A DISCUSSION OF "NOTES ON PRINCIPLES OF OIL 

 ACCUMULATION" BY A. W. McCOY^ 



CHESTER W. WASHBURNE 

 New York City 



In many ways this is one of the most interesting articles on 

 the accumulation of oil that has appeared. I have long held 

 many of the conclusions reached by Mr. McCoy in this paper, 

 and it is a great pleasure to find these ideas corroborated by his 

 experiments, which have been cleverly conceived and executed. 

 It is unnecessary to reiterate the good points of the paper. It 

 will be more useful to call attention to some of the more doubtful 

 conclusions, in the hope that further study by McCoy and others 

 may clarify these points. 



Origin of oil. — -The first experiment shows that liquid oil may 

 be formed by the deformation of oil shale which previous to de- 

 formation contained only solid organic materials. McCoy states 

 that "no appreciable amount of heat was developed." It seems 

 to me impossible to deform the steel cylinders and to crush and 

 shear the inclosed shale without causing an appreciable increase 

 in temperature. If the experiments had been carried out in 

 cylinders under water and if the temperature of the latter had 

 been measured after the completion of the experiment, I believe 

 McCoy would have found that there had been a material loss of 

 energy in the form of heat. Shale is notoriously a poor conductor 

 of heat. Therefore there must be a material rise in temperature 

 along every plane of shear. As stated by McCoy, differential 

 movement in shales probably is an important cause of the alteration 

 of solid organic matter into oils. However, it is probably heat 

 rather than pressure which causes this alteration. Heat is a com- 

 mon cause of the dissociation of various molecules. Pressure 



^Jour. Geol., XXVII (1919), 252-62. 



366 



