Knapping Control - Baja and California

In the archaeological residues from the manufacturing and use of flaked lithic tools, evidence of the failures of prehistoric knappers is at least as well preserved as evidence of their successes. Identifying the degree of knapping control represented in assemblages may offer insights into the sophistication and continuity of local knapping traditions, the social organization of knapping, and the relative values that were attached to labor and lithic resources. Additionally, isolating the effects of variable control may be important in identifying contrasts between assemblages that were due to other factors of interest, including material quality, end product, knapping strategy, and reduction stage.

Bifacial tools are the end products most likely to reflect clearly their makers’ skills. For most varieties of projectile points in particular, symmetry in two mirror planes parallel to the tool axis seems to have been a desired trait, probably for functional reasons but perhaps also aesthetically. The degree of departure from symmetry in projectile point forms may be a fairly reliable indicator of lack of knapping control. The mental templates underlying other flaked lithic tool types either were originally less sharp or are now less apparent, making the recognition of errors in execution correspondingly problematical. Broken tool blanks and preforms testify to major errors committed during tool manufacture; the specific character of those errors may often also be apparent. Unbroken blanks and preforms may represent tools that were abandoned because the efforts to shape them had reached an impasse, or they may have been stored items that were still suitable for shaping but were never completed.

Debitage analysis may be able to distinguish several indicators of knapping control. Locally, the detailed study by Martin D. Rosen (1982) of assemblages from two sites in the Jamacha area, SDI-4763 and SDI-5066, based in part on a methodological program of Carl James Phagan (1976), is of particular interest. Specific debitage attributes relevant in this context include:

Termination. Flakes and flake scars with non-feathered terminations may represent less-than-optimal knapping results. A hierarchy of termination types, in order of diminishing desirability, might be suggested to run from feathered to hinged to stepped or broken to outrepassé terminations.
Length-to-width ratio. Rosen (1982:148) suggested that “clustering around any value [of length-to-width ratio] would indicate extreme care in controlling the fracture variables (implement, form, vector, core preparation, etc.); while a wide range of values would indicate that generalized flake removal was occurring.” For the assemblages from SDI-4763 and SDI-5066, the mean ratios of length to width were found to be 1.05 and 1.09, and the standard deviations, 0.41 and 0.44, respectively. Rosen considered these to be relatively broad ranges, indicative of “generalized flaking practices.”
Flake longitudinal and transverse cross-sections. Relatively thick flakes were proposed by Phagan and Rosen to be indicative of the application of inadequate force. Flakes that thickened distally were considered to indicate excessive force.Given the possibility of assessing, on a relative scale, the knapping skill represented in archaeological assemblages, the contrasts between assemblages in this respect might be explained in several ways:
More experienced knappers were likely to exercise greater control than less experienced knappers. Prehistoric cultures in which considerable emphasis was put on producing carefully shaped stone tools would have produced more skillful knappers than cultures in which flaked lithic tools were little used or casual in form. If knappers were part-time or full-time specialists, their work would presumably have been more controlled. Assemblages which include the work of nonadult, learning knappers would show more errors than assemblages produced exclusively by adults. There may also have been some differences in knapping skill by gender.
Continuity in local knapping traditions may have been a factor in the quality of knapping. Innovations in tool-making objectives or unfamiliarity with the characteristics of locally available lithic materials may have been responsible for higher error rates.
The characteristics of different lithic materials may have set different limits on knapping control. Important characteristics would probably have included groundmass grain size, isotropy, hardness, and internal fracture patterns.
The value that was attached to lithic raw material may have influenced the care taken in its working. Knapping may have been less careful at quarries than in habitation areas, because transport costs had added to the value of lithic material in the latter setting. Exotic rock types may have been worked more carefully than local ones.

PROSPECTS

Future archaeological investigations and replicative experiments may be able to develop useful relative indices of knapping control. Applying these to archaeological assemblages may help to assess cultural changes, ethnic displacements, settlement organization, the division of labor within communities, and the relative importance attached to conserving labor or material.