Memorial to John Gordon Dennis1920-1989

CH A R LES T. W ALKER 833 Lees Avenue, Long Beach, California 90815

John G. Dennis died at his home in Long Beach, Califor­nia, on September 23, 1989, after a lengthy illness. He is survived by his wife, Margaret; a daughter, Miriam; and a son, Mark.

John was bom in 1920 in Berlin, Germany. Although he was the son of a German lawyer, it was geology, rather than law, that motivated John. For John, geology was both a voca tion and an avocation , and to the very end he approached the science with the enthusiasm of a young graduate. Indeed, his enthusiasm spilled over to his col­leagues and associates so that he had a profound influence on the careers of others.

John spent his early years in Berlin, but the rise of the Nazi regime in Germany during the 1930s caused his fam­ily to flee first to France and then to England. These appar­ently disruptive events early in John’s life did much to shape his future career because he received schooling in France and England, and when he graduated from Saint Paul’s High School near London, England, he was fluent in German, French, and English. Subsequently, he acquired a working knowledge of several other languages, and it was these linguistic skills that enabled him to contribute to international geological organizations and committees. As a result o f his international involvement, John was known as a geologist throughout the world. Hisnumerous publications in English, German, and French also reflect the linguistic skills that heacquired at an early age.

In 1938, John was awarded an entrance scholarship to Imperial College, London, but his studies were interrupted by war service with the British Army. He returned to Imperial College at the end o f the Second World War and received a B.Sc. degree in mining geology in 1948. After graduation, he worked for one year as a mining geologist in Nigeria and then spent a year at the Université de Neuchâtel, Switzerland, where he studied methods o f tectonic analysis. He returned to Africa in 1950 and again worked as a mining geologist in Namibia until 1952.

In 1952, John entered Columbia University, receiving his A.M. in 1956 and Ph.D. in 1957. During his stay at Columbia, he was able to apply his extensive field experience gained in Africa to geologic mapping during the summer months in Vermont and Quebec. This summer field mapping led to numerous publications from 1956 to 1964 on the structural geology of the northern Appalachians.

John Dennis began his teaching career in 1956 at Texas Technical College, and in 1962 he joined the faculty at California State University, Long Beach, where he remained until his death. A lthough John was known worldw ide as a structural geologist, his research interests also included the focal mechanisms of deep and intermediate earthquakes and the origin of the sialic crust.

John’s linguistic background enabled him to make many international contacts. His activi­ties included chairman and chief editor for the IGCP International Tectonic Lexicon Project; member of the International Commission for the Swedish National Research Council; session

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chairman, International Geological Congress, 1984; and editor for North America, Neues Jahrbuch filr Geologie und Paläontologie (1976 to 1989). He was also a visiting scientist at sev­eral overseas universities in Germany, Mexico, Sweden, and Switzerland, and was the featured speaker for the 100th birthday symposium for Hans Goos at the University of Bonn.

Although John was proud to be an American citizen, he maintained a special affection for Europe. He served as an example for all of us in the field of international relations. His child­hood experiences could easily have led to bitter memories of Europe, especially Germany. How­ever, he put these experiences behind him and established many contacts in Germany and else­where in Europe. He was a frequent visitor to Germany and spent his last sabbatical leave in that country. In the summer of 1988 he was invited to the town of his birth as a guest of the Berlin senate.

John Dennis is remembered as both a researcher and a teacher. He was a teacher in the broad sense, and by challenging students to think critically, he launched many on a research career. He was similarly a mentor to his colleagues and associates. Indeed, the last paper in which he was listed as an author owes much to his guidance, inspiration, and encouragement. He made his extensive knowledge of structural geology available to all in his textbook on the subject.

John’s colleagues, associates, and students have lost a great teacher and a true friend.

SELECTED BIBLIO G R A PH Y OF J. G. D EN N IS1956 Geology of the Lyndonville area, Vermont: Vermont Geological Survey Bulletin, no. 8,

98 p.1958 (with Eric, J. H.) Geology of the Concord-Waterford area, Vermont: Vermont Geological

Survey Bulletin, no. 11,66 p.1959 Notes on some cassiterite-bearing pegmatites in the Brandberg area of South West Africa:

Economic Geology, v. 54, p. 1115-1121.1960 Zum Bau der nördlichen Appalachen: Geologische Rundschau, v. 50, p. 554-557.1961 Structural geology of northern Vermont, Section VI: Montpelier, Vermont, New England

Intercollegiate Geological Conference, 53rd Annual Meeting Guidebook.1962 Fitting the continents: Nature, v. 196, p. 364.1963 Geavage experimentally induced in clay [abs.]: Geological Society of America Special

Paper 76, p. 42.1964 (with König, R. H.) The geology of the Hardwick area, Vermont: Vermont Geological

Survey Bulletin, no. 24,57 p.------ (with Stone, S. F.) The geology of the Milton area, Vermont: Vermont Geological Survey

Bulletin, no. 26,79 p.1965 (and Walker, C. T.) Earthquakes resulting from metastable phase transitions: Tectono-

physics, v. 2, p. 401-407.1966 (with Kirchmayer, M.) Information from joint diagrams: Rock Mechanics and Engineer­

ing Geology, v. 4, p. 37-40.1967 International tectonic dictionary: American Association of Petroleum Geologists Mem­

oir 7,196 p.1969 Zur genetischen Unterscheidung von gemeinen Klüften und Verschiebungen: Geologische

Rundschau, v. 59, p. 222-228.1972 Structural geology: New York, Ronald Press, 534 p.1976 Geosynklinale, Orogenese und Plattentektonik: Zeitschrift Deutsche Geologische

Gesellschaft, v. 127, p. 73-85.1978 (and Häll, R.) Jura-type platform folds: A centrifuge experiment: Tectonophysics, v. 45,

p. 15-25.

MEMORIAL TO JOHN GORDON DENNIS 143

1979 (and Murawski, H., and Weber, K.) International tectonic lexicon: Stuttgart, Schweizer­bart, 153 p.

1980 (and Kelley, V. C.) Antithetic faults and homothetic faults: Geologische Rundschau, v. 69, p. 186-193.

1981 (and Jacoby, W. R.) Geodynamic processes and deformation in orogenic belts, in Banks, M. R., and Green, D. H., eds., Orthodoxy and creativity at the frontiers of earth science: Tectonophysics, v. 63, p. 261-273.

1982 Orogeny: Stroudsburg, Hutchinson Ross, Benchmark Papers in Geology, v. 62,379 p.1983 (with Walker, C. T.) Exogenic processes and the origin of the sialic crust: Geologische

Rundschau, v. 72, p. 743-755.1987 Structural geology: An introduction: Dubuque, Iowa, Wm. C. Brown, 448 p.1992 (with others) Cenozoic attenuation detachment faulting: A possible control on oil and gas

accumulation in east-central Nevada: American Association of Petroleum Geologists Bulletin, v. 76, p. 1665-1686.

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