With National Science Foundation support, Dr. Timothy Scarlett and Dr. Jaroslaw Drelich from Michigan Tech will purchase equipment in support of their study of Fired Clay Ceramic Rehydroxylation Dating (RHX Dating), a novel chronometric (absolute dating) technique for archaeological ceramic. This grant helps Drs. Scarlett and Drelich collaborate with an international team of researchers, working to develop this new scientific tool.
This new dating technique, if proven valid and reliable, will effect substantial changes on archaeological practice. The ability to date ceramics directly can provide scientific insight into larger questions of human adaptation, cultural processes and change, colonization, trade and exchange. With a comparatively minor initial investment, an archaeology lab in the world could set up the relatively inexpensive instrumentation and produce RHX dates for ceramic samples. This technique, if proven, will provide an inexpensive tool that can be widely available for scientists around the world.
Using this grant, the investigators will purchase a Mettler Toledo XP26 Microbalance, which has a capacity of 52 g with 0.001 mg readability, two orders of resolution and sensitivity higher than the microbalance currently available in their laboratory. In addition, a Plexiglas exposure chamber will be built in which researchers can carefully vary and control the humidity and temperature of samples during rehydroxylation in order to match the environmental conditions to those of the depositional life of the archaeological samples.
RHX dating works by measuring the mass of water that has bonded with clay minerals in the ceramic fragment, then measuring the temperature-dependent rate at which that ceramic sample reabsorbs and bonds with water, and finally using those measures to calculate each fragment's age (or time since last firing). Initial experiments by the investigators identified both problems and promise in the RHX dating technique.
This project will have broad impacts on teaching, training, and learning in archaeological science. Drs. Scarlett and Drelich have built their research collaboration by creating discovery-based, hands-on learning opportunities for multidisciplinary teams of graduate and undergraduate students. This grant helps strengthen the developing collaborative relationship between the Industrial Archaeologists in the Department of Social Sciences and the ceramics specialists in the Department of Material Science and Engineering. Too few students study archaeology and materials science, and only a fraction of those have any exposure to the perspectives and interests from industrial archaeology.
Michigan Technological University used this National Science Foundation grant to purchase a microbalance and related equipment and run a series of experiments toward developing Fired-Clay Ceramic Rehydroxylation Dating, a new "absolute" dating tool for archaeological research. Michigan Tech purchased a Citizen CM11 Microbalance and Coy Humidity Control Glove Box for ongoing study of Rehydroxylation Dating (a.k.a. RHX dating). The microbalance has a capacity of 11 g with 0.001 mg readability, two orders of resolution and sensitivity higher than the balance that was available in our laboratory before the NSF award (100x more precise than our old balance). The environmental control glove box allows for careful control of temperature and humidity, essential to the ongoing experiments. Rehydroxylation dating, if proven, could revolutionize archaeological practice. The new microbalance and experiments at Michigan Tech have allowed a team of researchers to publish observations about this proposed tool. First, MTU proposed an expanded model that describes the overlapping processes of rehydration and rehydroxylation, thus providing a more robust tool that should result in more accurate dating. We also observed that labs may need to powder samples of ceramics with higher firing temperatures, such as stoneware or vitreous earthenware, so that researchers can consistently measure mass gain. Finally, work submitted for review describes the effect of variations of humidity on mass gain behavior. These new publications were collaboratively produced by student and faculty researchers at Michigan Tech, and a student is the lead author on the first publication. The support from the National Science Foundation continues to nurture our collaborative effort to use archaeological science and problems as a source of discovery-based learning projects for students, matching STEM educational development with real archaeological, anthropological, and historical research needs.