Leaving a mark

Graham Lee – Archaeological Officer

‘Rock Art’ in archaeological terms consists of markings made by human beings on exposed stone surfaces. The earliest rock art from around the world has been dated to between 10,000-50,000 years ago, whereas within the North York Moors National Park the rock art appears to belong to the time span between the Late Neolithic and the Early Bronze Age periods, approximately 3,200-1,500 BC. Motifs created by carving were made into the rock surface using a sharp tool with a ‘pecking’ technique and can range in complexity from simple cups and grooves to quite elaborate patterns. The cup marks (sometimes enclosed by an outer groove – then called cup and ring marks, Fig. 1) tend to be shallow, semi-spherical hollows between c.3-12 cms across, with the depth generally proportional to the diameter, depending on the amount of surface erosion that may have occurred.

Cup and ring marks - copyright NYMNPA

Fig. 1 (above): Cup and ring marks on a heavily marked rock on Fylingdales Moor. Two roughly pecked rings can be seen coming together in the centre-right of the image.

The main concentration of prehistoric rock art within the North York Moors National Park lies within Fylingdales Moor which was affected by a wildfire in 2003. Survey after the fire has significantly increased the known resource (as previously recorded by the local rock art experts and enthusiasts) by over 60% – from approximately 120 sites to over 200. Given that the wildfire affected just over half (c.250 out of c.480 hectares) of this surviving area of coastal moorland (north-east of the A171), and that the latter in total only forms a small proportion of the overall Fylingdales moorland block, the full extent of the distribution of carved rocks in the area probably still remains to be discovered. Some of the carvings appear so fresh that it is thought that they are likely to have become completely buried in prehistory, to then be revealed anew by the wildfire. Such a site is probably that represented by a site on Brow Moor (Figs. 2-3), which was discovered under burnt vegetation in October 2003 and provides an example of excellent preservation. The individual peck-marks which form the decorative markings in the stone can still clearly be seen.

Cup and ring marks - copyright NYMNPA

Fig. 2 (above) and Fig. 3 (below): A remarkably ‘fresh’ carving on Brow Moor, as discovered in 2003 and after a few years regenerative growth. Note the level of surviving detail, including the individual peck-marks.

Cup and ring marks - copyright Blaise Vyner

The heat of the wild fire resulted in damage to some of the rocks by causing the surface of the stone to crack and flake away (known as spalling, Fig. 4). In addition to this, the chemistry of the stone may also have been irreversibly altered, affecting the cements that hold the rock particles together. This can influence the subsequent absorption of moisture which, due to freeze/thaw action during winter, can cause further spalling. The loss of covering material, such as the layers of roots and peat which had grown over the rock surfaces, also appears to have left the carved rocks more vulnerable to disturbance and erosion.

Wildfire burn - cup and ring marks - copyright Blaise Vyner

Fig. 4 (above): Spalling damage to a rock on Fylingdales Moor, caused by heat generated from the wildfire. Clearly this can lead to irreversible damage to any surviving rock art.

All the known examples of rock art on Fylingdales Moor appear to be carved into the local middle Jurassic Dogger series sandstone. Many of these rocks are likely to have been exposed to the elements – to weathering and biological attack – for well over 4,000 years. During this period of time it is likely that other wildfire events will have occurred, together with fires set deliberately for land management purposes. The latter will have increased within the last 150-200 years as part of grouse moor heather management  but in recent decades management for wildlife, rather than grouse shooting, has become the priority on this estate. Controlled burning is designed to cause minimal heat and damage, however it may still – depending on the chemistry of the rocks in question, and the nature of the ‘burn’ – cause some negative impacts to the prehistoric carvings.

In order to tackle the potential future loss of detail to these sites, a range of recording techniques and practices have been employed. The Fylingdale Moor sites have all been recorded by local experts and enthusiasts (see Brown and Chappell 2005), but in particular a group of 26 carved rocks were chosen for monitoring in order to provide a baseline record of condition against which to assess erosion and damage in future years. These have all been recorded by stereoscopic photography by Historic England, with a further group of 12 laser scanned at 0.5mm resolution.

Accurate location is also an essential part of site management, due to the difficulties of relocating sites on large areas of open (often rather ‘featureless’) moorland where long heather or other dense vegetation has developed. In the last few decades practical management has tended to become more mechanical with the use of rotating chain flail cutters attached to tractors, both to create fire breaks and to harvest the heather, which is sometimes baled and used e.g. as an environmental filter. It is consequently of particular importance to know the precise location of all the rock art panels to ensure that potential damage does not accidentally occur.

Many of the examples of rock art on Fylingdales Moor are protected as Scheduled Monuments. As part of our work under Monuments for the Future, and previously under the Monument Management Scheme, we send volunteers out to make regular monitoring visits to check on monument condition – however it is not always easy to find the correct rocks! In some areas bracken has been a problem, not only damaging other archaeological features, such as Bronze Age burial mounds, which may be associated with the rock art but obscuring the rocks making them difficult to find and therefore vulnerable to accidental damage. Over the last few years we have worked with Natural England and the managers of Fylingdales Moor to ensure that appropriate bracken control has kept some of these features clear of vegetation.

Further Reading
Brown, P. M. and Chappell, G. 2005 Prehistoric Rock Art in the North York Moors, Tempus, Stroud
Vyner, B. E. 2007a Fylingdales Wildfire and Archaeology, North York Moors National Park.