590 F. G. CLAPP CLASSIFICATION OF PETROLEUM AND GAS FIELDS 



sive beds or laccoliths^ but figure 15 shows how the type is believed by 

 some to occur in Mexico, and undoubtedly exists in Cuba. The Furbero 

 field is reported by De Golyer*^'-^ to overlie and underlie an altered lacco- 



NoRTH ^=. 



PLA/M. 



t m'tlc = I Jpcb 



f^ARL5, CLAV5. 

 Qf)6 





A.and B. * Scopa^es. 

 C. = bike 



H: K. ' Line of ^ccfion 



CR055,5fCTlcy4 



vHrjr. Scale - i rn\U * i JocH. 

 l/frfico/ - ' ;oooff--/Iacb. 



Figure 14. — ^Pian and Cross-section of a Dike in Mexico 

 Showing occurrence of oil according to Subclass V (6) 



lith of gabbro in the Mendez shales, which are there baked and broken. 

 Thompson^° supposes that the structure of the field of the island of 

 Tcheleken, in the Caspian Sea, may be due to an underlying laccolith. 



'"'Econ. Geol., vol. 10, 1915, p. 653. 



^ojnstn. of Min. and Met, vol. 20, 1910-1911, p. 230, 



