Branner — Geology of the Hawaiian Islands. 309 



see 110 reason why they may not have been deposited on land, 

 for in structure and contents they are similar to the other 

 cinder cones on this and other islands of the Hawaiian group. 

 Cirques. — On the sides of Diamond Head near the top are 

 many small cirques that throw light upon the origin of these 

 topographic forms. The beds of tuff at the rim of the crater 

 dipping outward, erosion has cut deep funnel-shaped pits — 

 small cirques — in the outside of the crater. The back walls of 

 these pits are very steep, even vertical or overhanging in the 

 middle. In the development of these cirques or barriers 

 separating two of them disappear and the cirques unite at the 

 top but are separated below by symmetrical cones that form 

 the spurs or ridges that radiate from the main mountain. 

 Such cones are beautifully developed on the east face of 

 Diamond Head. I have tried in vain to represent the cirques 

 of Diamond Head by a diagram. The figure accompanying 

 shows their relation to the edge of the crater on the right. 



Section tliroiigh a cirque on the outer rim of a crater. 



On the island of Hawaii are several cirques of enormous 

 size. The one shown on the next page and made from 

 a photograph has walls said to be more than a thousand 

 feet high. The upper ends of several of the deep valleys of 

 northern Hawaii appear to have been cirques originally. It 

 should be noted that the rocks both of Hawaii and of Diamond 

 Head on Oahu in which the cirques are cut are of even texture 

 throughout, and that they spall off rapidly in small angular 

 lumps. Those who believe in the glacial origin of cirques iind 

 here good evidence that cirques both large and small may be 

 and are formed without the aid of ice. 



The craters near the Pali. — Dana mentions (Volcanoes, 

 2d ed.) the small crater at Pali as probably the last expiring 

 effort of the volcanic phenomena of the island of Oaliu. Mr. 

 S. E. Bishop in his interesting paper upon the geology of Oahu, 

 23ublished in the Hawaiian Annual for 1901, also speaks of this 

 crater. It occupies a striking position in relation to the topog- 

 raphy of the island. The structural relation of its tuffs are shown 

 by the accompanying sketch (fig. 7). It is clear that this crater 



