GEOLOGY OF CENTRAL MINAS GERAES, BRAZIL 



371 



truncated, it is safe to assume that all the rest of the region was 

 close to base-level. 



MESOZOIC — EARLY TERTIARY DEPOSITION 



Diamantina conglomerate. — On the truncated, even crest of the 

 Serra do Espinhago, high-level gravels, now cemented into a con- 

 glomerate, are found at various points along the range, particularly 



Fig. 8. — Peneplained crest of the Serra do Caraga, near Alegria. The inclined 

 quartzite strata have been trunkated and the old erosion surface still persists over 

 extensive areas on the top of the Backbone Range. 



in the vicinity of Diamantina. The top of the Backbone Range 

 in that region is very broad, partaking perhaps rather more of the 

 nature of a narrow plateau belt than of a mountain range. The 

 broad open tracts of comparatively level upland are so distinctive 

 as to have been termed chapadas (table-lands) by the natives. 

 While considerably dissected by subsequent erosion, the broad 

 open country upon the top of the Backbone Range is the modified 

 surface of the old peneplain (Fig. 9). At various points on these 

 chapadas, or upland plains, especially in hollows or former river 



