CABO BRANCO SANDSTONE REEF 



49 



At Cabo Branco a low reef about half a kilometer in length, of hard 

 rough black rocks, barely uncovered at half tide, stands squarely out 

 from the beach. Where examined near the shore these rocks are coarse 

 sandstones, cemented with iron and barren of fossils. The rocks ex- 

 posed in the cliff at Cabo Branco are chiefly sandstones. The lowest 

 ones are the same as the dark red sandstones exposed in the reef offshore ; 

 next above this the rock is purple, red, and gray mottled clay. This 

 clay ends a little more than 1 meter above high-tide level. Overlying 



Figure 4.— General View of Tertiary Sandstone Reef. 



the clay is a 5-meter bed of orange colored sands, false-bedded, with 

 lumps and streaks of white kaolin splotching its exposed surface. This 

 bed merges above into red and gray mottled sands and buff sands and 

 loam at the top of the exposed face of the bluff. No fossils were found 

 in any of these beds. 



The top of the hill at Cabo Branco is about 20 meters above high tide. 

 This point of land is the ocean ward or eastern end of the plateau on 

 which the city of Parahyba is built. The Cabo Branco hills continue 

 as an unbroken bluff from 30 to 50 meters high in a northwesterly direc- 

 tion to that city, while the peninsula ending at Cabedello at the mouth 

 of the Rio Parahyba do Norte is a flat sandy plain lying north of this 

 bluff. As the beds exposed at Cabo Branco contain no fossils, it is im- 

 possible to say whether they are Tertiary or Cretaceous, but the strati- 



VIII— Bull. Geol. Soc. Am.. Vol. 13, 1901 



