444 O. A. Derby—Oceurrence of Gold in Brazil. 
ing article on itacolumite. The quartzite, however, constitutes 
only a subordinate feature in this region which may be de- 
scribed as almost wholly gneissic; and the accompanying 
auriferous schists, which characterize the typical gold-mining 
region of Minas, have not been noticed in this part of the 
and cutting deeply into the hillsides, as extensive as can 
found any where in Minas. The feature that particularly 
lated beds have been followed, is the great superficial area and 
nearly uniform depth of the greater part of these old washings. 
They are suggestive of placers, but on entering them one is 
surprised not to find gravel heaps and only a comparatively 
