Knopf, Adolph

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(b. San Francisco, California, 2 December 1882; d. Palo Alto, California. 23 November 1966). Petrology, economic geology.

Adolph Knopf, son of German immigrants Anna Greisel and George Tobias Knopf, became one of the most influential geologist-educators in the United States. Born and raised in California he entered the University of the California at Berkeley and received a B. S. in 1904, an M.S. in 1905, and a Ph.D. in 1909. His mentor was Andrew Cowper Lawson, a master of field observations and a leading thinker in structural geology, petrology, and the origin of mineral deposits. From Lawson, Knopf learned the value of experience gained through field studies; he followed that lesson throughout his life and passed it along to his own students.

The summer of 1905 found Knopf in Alaska as a temporary employee of the U.S. Geological Survey; in the fall of 1906 he joined that institution as a permanent employee. continuing to work in Alaska until 1911 and submitting one of his studies, on the the deposits of the Seward Peninsula, for his Ph. D. dissertation, In 1911 Knopf was assigned to study the region between Butte and Marysville in Montana; this brought him into contact with the Boulder Batholith, a major geological feature he continued to study for the rest of his life.

Knopf married Agnes Burchard Dillon in 1908; they had three daughters and one son. The family lived in Washington, D.C., site of the headquarters of the U.S. Geological Survey. The months when fieldwork was possible found Knopf in the West; winter months were spent in Washington writing reports and completing petrographic studies. Through his combined field and laboratory studies, Knopf became distinguished both as an economic geologist and as a petrologist. In 1915 he commenced what was to become probably his most important work. a study of the Mother Lode district of California. Theresult appeared as Professional Paper 157 of the U.S. Geological Survey (1929) and was immediately recognized as a classic work. It is still one of the most important studies ever made of the geometry and petrology of an intricate system of faults and veins in a metamorphic complex.

Agnes Knopf died of influenza in 1918; in January 1920 Knopf started teaching at Yale and in June of the same year he married Eleanora Frances Bliss, a geologist with whom he had worked at the Geological Survey since 1912. No children were born of the second marriage. Among the faculty members at Yale when Knopf arrived was Bertram Borden Boltwood, who had, in earlier years, collaborated with Ernest Rutherford on studies of radioactivity, and who had demonstrated through chemical analysis that lead is the daughter product derived by radioactive decay of both uranium and thorium. Boltwood’s demonstration in 1907 that the proportions between uranium and thorium and the associated lead might be used to determine mineral ages had, by 1920, been strongly supported by a number of influential people, in particular Arthur Holmes in England and Joseph Barrell of the Yale faculty Knopf recognized the importance of radiometric dating, became a spokesman in seeking support for development of the technique, and published a number of important papers concerning the age of Earth. He did not carry out any of the measurements himself, but through the 1930’s and 1940’s he was the most influential scientist in the country supporting radiometric dating.

Knopf was a legendary teacher among graduate students. His lecturing style was not good and his successes in teaching undergraduates were few, but his close, interactive teaching with graduate students at Yale left a lasting impact, not only on the students themselves but also on the institutions they later joined, and thereby on the entire geological profession. A combination of careful field and rigorous laboratory observations underlay Knopf’s work, and he passed on a belief in this combination to students. Among those who have written of Knopf’s influence on them are James Gilluly and William W. Rubey. Knopf continued working after retirement from Yale, first as visiting professor, and then as consulting professor, at Stanford.

Knopf was elected to the National Academy of Sciences in 1931. He was a fellow of the Geological Society of America (president, 1944) and a member of the Society of Economic Geologists. He was awarded the Penrose Medal of the Geological Society of America in 1959. Perhaps the greatest honor paid Adolph Knopf is the frequency with which his former students mention in their published reminiscences that he played an essential role in their education and scientific development.


I. Original Works. “Geology of the Seward Peninsula Tin Deposits, Alaska,” “Bulletin of the U.S.Geological survey, no, 358 (1908); “The Seward Peninsula Tin Deposits,” ibid., no. 345 (1908), 251–267; “Some Features of the Alaskan Tin Deposits,” in Economic Geology, 4 (1909), 214–223; “The Eagle River Region Southeastern Alaska,” Bulletin of the U.S. Geological Survey, no.502 (1912); “Ore Deposits of the Helena Mining Region, Montana,” ibid no 527 (1913);“The Tourmalinic Silver-Lead Type of Ore Deposit,” in Economic Geology, 8 (1913), 105–119; “Mineral Resources of the Inyo and white Mountains. California,” Bulletin of the U.S. Geological survey. no 540 (1914).81–120;“A Geologic Reconnaissance of the Inyo Range and the Eastern Slope of the Southern Sierra Nevada, California, “Professional Papers of the U.S. Geological Survey no 110 (1918); “Geologyoo and Ore Deposits of the Yerington District, Nevada,” ibid, no. 114 (1918).

“Ore Deposits of Cedar Mountain Mineral County, Nevada,” in Bulletin of the U.S. Geological Survey, 725 (1921), 361–382;“Geology and Ore Deposits of the Rochester District, Nevada,” ibid., no 762 (1924);“The Mother Lode System of California,” Professional Papers of the U.S. Geological Survey no 157 (1929);“Age of the Earth; Summary of Principal Results,” in Bulletin of the National Research Council, 80 (1931), 3–9;“Age of the Ocean,” ibid 65–72;’Igneous Geology of the Spanish society of America, 47 (1936)1727–1784; “The Geosynclinal Theory,” ibid., 59 (1948)649–669;’Bathyliths in Time,” in Arie Poldervaart, ed., Crust of the Earth. Geological Society of America Special Paper No 62 (1955), 685–702;and’ The Boulder Bathylith of Montana,” in American Journal of Science, 255 (1957).81–103.

II. Secondary Literature, Robert G. Coleman “Memorial of Adolph Knopf,” in American Mineralogist 53 (1968), 567–576;and Chester R. Longwell, “Adolph Knopf.” in Biographical Memoirs. National Academy of Sciences 41 (1970.235–249.

Brian J. Skinner