908 



MISCELLANEOUS GEOPHYSICAL METHODS 



[Chap. 12 



the surface because of the action of ascending mineralized^^ solutions along 

 minute fissures and cracks developed in the overlying formation by dif- 

 ferential settling over a fold or lenticular deposit. He points out that 

 surface formations above oil deposits are frequently indurated, due to 



WELLS DRY IN MAIN 

 PAr SAND BUT PBO- 

 OUCiNG FBOM DEEPER 

 UQfil.Zat<. 



SUB - SOIL 



EUREKA OIL FIELD 



HARRIS COUNTY, TEXAS 



SUBTERREX 



SOILANE FOR ETHANE + PROPANE 



ON PARTS PCR OILUtON B* WFJ6HT) 



4a*WCLLS COMPLCTtO aCPOPC ftOILAfC SURVEY 



^OOWCLLS COM>LCTC0 ATTER SCMlANC SURVCV 



WELLS DRY IN MAIN 

 PAY SAND BUT PRO- 

 DUCING FROM DEEPER 

 HORIZON 



TOP-SOIL 



FAULT FROM 



.Sitl5;SUPE4Qt^I4 



Fig. 12-15. Ethane and surface-wax halos in Eureka field (after Rosaire) 



silification and calcification, and that this has been verified by low drilling 

 rates ("dome digging"), high seismic refraction speeds, erroneous dips in 

 reflection shooting, and high resistivities mapped in Eltran surveys.^ 



"McDermott (A.A.P.G. Bull., 24[5], 859-881 [May, 1940]) assumes that the 

 mineral waters are carried upward by the gases escaping from oil deposits below. 

 6» P. 817. 



