ENHS Nature Trails November 2000 Article 3

Floor Plans: a new application of paleoethnobotany
by Pete Helzer

My wife, Marge Helzer, has always had an interest in obscure corners of botany. When I first met her in 1986 she was able to identify over 150 species of trees from nothing more than a small bud at the end of a twig; a skill, as she put it, in rather limited demand. After a brief career with the US Forest Service, she discovered a passion for archaeology and finished a master_s degree at the University of Oregon in 1993. Sometimes chance encounters play a big part in the direction of people_s lives, and in Marge_s life, a double stroke of chance and luck has recently resulted in an interesting synthesis of her knowledge of plants and her proclivity for archaeological sleuth work.

In 1997, after a five year stint as a community college teacher, Marge was visiting an excavation near Fort Rock, Oregon with archaeologist Mel Aikens. Dr. Aikens asked Marge if she had any interest in paleobotany, explaining that there was a desperate need for someone to conduct macrobotanical analysis of soil samples; someone with the ability to identify small twigs and fragments of charred seeds from four and five thousand year old fire hearths. As a specialty this was rather uncharted turf. Typical archaeological investigations in the Great Basin place a strong emphasis on analyzing stone tools. If financial resources were left over, occasionally two or three soil samples were collected and analyzed for the presence of seeds. This was done primarily to help identify what plants indigenous peoples were exploiting for food. Although this is important information, Marge had other ideas about how the science might be applied.

There were problems. Seed fragment identification is not exactly a hot topic in the field of botany, and library searches were turning up nothing. Here is where luck enters the picture. Marge met Linda Scott Cummings, a botanist specializing in pollens and a rare expert in paleo seed identification, at a convention in Bend, Oregon. They became instant friends and soon Dr. Cummings had invited Marge to study at Paleo Research Labs in Golden, Colorado. Marge jumped at the chance. The two women worked eight hour days in the lab and talked late into the evenings. Dr. Cummings, as it turned out, had been thinking along the same lines as Marge for some time, but lacked a research vehicle to test her ideas. Soon the two women agreed on a strategy for testing their hypothesis that seeds dropped on ancient house floors leave a record of human activity areas. Marge returned to Oregon and started a two year project directing a group of U of O students in the excavation of a 4,300 year old house floor near Fort Rock, Oregon.

Now, two years after systematically collecting 250 soil samples from the house floor - and long hours in the lab peering through microscopes - the results are in. Because samples were taken in a grid pattern across the house floor at 50cm intervals, it was possible to assign colors based on the number of seeds recovered from each sample. Red was assigned to high density areas, with orange, yellow, green, and blue, representing progressively lower counts. The pattern of seed distribution across the house floor clearly indicated a pattern of human activity. The distribution of Chenopodiaceae and Amaranthus (goosefoot, waada, saltbush, pigweed) show food preparation and eating areas. The distribution of Scirpus seeds (bulrush) ,which are associated with woven mats (in addition to food), were comparatively more prevalent around the walls. A rather striking floor plan began to emerge. One feature, puzzling at first, was a high concentration of seeds that extended from the edge of a fire hearth to the east edge of the house wall. It has since been interpreted as a doorway.

What Marge Helzer's study has provided is something more than a list of edible plants. She has discovered a floor plan, sketched in the dirt with the smallest fragments of seeds by a people who walked on our planet 4,370 years ago. Her work is also testimony to luck, coincidence, friendship, and a tenacious interest in the natural world.

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