216 0. A. Deri// — Manganese Ore Deposits of Brazil. 



sartite and rhodonite as hitherto supposed. Numerous 

 localities in the Queluz and other districts in Brazil have been 

 prospected, in which at a comparatively slight depth the com- 

 mercial ore ran into an almost pure spessartite rock, and this 

 fact suggests the hypothesis that for the alteration to proceed 

 far enough to produce extensive deposits of merchantable ore, 

 the presence of large proportions of the less resistant carbon- 

 ate and of tephroite is necessary. So far as can be seen at 

 Piquery, rhodonite is an element of subordinate importance, 

 though it may be suspected to have been present in greater 

 force in the original type of the low grade ore characterized 

 by secondary quartz. 



Eio de Janeiro, Dec. 24th, 1907. 



