SERRA DO ESPINHAQO, BRAZIL 387 



With the exception of the sandstone blocks above mentioned, 

 the pebbles of the conglomerate, seen by the thousands in hundreds 

 of square meters of clean-cut fractures passing through them, are 

 exclusively of quartzite. These represent an older formation, to be 

 mentioned farther on, which is known to occur in other sections of 

 the Serra do Espinhafo and which may be presumed to occur also in 

 the Paraguassu section to the westward of the region here described. 

 The central portion of the range in this section and the country to 

 the westward are very imperfectly known, but the recurrence of dia- 

 mond camps justifies the presumption that the Lavras conglomerate 



Fig. 8. — View on the gneiss plain of Bahia, by Mr. J. A. Allen. 



recurs frequently, through folding, over a great part of it. The 

 westernmost of these camps is in the Serra de Assurua, a detached 

 mountain ridge near the river Sao Francisco. Burton (20), who 

 visited it, mentions the occurrence of a coarse conglomerate, which 

 he compared to the Old Red Sandstone of Scotland. 



Another section, intermediate between the two above described, 

 across the range and the adjacent country on each side, is given in 

 an interesting note by Mr. J. A. Allen, published in Hartt's Geology 

 and Physical Geography of Brazil. Mr. Allen's route was from 

 Chique-Chique on the Sao Francisco to Bahia, passing by Jacobina, 

 and thus about 100 kilometers to the southward of the first railroad 

 line above described. His profile of the route and sketches of charac- 

 teristic line of travel as being essentially over three distinct plateau 



