622 



J. C. Branner — Estancia Beds of Bahia. 



In the hills three kilometers north of Aracy on the Tucano 

 road are exposed red clays with greenish streaks and splotches 

 at the base. The clays are twenty-five meters or more in thick- 

 ness and rest upon the sandstone that underlies the town of 

 Aracy. They are followed higher up by an outcrop of granite, 

 but still farther north the red false-bedded sandstones appear 

 again, dipping 11° N. 50° W. magnetic. 



Fig. 5. 



Fig. 5. Section about three kilometers long northwest from Aracy, showing 

 the faulted Estancia beds against granites. 



The exposures of sandstone at this place are more than sixty 

 meters across. The rocks have a rusty color on the outside, 

 and are of a buff color on the inside. Usually the surfaces of 

 these exposures are covered with a thin black coating of man- 

 ganese. 



Col. Larangeiras of Aracy, who is remarkably well acquainted 

 with the geology of the surrounding region, informs me that 

 the ridges west of the town are all of granitic rocks, but that 

 the region to the east of these ridges is all of the sedimentary 

 beds as far as Soure. He notes also that the sedimentary beds 

 are not confined to the table lands on the east, but that every- 

 where they extend far west of the table lands. 



Fig. 6. 



Fig. 



Section across the western edge of the Estancia series near Aracy. 



Fazenda Jacu, where the fossil plants have been found, is six 

 and a half kilometers northeast of Aracy. The place belongs 

 to Francisco Ferreira da Motta, the son of Col. Larangeiras, 

 who was most cordial and helpful in giving information and 

 aid. The road from Aracy to Jacu passes all the way over 

 loose yellowish red sand with here and there loose fragments 

 of the Estancia sandstone which appears to underlie the region. 



The section given here shows the relations of the fossil-bear- 

 ing shales to the sandstone of Jacu, as indicated by the natural 

 exposures and in a well put down at that place. 



