948 



EXPLORATION GEOPHYSICS 



Weight dry sample 



Weight, in grams, of original sample used in analysis 

 corrected for moisture content which is determined 

 with a separate portion of the original sample. 



Results of Hydrocarbon Soil Surveys.- — ^The reported results of 

 several surveys are in apparent disagreement with the observations of 

 Laubmeyer and Sokoloff. Instead of a distribution pattern in which the 



ETHANE 



• ♦ WELLS DRILLED BEFORE SURVEV 

 • (|> WELLS DRILLED AFTER SURVEY 



SCALE 



^ 4 



5000 FEET 



Fig. 583. — Soil analysis for ethane and propane. Station interval 

 is 500 feet. (Horvitz, Geophysics, Vol. 10, No. 4.) 



higher concentrations of hydrocarbons occur in the soils over the center 

 of the productive areas, it was found that the higher concentrations are 

 present in shallow soils around the edges of the productive areas producing 

 the so-called "halo" pattern. 



Upon re-examination of the reports of the Russian investigators, it 

 was found that their data, in several instances, also indicated high concen- 



