NEW METHODS OF ELECTRICAL EXPLORATION IN SIBERIA 



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On the north-east section of the profile, the relationships of the right- 

 hand hranches of the two-way probe reflect the rise of the pre-Jurassic 

 rocks in a north-eastern direction (DZ-56, DZ-57). 



The results of the qualitative interpretation facilitate the selection of 

 parameters for subsequent quantitative calculations and improve their 

 reliability. 



Figure 5 gives a geoelectrical cross-section through the profile considered 

 above. As can be seen, the quantitative treatment agrees well with the qual- 

 itative impressions of the surface relief of the Paleozoic foinidation at the 



Fig. 5. Geoelectrical cross-section along AB profile. 1 — top surface of the Paleozoic 

 rocks according to data of layer processing of average curves of (juadrilateral and 



azimuthal probes. 



investigated section and, furthermore, indicate the structure of the sedi- 

 mentary succession. As well as the layer interpretation with the aid of the- 

 oretical graphs, the average KS curves were also processed by the method of 

 transformation into curves of axial i)robing<^). Fig. 6 compares the results 

 of the quantitative interpretation by botli methods along 40 km of the CD 

 profile. 



The second example refers to results of the application of two-way azimuthal 

 probes in 1956 at one of the sections of the Vagai-Ishim tectonic zone, where 

 the rocks of the pre-Jurassic foundation lie at depths greater than 1600 m. 

 The curves of the azimuthal probe clearly subdivide the geoelectrical cross- 

 section. They differentiate a thick succession of conducting friable deposits, 

 underlain by the highly resistant rocks which form the electrically reflecting 

 horizon. 



As shown above, the stratigraphic continuity of the high resistance, 

 electrical marker horizon is apparently not maintained in the zones 

 of development of effusively deposited rocks of the second structural 

 stage. At the present time, due to the absence of geological data, this problem 

 has been insufficiently studied. It can only be supposed that, depending 



