MÖSSBAUER STUDY OF AGING EFFECTS IN ANCIENT POTTERY FROM THE MOUTH OF THE AMAZON RIVER J. DANON, C. R. ENRIQUEZ, E. MATTIEVICH and MARIA DA C. DE M. COUTINHO BELTRÃO J. Phys. Colloques, 37 C6 (1976) C6-866 DOI: 10.1051/jphyscol:19766182