_The Island of Maui_ was built by two volcanoes. That forming West Maui
is deeply dissected into several high peaks. The old summit crater now
is encompassed by the head of Iao Valley. Mt. Kukui, the highest point,
has an elevation of 5,788 feet.
East Maui is built of three series of lava products from Haleakala
Volcano whose flows extended westward across the present isthmus to come
to rest against the base of West Maui Volcano. These represent three
great periods of activity, the latter two being separated by a long
interval of quiescence that was characterized by intense erosion and
mild, if any, eruptions. Geologists designate these three periods by the
names Honomanu, Kula, and Hana. The mountain was built over three rifts,
northerly, easterly, and southwesterly, each extending about fifteen
miles.
In earliest (Honomanu) time, about the beginning of the Ice Ages, a
symmetrical shield like Mauna Loa was built of pahoehoe and aa basalts
8,500 feet above present sea-level. During the next (Kula) cycle,
eruptions were more explosive in nature; flows were composed of more
viscous andesite between which layers of ash and soil accumulated. Big
cinder cones and extensive ash beds were formed at this time. Like Mauna
Kea today, the Honomanu dome was capped by a craterless mound of
cinders, 2,500 feet high, that was studded with many lesser cones. The
summit was a mile east of the present top on Red Hill and a thousand
feet higher than it is today.
As Kula eruptions declined and grew less frequent, running water cut
deeply into the sides of the mountain and excavated four great valleys,
Keanae, Kaupo, Kipahulu, and Waihoi, that had broad heads, thousands of
feet deep. Numerous lesser valleys were later to be buried more or less
by lava flows. Most of the eastern summit ridge was worn away; Kaupo and
Keanae Valleys met near the summit and fused into a great depression
like that near the head of Iao Valley today. At one time, a great flow
of mud, probably triggered by an earthquake, swept all before it as it
moved down Kaupo Valley into the sea. Its remnants today are 350 feet
deep at Puu Maneoneo near the coastal road. A similar mass movement of
rock on soft mud was started by an earthquake on April 2, 1868 at Wood
Valley, west of the Kilauea Section of Hawaii National Park; the flow,
in its precipitous descent, buried a village with 31 people and more
than 500 head of stock.
In recent times, volcanism again quickened at Haleakala, giving the
third (Hana) series of volcanics. This veneered the east and west slopes
of the volcano, covered the floor of the depression, and pushed great
lava flows through Koolau and Kaupo Gaps to the sea. Large flows and
cones mask the divide that delimited the two great valleys. During Hana
time, the northern rift alone remained inactive. The most recent
activity, dated by Hawaiian legend as 1750, is represented by two bare,
black flows above La Perouse Bay, the southwest corner of the island.
[Illustration: The Recent Cinder Cones.]
Haleakala Crater, 7 miles long and 2½ miles wide, is locally proclaimed
the largest extinct crater on earth, but the claim like the name is
inaccurate. Nevertheless, it possesses a most unusual geological origin
and beauty that give it a worthy place among the National Parks.
[Illustration: HAWAII NATIONAL PARK
HALEAKALA SECTION]
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