Ground stone from Isle of Man Meolithic

Oxford Archaeology North  recently excavated a Mesolithic house at Cass ny Hawin 2, Isle of Man. This house had burnt down leaving charred timbers and quantities of burnt hazelnut shell as well as the flint and stone tools lying where they were last placed before the conflagration.

The stone tools formed a fascinating collection including three unusual ground stones; bevelled pebbles and elongated hammerstones; several hammerstones or anvils as well as smoothers/rubbers; a dimpled cobble, and a grinding slab. A collection of distinctive, large, rounded cobbles was also made.  These tools were used, or placed, in an organised manner within the structure and the spatial analysis of the finds is explored in the report.

The publication of the site is expected soon but for now I want to share images of one of the ground stone tools.

This fine stone tool was made from an oval cobble of medium-grained sandstone and it was shaped by pecking and grinding to form a fine bifacial bevelled edge around the perimeter of the cobble. Both faces have been ground at slight inward angles to form a splayed long-section and are slightly concave in cross-section.

The bevels are particularly defined on the long edges of the cobble where they have been very finely ground to form a curved cross-section with a sharp edge. A distinctive feature is the raised ribbed pattern worked on the surface of the ground bevels on either side. When observed side-on these ridges are angled to form chevrons with the sharp edge of the bevel as the central spine The ridges or ribs are clearly linked with how the edges were ground – and it seems likely that the edge was grooved in this pattern prior to use or further shaping. The placing of these grooves may have been to provide purchase for a substance being processed, or as decoration, or perhaps as a means of decorating another surface on which this tool was subsequently used. These ridges have then been worn to a smooth and rounded finish or in some cases are quite flattened with further working.

Just what this tool was used for can only be guessed at but the distinctive features which include a finely bevelled edge with surface preparation in the form of a clear pattern of grooves suggests that it was manufactured for a very specific purpose. On its own, this finely-shaped object could be interpreted at many levels – it may not be a tool and instead could have been shaped as a decorative or symbolic object. However, there are two other pieces of ground stone which share some characteristics such as the flat faces and bifacially bevelled edges with this object but neither have been so finely altered to shape and this would suggest a more utilitarian use for the ground stone.

There are as yet no parallels for this tool form at other sites, Mesolithic or later. The closest published comparison is the perforated and ground stone disc from Nab Head Site 2 (David and Walker 2004, Figure 17.17.4). Despite the lack of a perforation on the Cass ny Hawin 2 example as well as a different outline in plan there is close similarity in the profile of the bifacially ground angled edge around the perimeter of both pieces. This is not to say that that these artefacts were made to be used in the same way – this is highly unlikely. However, it is perhaps evidence that the template for a regular bifacially ground edge existed and across regions and time though whether it was a functional or stylistic device cannot be determined yet. Of note is the decorative grooving forming raised chevrons around the spine of the bevelled edges of the Ronaldsway object which does not occur on the disc from Nab Head.

Worked ochre from Mesolithic sites

Ochre is a mixture of fine clay and iron oxide and it often occurs in conjunction with iron ores such as haematite. Though it occurs at many prehistoric sites in Britain it is usually present in only small numbers. Recent excavations by Oxford Archaeology North at the  Late Mesolithic site of Stainton, Cumbria has uncovered a very large assemblage of 582 pieces of ochre. This included  47 pieces with traces of working and several others with residue adhering to the surface.

The wear traces are visible as striations, gouge marks, grooves and worn faces and combinations of these various wear traces often occurred together on the larger or complete pieces.  Only a few pieces of ochre appear to have been used for sustained rubbing – enough at least to alter the profile of the lump significantly. The heaviest wear traces were made by gouging and the marks were formed by pushing a sharp point  into the centre of the ochre face.

A few pieces had a white substance adhering to the surface and SEM analysis by Karen Hardy, ICREA, Barcelona University has shown it to be an aluminium silicate, most likely kaolin.

There are many uses ascribed to ochre though few if any can be directly identified at archaeological sites.  Ochre is a strongly coloured red or orange pigment which can be rubbed on to an object in order to colour it. It can be used either dry or wet but when a lump of ochre or haematite is rubbed with water the colour is released very easily as a red viscous liquid reminiscent of blood and which can be applied like paint (Isbister 2000). As well as a decorative application ochre can also be used in the preparation of hides (ibid) and Hodgkiss (2010) notes that high iron content preserves leather. Isbister records many ethnographic applications of ochre in medicine and healing (Isbister 2000, 2009). Kaolin also has many and varied uses and in ways similar to or complementary with ochre. These materials were clearly used together at Stainton as demonstrated by the fragments of ochre with kaolin adhering to them but without supporting residue evidence from other materials it would be futile to speculate on their exact uses.

The assemblage of ochre from Stainton is the largest and most informative yet from an excavated Mesolithic site in Britain and the distinctive range of wear traces demonstrates that ochre (and kaolin) was used in a variety of ways and most likely for different jobs. The large size of the assemblage together with the range of uses could indicate that craft, manufacturing and processing activities at this site were carried out in an intensive way;  perhaps highly organised  into specialised areas for e.g. hafting and hide working.

An incised Mesolithic bevelled pebble from Scotland

Upper face of bevelled pebble showing bands of incised lines
Lower face of bevelled pebble


During recent excavations at Camas Daraich, Skye an incised bevelled pebble was discovered at the base of a midden layer dating to the Mesolithic .  Finds of incised or decorated stone and bone from this period are rare in Britain as a whole and this is the first of its kind from Scotland.

This is a classic elongated pebble form with a double bevel worn on the broader end and with some flaking from this end too. The bevels abut to form a ridge which runs at an angle to the faces. The pebble has a naturally shaped ‘handle’ which is a third of the total length of the tool. The incised pattern is formed of pairs of narrow, parallel bands which divide the tool obliquely into thirds. For a 3D image of this tool check:

There are  many possible interpretations for the presence of the incised lines on this stone tool. It is clear that the incisions are deliberate and composed but it cannot be determined yet whether they are, for example, purely functional, a deliberate abstract representation, a recording or message.  A full discussion of the meaning behind the incisions is in:

Clarke, A; Vila, A;  Estevez, J; Hardy, K 2012 ‘The Tie That Binds? An incised Mesolithic bevelled pebble from Camas Daraich, Skye’ Mesolithic Miscellany 22.1, October 2012, 3-9.

Craft specialisation in the Mesolithic


Recent excavations at  sites in Northern Britain have added to the repertoire of coarse stone tools known to have been in use during the Mesolithic. By analysing the distinctive wear traces on all the coarse stone tools from a site and by examining their context of deposition it has been possible to identify areas on site where specific activities were being carried out. Coarse stone tools appear to have been subject to some form of structured use and deposition and this appears in the archaeological record in three ways: by the dominance or single use of a particular tool type;  by the presence of discrete deposits of tools; or by a combination of both.  The evidence suggests that some sites were used for specific craft or processing activities over time, whilst other sites were used for multiple activities, perhaps related to repeated visits.

The full article is published as:

 Clarke, A 2009 ‘Craft specialisation in the Mesolithic of Northern Britain: the evidence from the coarse stone tools’, in N Finlay; S McCarten; N Milner and CR Wickham-Jones 2009 From Bann Flakes to Bushmills, Oxbow and can be downloaded here: