BOTANTICAL MUSEUM LEAFLETS VoL. 28, No. | 
MARCH 1980 
BIOGEOCHEMICAL RESIDUES AS 
ETHNOBOTANICAL INDICATORS’ 
ELIZABETH A. COUGHLIN * and JONATHAN E. ERICSON * 
In America, the archaeological application of chemical residue 
analysis of the soil is really in its initial stages. Soil phosphate 
analysis has been the dominant method used to date, although 
there is occasional use of other parameters, suchas pH by Weide, 
(1966) and the now classical C, N, Pand Ca analysis of Cook and 
Heizer (1965). 
Sjoberg (1976) has said: 
“Phosphate analysis is not only suitable for locating and 
delimiting sites, but can also serve as a useful tool in the 
interpretation of intrasites relationships. Experimentally, the P 
content has been used in estimating population size and the 
duration or intensity of settlements; to determine subsistence base 
and describe general diets; and to establish relative or even 
absolute chronology.” 
This paper proposes to expand the data base of soil residue 
analysis, particularly with respect to plant residue, by suggesting 
a new method of Trace Typing which utilizes a measurement of 
Trace Element Concentration (T.E.C.) and an associated new 
parameter of Enrichment Ratio which employs dendrochrono- 
logic data and contemporary botanicals. 
The development of this Trace Typing has been motivated by 
the concern that much evidence has been screened out on the 
back dirt of the archaeological site. 
Increasingly we see the need to verify specific functional 
attributes to sites, features, tools and other items. Although 
macroscopic evidence is usually employed to test the validity ofa 
1. Center for Archeological Research and Development Publication No. 4 
Paper presented at the Forty-fifth Annual Meeting, Society for American Archeo- 
logy, Philadelphia, Pa., May 1-3, 1980. 
Botanical Museum, Harvard University, Cambridge, Mass. 
Peabody Museum of Archeology and Ethnology, Harvard University, Cambridge, 
Mass. 
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