198 Annals of the Carnegie Museum. 



any departure from horizontality is recognizable. At Marvao the 

 sandstone seems to dip about ten degrees S. 60° W., but this is prob- 

 ably either local dip or false-bedding, though it is fairly constant for 

 several hundred meters. 



About forty kilometers west of Marvao dark-red sandstone appears 

 on the west side of Rio Sucuriu. This rock is different in physical 

 appearance from the Cretaceous material, and the exposure is believed 

 by the writer to mark the eastern limit at this place, of the Permian 

 rocks, which thence extend far to the west.^^ 



N or tJnve stern Ceard. Southward from Camocim, on the coast in the 

 northwestern part of the State of Ceara, gneiss first appears at eleven 

 kilometers along the railroad, with a steep south dip; but at Granja 

 the rock strikes about S. 50° W., and dips forty degrees southeastward. 

 Northeast of Granja, toward Parazinho, gneiss is exposed for about 

 twelve kilometers, seemingly with constant southeast dip. Sand and 

 dark-red iron-cemented sandstone of the coastal belt of Tertiary 

 material then cover the surface for a few kilometers; but two or three 

 kilometers southwest of Parazinho low knolls of gneiss rise above the 

 plain, and at the village the gneiss strikes S. 45° W., with dip of eighty 

 degrees to the southeast. Fracture planes traverse the rock at right 

 angles to the strike. One-half kilometer south of the village there is a 

 ledge of quartz; or possibly quartzite, conformable in strike and dip 

 with the gneiss, and this ledge also has fracture planes at right angles 

 to the strike. Southwest of Granja the strike swings to S. 65° W., 

 with vertical dip where noticed, eight kilometers from the town. 

 Thence southward wavy gneiss strikes west with nearly vertical dip. 

 About ten kilometers from Granja ledges of quartzite appear, seem- 

 ingly interfolded in the gneiss or schist, and thence to a dam site on 

 Rio Itacolomy, twenty-five kilometers from Granja, the quartzite 

 appears at intervals, in several places forming low ridges in the gneissic 

 plain. The strike swings through west to northwest, the dip at the 

 dam site being 45° to the southwest. In a few places the gneiss and 

 quartzite are overlain by thin-bedded red sandstone, one dip of 20° 

 eastward being seen. The material is presumably a remnant of the 

 Cretaceous rocks which compose the Serra Grande. 



Near Angico the gneiss dips northwest, but a short distance to the 

 south changes to south dip and continues thus to beyond Riachao. 



'■• The Permian Geology of Northern Brazil, by Miguel Arrojado R. Lisboa. Am. 

 Jour. Sci., May, 1914, pp. 425-443. 



