Crossing the Borders: New Methods and Techniques in the Study of Archaeological Materials from the Caribbean

82 / De Mille, Varney, and Turney
nology have allowed nonconductive materials to be imaged without being coated
with a thin layer of metal (typically gold or platinum), thus both the artifacts
themselves, when found broken with the bore exposed, as well as the casts could be
examined. A second reason for employing this imaging technique is for the purposes
of comparability with other work undertaken on manufacturing traces and
drilling technology by Gwinnett and Gorelick (1979, 1981; Gorelick and Gwinnett
1978).
A scanning electron microscope/ energy- dispersive spectrometer ( SEM/ EDXA)
capable of imaging in environmental mode was utilized in the Lakehead University
Instrumentation Laboratory (LUIL), and we were able to image our bead
bores and molds without any modifications. The beads and bores and molds were
scanned along their entire length, and at focal points of interesting features, and
the images were saved as computer files. However, the SEM we now have access
to at the LUIL could not produce images in the same low magnification (85x vs.
30x) as the SEM we utilized for our initial study (De Mille and Varney 2003). This
meant that a greater detail (mostly of the mineral and rock itself ) was visible, and
that the smaller field of view required complete pictures of boreholes to be composites
of a series of many images. The issue of direct comparability with our previous
work and that of Gwinnett and Gorelick (1979, 1981; Gorelick and Gwinnett
1978) was raised. As such, we made use of a stereoscope fitted with a digital camera
to visualize the bores and their replicas. Image Pro 5 software was then used to knit
together a stack of serial images taken at different focal distances to produce an accurate
3D image. We are confident that the combination of the SEM and the 3D
images taken through the stereoscope has allowed us a comprehensive view of the
bead bores and their replicas.
Experimental Drilling
In this initial phase of our experimental program, one drilling trial, in which a
5 mm hole was drilled in a calcite tablet using a wooden drill bit and a quartz sand
slurry as the cutting solution, was completed. We decided to begin our experiments
with the relatively soft mineral, calcite, common in the Antiguan assemblages.
The first experiment was chosen with wood as a drill bit, as no chert drill
bits small enough to have been used on the beads have yet been recovered archaeologically.
Further trials will include a variety of rock and mineral types, abrasives,
and drill bits.
It took six hours to drill a hole 5 mm deep. The drilling mechanism was a rotary
multitool (Einhell Model BSG30–40T) with speeds of approximately 10,000
rpm. A wooden toothpick, blunt end down, was inserted into the chuck of the tool.
We purposely did not drill through the tablet, allowing us to examine the leading
edge of the borehole. A small reservoir was built out of modeling clay to retain the
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