OKLAHOMA ACADEMY OF SCIENCE 83 



In this area there are two or tlirce drillers vv'ho are adepts in the 

 art of making well logs. One man in particular put at my disposal 

 the results of twenty-five years of experience as driller, contractor, 

 and producer in the area. Repeated tests showed that his logs were 

 quite as accurate as the average of the sections measured by a 

 geologist. In the rather large area over Avhich he had drilled, the 

 data which I have are adequate for almost any sort of subsurface 

 study that one could conceivably require. 



In spite of the large number of well logs available, some of them 

 vi unusually high quality, it was necessary, in order to understand 

 subsurface conditions, to give very close attention to all the avail- 

 able results of former field studies in and near the area. In the 

 Independence district these field studies have been unusually numer- 

 ous and valuable. Several of the bulletins of the Kansas Geological 

 Survey give much generally accurate information about the distribu- 

 tion and character of the formations which outcrop in and near the 

 district. The Independence Folio, by F. C. Schrader, is likewise very 

 well done. A rather intensive study of it, lasting several months, 

 showed that its main conclusions will probably stand for a long 

 time to come. 



In addition to the study of earlier field reports, which in this 

 case were much more abundant than many people think necessary for 

 the purpose of making a subsurface study, we found it advisable 

 to m.ake still further field studies. Some important correlations re- 

 mained uncertain until we had actually measured and described sev- 

 eral formations in the field. The moral is that for adequate interpre- 

 tation of subsurface conditions, one can hardly know enough about 

 the surface conditions. Conversely, the subsurface studies served 

 to clear up a number of points that the numerous excellent field 

 studies previously made had left uncertain. 



In attempting to get such an understanding of the Independence 

 district as would enable us to decide the very practical matter as to 

 the advisability of undertaking further operations there, it was 

 necessary to work out a good many separate problems. Some of 

 these were of a character that at first sight would seem eminently 

 unpractical. We put in much time and effort, for example, in study- 

 ing the exact thickness and character and variations of all the lime- 

 stones in different parts of the area. The limestones do not carry 

 much oil, it is true, but they are the markers. By correlating them 

 with the utmost possible accuracy we were able to save ourselves a 

 good many blunders we should otherwise have made in regard to the 

 relations of the various sands. 



It happens that the Independence district is located where many 



