Chopper

A chopper is a heavy, hand-sized cobble, pebble or thick spall with one sharp, usually convex working edge made by removing a few large flakes; the rest keeps its natural rind (cortex). Unifacial choppers are flaked from one face only, which gives a steep edge; bifacial choppers have flakes taken from both faces along the edge (Bell 1980; Peck 2011). The outline follows the original cobble, so shapes vary widely.

Choppers were made by direct percussion on a stream cobble or chert nodule, with little further shaping (Holmes 1919). Tough stone was favored, above all quartzite and cobble chert (Bell 1980; Quigg et al. 2010; Boen and Williams 2022). They were held in the hand rather than hafted (Bell 1980), often by a flat, unworked cortex end (Quigg et al. 2010).

Used edges show crushing, rounding, small hinge scars and sometimes polish. Archaeologists interpret choppers as tools for hacking meat and wood (Bell 1980) and for breaking bones for marrow (Peck 2011; Boen and Williams 2022). At the Pipeline site in the Texas Panhandle, use-wear study found wood fragments and silica polish on one chopper's edge and cooked wild-rye starch on another, used to pound seeds (Quigg et al. 2010). The key trait is a single flaked edge on an otherwise unworked, cortex-covered cobble.

Length mostly 50–120 mm (Bell 1980, Oklahoma). Five Late Archaic choppers from the Pipeline site, Texas: length 77–186 mm, weight 245–850 g (Quigg et al. 2010).

Found across North America wherever cobbles were at hand; reported, for example, throughout Oklahoma (Bell 1980), on the northern Plains of South Dakota and Alberta (Boen and Williams 2022; Peck 2011) and in the Texas Panhandle (Quigg et al. 2010). Bell (1980) found them most frequent on Archaic sites.

Identification tips: Look for cortex over most of the stone and one edge formed by a few large percussion scars, with crushing or polish from use. A cobble with one or two flakes knocked off and no edge wear is more likely a tested cobble from a quarry or gravel bar (Bell 1980).

Similar types: Hammerstone is battered along its edges but lacks a flaked cutting edge (Boen and Williams 2022). Chipped stone axes are notched or waisted for a handle (Bell 1980; Boen and Williams 2022). Adze has a unifacially bevelled bit (Connaway 1977).

Naming: Bell (1980) links the term to the pebble tools of the Old World Paleolithic and warns that a crude look does not mean great age. In the Lower Mississippi Valley, "chopper" has also named small, ovate chipped bifaces 41–79 mm long (n = 174, Denton site, Middle Archaic) and Baytown-period pebble tools once called Deasonville choppers (Connaway 1977). In the Northeast, Early Archaic "choppers" of soft sandstone, siltstone and phyllite are now often called tabular knives (Robinson and Crock 2006).

Dating evidence: In Alberta, choppers become more common in Bracken phase assemblages (about 2,800–2,100 B.P.), when mass bison kills began (Peck 2011).