365 SOBOLEV 



when in 1937, having analyzed some petrographic samples col- 

 lected by N. N. Urvantsev from the Taimir Peninsula, he suc- 

 ceeded in finding a unique basic rock resembling the ultrabasic 

 type. He concluded that this rock may be an analog of the South 

 African basic formations (melitite basalts) which accompany 

 the kimberlites. He also advanced the hypothesis concerning 

 the diamond-bearing potential of the northern Siberian plateau. 

 This hypothesis was confirmed first through the study conduct- 

 ed jointly with A. P. Burov of the geology of diamond deposits 

 in foreign countries, and by the discovery of extensive areas of 

 basic vulcanic rocks in Khatangi District. Rock samples from 

 this district were collected by members of the Arctic Institute 

 Expedition and tested by G. G. Moor in consultation with Sobo- 

 lev, whereupon Moor confirmed the hypothesis on the occurrence 

 of diamonds. In his report for 1940 to Gosplan S.S.S.R. (State 

 Planning Committee of the U.S.S.R. Council of Ministers) he 

 wrote: "The Siberian plateau has the greatest coincidence with 

 the kimberlite deposits of South Africa. This coincidence is 

 amplified even more by the discovery by the author, on the 

 Taymir Peninsula, and by G. G. Moor (in consultation with the 

 author) in the Khatangi River area, of basic rocks of the lim- 

 burgite, augite, and alnoite type, resembling the South African 

 melitite basalts which accompany kimberlites. Each expedition 

 operating in the northern Siberian plateau should give serious 

 attention to prospecting for diamonds. It is especially im- 

 portant to diamond prospecting in the active placers of precious 

 metals in the Norilsk area and in Vilyuy." Thus, V. S. Sobolev 

 predicted the location of diamond kimberlites not only in the 

 northern Siberian plateau generally, but also in the Vilyuy area 

 in particular. 



After the discovery .of kimberlites, Sobolev was invited to 

 take part in the expedition. He paid visits to diamond deposits 

 (1955), advised in petrographic and mineralogical analysis of 

 the materials, and jointly with A. ^P. Burov served as the scien- 

 tific editor of the first book on diamonds in Siberia. 



Of Vladimir Stepanovich's writings on the petrography of the 

 Ukrainian S.S.R.,one must mention first of all the monograph 

 on the petrology of the complex Korosten pluton which he feels 

 to have a direct connection with the petrology of traprock for- 

 mations. In this book the author once again stresses the im- 

 portance of the study of femic minerals of magmatic rocks. He 

 distinguishes the most important differences between the plateau 

 type of granites and those of folded areas, which are the result 

 of varying ferruginosity in femic minerals. He was the first to 



