Waring: Geology of Northeastern Brazil. 185 



sedimentary rocks, which probably range in age from early Paleozoic 

 to Tertiary. The succession of rocks in Bahia has been discussed 

 by Branner and Crandall'^ and by Soper.^ 



The succession of rocks in the northern area, in which most of the 

 writer's observations were made, have been discussed by Crandall,'*"^ 

 Soper^"' and Small. ^~^ 



The approximate areal extent of the several geologic formations 

 have been delineated on maps prepared by these geologists for the 

 Brazilian Government; and their data, together with those of himself 

 and others, have been brought together on one map by Dr. J. C. 

 Branner.^" Geologic boundaries along routes traversed are shown in a 

 few places on the accompanying maps (Cf. Plates IV and V), but the 

 data presented on these maps are primarily of the bedrock structure, 

 with observed occurrences of diabase, pegmatite, and other rocks of 

 minor areal extent. 



In the northern area a horseback trip was made by the writer from 

 Campina Grande westward to Therezina (on the Parahyba River), 

 and the principal railroad lines were traversed in 191 1 between 



- Prelitninai-y Report on the Geology of Portions of Bahia, Sergipe, and Alagoas, 

 by John C. Branner and Roderic Crandall. (Manuscript report of the BraziUan 

 Geological .Survey.) 



^ Geologia e supprimenlo d'agua siibterranca em Sergipe e no nordestc da Bahia, 

 pelo Engenheiro Ralph H. Soper. (Publication No. 34 of the Inspectoria de Obras 

 Contra as Seccas, Rio de Janeiro, 1914, pp. 17-45.) 



^General Notes on Northeastern Brazil, by Roderic Crandall. (Manuscript 

 report of the Brazilian Geological Survey, 1908.) 



^ Geographia, Geologia, Supprimento d'Agua, Transportes e Acudagem nos Estados 

 Orientaes do Norte do Brazil {Ceard, Rio Grande do Norte, Parahyba), por Roderic 

 Crandall. Publication No. 4 of the Inspectoria de Obras Contra as Seccas, Rio de 

 Janeiro, 1910, pp. 21-34. 



^ Geologia e Supprimento d'Agua Siibterranca no Rio Grande do Norte e Parahyba, 

 pelo Engenheiro Ralph H. Soper. Publication No. 26 of the Inspectoria de Obras 

 Contra as Seccas, Rio de Janeiro, 1913, pp. 18-30. 



' The Geology of Parahyba and Rio Grande do Norte, Brazil, by Ralph H. Soper. 

 Proc. Am. Phil. Soc, Vol. LV, No. i, 1916, pp. 1-20. 



* Geologia e Supprimento d'Agua Subterranea no Ceard e parte do Piauhy, pelo 

 Engenheiro Horatio L. Small. Publication No. 26 of the Inspectoria de Obras 

 Contra as Seccas, Rio de Janeiro, 1913, pp. 25-48. 



^Geologia e Supprimento d'Agua Subterranea no Piauhy e parte do Ceard, pelo 

 Engenheiro Horatio L. Small. Publication No. 32 of the Inspectoria de Obras 

 Contra as Seccas, Rio de Janeiro, 1914, pp. 29-58. 



'" Geologic map of Brazil by John C. Branner, in the press by the Geological 

 Society of America. 



