Nottoway River Survey Newsletter

Cactus Hill Site Project

April 2002


It has been two years since the last Nottoway River Survey report updating our ongoing research at the Cactus Hill archaeological site in Sussex County, Virginia.  Our current work, which has been funded by a second grant from the National Geographic Society and grants from the Virginia Department of Historic Resources, is the third phase of what we now envision as a five-phase project to be completed over the next several years.  A detailed report on the results of the third phase will be issued to the Committee for Research and Exploration of the National Geographic Society in 2003, but the results thus far have been very good and we would like to share some of them with you.

Phase three of the NRS Cactus Hill research project was initiated in 2001 to resolve critics concerns over the results of the 1997 through 1999 research findings presented in our March, 2000 report to National Geographic.  These findings also were presented at the April 2000 SAA Annual Meeting in Philadelphia.


The current research plan involved column analyses of off-site and additional on-site total phosphorus and phytoliths; 14C and OSL (optically stimulated luminescence) dating of geological strata and particularly OSL dating the pre-Clovis Blade level and sterile zone; detailed geoarchaeology, pedoarchaeology and geomicromorphology of the deposit in search of buried and remnant A horizons (old paleosols) at the critical Clovis and Blade levels; and, an independent assessment of the site and ongoing NRS research by the Committee for Research and Exploration.  We are delighted to report progress, and significant results, in all areas of the investigation. 

The total phosphorus tests for a second on-site column through the Clovis and pre-Clovis Blade levels have identified peaks at the occupation levels and valleys in the “sterile” zones.  An off-site column has shown consistent, low values of total phosphorus throughout the column.  This work was done in Dr. James C. Baker’s lab at Virginia Tech.  Matching phytolith tests are currently underway by Dr. Lucinda J. McWeeney at Yale University.

The NRS team pedoarchaeologist/geoarchaeologist Dr. Daniel P. Wagner, of Geo-Sci Consultants, Inc., in his reconstruction of the paleolandscape has identified remnant buried A horizons in the deposits at several locations.  This includes a faint buried A horizon, visible at some locations in area B of the site, separating the two deepest strata of human occupation.  One buried A horizon indexed by two corroborating 14C dates to approximately the Last Glacial Maximum at one location on site now has been dated in the same time range at a second location.  Also, charcoal recovered by NRS from four levels of iron-clay lamellae in a 12” deep soil column, extending from a Blade level downward to a geological buried A horizon, produced an accurate, average 14C date consistent with previous dates over the height of the column.  Again, these findings confirm the integrity of the deposit.

As a review of NRS’s accuracy in identifying morphological boundaries (cultural levels) in the deposit, archaeologist, Dr. Thomas R. Whyte, of Appalachian State University, performed an independent on-site quality control evaluation of the cultural level markers positioned in trench #2.  His analysis, through careful excavation of the trench wall profile, identified identical boundaries.

Dr. James K. Feathers, of the University of Washington, has completed dating two of a total of eight OSL samples in this phase of the project.  The two completed samples represent the Blade level (pre-Clovis), and 12” below the Blade level.  We are pleased to report that these dates closely agree with previous 14C age determinations.  Phase three of the luminescence dating program is in an early stage and all samples now are being processed to take into account the possible natural affects of radon in the deposit, and the affects of eluviation from fine particle iron-clay lamellae.

Geomicromorphologist, Dr. Richard I. Macphail, of University College London, UK, has found that Cactus Hill has broadly stratified archaeological deposits at the Clovis and Blade levels.  Also, he cautiously notes that there is evidence of ephemeral, relic soil horizons (old paleosols) at these levels separated by the NRS designated “sterile soil zone” which is of a different microfabric.  Dr. Macphail’s findings appear to corroborate years of NRS qualitative, macroscopic observations, and these finding may represent the “smoking gun” needed to clearly prove the case for a stratified, undisturbed Blade level below the Clovis level.

Geoarchaeologist, Dr. William R. Farrand, of the University of Michigan, and special consultant to the Committee for Research and Exploration of the National Geographic Society, in his independent report has found acceptable the overall stratigraphic integrity of the deposits at Cactus Hill.  Dr. Farrand also found the NRS research team’s performance satisfactory. 

We look forward to the opportunity to focus some of these new, exciting techniques and scientific tools in even deeper levels at Cactus Hill.

Joseph and Lynn McAvoy/NRS Cactus Hill Project