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PACIFIC SCIENCE, Vol XIX, July 1965 
Vacquier (1962) has proposed that such an 
assumption be used in determining the direc- 
tion and intensity of magnetization of sea- 
mounts by constructing a model from the 
bathymetry and computing the direction and 
intensity of magnetization which gives the best 
lit to the observed magnetic field. However, if 
tne primary source of the magnetic field ob- 
served over a seamount is an Intrusive body 
associated with the seamount, such a procedure 
could yield quite erroneous results. Evidence 
for such a situation has been reported for at 
least one seamount in the South Atlantic (Had- 
ley, 1964). Computations by the authors (un- 
published) show that several seamounts to the 
west of the Hawaiian Islands have dipole anom- 
alies associated with them which cannot be ex- 
plained by a constant direction and intensity of 
magnetization of the entire seamount with its 
low dipping slopes. 
A second point brought out by the present 
study in connection with interpretation of the 
magnetic field of submarine volcanic features is 
this: if highly magnetic intrusive rock is pres- 
ent, age dates or magnetic measurements made 
on dredged or cored flow material need not 
necessarily be related to the direction of rem- 
nant magnetization obtained from measure- 
ments of the magnetic field as obtained on a 
shipboard or airborne magnetic survey. 
ACKNOWLEDGMENTS 
The aeromagnetic surveys on which this work 
was based were carried out under NSF Grant 
No. gp 2256. The authors would like to ac- 
knowledge the assistance of Mr. Kenneth Culler, 
who piloted the plane, and Dr. G. P. Woollard, 
without whom the survey would not have been 
possible. 
REFERENCES 
Cox, A., R. R. Doell, and G. B. Dalrymple. 
1964. Reversals of the earth’s magnetic field. 
Science 144:1538-1543. 
Doell, R. R., and A. Cox. 1963. The accuracy 
of the paleomagnetic method as evaluated 
from historic Hawaiian lava flows. J. Geoph. 
Res. 68 (7): 1997-2009. 
Hadley, Marion L. 1964. A geomagnetic study 
of Vema Seamount, Trans. Am. Geoph. Un- 
ion 45 (4) : 62 1. 
McDougall, I., and D. H. Tarling. 1963. 
Dating of the polarity zones in the Hawaiian 
Islands. Nature 200:54-56. 
Tarling, D. H. 1963. Unpublished Ph.D. the- 
sis, Australian National University. 
Vacquier, V. 1962. A machine method for 
computing the magnitude and direction of 
magnetization of a uniformly magnetized 
body from its shape and magnetic survey. 
Proceedings of the Benedum Earth Magnet- 
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