Volume 19 Number 1 
BULLETIN 
of the 
AMERICAN ASSOCIATION OF 
PETROLEUM GEOLOGISTS 
JANUARY, 1935 

INFLUENCE OF GEOLOGICAL FACTORS 
ON LONGITUDINAL SEISMIC VELOCITIES! 
B. B. WEATHERBY? anp L. Y. FAUST? 
Tulsa, Oklahoma 
ABSTRACT 
An examination has been made of velocity data obtained from fifty wells located 
in eight states. There is definite evidence to show that the velocity of shale and sand- 
stone sections increases with the geologic age of the beds. Less reliable evidence points 
to a similar relationship for limestone velocities. 
The velocity of calcareous sandstones and shales is substantially higher than that 
of a norma] sand-shale section. 
The effect of depth on the velocity of a given section is investigated. There is a 
definite increase in velocity with depth in the case of shale and sand sections. 
Increase of velocity with age is ascribed to the general increase of the lithification 
of sediments with age. 
INTRODUCTION 
The idea that the longitudinal seismic velocity of sediments in- 
creases with the age of the sediments has been held rather generally 
for some time. It was to discover quantitatively what relationship 
existed that the writers have made an analysis of the velocity meas- 
urements available to them in the files of the Geophysical Research 
Corporation. The data used comprise velocity measurements of 
good quality taken in fifty wells selected from a total of seventy 
well velocities available. These wells are located in Mississippi, 
Louisiana, Texas, New Mexico, Oklahoma, Kansas, Colorado, and 
Pennsylvania. 
1 Read in preliminary form before the Geophysics Division of the Association at 
the Dallas meeting, March 24, 1934. 
* Geophysical Research Corporation. The writers express their thanks to John L. 
Ferguson, of the Amerada Petroleum Corporation, for his aid in supplying geologic data. 
I 
661. 
