Waring: Geology of Northeastern Brazil. 199 



Near Tucunduba, twenty kilometers northeast of Riachao, SmalU'^ 

 found gneiss and schist dipping northwest on the northern side and 

 southeast on the southern side of a low range there, which accordingly 

 seems to be anticlinal in structure. About thirteen kilometers south 

 of Pitombeiras steep north dip is exhibited, and ten kilometers farther 

 south quartz-gneiss dips north at sixty degrees. A short distance 

 beyond, however, schistose rock dips southeastward, and there is a 

 small area of limestone, which is burned in several kilns. One-half 

 kilometer south of the kilns, or one and one-half kilometers north of 

 Massape station, dark-red sandstone appears, dipping southeastward 

 at thirty degrees. The sandstone continues along the railroad to 

 one and one-half kilometers south of Massape-, where it lies directly 

 on the gneiss. The gneiss seems to dip steeply northward; the sand- 

 stone dips about eight degrees S. 60° E. Prominent cliffs in Serra do 

 Meruoca, to the southwest, seem from a distance to be also composed 

 of sandstone, which presumably belongs to the series which forms Serra 

 Grande. 



At Sant' Anna, northeast of Massape, a wide ledge of white rock, 

 which seemed to the writer to be pegmatite, crosses northward 

 diagonally across the river bed.^'^ Thence for three kilometers south- 

 eastward the surface is of sandstone, which is well exposed in Serra 

 da Rola, dipping twenty-five degrees northward. Small^^ found that 

 this sandstone extends several kilometers to the north, and forms a 

 gentle syncline north of Sant' Anna. 'He considers the area to be an 

 outlier of the Cretaceous sandstone of Serra Grande. He records^* 

 dips of 70°-90°, N. 20° E. (mag.?) in gneiss near Marco, fifty kilometers 

 north of Sant' Anna, and near Itapipoca, seventy kilometers east of 

 Sant' Anna, he found the gneiss dipping southeastward, close to the 

 granite of Serra de Uruburetama. In a hill near Serrote, forty kilo- 

 meters farther east, he noted vertical quartzite striking south. 



From Sant' Anna southeastward to Sao Pedro de Timbauba the 

 gneiss contains several areas with much quartz, seemingly as quartz 

 veins and pegmatite dikes. Along this distance the strike of the 

 gneiss swings from south-southwest through southwest to west, the 

 dip being near vertical southward. 



'^ Publ. No. 32, of the Inspcctoria, p. 49. 



"^ Small (Publ. No. 32 of the Inspcctoria, p. 50), considers this ledge to be prob- 

 ably of haplite. 



1" Publ. No. 32 of the Inspectoria, pp. 50-51. 

 '" Publ. No. 32 of the Inspectoria, pp. 45-47- 



