THE GEOLOGY OF ARCTIC EURASIA AND 

 ITS UNSOLVED PROBLEMS^ 



I. P. Tolmachev 



The Present Status of Knowledge 



Arctic Eurasia is one of the least-known parts of the earth's 

 surface whether we consider its geology or its topography. Large 

 sections of it have not been surveyed at all or in sketchy recon- 

 naissance only. Even the Arctic shore line cannot be considered well 

 established, especially in the Asiatic sector, where every new expedi- 

 tion makes important corrections upon the maps. Geologists have 

 been able to examine the rocks only at widely separated localities 

 and often under conditions which severely limited their observations. 

 Many geological data were gathered by explorers without geological 

 training or by uneducated hunters and traders. 



Unrelated and sometimes inexact data were often summarized and 

 interpreted by scientists unfamiliar with Arctic geology and infiu- 



1 On the general subject of this paper the reader may also wish to consult W. A. Obrutschew (V. A. 

 Obruchev): Geologic von Sibirien (in series: Fortschritte der Geologie und Palaeontologie, Vol. 15). 

 Berlin, 1926, with references to the literature. Certain aspects of Eurasian geology are discussed in 

 F. B. Taylor: Greater Asia and Isostasy, Amer. Journ. of Sci., Ser. s. Vol. 12, 1926, pp. 47-67, and 

 Emile Argand: La tectonique de I'Asie, Compte Rendu de la XIII^ Session du Congres Geol. Internatl. 

 en Belgique, IQ22, Vol. i, Liege, 1924, pp. 171-372. R. L. Samoilowitsch (Samoilovich) : Geologische 

 Aufgaben der Arktisforschung, in "Internatl. Studiengesell. zur Erforschung der Arktis mit dem Luft- 

 schiff: Verhandl. der i. ordentl. Versammlung in Berlin, 9.-13. Nov. 1926," Petermanns Mitt. Erg&n- 

 zungsheft No. igi, 1927, pp. 30-42, lays special emphasis on Eurasia. 



It should be explicitly stated, however, that the greater part of the data and conclusions of the 

 present paper is founded on the personal observations of the writer during his travels in northern Asia 

 and Europe, many of which observations have not yet been published. 



Of those that have been published the following may be mentioned, together with two papers by 

 others that deal with an expedition under the leadership of the writer: 



I. P. Tolmachev: (The additions to the geographical and geological map in the region visited by 

 the Khatanga Expedition in the year 1905), Petrograd, 1915. 



idem: Novyya dannyya po geografii Syevernoi Sibiri (New data on the geography of northern 

 Siberia), Izvyestiya Imp. Akad. Nauk, Ser. 6, Vol. 4, St. Petersburg, 1910, pp. 989-998. 



M. Kozhevnikov: Marshrutaya semka basseina ryeki Khatangi v 1905 godu (Route survey in the 

 basin of the Khatanga River in the year 1905), Zapiski Voenno-Topogr. Upravl. Glavn. Upravl. Generaln. 

 Shtaba, Vol. 64, St. Petersburg, 1910, pp. 77-100, with map in 1:4,200,000. 



Helge Backlund: Travaux et resultats de I'expedition de la Khatanga (1905). La Geographie, 

 Vol. 17, 1908, pp. 1 17-124, with map in 1:4,200,000. 



I. P. Tolmachev: (Along the Chukchi coast of the Arctic Sea: Preliminary report of the director 

 of the Expedition for the Exploration of the Coast of the Arctic Sea from the mouth of the Kolyma to 

 Bering Strait, organized in 1909 by the Merchant Marine Section of the Ministry of Commerce and 

 Industry), 117 pp., with map in 1:4,200,000, Ministry of Commerce and Industry, St. Petersburg, 1911. 



idem: Formy poverkhnosti i stroenie zemnoi kory v predyelakh Zapadnoi Sibiri (Surface con- 

 figuration and crustal structure within the limits of Western Siberia), Chapter i, pp. 1-86, of Vol. 16 

 of "Rossiya: Polnoe geograficheskoe opsisanie nashego otechestva" (Full geographical description of 

 our country), edit, by V. P. Semenov-Tyan Shanski, St. Petersburg, 1907. 



idem: Geologicheskoe stroenie (Geological structure). Pp. 104-120 of Vol. 2 of "Aziatskaya 

 Rossiya, " 3 text vols, and an atlas, Bureau of Internal Colonization of the Dept. of Land Organization 

 and Agric, St. Petersburg, 1914. — Edit. Note. 



75 



