200 Annals of the Carnegie Museum. 



Southward from Massape along the railroad the gneiss is much 

 veined with quartz, and disintegrated; and no good exposures showing 

 the strike were seen until twelve kilometers south of Carire. The 

 strike there seems to be westward, with steep north dip; but eight 

 kilometers farther south the dip seems to swing to the northeast, and 

 at Santa Cruz a steep southeast dip was noted. For a few kilometers 

 to the north and south of Ipii the railroad crosses sandstone at the 

 base of Serra Grande, which rises abruptly from the gneissic plain, 

 as shown in Plate VIII, fig. 2. Gneiss reappears along the railroad 

 three kilometers south of Ipu, though too deeply disintegrated for its 

 structure to be easily determinable. Near Nova Russas, and thence 

 southward to Novilho (the railroad terminus in 191 1), the gneiss 

 seems to have constant southwest strike, with steep northwest dip. 



From Fortaleza to Iguatii. The observations of strike and dip along 

 the railway between Fortaleza and Iguatii were taken, and checked, 

 from the rear of the train during four trips over the line. Although 

 some of these observations of direction may be in error, it is believed 

 that they show correctly the general character of the folding along 

 this strip of country. 



Southward from Fortaleza gneiss was first seen, outcropping from 

 beneath the coastal belt of sedimentary materials, near Monguba. 

 It there strikes south, with nearly vertical dip, and is cut by small 

 pegmatite dikes. Thence southward the strikes gradually swing to 

 about S. 60° W., near Acarape with steep northwest dip. At Itapahy, 

 crystalline limestone and quartz associated with the gneiss, strike 

 southwestward with nearly vertical dip. From Itapahy to Baturite 

 the rock seems to be all gneissic, but the strike seems to vary con- 

 siderably, swinging from southwest to northwest and back to south- 

 west, with dips that indicate much folding into steep anticlines and 

 synclines. The character of the rock also changes considerably, 

 being crushed gneissic to about Canafistula, where it more resembles a 

 crushed granite. At Aracoyaba it might be classed as a granitic 

 gneiss. Thence to beyond Baturite there is deep red (decomposed 

 granite?) soil. Between Baturite and Junco the strike seems to be 

 fairly constant, westward, but reversals in dip show considerable 

 folding. For some distance south of Baturite gray soil (gneissic?) 

 covers the surface, but near Riachao fresh gneiss with wide banding 

 is exposed. Thence southward it is again disintegrated on the surface, 

 and three kilometers south of Castro the rock is more granitic. Fresh 



