188 J. C. BRANNER AGGRADED LIMESTONE PLAINS, BAHIA, BRAZIL 



The geologic relations of the Bahia limestones to the other rocks of the 

 State will be seen in the following tentative table of the general groups or 

 divisions of the rocks : 



Geologic Divisions of the State of Bahia 



Divisions Tiiickness in meters Ages 



Catinga limestones 10 Tertiary to Recent. 



Taboleiro series 200+ Tertiary. 



Sergipe series 300+ Cretaceous 



Salitre limestones 350 Jura ? 



Estancia red beds 350 Trias ? 



Lavras series 700 Carboniferous ? 



Cambao quartzites 100 . . (Probably part of Lavras series.) 



Caboclo shales (possibly the 



Paraguassti of Derby) 500 Devonian ? 



Jacuipe flints 100 . . (Probably part of Caboclo series.) 



Tombador sandstones 400 Silurian ? 



Minas (or Jacobina series) ..... 1,000 Cambrian ? 



Crystalline complex pre-Canibrian V 



It will be noted that the ages of all the divisions below the Cretaceous 

 is questioned. The ages here suggested for the doubtful divisions are 

 based on ph3^sical breaks and differences, and are subject to revision. In 

 connection with the principal subjects of the present paper, the ages of 

 these divisions are of no especial importance save in the case of the 

 Catinga deposits. 



The Limestone Horizons 



Limestones are found in four of the divisions given in this table. Be- 

 ginning with the oldest, these are : 



1. White marbles in the crystalline complex, supposed to be pre-Cam- 

 brian. 



2. Blue and gray limestones and marbles in the Salitre limestone 

 series, believed to be Jurassic. 



3. Gray and cream colored limestones in the Sergipe series, of Cre- 

 taceous age. 



4. The Catinga limestones of recent origin, but probably beginning in 

 the Tertiary. 



Farther up the valley of the Eio Sao Francisco there is another lime- 

 stone of Silurian age at Bom Jesus da Lapa,^ and it is quite possible that 

 some of the limestones here set down as Salitre belong with the Silurian 

 beds at Bom Jesus. 



2 O. A. Derby : Archives do Museu Nacional, vol. ix, p. 72. 



