Raw Material Studies (continued)

Typo-technological issues

A basic understanding of lithic raw materials is essential, as this allows the specialist to fully comprehend the variation present in lithic collections. Some typological variation is entirely due to function (a specific tool form may allow a specific task to be carried out in the most efficient manner), some is due to stylistic considerations (a specific tool form may be important as a means of group identification; below), but some variation may also largely be a consequence of raw material properties.

Most commonly, the preferential use of one specific raw material led to the production of characteristic core forms, as the properties of that particular raw material determined the use of specific technological approaches or operational schemas. Pitchstone (Ballin 2009), for example, is characterized by a number of different properties, each of which resulted in the ubiquity or scarcity of certain core forms: 1) the tendency to break into tabular pieces led to the formation of many small squat or cubic cores, frequently with a flat 'back-side' (this also characterizes chert); 2) the exaggerated tendency of pitchstone blades to curve along their long axes led to the formation of small discoidal cores; and 3) its brittleness made this raw material less suitable for hammer-and-anvil production, resulting in low numbers of bipolar cores.

Quartz (Ballin 2008) is generally considered a 'difficult' raw material, defined by intricate fracture patterns, which lead to many cores being rather chunky, and with quartz operational schemas being less sophisticated than contemporary schemas in other raw materials. One consequence of this was that, in many parts of north and west Scotland, bipolar approaches were preferred, although some pure or fine-grained quartzes allowed more traditional platform techniques to be applied.

Nodule size was also an important technological determinant. 'It is generally accepted, that small pebbles are ill-suited for platform technique (eg, Finlayson 2000, 105; Callahan 1987, 63), as 1) they do not contain sufficient mass to allow the necessary decortication and preparation of platforms, flaking-fronts and platform-edges, 2) due to their small size and curved exterior, primary blows tend to glance off these pebbles; and 3) small pebbles have so little mass that a blow tends to move the hand and pebble, rather than detach a flake' (Ballin 2008, 69).

Where more than one raw material was available to prehistoric people, certain raw materials were commonly preferred for certain tasks or tool forms. Although ideology (like group identity and religion) may occasionally have played a role in connection with these choices, many of those preferences are likely to express functionality, in the sense that specific raw materials produced particularly sharp cutting-edges (knives), or they may have been valued for their durability (scrapers). At Upper Palaeolithic Howburn in South Lanarkshire, certain raw materials were clearly preferred for certain tool forms, and those preferences may represent a complex mixture of ideological and functional choices (Ballin et al. 2010, forthcoming).

click to enlarge
Quartz barbed-and-tanged arrowheads from Calanais, Lewis, Western Isles (Ballin 2008).

Quartz barbed-and-tanged arrowheads from Calanais, Lewis, Western Isles (Ballin 2008).