Annals N. Y. Acad. Sci. 



Volume XXII, Flate III 



AKCHEAX AND OTHER PRE-CAMBRIAX AREAS OF SOUTH AMERICA 



The solid black represents the Archean ; the. horizontally lined area represents the 

 hasal highland formation, which is generally considered to be pre-Camhrian and which 

 is covered by alluvial deposits along the Amazon (dotted area). 



