The Organization of Chipped-Stone Economies at Piedras Negras ...

medium-sized, laurel leaf unifaces were found, but only in cache deposits. Furthermore,
these examples are often notched around the centerline of the piece, probably to express
some further symbolic meaning, or as an alternate hafting mechanism.
5.4.1.2.6: Medium laurel leaf biface, thick (see Figure 5.2 #15; see Section 5.4.1.1.6 for
description).
5.4.1.2.7: Medium stemmed biface (see Figure 5.2 #16). The preform for the medium
stemmed biface type was manufactured with a direct percussion technique. It is between
8 cm and 12 cm long. The proximal end features a finely crafted stem, which was shaped
with a pressure-flaking technique. The shoulders, or tangs, of the biface were notched by
pressure flaking or by indirect percussion. The margins were finished with a pressure
flaker. A thin, lenticular cross section was a desired result of the reduction process.
The stem in these pieces represents another hafting strategy, but there is
substantial variety in the way the stem has been manufactured. For most of the examples,
the stem is quite short, and varies from a tapered stem to a nearly straight stem (Willey
1972:163). The medium-sized stemmed bifaces were made of medium- to fine-grained
microcrystalline quartzes and were reduced using a soft- or hard-hammer, direct-
percussion technique. First, either a celtiform or laurel leaf biface was produced, and
then, using a pressure-flaking technique, the point was sharpened and the stem was
formed. Although the stem may have been chipped using an indirect-percussion
technique, there is not much evidence for this (e.g., wide semicircular notching scars),
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