Wariijg: Geology of Northeastern Brazil. 211 



however, that although the series has wide distribution, it occupies 

 much more restricted areas than has been heretofore assumed, and 

 that the greater part of the schist belongs to the crystalline series. 

 The reasons for believing this are: The gneissic or crystalline schistose 

 appearance of most of the material observed ; the relative scarcity of 

 deposits of quartzite and. crystalline limestone in the series; and the 

 difficulty of accounting for wide areas of schist of the series by repe- 

 tition due to close folding or to faulting, because the dip of the folia- 

 tion planes seems to have constant direction at angles of 70° to 90° 

 for distances of many kilometers. 



The following notes on observed occurrences of the Ceara Series are 

 presented for such information as they may furnish on the areal 

 distribution of these ancient sedimentary rocks. 



On the journey westward from Campina Grande quartzite was first 

 definitely observed four kilometers north of Periquitos; but to the 

 south, toward Viragao, a thick white ledge probably is also composed 

 of quartzite, and northeast of Batalhao schists, which weather into 

 gravestone-like projections, may belong to the series. It seems as if a 

 considerable belt between Batalhao and Parellas may be composed 

 of the quartzitic and schistose members of the series. 



East of Caico crystalline limestone is exposed for perhaps two 

 kilometers in the vicinity of Barra do Mainoso. In the vicinity of 

 Caico and for at least five kilometers northward there are wide white 

 ledges, which were taken to be quartz-veins. They may possibly be 

 quartz-lenses in schists of the Ceara Series. 



About twenty-five kilometers southeast of Apody a bed of schist 

 and crystalline limestone a few meters thick flanks a low ridge, which 

 seems to be largely composed of cherty material. Crystalline lime- 

 stone is also exposed on the opposite, or northern, side of the ridge, 

 which may constitute a narrow anticlinal zone of materials of the 

 Ceara Series. 



Serra Arare, near the mouth of Rio Jaguaribe, is composed in part 

 of red quartz-schist or quartzite; and minor ledges of white quartzite 

 (or veins of quartz) traverse the lowland near the base of the small 

 mountain. 



In the remarkably straight east- west range formed by the serras 

 Vital, Santa Catharina, and Melado, quartzite and mica-schist are 

 well exposed where the range is crossed by the Rios Pianco, Aguiar, 

 and Piranhas. To the writer the range seemed to be perhaps a narrow 



