THE LOOP METHOD IN EXPLORING BURIED STRUCTURES 245 



is a funnel-shaped depression filled with volcanic deposits interstratified 

 with marine sediments ^^K All three folds are represented in the form of 

 periclines, surrounding a large depression, in which many deposits of the 

 Kerch peninsula are found. By means of the geological survey and the loop 

 method, hinges were traced for a number of anticlines of the Zaparpach- 

 skian part of the peninsula <^^)' ^^^K 



Interesting work was carried out by the loop method in connection with 

 electrical profiling on the Borzovskaia area. This work showed the course 

 of the structure and established the lines of faulting, which conditioned 

 subsequent exploratory drilling. 



The work carried out on the neighboring area mapped the Glazovskaia 

 structure and established its connection with the Western periclinal closure 

 of the Mayakskaia structure (^^). 



On the Glazovskaia structure its asymmetry w'as confirmed (wide and 

 gentle southern liml) and a steep northern) and the zone crumpling was 

 shown on the northern limb near the hinge. The latter is apparently the 

 consequence of mud volcanism and diapiric processes ^^K 



The most effective was the work with the loop method in the flat south- 

 western part of the Kerch peninsula, made up of homogeneous muddy 

 Maikop formation. The lithologically homogeneous sections, devoid of distinct 

 marker horizons and the poor exposure of autochthonous rocks considerably 

 hindered the geological survey of this region and the tectonics of the plain 

 were known only in a very general form ^^\ and only a few anticlines were 

 traced in this area. 



With the loop method in a short period (4 field seasons) on the territory 

 of the south-western plain, 24 structures were mapped of which 6 [Yuzhno- 

 Andreevskaia, (Karachskaia) Zhuralevskaia (Chaltemirskaia), Kol-Alchins- 

 kaia, Ul'yanovskaia (Mangutskaia) Yuzhno-Marfovskaia and Mar'inskaia] 

 were demonstrated by this type of investigation. Furthermore there were 

 considerable corrections for the majority of the other structures (^^^ 



According to geophysical data, the Moshkarevskaia (Kerleutskaia) structure 

 is a small fold in the southern part of the western depression of the large 

 Shirokovskaia (Uzun-Ayakskaia) structure, whereas, according to geological 

 ideas, its axis continues further to the east ^^^K The Shirokovskaia struc- 

 ture owing to the axial variation of plunge is subdivided into 3 culmi- 

 nations. Furthermore, it is genetically connected with the Kuibyshevskaia 

 fold, which complicates its northern limb. As well as the convergence of the 

 Moshkarevsk and Shirokovsk anticlines, which localizes the petroleum de- 

 posit, other similar convergences of the Zhuravlevskaia (Chaltemirskaia) and 

 Seleznevskaia (Mamatskaia), on one hand and of Ul'yanovskaia (Mangu- 



