Professor Emeritus


Research Interests

Radiometric dating methods, esp. 40Ar/39Ar techniques
Geomagnetic field behavior, esp. Polarity reversals
History and timing of volcanic events
Impact history on the early Moon
Age of the Earth


A.B., Geology, Occidental College, 1959
Ph.D., Geology, University of California, Berkeley, 1963

Academic Honors

Fellow, American Geophysical Union, 1975
American Academy of Arts & Sciences, 1992
Honorary D.Sc., Occidental College, 1993
National Academy of Sciences, 1993
Public Service Award, Geological Society of America, 2001
National Medal of Science, 2003


Dalrymple, G. B., 1991, The Age of the Earth: Stanford University Press, 474 pp..

Dalrymple, G.B., and Ryder, G., 1996, Argon-40/Argon-39 age spectra of Apollo 17 highlands breccia samples by laser step-heating and the age of the Serenitatis Basin: Journal of Geophysical Research (Planets), vol. 101, p. 26,069-26,084..

Wolfe, E.W., Wise, W.S., and Dalrymple, G.B., 1997, The geology and petrology of Mauna Kea Volcano, Hawaii--A study of postshield volcanism: U.S.G.S. Prof. Paper 1557, 129 pp + maps..

Izett, G.A., Cobbin, W.A., Dalrymple, G.B., and Obradovich, J.D., 1998, 40Ar/39Ar age of the Manson Impact Structure, Iowa, and correlative impact ejecta in the Crow Creek Member of the Pierre Shale (Upper Cretaceous), South Dakota and Nebraska: Geol. Soc. American Bulletin, vol. 110, p. 361-376..

Dalrymple, G.B., and Hamblin, W.K., 1998, K-Ar ages of Pleistocene lava dams in the Grand Canyon in Arizona: Proceedings of the National Academy of Sciences, vol. 95, p. 9744-9749..

Dalrymple, G.B., Grove, M., Lovera, O.M., Harrison, T.M., Hulen, J.B., and Lanphere, M.A., 1999, Age and thermal history of the Geysers plutonic complex (Felsite unit), Geysers geothermal field, California: a 40Ar/39Ar and U-Pb study: Earth Planet. Sci. Lett. vol. 173, P. 285-298..

Dalrymple, G.B., 2001, The age of Earth in the twentieth century: A problem (mostly) solved. pp. 205-221 in Lewis, C.L.E., and Knell, S.J. (eds), The Age of the Earth: from 4004 BC to AD 2002. Geological Society of London Special Publication 190..

Davis, A.S., Clague, D.A., Bohrson, W.A., Dalrymple, G.B., and Greene, H.G., 2002, Seamounts at the Continental Margin of California: A different kind of oceanic intra-plate volcanism: Geol. Soc. Amer. Bull, vol. 114, p. 316-333..

Dalrymple, G.B., 2004, Ancient Earth, Ancient Skies: Stanford University Press, 247 p.

Dalrymple, G.B., 2007, The ages of the Earth, Solar System, Galaxy, and Universe. Pp. 150-179 in Peto, A.J., and Godfrey, L.R., eds., Scientists Confront Intelligent Design and Creationism: W.W. Norton, 463 pp.