Esper S. Larsen
Esper Signius Larsen , Jr. (Born March 14, 1879 in Astoria , Oregon ; † March 8, 1961 ) was an American geologist , petrologist and mineralogist .
Life
Larsen grew up in Portland , where his father owned several retail stores and was a Danish consul. After high school, he worked in retail for four years and studied mineralogy and geology from 1902 at the University of California, Berkeley , graduating in 1906. He was then an instructor at Berkeley and from 1907 to 1909 assistant petrographer at the geophysical laboratory of the Carnegie Institution in Washington , DC , where he worked with Frederick Eugene Wright and published on quartz as a geological thermometer .
In order to obtain data for the application of the immersion method, he began to determine the optical data (refractive index) of over 600 minerals. He published his results in 1921 in The microscopic determination of nonopaque minerals , which he continued with the United States Geological Survey (USGS), where he was from 1909 to 1923. Thanks to its data collection, the immersion method could be used there in particular to determine minerals. During the First World War, he spent three years prospecting for tungsten and molybdenum . In 1918 he submitted his doctoral thesis in Berkeley ( Areal geology of the Creed Mining District, Colorado ). From 1918 to 1923 he was head of petrography at the USGS. At the USGS, he was particularly concerned with field work, especially in the volcanic rocks of the San Juan area in Colorado and New Mexico . He worked with Whitman Cross , who had been exploring for the USGS there for many years, and the mineralogist William H. Emmons . The work kept him busy until the 1940s and resulted in a number of publications by Larsen, some with his son. Another regional focus of his research in the 1930s was the batholith in the Corona Quadrangle in Southern California , where he mapped shortly after his studies in 1906, and the Highwood Mountains in central Montana . From 1923 until his retirement in 1949 he was Professor of Petrography at Harvard University . After his retirement he moved to Washington DC and remained an advisor to the USGS until 1958.
He was later involved in the historical debate about the origin of granites, advocating magmatic origins. He also developed a method of geological age determination (Larsen method) from the determination of the uranium-lead ratio in zirconia.
Larsen was a member of the American Academy of Arts and Sciences (1925) and the National Academy of Sciences (1944). In 1928 he was President of the Mineralogical Society of America . His son Esper Larsen III was also a geologist with the USGS.
Fonts
- with Frederick E. Wright Quartz as a geologic thermometer , American Journal of Science, Volume 27, 1909, pp. 421-427
- The microscopic determination of nonopaque minerals , US Geological Survey Bulletin No. 679, 1921 (reprinted with Harry Berman 1934)
- with Whitman Cross: The geology and petrology of the San Juan Region of Southwestern Colorado, US Geological Survey Professional Paper, 1956
- The petrographic province of central Montana , Bulletin Geological Society of America, Volume 51, 1940, pp. 887-948
Honors
- A mineral newly discovered in 1828 was named larsenite in his honor .
- In 1941 he received the Roebling Medal and in 1953 the Penrose Medal .
Web links
Individual evidence
- ^ New edition in 1934 with Harry Berman
- ^ Mindat - Larsenite
| personal data | |
|---|---|
| SURNAME | Larsen, Esper S. |
| ALTERNATIVE NAMES | Larsen, Esper Signius (full name) |
| BRIEF DESCRIPTION | American geologist, petrologist, and mineralogist |
| DATE OF BIRTH | March 14, 1879 |
| PLACE OF BIRTH | Astoria , Oregon |
| DATE OF DEATH | March 8, 1961 |