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Lithic use-wear (lithic microwear) analysis research

Lithic microwear analysis is advancing, and it is revealing a new aspect of lithic studies.

At the Center for Obsidian and Lithic Studies, use-wear analyses of lithic artifacts from Paleolithic and Jomon sites will be carried out to accumulate fundamental data about the temporal and spatial differences of resource exploitation among prehistoric hunter-gatherers in the Japanese archipelago.
Lithic use-wear (lithic microwear) analysis is a method to infer the used edges and use motions of stone tools, and their worked materials, based on the observed physico-chemical alterations on flaked surfaces.
Lithic use-wear is roughly divided into six categories: 1) breakage, 2) abrasion (rounding), 3) microflaking (microchipping), 4) striation, 5) use-wear polish (micropolish, polished surface), and 6) residue. 1) The breakages are the macroscopic fractures which occur due to contact with the worked material. 2) Abrasion is the macroscopic and microscopic quantitative wear of the stone tool surface. 3) Microflaking involves the microscopic scars produced along an edge of a stone tool as the result of utilization. 4) Striations are the linear traces considered to be formed by contact with the particles of worked material, sand grains, and microflakes detached from stone tools during usage. 5) Use-wear polish is the altered zone on a lithic artifact which is visible as a shinier or rougher area compared with the surrounding surface. 6) Residue is a particle of worked material or haft adhering to the stone surface, including vegetal fibers, wood, starch granules, blood, hair, bone, ivory and so on.
For lithic use-wear analysis, it is most important to experimentally recognize the correlation between a trace of physico-chemical alteration and its formative agency. The attempt to discover the relationship between traces and their causative agencies can lead us to recognize the principles of trace formation dynamics, and the experimental approach makes it possible to empirically test the regularity of their correlation.
In order to observe the details of a morphological feature of lithic use-wear traces, not only the naked eye and loupes but also various microscopes are usually employed. Macroscopic traces such as breakages, abrasions, microflaking, and striations, are observable with a stereomicroscope at relatively low magnifications (up to 100 X). With an emphasis on the observation of microscopic traces, especially abrasions, striations, polishes, and residues, we need to use an incident light microscope, a digital microscope, and a scanning electron microscope at relatively high magnifications (more than 100 X).