A UNIVERSAL DIP CHART 
FOR USE WITH SEISMIC METHOD OF GEOPHYSICAL PROSPECTING 
(REFRACTIONS) 
O. C. LESTER, JR.* and S. W. WILCOX+ 
The purpose of this paper is to present and discuss a dip chart or 
family of curves, by means of which the dip of subsurface beds may 
be determined by inspections of the curves, after the apparent velocity 
has been determined from a refraction profile. The theory is based on 
the assumption of rectilinear propagation of sound waves, as discussed 
by D. C. Barton, C. A. Heiland and others in “Geophysical Prospecting— 
1929.” 
Assuming the dip equations as derived by Schweydar# as a starting 
point, we have: 
Schweydar Equations 15 and 17. “Geophysical Prospecting—1929”, C. A. 
Heiland. 

1 1 1 
= —— (Cos « — —— Vy 1—q’sin ) ## 15 
Vox V: q 
1 1 1 
(COs) Oe nV lg sini os) HHH IT 
Vo- V: q 

# Note: See Article on Seismic Prospecting, by C. A. Heiland, “Geo- 
physical Prospecting—1929.” Page 639. Equations 15 and 17. 
## Note: This equation (15) as given in the book is in error due to 
misprint. The term before the parenthesis should be 
1 1 
— rather than 
V. V>+ 

as given. 
##+# Note: Notation in book apparently reversed in equations 15 and 17 
as to direction of dip. 
*Geophysical Research Corporation, Los Angeles, Calif. 
{Seismograph Service Corporation, Tulsa, Okla.; formerly with Geo- 
physical Research Corporation. 
tAmerican Institute of Mining and Metallurgical Engineers. 
