271 OBRUCHEV 



Obreimov proposed and developed a method for determining 

 dispersion which can be applied to a study of crystals under- 

 going chemical reactions and to control of fractionation of mix- 

 tures. 



In 1960 Obreimov was awarded the S. I. Vavilov Gold Medal. 

 Bibliography: 



and T. N. Shkurina. Identification of hydrocarbons by a dis- 

 persion curve. Proc. Acad. Sci. U.S.S.R., Sect. Chem., 



1955, #5. 



Formation of ultramicroscopic heterogeneities during plas- 

 tic deformation of rock salt. Doklady Akad. Nauk S.S.S.R., 



1956, 108, #3. 



Office: Leningrad Physico-Technical Institute of USSR 



Academy of Sciences 

 Sosnovka 2 

 Lesnoy, Leningrad, USSR 



OBRUCHEV, SERGEI VLADIMIROVICH (Geologist) 



S. V. Obruchev was born February 3, 1891. He is the son of 

 the Russian geologist V. A. Obruchev, 1863-1956. S. V. Obru- 

 chev graduated from Moscow University in 1915. While con- 

 ducting geological studies of the Yenisei basin from 1917 to 

 1924, he delineated and described the Tungusskii coal basin. 

 He was awarded a Stalin Prize in 1946, and became a Corre- 

 sponding Member of the U.S.S.R. Academy of Sciences in 1953. 

 In 1926-35 Obruchev studied the practically unknown regions 

 of Northeastern U.S.S.R., the river basins of Indigirka and 

 Kolyma, Chukotskii region. He developed schemes of ore de- 

 scription, geomorphology and geological structure of Northeast- 

 ern Asia. He proposed uniting the mountain structures of the 

 middle of Indigirka River and Kolyma under the name of Cher- 

 skii Ridge. In 1937-54 he studied the ridge of Eastern Sayan, 

 Khamar-Daban and Eastern Tuva. He also did research on the 

 geology and geomorphology of other regions of the U.S.S.R. He 

 is the author of a series of scientific -popular books (Unknown 

 Mountains of Yakutiya, 1928; On the Persei Through Polar 

 Seas, 1929; Kolyma Land, 1933; A Plane in Eastern Arctic, 

 1934; Into Unexplored Territories, 1954.) He compiled a Hand- 

 book of a Traveler and Student of Local Lore (2 volumes, 1949- 

 1950). 

 Bibliography: 



Tungusskii basin (South and Western part), I -II, Works of 

 the All- Union Geological Prospecting Society of the People's 



