246 
: 6 ; 
aes, > ‘ Dee 
DYNAMICAL GEOLOGY. —— [Boox II. _ 
Mauna Loa (Fig. 51), a flat lava-cone 13,760 feet above the sea, 
lies a crater, which in its deepest part is about 8000 feet broad, with 
Mauna Kea, 13,950 feet. 
Mauna Loa, 13,760 feet. 
Fic. 51.—PRoFILE oF Lava DOMES oF Hawalt. 
vertical walls of stratified lava rising on one side to a height 
of 784 feet above the black lava-plain of the crater-bottom. 
From the edges of this elevated cauldron the mountain 
slopes outward at an angle of not more than 6°, until at a 
level of about 10,000 feet lower, its surface is indented by 
the vast pit-crater, Kilauea, about two miles long, and 
nearly a mile broad. So low are the surrounding slopes 
that these vast craters have been compared to open quarries 
on a hill or moor. The bottom of Kilauea is a lava-plain, 
dotted with lakes of extremely fluid lava in constant ebulli- 
tion. The level of the lava has varied, for the walls sur- 
rounding the fiery flood consist of beds of similar lava, and 
are marked by ledges or platforms (Fig. 52), indicative of 
former successive heights of lava, as lake-terraces show 
former levels of water. In the accompanying section 

Fig. 52.—Puan or Lava-cavLpron, Kinavna, Hawa (Dana). 
(Fig. 53) the walls rising above the lower pit ') were 
found to be 342 feet high, those bounds fF ae 
terrace (0  n' o') were 650 feet high, all being composed 
of innumerable beds of lava, as in cliffs of stratified rocks. 

Much of the bottom of the lower lava-plain has been 
crusted over by the solidification of the molten rock, But 
large areas which shift their position from time to time 
remain in perpetual rapid ebullition. The glowing flood, as it boils 
:' 
Ellis, Polynesian Researches. 

