At Cactus Hill, 45 miles south of Richmond, Virginia, archaeologists led by Joseph McAvoy of the Nottoway River Survey have been working since 1995 to uncover evidence of some of the earliest inhabitants of North America. The site, owned by International Paper Corporation and located on sand dunes above the river, has yielded several levels of prehistoric occupation with two distinct levels of early Paleoindian habitations. The level radiocarbon dated to 10,920 BP contained fluted stone tools of the Clovis type, which are believed to have been used between approximately 11,500-10,000 BP. Beneath lies evidence of an earlier human occupation on the same site, including white pine charcoal from a hearth context dated to 15,070 radiocarbon years BP.
Several lines of research were used to confirm the accuracy of the dates, and to reconstruct the environment at the time the site was in use. Soil analysis by James C. Baker of Virginia Tech showed that the site was formed by wind-blown sand deposits. James Feathers of the University of Washington used optically-stimulated luminescence (OSL) to corroborate the radiocarbon dates, and to show that the buried sand levels had been undisturbed by later deposits. The OSL technique is based on the fact that natural radiation in minerals such as quartz causes electrons to change position at a regular rate, so long as they are not exposed to heat or light. Using a laser causes the electrons to return to their original positions, emitting a glow which can be measured to provide an accurate date for the time they were last exposed to light.
Charred plant remains (some, later used for radiocarbon dating) were identified by paleoethnobotanist Lucinda McWeeney of Yale University. The organic materials included white pine and spruce charcoal, suggesting the area had a cooler climate at the time of the earliest occupation than today. After processing a column sample of sediments for phytoliths (silica fossils that formed in the plant cells) McWeeney was able to demonstrate that there is a strong correlation between the stone artifacts and increased plant use at the site. The correlation also suggests that the human occupation levels are not mixed. Remains of calcined bone identified as mud turtle and white-tailed deer suggest that the site may have been a seasonal hunting camp.
Studies at another area of the site by Dr. Carol Mandryk at Harvard University's Department of Anthropology could not conclusively demonstrate undisturbed sediments. Tests performed for the area that produced the 15,000 year-old date, however, do show relative stratigraphic integrity.
The consensus of the scientific evidence collected is that the site was occupied as early as 15,000 years ago, by people using unfluted bifacial tools. This makes Cactus Hill one of the two earliest known sites (along with Meadowcroft Rock Shelter in Pennsylvania) for human occupation in eastern North America. The National Geographic Society is sponsoring further research at the site.
[National Geographic Society, Public Affairs Dept; Lucinda McWeeney, personal communication.]
Athena Review Image Archive | Guide to Archaeology on the Internet | free trial issue | subscribe | back issues
index of Athena Review |
Copyright © 1996-2003 Athena Publications, Inc. (All Rights Reserved).