22 E. E. ROSAIRE 
EAST TEXAS 
The area has been intensively explored by surface methods, re- 
fraction seismograph, the torsion balance, and the reflection seismo- 
graph.’ At present, even this last method yields only marginal pros- 
pects. The discovery of a new objective, such as production in the 
Trinity Sand series, can result only in a revival of deeper exploration 
by the reflection seismograph, for the results to date of all methods 
used in that area should now be listed as future library methods. 
CENTRAL OKLAHOMA 
The appropriate methods in the past have been surface methods, 
subsurface methods, and the reflection seismograph. The stage of 
prospect discovery by the reflection seismograph has been current for 
several years, and is drawing to a close, with the prospects for dis- 
covering new objectives rather poor. 
EASTERN OKLAHOMA 
WEST VIRGINIA 
OHIO-INDIANA 
ILLINOIS 
In all four of these provinces, the use of surface and subsurface 
methods is generally assumed to have practically exhausted the 
possibilities prior to the advent of geophysics. Although there is 
thought to be little hope of new objectives, still geophysical methods 
have not been intensively applied. 
CALIFORNIA 
Most of the existing known structures have, in general, been so 
highly folded that nearly all possibilities appear to have been ex- 
hausted prior to the introduction of geophysics. There exists, at pres- 
ent, an almost hysterical exploration activity, based on the use of the 
reflection seismograph to discover as well as to evaluate deep-seated 
prospects, with no great encouragement shown to date. Deeper ob- 
jectives are being discovered with almost monotonous regularity in the 
known fields, but these newly recognized horizons may be too deeply 
buried if future discoveries are not as highly folded as the known 
fields. Perhaps the discovery of the Bosco oil field in South Louisiana 
will prove to be the result of good strategy on the part of the Superior 
Oil Company of California. 
* 7 At least to the Georgetown Limestone. 
266 
