L earning Objective 18b

18.b. Be able to describe the major events of formation and weathering which have taken place on the island of Maui.

I. GENERAL FEATURES.
A. The present day island of Maui is actually part of a more massive volcanic structure composed of six major volcanic masses.

B. Maui Nui, as this structure is called, is made of four existing islands, Maui, Lana'i, Kaho'olawe and Moloka'i. In the recent geologic past during lower sea levels, these islands would be united into a single structure. Now they are separated by shallow seas.

C. The broad plain connecting the two volcanoes of West and East Maui formed when new flows from the younger Haleakala volcano backed up against the older West Maui volcano. This is much like the Leilehua plains connecting the two mountain ranges of O'ahu.

II. TWO MAJOR PARTS OF MAUI correspond to the two vents of the hot spot.
A. West Maui:
1. West Maui is the older part of the island. Its volcano may be extinct. Its highest point is Pu'u Kukui, about 5,700 feet (1,736 m.), and it is usually shrouded by heavy clouds.

2. Iao Valley's sheer cliff boundaries nearly coincide with the former boundary of the main caldera. Lavas which once filled the caldera are now primarily gouged out by stream erosion.

B. East Maui:
1. East Maui's Haleakala's volcano has erupted as recently as 200 years ago. It is considered dormant. Its crater is about 7 miles long, 2 miles wide and 1/2 mile deep.

2. The magnificent crater is primarily erosional in nature. It is formed by the expanded heads of two valleys resulting in a single large depression. After a very deep erosional basin was formed, renewed volcanic activity flooded it with lava flows and cinder cones.

3. Erosion has been uneven in the crater, with more rapid erosion on the rainy northern and eastern side of Haleakala.

Click here to leave your comments and suggestions.

Learning Objectives
[1 ] [2 ] [3 ] [4 ] [5 ] [6 ] [7 ] [8 ] [9 ] [10 ]
[11 ] [12 ] [13 ] [14 ] [15 ] [16 ] [17 ] [18 ] [19 ] [20 ]
[21 ] [22 ] [23 ] [24 ] [25 ] [26 ] [27 ] [28 ] [29 ] [30 ]
[Learning Objectives Numerical Index]
[Learning Objectives Descriptive Index]
[Main Menu]