Waring: Geology of Northeastern Brazil. 209 



no good observations of the strike were obtained. At Bananeiras, 

 fifteen kilometers northwest of Cachoeira, gneiss is well exposed in the 

 channel of the Rio Paraguassu, dipping 70 degrees to the southwest. 

 Westward from Cachoeira, gneiss is exposed along the railroad shortly 

 after leaving Sao Felix. The strike is northward, with steep west dip, 

 and continues thus nearly to Pombal, where a reversal in the dip 

 indicates a synclinal fold. Thence to Candial there is apparently 

 some crumpling, as the strike, as observed from the train, seems to 

 change its direction, as indicated on the map, Plate V, Avith dips lower 

 than usual. Westward from Candial the strike seems to be constantly 

 northward, with steep dip to the east. At Tapera a small vein of 

 serpentine was observed in the country-rock, which in the vicinity is 

 granitic rather than gneissic. On the south side of the railroad 

 between Tapera and Tanquinho there is a group of granitic hills which 

 are carved into cavernous forms by the weather. Along the railroad, 

 however, the rock is gneissic; and beyond the group of hills, unless 

 the observations are in error, the strike swings to northwest. Between 

 Lapa and Sitio Novo the strike returns to a north-south course. 

 Westward from Sitio Novo, to and probably beyond Caixao, the rock 

 is granitic rather than gneissic. 



The most salient feature in the structure of the basement rocks in 

 this southern area, west and northwest of Bahia, seems to be the pre- 

 vailing northward strike, conformable with the trend of the principal 

 mountain ranges. Some crumpling seems to have taken place in 

 restricted areas, but in general the foliation planes seem to hold con- 

 stant strike over long distances. 



The Ceara Series. 



Notes concerning the character and distribution of the rocks of the 

 Ceara Series have been published by Crandall,^^ Small,^^ and Soper,^^ 

 in reports issued by the Brazilian Government. Crandall, who 

 named the series, and has examined these ancient sedimentary rocks 

 more closely than others, says that the series seems to consist chiefly 

 of schists, which in the southern part of the State of Parahyba possibly 

 attain a thickness of a thousand meters. In places a hard, quartzitic 



3' Publ. No. 4 of the Ijispecloria, pp. 22-25. 

 32 Publ. No. 25 of the Inspectoria, p. 38. 



'3 Publ. No. 26 of the Inspectoria, p. 19, also Proc. Am. Phil. Soc, Vol. LV, No. i, 

 1916, p. 7. 



ANN. CAR. MUS., XIII, I5, DeC. 9, 192O. 



