THE MAKALAPA AND TANTALUS SERIES 41 



there is an extensive cut in the tuff, showing 10 or 12 feet of the tuff in 

 a fresh condition. The lower part is fine grained, 8 feet thick, the upper 

 a coarse sandstone, almost a conglomerate, 2 feet thick, with 4 or 5 feet 

 thickness of sandy beds at the top. It is a palagonite, a tuff somewhat 

 altered by heat and moisture, with a distinct resinous luster. All the 

 tuff cones of this region are composed of this rock. 



MAKALAPA 



Between Puuloa and Halawa stations is a promontory of palagonite, 

 around which the railroad makes a long curve, but will shortly take a 

 new course cut through the rock. Coral limestone full of shells and 

 polyp structures rests on and is intercalated with the tuff along the rail- 

 road in both cuts to the height of 15 or 20 feet. The finest examples of 

 tree stems seen anywhere along the railroad appear in this cut. One of 

 the stems measured 15 feet in height, penetrating both the fine and 

 coarse tuffs. 



Climbing the bluff, there is an upward slope for half a mile to the crater 

 of Makalapa, perhaps 80 feet above tidewater. The pit is not seen till 

 you stand close to it — a very pretty basin, an eighth of a mile in diam- 

 eter, broken down on the southwest side. The tuff contains various 

 basalts, lavas, limestones, and corals of all sizes up to 41 feet in diameter 

 strewed on the surface like those figured near Salt lake. Some of the 

 limestone fragments have been affected by the heat so as to have become 

 partially fused. At the west end of the new railroad cut the soil crops 

 out beneath the tuff, evident^ continuous beneath both the Aliapakai 

 and Makalapa flows. The tuff thins out and disappears at Halawa 

 stream, but the soil increases in amount and merges into the layers al- 

 read}^ described at Aiea. It is noticeable that the strata are depressed 

 at every small valley traversed, presumably because of the removal of 

 the soil beneath by aqueous action. The eastern branch of Halawa val- 

 ley was cut off by Aliapakai, precise^ as was the w r estern branch of 

 Moanalua. The island Kuahua is also composed of tuff, 20 feet thick, 

 exposed. Evidently this was once continuous with the same material 

 upon the mainland. 



TANTALUS SERIES OF CRATERS 



A road with easy grades starts from both sides of Punchbowl, zigzags 

 up a long slope covered by eucalyptus trees planted under governmental 

 authority, and finally reaches the base of the volcanic cone called Tan- 

 talus by foreigners and Puu Ohia by, the Hawaiians, whose summit is 

 2,013 feet above the sea. The crater has a level top, over a quarter of a 

 mile in diameter, 400 feet high, with the breakdown on the southeast 



