VOGT, JOHAN HERMANN LIE

(b. Tvedestrand, Norway, 14 October 1858; d. Trondheim, Norway, 3 January 1932), geology.

Vogt was the son of a physician and, on his mother’s side, the nephew of Sophus Lie. After studying for a year at the Dresden Polutechnikum, he transferred to the University of Christiania (Oslo), where he graduated as a mining engineer-geologist in 1880. He did graduate work at Stockholm in 1882, studying geology under W. C. Brøgger, metallurgy under Richard Åkermann, and chemistry under W. Eggerts. Vogt was appointed professor of metallurgy at eh University of Christiania in 1886 and in 1912 moved to the Technical University of Norway at Trondheim, where he was professor of geology, ore deposits, and metallurgy (expect iorn). He retained this post until his retirement in 1929.

Vogt was a pioneer in ore geology and in the physical chemistry of silicates as a basis for igneous rock petrology. His work in the latter field began with studies of slag minerals. In a series of papers, the first of which appeared in 1883, he provided the first descriptions of a number of slag minerals: enstatite. wollastonite (pseudowollastonite), fayalite, monticellite varieties, åkermannite, oldhamite, manganblende (alabandite), troilite, and sphalerite. Vogt soon began using the crystallization of slags as a model for silicate crystallization in igneous rocks, as shown by the title of his papers of 1888-1890: “Beiträge zur Kenntnis der Gesetze der Mineralbildung in Schmelzmassen und in den neovulkanischen Egussgesteinen,” Inspired by his mineralogical studies of slags, he generalized his studies of ores and silicate rocks in “Die Silikatschmelzlösungen” (2 pts., 1902), a pioneer paper in which the crystallization relations of the different minerals and their dependence upon eutectic relations are considered. The lowering of melting points in melts with several components and the importance of eutectic compositions in binary series are discussed. The general relationships are applied to natural silicate melts and specifically to the eutectic relation between quartz and feldspars in igneous rocks. Bearing still more directly on natural relationships is “Physikalisch-chemische Gesetze der Kristallizationsfolge in Eruptiv-Gesteinen” (1905), in which the crystallization within the ternary feldspar system orthoclase-albite-anorthite and the granite system quartz-orthoclase-al-bite is discussed.

In another classic paper, “Über anchi-monomineralische und anchi-eutektische Eruptiv-Gesteine” (1908), Vogt discussed magmatic differentiation, on the basis of the theory proposed by Brøgger and several other leading petrographers at the turn of the century, treating the parallelism between crystallization and differentiation of silicate melts. In this work he stressed the importance of eutectic crystallization as a major factor in magmatic differentiation. Since he emphasized the physicochemical laws governing the crystallization and development of igneous rocks, Vogt was sharply critical of the static petrographic system developed by Cross. Iddings, Pirsson, and Washington (CIPW). During World War I, Vogt studied mixed systems of silicates and sulfides, stressing the importance of the low mutual solubility of such melts. This result was fundamental to his treatise on magmatic sulfide ore formation, especially nickel ore. Publications from Vogt’s last ten years where marked by his continued analysis of the physicochemical laws governing magmatic differentiation.

Vogt’s first paper in English appeared in Journal of Geology: “The Physical Chemistry of the Crystallization and Magmatic Differentiation of Igneous Rocks” (1921). Nearly the same title was used for the three-volume work published at Oslo (1924-1931). The most important part of the first volume is the discussion of the concentration of mixed crystals with high melting points in early-formed rocks and that of mixed crystals with low melting points in the magmatic end stage. The second volume deals with the relations of the ternary feldspar system orthoclase-albite-anorthite, based on many analyses; and the third, which concentrates on the rocks of the magmatic end stage, also contains a large number of chemical analyses. Not all of Vogt’s main conclusions have proved correct, but he applied the principles of physical chemistry to natural silicate systems more intensely than anyone else of his generation and therefore is often called the father of modern physicochemical petrology. Among the many terms Vogt introduced is “cotectic” curves, applied to what were formerly called eutectic lines or reaction lines. His last paper was “What We May Learn from Brøgger’s Essexitic Hurum Volcano Concerning Magmatic Differentiation” (Festschrift Brt gger, Norsk geolo,kisk tic/sskrift 119321).

Vogt’s other main field of interest was ore geology, in which he was considered a leader at that time, although his work was less original. His most important general contribution is the concept of a group of magmatic ore deposits-ilmenite, chromite, and nickeliferous pentlandite-formed early in the crystallization sequence. Vogt’s early contributions (1884–1889) concerned important ore deposits in Norway. In these papers he supported the proponents of a sedimentary origin for pyritic sulfide ores. Soon afterward, Vogt changed his views on ore genesis from the syngenetic to the epigenetic theory, which in the 1870’s was supported by Theodor Kjerulf and had originated with J. Durocher and Duchanoy around 1850. A magmatic, epigenetic view of sulfide ore deposits was maintained in Vogt’s first well-known paper published in Zeitschrift für praktische Geologie : “Über die Kieslagerstatten von Typus Roros, Vigsnas, Sulitjelma in Norwegen and Rammelsberg in Deutsch-land.” Vogt’s views were based on sharp field observations, a very good memory, and extensive travel. In the 1880’s he visited European universities and observed many important ore deposits. He therefore was well qualified to write Die Lagerstätten der nutzbaren Mineralien und Gesteine (1910-1921) with F. Beyschlag and P. Krusch. Important at the time, this two-volume treatise remains a major handbook of ore geology.

Vogt was active in polities for several years and was always eager to apply his theoretical knowledge of ore deposits to practical purposes, seeking new ore fields and helping to develop existing ones. This interest is reflected in a work published in 1895, “Kobberets historie i fortid og nutid og om udsigterne for fremtiden, med saerligt hensyn til den norske bergverksdrift på kobber” (“The History of Copper in the Past and Present and the Prospects for the Future, with Special Regard to the Norwegian Mining of Copper”).

Vogt received an honorary doctorate from the University of Aachen in 1911, the Penrose Medal of the Society of Economic Geologists (United States), and the Wollaston Medal of the Geological Society of London.

BIBLIOGRAPHY

There is a complete bibliography of Vogt’s more than 200 published works in Norsk geologisk tidsskrift, 11 (1932), 454–466. The titles of his most important publications are mentioned in the text.

The only detailed biographies were published in Norwegian, some soon after his death and one commemorating the centenary of his birth—J. A. W. Bugge, in Kongelige Norske videnskabers selskabs forhandlinger, 31 , (1958).

Christoffer Oftedahl

Vogt, Johan Hermann Lie (1858–1932) A Norwegian geologist, Vogt was professor of metallurgy at the Technical University of Norway. He did important work on the chemistry of silicates, and on differentiation in cooling magmas. He also made studies of ore geology, especially magmatic ores.