276 



GRAVITATIONAL METHODS 



[Chap. 7 



Fig. 7-109 shows a small portion of this region between the oil fields of 

 Dossor and Iskin. At Dossor, where the depth to salt is of the order of 

 400 meters, the gravity anomaly is 31 milligals. Other domes in this area 

 produce anomalies of the order of 15 to 25 milligals. Since 1935, detail 



\ 





y 



/ /■ 









^.Mftf-Zk 



V -^ 



Fig. 7-106. Torsion balance results and geologic section, Liibthecn-Jcsscnitz salt 



dome (after Seblatnigg). 



work on the geophysically discovered domes has been under way with 

 torsion balance and reflection seismograph. 



In another salt dome country, Rumania, the torsion balance has like- 

 wise been very successful. The first measurements there were probably 

 made by W. Schweydar in 1918. Geophysical work of increasing scale 

 was then initiated by commercial companies. In 1928 the Geological 



