His Ph.D. was awarded in 1941 based on lab studies of complex formation between lead and chloride ions in aqueous solution.
Garrels worked for the United States Geological Survey during World War II and returned to teach at Northwestern until 1952.
Also in 1952 he published a technical paper, "Origin and Classification of Chemical Sediments in Terms of pH and Oxidation-Reduction Potentials."
[1] In 1974 he returned to Northwestern University and published important studies on the sulfur and carbon isotopic compositions of Phanerozoic rocks with Abraham Lerman and Frederick T.
He was a poet-scientist: Cycle of Pby Robert M. Garrels I put some P into the seathe biomass did swell But settling down soon overcameand P went down toward Hell From Purgatory soon releasedit moved up to the land To make a perfect rose for theeto carry in thy hand But roses wilt and die you knowthen P falls on the ground Gobbled up as ferric Pa nasty brown compound The world is moral still you knowand Nature's wheels do grind Put ferric P into the seaand a rose someday you'll find[2] He moved to the University of South Florida at St. Petersburg in 1979, holding the St. Petersburg Progress Chair in Marine Science, and spent summers at the Université Louis Pasteur, Strasbourg; the Université Libre, Brussels; and Yale, where he held an adjunct professorship.