Grubenmann, Johann Ulrich

(b. Trogen, Appenzell, Switzerland, 15 April 1850; d. Zurich, Switzerland, 16 March 1924)

mineralogy, petrography.

Grubenmann was the only surviving child of Johann Kaspar Grubenmann and Katharina Eugster. Among Grubenmann’s ancestors was the distinguished Johann Ulrich Grubenmann, who in 1775 erected the wooden bridge across the Rhine at Schaffhausen, a milestone in the history of wide-spanned wooden bridges. At the time of Grubenmamn’s birth the family was living in extremely reduced circumstances and the boy had to contribute to its means by hard work during his school years. Through scholarships and the help of friends he was able to complete his education and in 1874 he obtained the diploma of certified teacher in natural sciences from the Swiss Federal Institute of Technology. That year he was elected professor of chemistry, mineralogy, and geology at the cantonal school of Frauenfeld, which he also served as rector from 1880 to 1888.

In 1876 Grubenmann married Ida Caroline Baumer; she died in 1880, a month after the birth of their son Max Alfred. He married a second time in 1881 and, by his wife Lisette Augusta, had a son, Max Carl, and a daughter, Ida Clara.

In addition to his teaching responsibilities, Grubenmann carried out petrographic fieldwork in the volcanic area of Hegau, Germany, and in the Alps. He also visited the volcanic districts of Italy and spent some time studying in Munich (1875–1876) and Heidelberg (1886). He received the Ph.D. from the University of Zurich in 1886 with a thesis on the “basalts” (now called olivine melilithites) of Hegau. Two years later he qualified as Privardozent at Zurich and on the death of G. A. Kenngott became professor of mineralogy and petrography and director of the Mineralogical and Petrographical Institute of the Institute of Technology and the University of Zurich. He also was dean of the Faculty of Philosophy (1896–1898) at Zurich and chairman of the division for natural sciences (1907–1909) and rector (1909–1911) at the Institute of Technology. He retired in 1920 but remained scientifically active. In 1921 Grubenmann founded Schweizerische mineralogische und petrographische Mitteilungen, which he edited until his death.

Grubenmann devoted himself to the study of metamorphic rocks at a time when petrographic research was mostly occupied with the seemingly genetically simpler rocks of magmatic origin. From the outset he recognized the importance of a physicochemical approach to his studies. In recognition of his achievements and those of his Viennese friends and colleagues F. Becke and F. Berwert, the Viennese Academy of Science entrusted the three scientists with the task of studying the crystalline schists of the eastern Alps. Their researches culminated in the publication of the classic treatise “Ueber Mineralbestand und Struktur der kristallinen Schiefer” (1903). A further result of these studies was Grubenmann’s publication of Die kristallinen Schiefer (1904–1907), which went through two editions. Part 1 of the third edition, entitled Die Gesteinsmetamorphose, was published separately in 1924 in collaboration with Grubenmann’s pupil and successor Paul Niggli.

Grubenmann’s work was based entirely on observations in nature. He proceeded from the recognition that the mineral composition of metamorphic rocks of a given chemical composition must depend upon the conditions of pressure and temperature (P-T conditions) prevailing at the time of their formation. Accordingly, he created a rock classification in which for each of twelve chemically defined groups or orders the mineral compositions for varying P-T conditions were systematically studied.

The American scientist C. R. Van Hise had already distinguished between two main zones of rock formation within the earth’s crust. One zone was characterized by the relatively low values of pressure and temperature normally found in the upper regions of the earth’s crust. The second zone was dominated by relatively high values of pressure and temperature such as normally belong to the deeper regions. These two genetic zones were known as the epizone and katazone respectively. Studies carried out by Grubenmann on the rocks of the southern flank of the Gotthard massif indicated the necessity of recognizing a third, so-called mesozone, lying between the two other zones and having intermediate P-T conditions. This extension of the zonal principle proved most useful in later studies. For each of the twelve previously mentioned orders Grubenmann examined and defined the typomorphic mineral composition prevailing in each of the three zones. He proposed a nomenclature based on these relationships and his terminology is widely accepted.

Although rocks were Grubenmann’s chief preoccupation, he was also interested in mineralogy. An important publication in this field was his monograph (1899) on the magnificent rutilated quartzes from Piz Aul, Graubünden, which he acquired for the Zurich collection. Grubenmann was also a successful organizer. He expanded the Minerological and Petrographical Institute by adding a chemical laboratory that produced numerous chemical analyses, mostly of metamorphic rocks, and where, perhaps for the first time in Europe, students were given the opportunity for systematic training in rock analyses. Grubenmann founded and for twenty-five years presided over the Swiss Geotechnical Commission whose task it was to locate natural raw materials in Switzerland. On his initiative a series of monographs dealing with building stones, roofing slates, clay deposits, and coal and peat occurrences were published.

BIBLIOGRAPHY

I. Original Works. Grubenmann’s works include “Die Basalte des Hegaus, eine petrographische Studie,” inaug. diss. (Univ. of Zurich, 1886); “Prinzipien und Vorschläge zu einer Klassifikation der kristallinen Schiefer,” in Collected Works of the Tenth International Geological Congress, Mexico (1896); “Ueber die Rutilnadeln einschliessenden Bergkristalle vom Piz Aul im Bündneroberland,” in Neujahrsblatt der Naturforschenden Gesellschaft in Zurich, 101 (1899); Die kristallinen Schiefer, 2 vols. (Berlin, 1904–1907; 2nd ed. 1910); Ueber einige schweizerische Glaukophangesteine (Stuttgart, 1906); “Struktur und Textur der metamorphen Gesteine,” in Fortschritte der Mineralogie, Kristallographie und Petrographie, 2 (1912); and Die Gesteinsmetamorphose (Berlin, 1923), written with P. Niggli.

The treatise “Ueber Mineralbestand und Struktur der kristallinen Schiefer” was published under Friedrich Becke’s name in Denkscriften der Akademie der Wissenschaften, 75 (1903).

II. Secondary Literature. For information on Grubenmann, see J. Jakob and A. H. Schinz, “Verzeichnis der Publikationen von Prof. Dr. U. Grubenmann, herausgegeben auf seinen 70. Geburtstag, den 15. April 1920,” in Viertel jahrsschrift der Naturforschenden Gesellschaft in Zurich, 65 (1920), with complete bibliography; P. Niggli, “Prof. Dr. U. Grubenmann,” in Verhandlungen der Schweizerischen naturforschenden Gesellschaft (Lucerne, 1924); and R. L. Parker, “Prof. Dr. U. Grubenmann,” in Zentralblatt für Mineralogie, Geologie, und Paläontologie (1924).

The Swiss author Arnold Kübler (once a pupil of Grubenmann) gives an extremely lively portrait of the university professor in his novel Oeppi der Student (Zurich, 1947), in which Grubenmann appears under the pseudonym “Zwiesand”.

Conrad Burri