HAWAII NATIONAL PARK
HALEAKALA SECTION

[High-resolution Map]

NUMBERED POINTS 1. PARK ENTRANCE; SILVERSWORD INN 2. HOSMER GROVE CAMPGROUND AND PICNIC AREA 3. ADMINISTRATION BUILDING, HAWAII NATIONAL PARK, HALEAKALA SECTION 4. KALAHAKU OVERLOOK; SILVERSWORD PLANTS 5. OBSERVATORY 6. WHITE HILL, START OF SLIDING SANDS TRAIL 7. RED HILL; SUMMIT OF HALEAKALA 8. SKYLINE DRIVE 9. START OF HALEMAUU TRAIL 10. HOLUA CABIN 11. SILVERSWORD LOOP 12. ANCIENT HAWAIIAN TRAIL 13. BOTTOMLESS PIT 14. KA MOA O PELE TRAIL 15. BUBBLE CAVE 16. WAIKAU CABIN 17. VOLCANIC DIKES; ANCIENT DIVIDE BETWEEN KOOLAU AND KAUPO RIVER VALLEYS 18. LAUULU TRAIL 19. PALIKU CABIN 20. KIPAHULU VALLEY 21. KAUPO TRAIL KIPAHULU FOREST RESERVE KOOLAU FOREST RESERVE HALEAKALA RANCH

THE GEOLOGICAL INTERPRETATION

The summit depression of Haleakala stimulates speculation, and competent geologists have come up with widely differing hypotheses regarding its origin. In the account of their visit (see The Historical Background, [p. 29]), the first foreign visitors naturally used the term “crater,” which has been in vogue ever since. Pickering and Drayton of the Wilkes Expedition remark, “The crater of Haleakala, if so it may be called, is a deep gorge.”[10]

Drayton’s sketch was the first published map of the crater. James Dana, the great geologist with the Expedition, sailed past the mountain and later wrote a physiographic description based on notes made by Pickering and Drayton. In the official report, he expressed the idea, suggested by the crude map, that the mountain has been ripped apart by mighty convulsions that attended the most recent activity, so that the northeastern (Hana) part was separated along a zigzag crack from the rest of the mountain by the width of Keanae and Kaupo Valleys.[11] During the great eruptions that attended the rending, lava covered the floor and poured in great floods through Koolau and Kaupo Gaps.

W. D. Alexander, who surveyed the crater in 1869, believed: “... this is a real terminal crater, and not merely ‘a deep gorge open at the north and east’ or a caldera. I have indeed heard the theory proposed that the mountain is but a wreck of a complete dome with a small terminal crater, the whole top of which has fallen in and been carried away, as is supposed to have been the case with some of the volcanoes of Java, and the caldera of Palma.”[12]

C. E. Dutton, volcanologist of the United States Geological Survey, objected to Dana’s explanation and wrote that the depression is “strictly homologous” to Kilauea Crater, that is, a collapsed caldera.[13] He assumed that this had been tapped by the upper ends of Keanae and Kaupo drainages. In 1887, Dana had opportunity to make a quick trip through the crater and down Kaupo Valley, so that he tempered his earlier opinion and decided that Keanae and Kaupo valleys might be graben.[14] Reginald Daly of Harvard rejected the hypothesis that the depression was like Kilauea Crater, since arcuate faults so prominent at Kilauea are apparently absent at Haleakala.[15] In his paper on petrography, Whitman Cross stated, “What is commonly called the crater of Haleakala appears to me to be, in some part at least, a result of erosion.”[16] At about the same time, Sidney Powers stated his belief that Kipahulu and Waihoi Valleys are graben, but he based his opinion on “authentic reports” and does not claim that he saw the valleys.[17]

Ahinahina (silversword).