SOKOLOV, DMITRY IVANOVICH

(b. St. Petersburg, Russia [now Leningrad. U.S.S.R.], 1788; d St. Petersburg, 1 December 1852)

geology.

Sokolov’s father, a locksmith,invented a machine for turning screws that was used in the fountains of St, Petersburg. After his death in 1796 Sokolov was sent to the preparatory class of the St. Petersburg Mining School, which was reorganized in 1804 as the Mining Cadet Corps and, in 1834, as the institute of the Corps of Mining Engineers (now the Leningrad Mining Institute). He remained associated with this institution throughout his life.

After graduating in 1805, Sokolov worked in the laboratory of the Mining Cadet Corps as assayer and then began lecturing, first in metallurgy and assaying and later in geognosy and mining. In 1813 he was appointed supervisor of the mineralogical laboratory and from 1818 was also in charge of the collection of models. He continued his chemical research following his appointment as director of the joint laboratory of the Mining Cadet Corps and the Department of Mining and Salt Works, In 1817 he participated in the creation of the Mineralogical Society in St. Petersburg.

In 1822 Sokolov became professor of geognosy and mineralogy at St. Petersburg University. where he taught for more than twenty years while serving at the Mining Cadet Corps as class inspector, from 1826, and as assistant director in charge of teaching (1834–1847). He was also active in the creation in 1825 of Gorny zhurnul (“Mining Magazine”), the first specialized periodical in Russian, of which he became editor. In 1839 Sokolov was elected member of the Russian Academy of Sciences and, in 1841, honorary member of the division of language and philology of the St. Petersburg Academy of Sciences for the compilation of a dictionary of Old Church Slavonic and Russian.

Sokolov’s marriage to Ekaterina Nikolaevna Prytkova was childless: their adopted daughter took care of him during his old age and illness.

Sokolov’s early training as an experimental chemist enabled him to approach the problem of the classification of minerals in a new way. An advocate of the atomistic concept, which was then only beginning to win recognition, he believed that the physical properties of minerals depend upon vectorial atomic forces. Sokolov attached primary importance to chemical composition and classified minerals according to their cations. On the basis of similar properties, he outlined their natural groupings long before Mendeleev’s periodic system. Thus his first category included lithophile elements of the first four groups of Mendeleev’s periodic table, while his second category of metals comprised only the chakophilc elements.

sokolov correctly attributed the physical properties of ties of minerals—morphology, shape, color, luster, hardness, cleavage—to their chemical composition and regarded physical features as secondary. Although he did not take them into consideration in his classification, he did stress their importance for determination. Following the traditions of the Russian mineralogical school of Lomonosov and Severgin, Sokolov was especially concerned with paragenesis and, in his textbook of mineralogy, discussed the association of minerals, indicating that some, like cinnabar, have no characteristic paragenesis.

By the late 1820’s Sokolov’s early neptunist views had been superseded by the plutonist approach: and he came to regard most minerals, rocks, and ores as the result of crystallization from a magmatic melt. In his petrographic descriptions he consistently attempted to give not only a chemical and mineralogical description but also an account of their genesis. He distinguished magmatic from sedimentary rocks, adding in the 1830’s the category of metamorphic. His interest in problems of petrology led him to conclude that the comparatively limited variety in rock composition could be explained by affinities of chemical elements. He also emphasized the importance of geological conditions in the physicochemical environment (pressure, temperature, presence of water vapor), assuming that with a variation in these conditions a change in petrology occurs.

In associating the conditions of ore formation with the specific features of geological environment, Sokolov attached decisive importance to processes occurring deep within the earth, und tried to distinguish periods of ore formation and provinces. He considered pneumatolytic and contact deposits the most important genetic types and distinguished the hydrothermal concentration of ore.

Sokolov’s papers were also devoted to the problems of metalliferous placers. Contrary to prevalent concepts, he demonstrated that placers are located near the outcrops from the weathering of which they originated; this fact substantially altered methods of prospecting for gold. His distinction of metalliferous zones and belts of varying composition laid the foundation of modern concepts of metallogenetic provinces.

On Sokolov’s initiative, work was begun on the geological mapping of Russia, and his suggestions resulted in the undertaking, in 1834, of geological surveys of individual mining regions. These surveys were carried out on his instructions and proceeded under his direct supervision. By 1841 the first geological maps of European Russia had been published. The development of geological surveying had necessitated detailed stratigraphic subdivision. Of great importance for mapping was the summarized stratigraphic table compiled by Sokolov in 1831 and substantially modified in 1839.

Sokolov’s three-volume textbook Kurs geognosii (“Course of Geognosy,” 1839) contains a large section that would now be described as a history of geology; it gave a detailed description of all the geological systems then known. In this work Sokolov first distinguished an independent system at the top of the Paleozoic deposits, which two years later was named the Permian system and was included in international stratigraphic tables by Murchison. Sokolov also pointed out the essential differences between Lower and Upper Silurian deposits warranted his describing each as an independent system.

In sedimentology Sokolov asserted that sedimentary masses are originally deposited horizontally and are only later compressed into folds, whereas lamination is an indication of episodic changes in the environment.

As early as 1820 Sokolov began to advocate that current geological phenomena can serve as a prototype for past events reflected in the geological sequence and that geological processes proceeded in the same way throughout history. He stressed this approach even more insistently, especially after the appearance of Lyell’s Principles of Geology (1830–1833), which contributed to the development of the actualistic method and the worldwide dissemination of uniformitarian concepts, certain elements of which were contained in Sokolov’s views.

Here, however, he did not take the position of formal uniformitarianism but systematically stressed that physicochemical conditions in the earth’s interior, as well as paleogeographical conditions on its surface, are consistently changing and that, consequently mineral and petrogenesis are not uniformitarian. In this respect Sokolov developed Lomonosov’s views on the continual transformation of the world environment am believed that there is a continuous development process in both organic and inorganic nature. Advocating the existence of transformistic phenomena. which alter the organic world, Sokolov pointed out that this process is directed toward the origin of increasingly more highly organized forms—ideas that contained the rudiments of evolutionary concepts.

Sokolov actively disseminated advanced geological ideas through his textbooks and public lectures, which attracted a broad audience. His highly praised books were awarded three prizes by the St. Petersburg Academy of Sciences. Despite the rapid development of geology, Sokolov’s textbooks remained valid: Kurs mineralogii (“Course of Mineralogy”), for example, was still in use after his death.

BIBLIOGRAPHY

I. Original Works. Sokolov’s writings include “Kratkoe nachertanie gornykh formatsy po noveyshemu sostoyaniyu geognozii” (“A Brief Outline of Rock Formations According to the Latest State of Geognosy”), in Gorny zhurnal nos. 4–5 (1831); Rukovodstvo k mineralogii s prisovokupleniem statisticheskikh svedeny o vazhneyshikh solyakh i metallakh (“Textbook on Mineralogy With Additional Statistical Data on the Most Important Salts and Metals”), 2 vols. (St. Petersburg, 1832) and supplement (St. Petersburg, 1838); Kurs geognosii (“Course of Geognosy”), 3 vols. (St. Petersburg, 1839); and Rukovodstvo k geognozii (Handbook of Geognosy”), 2 pts, (St. Petersburg, 1842).

II. Secondary Literature. On Sokolov and his work, see E. A. Radkevich. Dmitry Ivanovich Sokolov 1788–1852 (Moscow, 1959); and V. V. Tikhomirov, “Dmitry Ivanovich Sokolov (k 100-letiyu so dnya smerti” (“... on the Centenary of His Death”). in Byulleten Moskovskogo obshchestva ispytatelei prirody, Ser. geolog., 27 . no. 6 (1952).

V. V. Tikhomirov