PPT Slide

We classified artifacts using Sullivan and Rozen’s (1985) framework for debitage analysis. Although the system is imperfect for distinguishing between bipolar and free hand percussion, we do expect to see some general trends. Bipolar reduction does produce pieces that would be classified as flakes or broken flakes, identified by the presence of a point of force and single interior surface, but we would expect that the proportions of what Sullivan and Rozen would classify as debris debris and flake fragments would be higher in assemblages produced using bipolar reduction.Table 4 shows the breakdown of types, demonstrating that the proportions of debris and flake fragments are not

particularly high. This suggests that the perceived technological differences between patinated and unpatinated objects are supported by empirical data. Although we have not analysed a sample of unpatinated Kintampo material from Birimi for comparison, other analyses of Kintampo material from the region demonstrate that assemblages aredominated by artifacts with the attributes of bipolar reduction.

Possible Explanations

There are several possible explanations for the presence of artifacts produced using two different technologies on the same surface of the site

1. All artifacts were produced at the same time but more than one reduction sequence was employed

2. All artifacts were produced at the same time and form a part of the same reduction sequence.

For example, free hand percussion may have been employed early in the reduction of large nodules  and bipolar percussion employed later as the nodules became too small to knap freehand

3. The artifacts were produced during two temporally separate occupations of the site

We prefer the third explanation because it accounts for the difference in patination of the artifacts produced using different technologies

Future research will include an examination of the distribution of artifact types and the frequency of markers of bipolar technology in the

unpatinated Kintampo assemblages. At this time we are confident that there are two components represented on the surface. The

attribution of one of these to the MSA is based both on an Optically Stimulated Luminescence determination of ca 30,000 years on sediments

from the layer in which the in situ MSA artifacts were recovered, and on artifact technology and typology

Alicia knapping material brought from mudstone source

Acknowledgements: Funding for excavations at Birimi was provided by the Social Sciences and HumanitiesResearch Council of Canada. Analysis of the MSA materials was supported in part bya College of Liberal Arts Scholarship Support grant and a Research and Productive Scholarship grant both from the University of South Carolina. Students who assisted with the lab work include Claudia Carriere, Dennis Duval, Jodi Barnes and Jennifer Massey.

Debitage Analysis

References Cited:

Casey, Joanna2000 The Kintampo Complex: The Late Holocene on the Gambaga Escarpment, Northern Ghana. Cambridge Monographs in African Archaeology No. 51; BAR International No. 906. Oxford: Archaeopress.

Hawkins, A., J. Casey, L. Pavlish and R. HandcockIn Press Instrumental Neutron Activation Analysis of Siliceous Mudstone from the Birimi Site, Northeastern Ghana. Proceedings of the 31st International Symposium on Archaeometry, Budapest, Hungary Vol. II. Edited by Erzebet Jerem and Datalin T. Biro. BAR International. Oxford: Archaeopress.