- The Minori Cave Expedient Lithic Technology
Minori Cave is a limestone tunnel cave in the Cagayan Valley in northern Luzon. Chamber D, located at one of the cave's two entrances, was excavated by the Philippine [End Page 390] National Museum in 1981–1982, and then by Mijares and another museum researcher in 1999, and they obtained a radiocarbon date on charcoal of around 4600 yr B.P. Most of the stone artifacts are of andesite with a smaller contingent made of chert. During his graduate studies program at the University of New Mexico, Mijares analyzed the technology and use-wear traces of a sample of 110 Minori flakes in the context of studies he undertook on experimentally knapped and utilized andesite and chert flakes. One particular concern of Mijares is to show the likelihood that prehistoric Philippine inhabitants had used andesite flakes as tools, as this would serve as a reprimand to those Philippine archaeologists who routinely ignore andesite artifacts. His second main objective is to investigate the hypothesis that the "stagnant" nature of stone knapping in the Philippines (and elsewhere in Southeast Asia) reflects the prevailing focus on producing expedient stone tools to work the wide range of useful plant material found in the region's forests. These are important matters, and the publication of Mijares' thesis research is a fitting commencement to the Contribution to Archaeology Series set up by the faculty and sta¤ of the Archaeological Studies Program at the University of the Philippines, as Victor Paz (in his capacity as series editor) notes in his preface.
Following standard practice in the Philippines, Mijares defines a flake tool as a flake with, first, a serviceable sharp edge and, second, the appropriate dimensions to be held between thumb and index finger in a way that exposes the sharp edge. This definition would especially apply to Mijares' seventeen experimentally knapped flake tools (eleven of andesite, six of chert) because they are on average longer and wider than the specimens in his sample of Minori flake tools (as recognized by Mijares) and their working edge tends to be more acute. This observation comes from Mijares' tables, which summarize the statistics of eighteen technological variables (eight metrical and ten nominal) for both the Minori and the experimental flakes. The seventeen experimental flakes were then subjected to a range of slicing, sawing, cutting, scraping, whittling, and chopping tasks over periods between 16 and 58 minutes. The utilized edges were observed at 10×, 50×, and 200× magnification and their traces of use wear, in the form of use-scar terminations, presence of polish, and direction of any striations, recorded. Magnification at 200 allowed the most useful observations, and these suggested a relationship between use wear and type of task, at least when carried out on hard plant material (bamboo and rattan); meat cutting left far fewer use-wear traces, especially on the andesite flakes. Finally, the experimentally determined usage signature was sought on Mijares' sample of Minori flakes, and found on 74 percent of the andesite flakes and all of the chert flakes.
With respect to Mijares' first research objective, he concludes that use-wear traces can be recorded on andesite flakes, especially at magnifications of 200× and higher, even though the procedure is tedious and may involve inspection of individual phenocrysts. However, to explain why a smaller proportion of andesite flakes revealed any use wear compared to chert flakes, Mijares suggests that the prehistoric occupants of Minori had recognized the inferior quality of andesite tools compared to chert tools. Other possible explanations, such as the greater difficulty in recognizing edge wear on andesite compared to chert, especially if a soft material such as flesh had been worked and particularly when we consider the confounding e¤ects of contact with deposit in the site and then (in the case of the flakes excavated in the 1980s) edge damage during curation, are not addressed. With regard to the second research objective, Mijares...