Hi there, my name is Moira Magni. I am a senior undergraduate student at UMass Boston majoring in Anthropology, and I am hoping to continue my education in archaeology. A group of us recently finished working with Steve Mrozowski at Hassanamesit Woods and have spent the last two weeks learning from Heather Law Pezzarossi in the Fiske Center lab. As we made our way out of the field and began to familiarize ourselves with the lab, we discovered our growing interest in archaeobotany, particularly after Heather Trigg and Sue Jacobucci provided a demonstration on taking pollen core samples from the Sarah boston Site at Hassanamesit Woods.

A few weeks ago we were lucky enough to spend the morning with Heather Trigg, who introduced us to the Fiske Center’s Flote-Tech and provided us with a crash-course in flotation. Archaeologists rely on flotation to help separate out the botanical matter from the samples of dirt they collect on site. When we put the sample in the water tank, the sediment sinks, but the plant matter floats to the top, which we can then collect for further ethnobotanical analysis. We look for a variety of botanical materials using the flotation technique, but the most common things we find are seeds and charcoal– we call these macrobotanicals.

We learned basic terms and steps to preparing the machine by filling it with water (enough to cover the jets!) and making sure to place the mesh baskets and cloth into the machine before any samples are added. Once the sample has been properly recorded, measured and added to the flote-tech, Heather taught us the importance of patience in flotation. It is important to be an active participant in the flotation process by helping the flotables move over the waterfall, constantly stirring the soil with your hands.

Another important step is judging the best time to insert the bar. The bar is a metal slide that assists any straggling “near flotables” in making their way to both the waterfall and the cloth that catches the fraction. The bar stirs up the water with a bit more force and catches the remaining “light fraction” (the plant remains that float) before the cloth is changed in preparation for the “heavy fraction” (the remaining sample that does not float). Once the cloth is changed, the heavy fraction is at the bottom of the basket is transferred to the new cloth and both fractions are laid out to dry.

We spent the morning processing a few samples on our own and then made our way down to Heather’s lab where we used microscopes to view the differences between specific types of seeds and other botanical remains that we might typically find in “light fraction” samples. Many of these were discussed as part of the assemblage found at Rich Neck Plantation (e.g. corn, rye, sorghum, raspberry, etc.). We were also given a brief introduction to the Fiske Center’s pollen database and the time and energy that have gone into building it.

While being introduced to the processes of flotation, sample preservation and analysis was exciting; Heather also helped us to understand the larger purpose behind paleoethnobotany and how it helps us learn about the past. It was exciting to begin understanding how something so small can help to reconstruct past environments (e.g., grassland vs. forest, moisture, temperature, etc.) and to express the relationship past peoples had with those environments. Learning how important context and processes like carbonization and preservation are to the reconstruction process was also incredibly interesting, and we want to thank to both Heather Trigg and Sue Jacobucci for taking the time to teach us!