BRANNER: THE STONE REEFS OF BRAZIL. 107 



There are excellent illustrations of such spits and barrier islands along 

 the coast of :N"ew Jersey. Island Beach is twenty miles long from Bay 

 Head to Barnegat Inlet, and is almost perfectly straight. Between this 

 bar and the shore is a broad sound, Barnegat Bay, which will eventually 

 silt up if the encroachment of the sea does not cut the beach away.^ 



Long Beach, from Barnegat City to Great Bay, is twenty-two miles 

 long, nearly straight, and is nowhere naturally connected with the main- 

 land. The beach at Atlantic City, New Jersey, is nine miles long, with 

 a marsh from three to six miles wide between it and the mainland.^ 



Sandy Hook, at the entrance of New York harbor, is now a spit 

 thirteen miles long, measured from Long Branch to the point of the 

 hook. Professor Cook points out that the spit formerly » joined the 

 Navesink Highlands, while the Navesink River entered the Atlantic 

 south of the highlands. Within recent times the beach has been thrown 

 up outside and half a mile away, and the spit has been made into a 

 continuous beach from Sandy Hook to Long Branch.* 



Similar barrier beaches border the coasts of North Carolina, Texas, 

 Mexico, Yucatan, and Rio Grande do Sul in Brazil ; in the same cate- 

 gory belong the lidi, or long bars, about the mouth of the Po ; others 

 about the mouths of the Nile and the Rhone ; the Hafifs of the south 

 shores of the Baltic Sea ; the spits of the Sea of Azov ; the long bars off 

 Lake Chilka, on the east coast of Hindostan, etc. In many instances 

 these beaches are phases of the seaward extension of deltas ; that is, the 

 materials have been brought down from the land by the streams behind 

 them. Many such beaches have lakes shut in behind them. 



Another convenient illustration in Brazil itself is the low beach be- 

 tween Cape Frio and Itaipu peak near Rio de Janeiro. Here the low, 

 flat, sandy beach lies in front of a series of lakes shut in between the sea 

 and the lofty mountains north of them. 



The rate of growth of a beach-line depends partly upon the frequency 

 and force of storms along the coast, partly upon the nature of the rocks 

 of the shores, partly upon the slope of the land, and hence upon the rate 

 of stream cutting, and partly upon off-shore submarine topography. 



Application to the Brazilian stone ?-ee/s. — The straightness of the 

 Brazilian reefs shows that they are the remains cither of off-shore (or 



1 Vicinity of Barnegat Bay. Atlas sheet 13. Geol. Surv. of N. J., 1889. 



2 Topographic map of Egg Harbor and vicinity. Atlas Sheet 16.' Geol Surv ' 

 of N. J., 1889. 



3 Sandy Hook topographic sheet. U. S. Geol. Survey. 

 * Ann. Rep. State Geologist of N. J., 1885, p. 77-78. 



