Norman L. Bowen
Geochemistry and Geochronology
A founding father of experimental petrology.
Bowen brought together the disciplines of geology and chemistry to create the new science of experimental petrology, the experimental study of rocks. Already an amateur geologist, he graduated from Queens University with a scholarship which he took to MIT, studying under fellow Canadian Reginald A. Daly.
The 1910s and 1920s were the right time for the development of a new stage in the experimental examination of geological formations. Crustal rocks had been studied all over Europe and North America, and speculation about how the earth's crust had formed, especially with regard to igneous and metamorphic rock, was rampant. In addition, many experimental techniques to create high temperatures were just starting to be developed. The melting point of anorthite was already well established and used as a point for thermocouple calibration.
Bowen undertook to experimentally recreate the temperature and composition regimes in which dominant kinds of crustal rocks formed. His background in both chemistry and geology, as well as his strong ability of field observation, made him uniquely suited to this task.
With his new PhD, Bowen accepted a position at the Geophysical Laboratory, Carnegie Institution of Washington and started work there in 1912. He continued his studies of crustal rocks, now examining the albite-anorthite system which forms plagioclase, the most abundant mineral in Earth's crust. He was able to experimentally demonstrate the truth of theories about rock formation which were decades old, but not yet proven. In 1928, he published The Evolution of the Igneous Rocks, which became the handbook for petrologists worldwide.
In 1937, Bowen left the Geophysical Laboratory and taught at the University of Chicago for ten years. He then returned to the Laboratory where he remained until his retirement in 1952.
Sources: Earth Sciences History, 1992, v. 11, no. 1, p. 45-55; Image: AGU Volcanology, Geochemistry and Petrology website.