BOTANICAL MUSEUM LEAFLETS 
HARVARD UNIVERSITY 
CAMBRIDGE, MASSACHUSETTS, DECEMBER 7, 1976 VoL. 25 No.1 
SILICIFICATION OF WOOD 
RICHARD F. LEO! AND ELSo S. BARGHOORN 
This work represents an effort to contribute toward an 
understanding of the long standing enigma of how wood be- 
comes petrified with silica. Following a general discussion of 
biogeochemical topics relating to fossil wood, a low tempera- 
ture laboratory process is reported, describing how contempo- 
rary wood can be impregnated with silica to form replicated 
structures comparable to those observed in natural petrifac- 
tions. In the third section, a physical model is presented, de- 
picting how silica is believed to be emplaced in wood with 
respect to cellular morphology. Next, in section IV, a chemical 
hypothesis is introduced. This hypothesis suggests chemical 
bonding to be operative in the mechanism of wood silicifica- 
tion. In the final section, the geochemical parameters inferred 
for the natural process are summarily discussed. 
It might be noted here that some of the thoughts expressed 
on the topic of petrifaction are admittedly speculative. It is 
hoped these thoughts will serve as a stimulus for further dis- 
cussion and study of the problem by others with an interest in 
wood silicification. It would be desirable to understand further 
the actual nature of the chemical interaction of silicia in solu- 
tion with wood components and their derivatives, not just for 
the petrifaction problem alone, but for the role plant-derived 
organic matter has in many geologic and soil processes of both 
academic and economic interest. 
I. AN INTRODUCTION TO THE 
BIOGEOCHEMISTRY OF FossiL Woop 
Wood Composition 
The principal chemical components of wood are cellulose, 
hemicellulose, and lignin. Both cellulose and hemicellulose are 
‘Current address: Instituto de Quimica, Facultad de Ciencias, Universidad Central 
de Venezuela, Apartado 10098, Caracas. 
