The Effect of Indentor Type on Flake Attributes: Evidence from a Controlled Experiment

Citation: Andrew Peclin (1997) The Effect of Indentor Type on Flake Attributes: Evidence from a Controlled Experiment. Journal of Archaeological Science (RSS)
DOI (original publisher): 10.1006/jasc.1996.0145
Semantic Scholar (metadata): 10.1006/jasc.1996.0145
Sci-Hub (fulltext): 10.1006/jasc.1996.0145
Internet Archive Scholar (search for fulltext): The Effect of Indentor Type on Flake Attributes: Evidence from a Controlled Experiment
Download: http://www.sciencedirect.com/science/article/pii/S0305440396901454#
Tagged: Anthropology (RSS) lithics (RSS), expermental archaeology (RSS), stone tools (RSS)

Summary

Andrew Peclin’s paper, The Effect of Indentor Type on Flake Attributes: Evidence from a Controlled Experiment, seeks to clearly identify the effects of soft and hard indentor types on stone flakes that are commonly found as part of the archaeological record. For the sake of this discussion an indentor can be defined as any object used to strike a stone core in the process of flint-knapping. Throughout history and prehistory, hard indentors are traditionally stones that are harder than the material being struck, where as soft indentors are usually bone or antler. Peclin identifies numerous papers and experiments previously conducted that attempt to identify the kinds of fractures and flake shapes that would be produced by different forms of indentors. He then uses his own controlled experiment to confirm or counter the findings in some of these papers with the intent of clarifying which observable traits of flaked stone can be attributed solely to indentor type.

In order to accomplish this, Peclin used a custom rig to mimic a percussive strike on a controlled plate glass surface. This rig was designed to allow either a steel ball bearing to operate as the hard indentor or an antler sphere of identical size as the soft indentor, to the end of the swinging arm. The weight of the arm was also adjustable to compensate for the missing mass of the less dense antler indentor. The glass plates used to act as the cores were 10 x 10 x 1.27 cm cut to provide uniform striking platforms and outside edges, these plates were also held in a jig designed in such a way as to not interfere with the flaking of the glass as it was struck.

For the experiment itself, the hard or soft indentor was placed on the swinging arm with the appropriate amount of weight(a total of 1500g for both hard and soft) and allowed to swing downward using only gravity towards the glass plates. The data that was too be collected was for flakes from the two kinds of indentor, but also from strikes against various platform widths for each type of indentor. The length, width, and mass of each flake was recorded for each type of indentor and striking platform, as were the specific flake and core attributes particularly bulb lengths, ring cracks and the presence of a lip around the ring crack.

The results presented by the author are quite extensive, with a considerable number of tables providing the data. Taking all of the data into account, the author determined that indentor type was a sole factor only in determining the length and width of a flake, whereas the total mass of a flake remained the same if the striking platforms were of identical size. The size of the striking platform was the only factor that proved to have any direct relation to the thickness of the flake produced. Certain other qualities appeared to have some correlation to indentor type in this highly controlled environment, however the author noted that these factors cannot be directly attributed solely to indentor type. Indeed, any of these qualities can be produced through the differences in technique and skill of the individual making the artefact so these elements cannot be considered diagnostic. Peclin then postulates that the use of soft indentors can be attributed to their ability to create thinner flakes allowing for conservation of materials that could be useful for highly mobile groups or those who occupy areas that have minimal access to acceptable stone resources.

Theoretical and Practical Relevance

These experiments run counter to some arguments placed forth by previous authors and work to further strengthen the position of others within the context of attempting to determine the manner in which lithic artefacts are produced.

This is an exceptionally thorough piece of experimental archaeology being attempting to answer a very difficult question. I applaud the author for admitting the limitation of their experiment in the face of confounding factors inherent in the process of producing lithic assemblages and find the extrapolation of data into economy of resources provided by soft indentors to be quite insightful.