare exceptions is Croftmoraig which provides the subject matter of Chapter 10. Here it is possible to see how some of the themes considered in this account came together in a single place and the ways in which those different elements were expressed over time.

  CHAPTER TEN

  Croftmoraig: the anatomy of a stone circle

  Richard Bradley

  Figure 10.1. Croftmoraig stone circle viewed from the northeast (Aaron Watson).

  From 1965 to 2012: a change of emphasis

  An excavation report is necessarily a product of its time and needs to be understood in that light. It can never provide an objective or comprehensive record, no matter how hard its author tries to do so. Every project took place for some reason, but it is easier to work out which ideas fieldworkers had in mind than it is to identify those that were not considered.

  The 1965 excavation at Croftmoraig illustrates this point. It had two explicit aims. The first was to establish the date and structural sequence at a major stone circle on the edge of the southern Highlands of Scotland. That was part of a more general project to characterise the earlier prehistoric architecture of Northern Britain. Thirteen years before, it had led one of the excavators, Stuart Piggott, to investigate the Clava Cairns (Piggott 1956). At the same time the work was important as it was hoped to display the monument to the public. The first objective was fulfilled by the publication of an excavation report, but the site has never attracted many visitors because it is difficult to park there.

  Other ideas were current between the 1965 excavation and the dissemination of the results six years later. The most influential were the work of Alexander Thom who envisaged an unexpected level of sophistication in the planning and construction of stone circles. He also suggested that a significant minority of those sites observed celestial alignments (Thom 1967; 1971). Piggott was aware of these issues from his own work at Stonehenge, but Thom’s ideas did not influence the interpretation of Croftmoraig. A second feature that attracted attention at the time was sourcing of the raw materials used in early monuments. Again this work was influenced by the evidence from Stonehenge (Parker Pearson 2012). The rocks employed at Croftmoraig were identified in the excavation report which showed that they could have been obtained close to the site (Piggott and Simpson 1971, 15).

  Other features of this monument did not call for attention in the way they would do today. The 1971 paper makes little of the fact that the stone settings were on top of a natural mound, nor does it explain how radically its profile was altered as those structures were built. It says little about the glacial erratic embedded in its surface, dismissing it as a geological element but at the same time interpreting it as the position of a hearth. Nor did the petrological report go beyond the identification of the stones – nothing was said about their distinctive appearance. What seem to be omissions today were entirely consistent with the task that prehistorians set themselves in the 1960s. Their aim was to define important traditions of ancient architecture and this obliged them to observe the distinction between culture and nature that was accepted without question at the time. It explains why phenomena that cut across that boundary attracted little attention. Piggott and Simpson were content to identify the prehistoric structures found in their excavation and did not concern themselves with the less tangible features that have been discussed in recent years. It would be another three decades before the nearby concentration of carved rocks on the Ben Lawers estate was recognised and studied (Hale 2003; Bradley et al. 2012). One aim of this chapter is to incorporate these elements in a new interpretation of Croftmoraig. The other is to draw on the structural sequence established by the excavation reported in Chapter 5.

  The local setting – nature, cul
ture and monument building

  The character of the monument was influenced by the local topography and by the existence of other structures in the area. The siting of Croftmoraig appears unremarkable, but it was one of at least four stone circles associated with Loch Tay, one of the longest and deepest bodies of fresh water anywhere in Scotland. This particular monument was constructed 3 km from its eastern limit. At its western end is Killin where a small stone setting was built (Coles 1910, 130–32) (Fig. 10.2). Two more monuments share similar associations. At Acharn, 11 km southwest of Croftmoraig, a stone circle overlooks the eastern section of the loch from a height of 350 m (Coles 1910, 132–36), and on the south-facing slope there is Machuim where a similar structure is almost 200 m up the hillside (Coles 1910, 126–30). Its position is particularly interesting in view of the concentration of rock carvings on the high ground above it (Hale 2003; Bradley and Watson 2012).

  Decorated rocks of this kind were first made before the local stone circles were built, but their wider distribution sheds some light on the special importance of this area. They are most frequent above the northern shore of Loch Tay, where the majority are found along the section which extends from northeast to southwest – the directions of the midsummer sunrise and midwinter sunset respectively. That may be significant because an observer positioned by the rock carvings could watch the passage of the sun across the sky and would sometimes see its light reflected in the water. There are two reasons for drawing attention to this relationship. The first is that exactly the same axis seems to have influenced the siting of Neolithic and Bronze Age monuments in the Kilmartin complex which is readily accessible from this region; it was equally important in the distribution of Clava Cairns which are commonest where river valleys share the same orientation (Bradley and Watson 2012). The second is the importance of south-western alignments in Copper Age and Bronze Age stone circles, including Croftmoraig itself. This observation was considered in Chapter 7.

  Just as the siting of Croftmoraig may have been influenced by the position of the loch, it may also have acknowledged the confluence of two important rivers in the valley below the circle (Fig. 10.3). One was the Tay, whose name ‘the silent one’ or ‘the strong one’ may refer to an ancient deity (Strachan 2010, 13); the other was the Lyon. Both were associated with important concentrations of earlier prehistoric monuments (Stewart 1961). Among the first were three Neolithic structures: a long mound near Fortingall close to the bank of the Lyon; the excavated round barrow at Pitnacree in Strath Tay (Coles and Simpson 1965); and the timber cursus at Castle Menzies which is only 4.5 km from Croftmoraig (Halliday 2002). Later monuments were even more abundant. Those in Strath Tay include a series of large round barrows, an unusual number of the stone settings described as four posters (Stewart 1961), and the important ring cairn of Sketewan (Mercer and Midgley 1997). How were such monuments related to the pattern of settlement? Fieldwalking in 1994 showed that the main areas of earlier prehistoric activity were on the lower terraces of the river valley where most of these structures were built (Phillips et al. 2002). Pollen samples associated with rock carvings in two upland basins on Ben Lawers suggest that they were used for summer pasture (Bradley et al. 2012, 52–56). Neither study provided much evidence of chronology.

  Figure 10.2. The small stone circle at Killin close to the west end of Loch Tay (Aaron Watson).

  Figure 10.3. The siting of Croftmoraig in relation to Loch Tay and Schiehallion. From an early twentieth century survey (contours at 250 ft./c.80 m intervals).

  Figure 10.4. The stone circle viewed from the northeast, emphasising the profile of the mound on which it was built (Aaron Watson).

  Figure 10.5. The Machuim stone circle built on an artificial mound on the north side of Loch Tay (Richard Bradley).

  In some respects Croftmoraig resembles other monuments in the region. The stone circles close to Loch Tay belong to one of the architectural traditions discussed in Chapter 7. They were of modest size and could be slightly oval rather than circular. In some cases they were graded towards the southwest, and three of the sites include cup marks. A still more striking feature is the presence of a mound. Excavation at Croftmoraig established that the ‘platform’ on which the monument was built was of geological origin (Fig. 10.4), but that was not the case at Machuim where it was a conspicuous cairn (Coles 1910, 126–30) (Fig. 10.5). A further variation is seen 9 km from Croftmoraig where a setting of four monoliths at Lundin was erected on top of another glacial mound, but in this case it was modified by digging a shallow ditch around it (Stewart 1966). Clearly there was a continuum between geological features and earthworks that were deliberately constructed.

  Figure 10.6. The profile of Schiehallion which appears on the horizon viewed from the stone circle (Aaron Watson).

  If the mounds and the carved rocks cut across the distinction between culture and nature followed in the 1960s, the same is true of the raw materials incorporated in the stone circle at Croftmoraig. The excavation report established that they could have been obtained locally, but it did not draw attention to their distinctive properties. It may be no accident that the same kinds of stone were selected for embellishment on Ben Lawers: mica schist and epidiorite. As Rosemary Stewart (pers. comm.) observes:

  epidiorite is a massive, fine- to medium-grained, crystalline rock that weathers to a relatively smooth, rounded shape without fissures, bedding or joints. The crystalline surface reflects the light, giving a shimmering appearance. The schist at the site varies in grain size from coarse to fine. The fine-grained types have a similar overall appearance to the epidiorite, but the coarser types give the monoliths a blocky, foliated, angular appearance. There are prominent quartz veins and mica plates which provide distinctive shiny, sparkling surfaces. Garnets are visible in some of the schist.

  Two observations are worth making here. At Croftmoraig the stones that sparkle in strong light were placed towards the south and west of the circle and also in the perimeter wall. Epidiorite and the fine-grained schist, on the other hand, are represented in the eastern half of the main circle and the inner setting of monoliths. It also provides the material of the portal stones. This distinction is unlikely to have come about by chance. Excavation around a series of decorated rocks 12 km from Croftmoraig showed that the surfaces that sparkle in sunlight were associated with more pieces of flaked and broken quartz than the exposures of epidiorite. The amount of quartz was related to the visual effects created by the rock itself and not to the extent of the pecked designs. Nor was the hardness of the raw material related to the number of fractured hammerstones. People may have refreshed the surface of the rock at intervals to make it sparkle (Bradley et al. 2012).

  The Ben Lawers ridge cannot be seen from Croftmoraig, but the siting of the monument is revealing in other ways. Although it is set back from the valley of the Tay, to the east there is rising ground. In the opposite direction the monument faces one of the most dramatic mountains in the southern Highlands. Schiehallion rises to a height of 1083 m and is the only distinctive peak that can be seen from the circle (Fig. 10.6). To the southwest, however, there is a shallow pass leading between Loch Tay and Strath Bran, and here there is a concentration of decorated outcrops.

  Two natural processes draw attention to the siting of Croftmoraig (I am grateful to George Currie and Douglas Scott for details of their discoveries). The first is particularly striking. Viewed from the position of the stone circle, the midsummer sun sets into the side of Schiehallion (Fig. 10.7). It moves along the skyline before it disappears behind the mountain, which glows like an active volcano. Although the sun would not have been in the identical position four thousand years ago, the same effect would have been visible then. A second phenomenon can be viewed from the circle at the midwinter solstice. In this case it is the long axis of the oval stone setting that assumes a special significance as it is directed towards the position of the setting sun as it travels down the side of a nearby hill. In this case the effect is very different, for
it is visible over a longer period, but only around the solstice does the sun sink below the local horizon (Fig. 10.8). At other times it is too high for this to happen. It may be because both the turning points of the year could be observed at the same location that the stone circle was built here. Otherwise it might have occupied a more prominent position.

  Figure 10.7. A sequence of photographs showing the position of the midsummer sun as it sets behind Schiehallion. The views are taken from the rising ground immediately above the stone circle. This image should be compared with Figure 10.6 which was taken from the same location (Richard Bradley).

  One other observation is important in sketching the local context of Croftmoraig. This is the position of the banded erratic embedded in the surface of the glacial mound. It is an unusual kind of schist (Rosemary Stewart pers. comm.) and is exceptionally hard. It had been rounded and polished by natural processes and bore a series of scratches which probably result from its transport by ice. The surface is perfectly smooth and is characterised by a striking series of coloured bands, which vary from a creamy yellow to blue-green. It also includes a series of blue-grey speckles. These features are most apparent when the surface is moist. Several large flakes had been removed from its upper surface, almost certainly by human agency (Fig. 4.16). The stone recalls the distinctive appearance of the banded pebbles occasionally employed for axeheads and maceheads during the prehistoric period. Although glacial erratics are common in the local landscape, this stone is most unusual and cannot be matched among the material on the beach at the east end of Loch Tay.