Littoral Sedimentary Processes — I nman, Gayman and Cox 
107 
Fig. 1. Index chart and exposure to waves and winds. Heavy arrows indicate directions of approach of the 
five major wave types which affect the island. 
mea River, which drains the major canyon on 
the island and is in an area of relatively light 
rainfall. The most typical of the lee beaches in- 
vestigated lay along the shores of the Mana 
Coastal Plain. 
During the study, it was observed that beach 
and dune rock is especially well developed along 
portions of the Kauai coast. This was the sub- 
ject of a special investigation by Emery and 
Cox (1956). Some additional observations are 
discussed under the section on sediments. 
PHYSIOGRAPHY 
Kauai is one of a chain of volcanic islands in 
the Hawaiian Archipelago. It formed as a shield 
volcano built up from the deep floor of the Pa- 
cific Ocean by thin flows of basaltic lava. The 
original shield collapsed to form a broad cal- 
dera, which subsequently filled with thicker lava 
flows and talus deposits. The caldera is now al- 
most obscured by faulting, extensive erosion, 
and stream cutting. Ninety % of the flows are 
composed of normal olivine basalt, while the 
remaining rock is a basalt either very rich (pic- 
rite-basalt) or very poor in olivine. A compre- 
hensive and up-to-date review of the geology of 
Kauai is given by Macdonald, Davis, and Cox 
(I960). 
The ocean floor around Kauai is characterized 
by a number of sloping terraces which are ter- 
minated on their seaward side by a marked in- 
crease in slope. Although the depths of the 
breaks in slopes at the outer edges of the ter- 
