Rittmann, Alfred (Alfredo) Ferdinand

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(b. Basel, Switzerland, 23 March 1893; d. Piazza Armerina, Sicily, 19 September 1980), volcanology, petrography, mineralogy.

Rittman was one of the fathers of modern volcanology. Through his long-standing studies in the volcanic areas of Southern Italy, he contributed to the understanding of the geological history of the Italian volcanoes, to the physical chemistry of volcanic processes, and to the petrography of volcanic rocks. His Volcanoes and Their Activity became a leading textbook on volcanism for several decades.

Rittmann was born into an old Swiss middleclass family as the sole son of the Basel dentist August Rittmann and his wife Frieda Urech Rittmann. Due particularly to his paternal grandfather, he developed an early interest in mineralogy and petrography. At age fourteen, Rittmann studied the famous textbook on mineralogy by the German mineralogist Friedrich Klockmann. At age fifteen, he had his own collection of minerals, the newest microscopical equipment, and a great number of commercially available sets of thin sections. Within a further year he became a self-taught expert in using the polarizing microscope.

In 1912, Rittman entered the University of Basel to study natural sciences, especially earth sciences, and music. Among his teachers were the Swiss mineralogists and geologists Karl Schmidt and Heinrich Preiswerk-Becker. In 1917 he changed to the University of Geneva, where the geologist Louis Duparc became his teacher. In 1921 he received his PhD with a study of a series of platiniferous rocks from the Urals. In the same year he finished his musical education at the Geneva Conservatoire.

In the following five years Rittmann travelled extensively. He visited the centers of mineralogy and petrology, as well as of music cultivation, studying with, amongst others, Friedrich Becke in Vienna, Alfred Lacroix in Paris, Victor Goldschmidt in Heidelberg, and Rudolf Gross in Hamburg. Gross taught him the new techniques of x-ray crystallography. A later result of early interests was his zonal method for the determination of plagioclase feldspars (1929).

Petrographer at Naples— Privatdozent in Basel In 1926 Rittmann joined the staff of the Volcanological Institute of Immanuel Friedländer at Naples as a petrographer. In these years Mount Vesuvius was in continuous activity, culminating in single spectacular eruptions—an ideal field laboratory for a young volcanologist. Further areas of research became the Campi Flegrei, the Island of Ischia, and the Stromboli volcano—whose crater terrace he entered (Figure 1).

Several reports on volcanological observations and a monograph on the geology of Ischia were first results. From the study of the various emissions of Mount Vesuvius, Rittmann proceeded to a comprehensive discussion of its structures and the magmatological development of the Somma volcano. He proved the assimilation of carbonate rocks as it has been discussed by others, including the American geologist Reginald Aldworth Daly. Thus he explained the anomalous differentiation order of Vesuvian lavas from the original Somma-period to the present Vesuvius (trachyte—orvietite—ottajanite—vesuvite) (Figure 2).

These early studies showed Rittmann’s new concept of volcanology, first and foremost, as magmatology. Contrary to the then-prevailing conception of volcanic eruptions as a mere consequence of tectonic movements, he emphasized the active role of magma. Magma’s physico-chemical characteristics were considered as the key to understanding volcanism, and volcanic activities as the essential source for the composition and the dynamical processes of the Earth’s interior.

When the Institute Friedländer was closed in 1934, Rittmann returned to Basel where, from 1935 until 1941, he lectured at the university as a Privatdozent for petrography, volcanology, geochemistry, and geophysics. In 1936 he accompanied an expedition to Greenland guided by the

Danish geologist and polar researcher Lauge Koch. During a short stay in Iceland Rittmann explored the volcanoes at the Myvatn in the north-eastern part of the island. In the same year (1936) the first edition of his textbook Vulkane und ihre Tätigkeit was published. The second edition (1960), which was translated into six languages, became an integral part of the study of earth sciences.

Geological Theory—Practical Geology During the Basel years Rittmann also set forth some more theoretical—and partly controversial—ideas on petrography, geodynamics, and the early geochemical history of the Earth. Together with the German geologist Hans Cloos, he developed a new classification and nomenclature of plutonic rocks (1939). They distinguished five classes of granitic rocks according to origin, that is, first an ultrametamorphic origin, and then four classes for the intrusion and congealing of peculiar types of magma.

A year before, Rittmann suggested a viscous, basic composition of the Earth’s primeval congealing crust, instead of a granitic-gneissic one. The incipient sialic crust should have been a product of its decomposition. However, he did not explain where essential remains of this decomposition (such as sodium, or iron) went. In 1941, together with the Swiss physicist Werner Kuhn, he developed a new geochemical theory of the Earth’s interior. Instead of the widely accepted iron-nickel core, they assumed a core of solar matter, that is, of highly compressed gaseous hydrogen. In 1942 he explained the process of orogeny as production, or restoration, of a state of thermal equilibrium. This paper included a rough idea of continental drift, caused by convection currents, whereby the mid-Atlantic ridge was seen as a kind of volcanic mountain range.

Because Rittmann’s hope for a university career in his native country was not fulfilled—and German universities were out of the question because of the political situation—Rittman, after two years in the service of the Swiss National Defence, went back to Italy in 1941. He directed the national Centro delle ricerche geominerario of the Istituto della Ricostruzione Industriale (IRI) in Rome. From 1945 to 1949 he also directed the Centro Geologico Silano of the Consiglio Nazionale delle Ricerche at Naples. There he was mainly engaged in practical geological work. In 1949 he was called as a guest professor to the Institute of Geology and Mineralogy of the University of Alexandria (Egypt), becoming an ordinary professor one year later. In 1953, Rittmann changed to the University of Cairo as professor of petrography, ore geology, and geochemistry. At the same time he directed the Institute of Crystal Optics of the Egyptian National Research Council at Cairo-Dokki. There he produced several papers on crystal optics, most of them in collaboration with his student Essam E. El-Hinnawi (El-Hinnawy).

President of the IAV In 1957, at age sixty-four, Rittmann returned once more to Italy. He became a professor at the University of Catania, and one year later the director of the Istituto di Vulcanologia (which became the Istituto Nazionale di Geofisica e Vulcanologia), including the Mount Etna volcanological observatory. Further areas of research became the Iblei Mountains, Pantelleria Island, and—again—Ischia.

Beginning in 1954, he was also the president of the International Association of Volcanology (IAV), which later became the International Association of Volcanology and Chemistry of the Earth’s Interior (IAVCEI). He held this post until 1963. He used this position to promote the establishment of an international institute of volcanology at Catania, for instance, by the organization of an international symposium on volcanology, in particular on ignimbrites, at Sicily in 1961. In 1967, the Istituto Internazionale di Vulcanologia began its official work, supported by the Italian Consiglio Nazionale delle Ricerche and by UNESCO.

In the same year a preliminary report to the mining division of the Comitato Nazionale dell’Energia Nucleare on the calculation of stable mineral assemblages in igneous rocks became the initial step for a new method of norm calculation known as the Rittmann norm. Rittmann had been engaged in the problem of the interaction between the mode and the chemical composition of volcanic rocks since the early 1940s. Results included new ideas on the nomenclature of volcanic rocks (1952) and the serial indices of igneous rocks (1957–1958) designed to order them according to the respective suites, that is, provinces. The Rittmann norm should have produced better results for melanocratic and highly subsilicic rocks than the commonly used CIPW norm. Its application, however, required extensive chemical analyses, and the calculation itself was hardly possible without modern computers. Consequently a comprehensive discussion of the Rittmann norm was not published until 1973.

Altogether, Rittmann wrote more than one hundred fifty monographs and papers on nearly all topics of volcanology, including several popular essays. His last book (I vulcani, 1976) was written with Loredana Rittmann, his daughter and only child from his marriage with Clementina Militerni of Naples. Rittmann was appointed an honorary member of the Geological Society of Egypt, and the Schweizerische naturforschende Gesellschaft, as well as a foreign correspondent of the Geological Society of America. In 1956 the German Geologische Vereinigung awarded him the Gustav Steinmann Medal. In 1959 he became an honorary doctor of the University of Bern, one of the rare acknowledgments which his work found in his native country.


Rittmann’s papers (manuscripts, and correspondence) are held by the manuscript department of the Library of the University of Freiburg (shelf mark: Rittmann GA 47, including a catalogue of the materials); a catalog of the letters can be found at the manuscript database of the Staatsbibliothek Preuischer

Kulturbesitz in Berlin, available from http://kalliope.staatsbibliothek-berlin.de.


Étude pétrographique sur une série de roches des gîtes platinifères de l’Oural. Bad Salzuflen: H. Uekermann, 1922. “Die Zonenmethode. Ein Beitrag zur Plagioklasbestimmung mit Hilfe des Theodolithtisches.” Schweizerische mineralogische und petrographischeMitteilungen 9 (1929): 1–46.

Die Geologie der Insel Ischia (including a geological map

1:10.000). Zeitschrift für Vulkanologie, Supplement 6. Berlin: Reimer, 1930. Reprinted Amsterdam: Swets and Zeitlinger, 1969; revised edition, together with Violetta Gottini, posthumously, Bolletino del Servizio Geologico d’Italia 51 (1980): 131–274. “Die geologisch bedingte Evolution und Differentiation des

Somma-Vesuv Magmas.” Zeitschrift für Vulkanologie 15 (1933): 8–94.

Vulkane und ihre Tätigkeit. Stuttgart: Ferdinand Enke, 1936.

2nd, enlarged and revised ed., 1960. 3rd, completely revised ed., 1981. Translation of the first edition (revised and enlarged) into Italian by Felice Ippolito (Vulcani, attività e genesi. Naples: Ed. Politechnica, 1944). Translations of the second edition into English by Ewart Albert Vincent (Volcanoes and Their Activity. New York: Interscience Publishers, 1962); French by Haroun Tazieff (Les volcans et leur activité. Paris: Masson, 1963); Russian (Vulkany i ich dejatel’nost.’ Moskau: Izd. Mir, 1964); Italian, enlarged and revised, by Glauco Gottardi (I vulcani e la loro attività. Bologna: Cappelli, 1967; rep., 1972); Romanian (Bucharest, Romania: Ed. Technica, 1967); and Japanese.

“Die Vulkane am Myvatn in Nordost-Island.” Bulletin volcanologique 4 (1938): 3–38.

With Hans Cloos. “Zur Einteilung und Benennung der

Plutone.” Geologische Rundschau 30 (1939): 600–608. “Studien an Eruptivgesteinen aus Ost-Grönland.” Meddelelser om Grønland, udgivne af Kommissionen for videnskabelige undersøgelser i Grønland 115, no. 1 (1940): 1–156.

With Werner Kuhn. “Über den Zustand des Erdinneren und seine Entstehung aus einem homogenen Urzustand.” Geologische Rundschau 32 (1941): 215–256. “Zur Thermodynamik der Orogenese.” GeologischeRundschau 33

(1942): 485–498.

With Felice Ippolito. “Sulla stratigrafia del Somma-Vesuvio.”

Atti della fondazione politecnica del mezzogiorno, 3 (1947): 1–37. “Origine e differenziazione del magma Ischitano.” Schweizerische mineralogische und petrographische mitteilungen 28 (1948): 643–698. “Zur geochemischen Entwicklung der prägeologischen

Lithosphäre.” Schweizerische mineralogische und petrographische Mitteilungen 28 (1948): 36–48. “Nomenclature of Volcanic Rocks Proposed for the Use in the

Catalogue of Volcanoes, and Key-Tables for the Determination of Volcanic Rocks.” Bulletin Volcanologique 12 (1952), 75–102. “On the Serial Character of Igneous Rocks.” Egyptian Journal of

Geology 1 (1957): 23–48.

With Essam E. El-Hinnawi. “Optical and Crystallographic

Properties of Some Aromatic Disulphides.” Egyptian Journal of Chemistry 2 (1959): 29–36. “Die Bimodalität des Vulkanismus und die Herkunft der

Magmen.” Geologische Rundschau 57 (1967): 277–295. With Lucio Villari, Maria DiRe, and Romolo Romano. “Studio geovulcanologico e magmatologico dell’Isola di Pantelleria, with a geological map 1:50.000.” Rivista Mineraria Siciliana18, no. 106–108 (1967): 147–182.

With Violetta Gottini, Wolfgang Hewers, et al. Stable Mineral

Assemblages of Igneous Rocks: A Method of Calculation. Berlin: Springer, 1973. Translated into Russian (1975) and Chinese. “Chemistry of Lunar Rocks with Volcanological and

Magmatological Considerations and a Model of the ‘Hot Moon.’” In Volcanoes and Impact Craters on the Moon and Mars, edited by Piero Leonardi. Amsterdam: Elsevier, 1976. With Loredana Rittmann. I vulcani. Novara: Istituto Geografico

De Agostini, 1976. Translated into German by Erwin Felkel (Vulkane in Farbe. München: Südwest Verlag, 1977); English (Volcanoes. London: Orbis Publishing, 1976; rep., 1978); and French (Les Volcans. Paris: Atlas, 1976; rep., 1985).


Cristofolini, Renato. “Ricordo di Alfredo Rittmann.” Rendiconti della Società Italiana di Mineralogia et Petrologia già Società Mineralogica Italiana 37 (1981): xv–xxii. Most complete available bibliography.

Keller, Jörg, and Ernst Niggli. “Alfred Rittmann (1893–1980).”

Schweizerische mineralogische und petrographische Mitteilungen 60 (1980): 305–309. With portrait and selected bibliography. Pichler, Hans. “Alfred Rittmann 23 März 1893–19 September

1980.” Geologische Rundschau 72 (1983): vii–xi. With portrait.

Bernhard Fritscher