Stone tools for grinding and pulverizing foods and other substances have played an important role in subsistence economies worldwide since ancient times. With National Science Foundation support, Dr. Margie Burton and a team of Native Americans and U. S. archaeologists will conduct experiments with replicated tools to generate data that will aid in understanding how and why grinding tools changed through time. Previous studies involving controlled grinding experiments have focused on agricultural or emerging agricultural societies. In contrast, the goal of this project is to achieve a better understanding of grinding tool assemblages related to hunter-gatherer societies, which are typical of the majority of human history. The project consists of an experimental component and an archaeological component that uses previously excavated, curated collections. The San Diego County, California region, which has one of the densest concentrations of hunter-gatherer archaeological sites in North America dating from more than 9000 years ago, is used as a case study. The experimental component will measure grinding efficiency of different tool types and will define characteristic use-related damage patterns for different food and non-food substances using replicated tools. A set of 27 grinding experiments (3 tool shapes x 3 stone material types x 3 substances for grinding) has been designed based on the existing archaeological and ethnohistorical record for the San Diego area. The archaeological component will compare the experimentally-determined efficiency and use-wear criteria to archaeological grinding tool assemblages. Selected assemblages are from Archaic and Late Prehistoric hunter-gatherer sites in San Diego County, a cultural sequence that is thought to be characterized by increasing social complexity and resource intensification and decreasing population mobility.
The intellectual merit of the project lies in the experimental baseline of detectable criteria for grinding tool use and processing efficiency that will result. These data will enable archaeologists to test common assumptions correlating tool form with function and to evaluate grinding tool choices made by hunter-gatherers, thus allowing better-informed interpretations of social and economic implications of changes in grinding tool assemblages. The relationship between technological change and economic and social conditions is one of the most significant issues in modern archaeology and society today.
Broader impacts of this project include important educational benefits. Grinding experiments are organized as a series of public classes, providing a collaborative learning experience for volunteers, and middle-school and high-school students that will emphasize the scientific process. Native Americans will contribute knowledge and expertise in traditional grinding methods that are important to the scientific results. In addition, their participation with other segments of the public in the experimental phase will help to promote understanding and appreciation of the San Diego region's cultural heritage. The project also offers an archaeology graduate student an opportunity to work with middle/high school students and volunteers on an experimental archaeology project. Laboratory equipment, experimental tools, and photodocumentation of use-wear patterns that result will remain at the San Diego Archaeological Center, a non-profit curation facility, museum, and research center. All equipment and materials will be made available to researchers for use in comparative studies. Center staff trained in grinding tool use-wear analysis as part of this project will be able to share their expertise with other investigators. This will enhance local and regional infrastructure for archaeological research and will promote partnerships and collaborations between cultural resource management firms and academic and cultural institutions.
