Late Paleoindian biface manufacture: a case study from the Mackenzie I site (DdJf-9) near Thunder Bay, Ontario

The Mackenzie Sites appear to form part of the Late Paleoindian Lakehead Complex that occupied the unglaciated peninsula between Glacial Lakes Agassiz and Minong during the terminal Pleistocene. A number of sites and isolated projectile point finds have been discovered throughout the region. Most excavated collections consist of quarry workshops, yielding vast lithic assemblages snapshots of the reduction sequence and very few diagnostic tools. In contrast Mackenzie I (DdJf-9) appears to be an extensive and repeatedly used stream mouth habitation site. Its vast lithic assemblage includes specimens attributable to the full range of the lithic reduction sequence and a large number of diagnostic tools. Biface assemblages from other sites within the Lakehead Complex have been analyzed in an attempt to determine the lithic reduction sequence. These sites have provided partial insight in understanding the middle stages of the Lakehead Complex reduction sequence. Mackenzie I offered the chance to observe the complete sequence of lithic reduction. The biface assemblage consists of 667 bifaces that could be placed in Stage 1-5 reduction. Am additional 223 bifaces were unstageable, 21 anomalous bifaces fell outside the normal range of variation, and 532 were classed as formal tools.
\nThe biface stages were determined using metric and non-metric attributes in an attempt to further define the Lakehead Complex reduction sequence as previously established. Bifaces from Mackenzie I include Stage 1 through to Stage 6 (the last stage representing formal and diagnostic tools). It also became apparent that there were two trajectories of manufacture used in the production of the Mackenzie I assemblage. Large tabular blanks were reduced by systematic removal of flakes using direct percussion techniques, termed the Biface Trajectory. Where thin narrow flakes were reduced using refined methods of flake removal using either indirect percussion or directed pressure flaking, this was termed the the Flake/Blade Trajectory. It also became apparent that there was a selection of flake blanks, reduced for the specific purpose of manufacturing projectile points. Many of the projectiles at Mackenzie I exhibit a slight twist and/or curvature. Such attributes can be attributed to the nature of the blank and the subsequent methods of flake removal. Since the initial identification of the Lakehead Complex projectiles, they have been characterized by their refined parallel oblique flaking pattern. It was not until the excavation of Mackenzie I that the prevelance of this manner of flaking (99%) became apparent. This analysis has revealed that parallel oblique flaking enters the lithic reduction sequence at Stage 3, but with significantly wider flake scars. It is hypothesized that this was a result of the preferred lithic raw material. The Gunflint Formation cherts that were heavily utilized at Lakehead Complex sites are very hard, yet brittle and contain joint plane faults and iron-oxide inclusions. The Mackenzie I assemblage also indicates the presence of a blade technology being used alongside the bifacial toolkit. These blades are easily producible on high quality tabular blocks of the Gunflint Formation chert. It appears that blades, blade/flakes and large tabular blocks were all utilized in order to produce the Mackenzie I toolkit. These were all nearly exclusively finished using parallel oblique flaking techniques.

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