o^A 



C. X. GOULD CRYSTALLINE ROCKS OF THE PLAINS 



in northwestern Arkansas. Some of these wells, as, for instance, two in 

 the Cnshing field, are known to be on well-marked anticlines, which have 

 yielded large amounts of petroleum, while others occur where there is 

 little surface indication of structure and where no oil has been found. 



It must be remembered that out of several thousand wells drilled in 

 southeastern Kansas and northeastern Oklahoma onlv a verv few have 



K 



N 



s 



K I. A H M A^-\ 



TEX.A S 



M| Pn»-C«M6RiAN Crystal LINE 

 • Wells Reacmino Crvstauline Rocks 



Figure 3. — Location of buried Granite Ridpes in Kansas, Oldalioma, and Texas; also 

 Location of Wells icliicli have reached Granite 



jjassed entirely through the sedimentaries. The common interpretation 

 of the presence of granite in these wells is either that they were drilled 

 at a place where the granite basement was comparatively near the sur- 

 face, or that the well chanced to be located over a buried monadnock. 



I realize very keenly the tendency to derive conclusions from insuffi- 

 cient data, and to postulate buried ridges in likely regions. While it may 

 be a geometrical axiom that three points ip a row indicate a straight line. 



