FRESH-WATER SPRINGS IN THE OCEAN. 



6/5 



who were crowded forward so furiously that they were precipitated 

 down this pali of a thousand feet, where their bones could be seen till 

 quite recently. This pali is one of the most interesting sights visited 

 by modern tourists. 



The Pliocene Tertiary. 



These are quite extensive plains near the sea level composed partly 

 of sediments derived from the decay of the basalts and other igneous 

 products, and partly of calcareous marine deposits. "Without attempt- 

 ing precision of delimitation, our map presents an approximate contour 

 line of 500 feet altitude, which may represent the upper border of the 

 terrane, which is clearly proved by its fossils to belong to the Pliocene 



Fig. 2. Erosion on the Waianae side of kaala. 



Tertiary.* This band has a very variable width, dependent upon the 

 amount of subaerial erosion, being the most extensive in valleys like 

 those of Waianae and Waimanalo and in the more open area between 

 the two mountain ranges. It is upon these plains that several large 

 sugar plantations have been installed, for whose benefit numerous 

 artesian wells have been sunk. In the southern part of Oahu there 

 is a continuous belt of cane-fields eighteen miles in length, and averag- 

 ing two in breadth to the west of the city of Honolulu. Others are near 

 Waianae and Waialua. 



The sugar plantations were at first located upon other islands 

 of the group, as on Kauai, Hawaii and Maui, where plenty of streams 

 of water afford plentiful supplies for moistening the soil, or to trans- 



*W. H. Dall, Bulletin Geol. Soo. America, Vol. XI., p. 57. 



