BULLETIN OF THE AMERICAN ASSOCIATION OF PETROLEUM GEOLOGISTS 
VOL. 18, NO. 1 (JANUARY, 1934), PP. 3-12 
RELATIONS OF GEOPHYSICS TO GEOLOGY! 
PAUL WEAVER? 
Houston, Texas 
ABSTRACT 
The present aim of geophysical methods is to construct subsurface contour maps. 
Three principal methods, viz., measurement of gravity, of magnetic field, and of elec- 
tric field, are forms of measurement of a potential function, and consequently have in- 
herent limitations for construction of contour maps. 
Another principal geophysical method is the seismic, which does not measure a 
potential function, and is inherently suitable for constructing contour maps. 
Both types of methods have difficulties in constructing contours due to variations 
in physical character of rocks. Suggestions are made for codperation of geology and geo- 
physics to minimize these difficulties. 
If we study current scientific literature, we observe that new 
phenomena are being discovered in all branches of physics by precise 
measurements aided by mathematical analyses, and that the tools and 
technique for applying these discoveries to commercial processes are 
being evolved at the greatest speed in history. Geophysics has kept 
pace in this general development of physics and attempts are being 
made to increase its applications to commercial processes in all direc- 
tions. It is the purpose of this discussion to survey the commercial 
application of geophysics to the oil development problems and espe- 
cially its relation to the similarly expanding efforts in geology. 
In this rapid development of science, it is always necessary to 
examine critically each new process to be sure that it has a place in 
commercial work. Some of our advances are not yet necessary for the 
present state of commercial operation. We may illustrate in the follow- 
ing manner. 
More than nine-tenths of the people in the world to-day probably 
think that the sun rises every morning in the east and sets every 
evening in the west. This interpretation of what they see is sufficient 
for their actions, and they need no other in their daily chores undess 
they be seafaring people who steer their own boat; in such a case they 
can determine their position at sea best by studying astronomy and 
learning that the earth moves, not the sun. Similarly, the average man 
in oil (including the geologist) will not learn the later developments in 
1 Read before the Association at the Houston meeting, March 24, 1933. Manuscript 
received, November 4, 1933. Presidential address, Society of Petroleum Geophysicists. 
? Gulf Production Company. 
Si ae 525 
