J. D. Dana — Geological History of Maui. 89 



somewhat toward its head, and in this upper part an extensive 

 plateau occupies the center. The torrent of the valley is here 

 divided between two tributaries, one running either side of the 

 plateau. The height and rather bold sides of the plateau at 

 the head of the valley, and its size and position, taken in con- 

 nection with its location near the center of the mountain range, 

 appear to make it pretty certain that the plateau represents 

 the floor, or rather what is left of the central area, of the great 

 crater. I looked for the edges of lava streams in the en- 

 closing walls in order to make out their pitch and the thickness 

 of the beds. But dense vegetation so covers everything that 

 distant views are of no geological value, and one day's excur- 

 sion was not sufficient for a climb of the heights. 



As to the former crater condition of the other two valleys 

 mentioned, I know nothing from personal observation. The 

 idea of their having been craters is based on the size, depth, 

 and boldness of the walls and the ampitheater-like head. But 

 these features are common results of denudation in old volcanic 

 islands, and therefore, in the question here considered I give 

 them little weight. 



3. The Eccentric form of the Maui Volcanoes. 



The map of Maui illustrates a Hawaiian feature of volcanic 

 mountains which may be common in other regions. The chief 

 crater of the mountain is not at its center. In Haleakala the 

 ratio of the radii east and west of the crater is 2:3; and in 

 West Maui, 8 : 11. The shorter radius is to the south-south- 

 east of the crater in one and to the southeast in the other. 



In Hawaii it is not easy to mark off the true base of Mt. 

 Loa. But we have the fact that in both the summit crater and 

 Kilauea, the form is oblong, and each has its intenser activity in 

 the more southern portion — the south-southwestern in one, and 

 the southwestern in the other. The effect is not due to the 

 to the winds, for the mountains consist almost solely of lava- 

 streams. 



4. Drift-made ridge of consolidated coral sand. 



The positions of the high ridge of consolidated coral sand of 

 Wailuku are indicated on the map. Whether proof of eleva- 

 tion or not is yet undecided. I was informed that the sands are 

 at the present time drifted by the trade-winds to the farther 

 inland limit of these ridges and over their surfaces — a fact 

 which seems to show that present conditions are sufficient for 

 their production. 



