V. SOME FEATURES OF THE GEOLOGY OF 

 NORTHEASTERN BRAZIL. 



By Gerald A. Waring. 



(Plates IV-X.) 



Outline of Contents of Article. 



Page 



Introductory 183 



Geologic features treated 186 



Structure 186 



From Campina Grande westward. . .--; 186 



Northwestern Ceara .' 198 



From Fortaleza to Iguatu 200 



West of Natal 202 



From Natal to Recife 202 



Salient features of the bedrock structure in the north 203 



Structure south and west of Recife 205 



Structure in the southern area 205 



The Ceara series 209 



The granites 215 



Resume of major features 216 



Minor features ■. 216 



Quartz gravels 216 



Basic igneous rocks • 219 



Springs ,. 221 



Appendix. 



Fossil mammals collected at Pedra Vermelha, Bahia, Brazil, by Gerald A. 



Waring 224 



By W. J. Holland 



Introductory. 



During the years 1910-1913 the writer was engaged in recon- 

 naissance work for the Brazilian Government, seeking to ascertain the 

 possibility of storing supplies of surface-water and developing ground- 

 water supplies in the arid northeastern portion of that country. 

 Although observations of the geology along the routes traversed were 

 in many places unsatisfactory because of the exigencies of the main 



183 



