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Thomas Krogh (Staff Scientist 1966-1975) Honored

A special issue of the Canadian Journal of Earth Sciences (CJES) was published on 23 February in honor of former Geophysical Laboratory Staff Scientist, Thomas Edvard Krogh (1931-2008).

The volume highlights Thomas’ scientific achievements in the early 1970s in the field of U-Pb geochronology, in particular his development of high-resolution tools and laboratory methodologies that led to more precise dating of Precambrian rocks.  His work revolutionized the technique of radiometric uranium-lead dating and shed light upon our understanding of Earth’s evolution through time.

As a Staff Scientist at Carnegie from 1966 to 1975, he refined the U-Pb isotopic dating technique through hydrothermal decomposition and a reduction of both Pb contamination levels and sample sizes.  Along with his colleague Gordon Davis, he was able to produce the first mixed Pb-U spike, and later with Randy Parrish in the 1980s, a large quantity of purified Pb for distribution.  The combination of these discoveries greatly improved how scientists determine the age of rocks.  Following his years at the Geophysical Laboratory, he accepted a position as Director of the Geochronology Laboratory at the Royal Ontario Museum in Toronto, Canada.

A native of Canada, Thomas was born in Peterborough, Ontario on 12 January 1936.  He studied geological engineering at Queen’s University, where he obtained a bachelor’s and master’s degree in geology.  He received his Ph.D. in geochronology from the Massachusetts Institute of Technology in 1964.  The impact of his work remains visible today in the way in which scientists around the world understand geologic processes.