360 
PACIFIC SCIENCE, VoL XIX, July 1965 
Fig. 1. Bouguer anomaly map of the island of Nii- 
hau, Hawaii. 
West of the Hawaiian ridge it is possible that 
these lineaments have been covered by sedi- 
ments; magnetic anomalies (U. S. Navy Ocean- 
ographic Office, 1962) suggest that they do 
exist, as geophysical expressions if not topo- 
graphic ones. 
Bathymetric data, as well as geomagnetic data 
from sea-borne surveys demonstrate a remark- 
able linear pattern of folding or faulting which 
seems to be a fundamental characteristic of 
the floor of the Pacific Ocean. This pattern is 
clear in the northeastern Pacific, but is con- 
fused elsewhere by the growth of volcanic 
chains. In the area of the Hawaiian Islands a 
line of growing volcanoes is covering the pre- 
existing ocean floor with its eroded and ex- 
truded products. The Kaula-Niihau-west Kauai 
volcanic group, although associated structurally, 
chemically, and generically with the younger 
volcanoes to the southeast, seems — by virtue of 
its strike — to be controlled by the confluence 
of recent tectonism with earlier structure. 
REFERENCES 
Hawaii Institute of Geophysics. 1965. 
Data from gravity surveys over the Hawaiian 
Archipelago and other Pacific islands. Hawaii 
Inst. Geoph. Rept. 65-4, March 1965. 10 
tables. 
Kinoshita, W. T., H. L. Krivoy, D. R. 
Mabey, and R. R. MacDonald. 1963. Grav- 
ity survey of the Island of Hawaii. In: Short 
papers in hydrology and geology. U. S. Geol. 
Survey Prof. Paper 475-C: Cl 14-016. 
Macdonald, G. A. 1947. Petrography of Nii- 
hau. Hawaii Div. Hydrography Bull. 12(2): 
39-51. 
Stearns, H. T. 1946. Geology of the Hawaiian 
Islands. Hawaii Div. Hydrography Bull. 8, 
106 pp. 
1947. Geology and ground- water re- 
sources of the Island of Niihau, Hawaii. Ha- 
waii Div. Hydrography Bull. 12:1-38. 
U. S. Navy Hydrographic Office. 1961. 
Sheet BC1604N. 
U. S. Naval Oceanographic Office. Geo- 
magnetics Branch, Marine Surveys Division. 
1962. A marine magnetic survey south of 
the Hawaiian Islands. Tech. Rept. 137. 
