Biology ETDs

Publication Date



Flotation analysis (the examination of small-scale botanical remains recovered by a simple water separation technique) was undertaken at site 29SJ627, a small pueblo in Chaco Canyon, New Mexico. Altogether 69 samples were examined, yielding 5208 seeds from approximately 30 plant taxa. All plant taxa encountered in flotation samples are growing in Chaco today, with the exception of the domesticates corn and squash, and the riparian Scirpus (bulrush). The assemblage of seed types recovered by flotation indicates that the prehistoric plant community was essentially similar to today's, with increased emphasis on arboreal and riparian species and that weedy types were more abundant, probably due to the disturbing effect of man and the selection of these taxa for food plants. Plant remains were considered likely to be economic if ethnobotanical records pointed to use of the plant by historic peoples of the Southwest or if burnt specimens were found in the site. Economic taxa included Chenopodiurn, Amaranthus, Portulaca, Cycoloma atriplicifolium Mentzelia albicaulis, Oryzopsis hymenoides, and probably Descurainia pinnata, Physalis, Heliantheae, and Sporobolus cryptandrus. Flotation data was used to delineate temporal and room functional differences within the site. Sampling considerations, such as the most efficient sample size and the appropriate number and locations of samples taken from the site, were examined.

Project Sponsors

The Chaco Center, National Park Service, Grant No. 7000-5-0802



Document Type


Degree Name


Level of Degree


Department Name

UNM Biology Department

First Committee Member (Chair)

Loren David Potter

Second Committee Member

Rex Gordon Cates

Third Committee Member

William James Judge

Included in

Biology Commons