Robert Minard Garrels was an American geochemist. Garrels applied experimental physical chemistry data and techniques to geology and geochemistry problems. The book Solutions, Minerals, and Equilibria co-authored in 1965 by Garrels and Charles L. Christ revolutionized aqueous geochemistry. Garrels earned a bachelor's degree in geology from The University of Michigan in 1937. He went on to earn an M.S. degree from Northwestern in 1939, his thesis work was on iron ores of Newfoundland in 1938. His Ph.D was awarded in 1941 based on lab studies of complex formation between lead and chloride ions in aqueous solution.
Life and career
Garrels worked for the U.S. 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." with W. C. Krumbein, which was to become a classic study of sedimentary rocks from a physical chemistry viewpoint. This and following works revolutionized sedimentary and aqueous geochemistry. He joined the USGS again for a time, but returned to academia at Harvard in 1955. He became full professor in 1957 and later department chair. His work and the lab he supervised at Harvard produced many classic works including the Solutions, Minerals, and Equilibria text. Here between 1960 and 1962 he along with his colleagues published the classic studies:
"Oxidation of Pyrite by Iron Sulfate Solutions"
"Stability of Some Carbonates at 25°C and One Atmosphere Total Pressure"
"Control of Carbonate Solubility by Carbonate Complexes"
"A Chemical Model for Sea Water at 25°C and One Atmosphere Total Pressure"
He returned to Northwestern in 1965 and conducted influential studies on the silicate and carbonate buffering of seawaters, the genesis of groundwaters and the theoretical treatment of irreversible reactions in geochemical processes. In 1969 he moved to the Scripps Institution of Oceanography and later to the University of Hawaii. During this time he worked on thermodynamic properties of silicate minerals and also published "Cycling of Carbon, Sulfur, and Oxygen through Geologic Time" with Ed Perry in 1974. In 1974 he returned to Northwestern and published important studies on the sulfur and carbon isotopic compositions of Phanerozoic rocks with Abraham Lerman and Fred MacKenzie. Garrels had broad interests beyond geology. He enjoyed travel and wine. He was athletic, holding the world high jump record for men over 57 years of age. He was a poet-scientist: Cycle of P by Robert M. Garrels I put some P into the sea the biomass did swell But settling down soon overcame and P went down toward Hell From Purgatory soon released it moved up to the land To make a perfect rose for thee to carry in thy hand But roses wilt and die you know then P falls on the ground Gobbled up as ferric P a nasty brown compound The world is moral still you know and Nature's wheels do grind Put ferric P into the sea and a rose someday you'll find He moved to the University of South Florida at St. Petersburg in 1979, holding the St. Petersburg Progress Chair in Marine Science, and spending summers at Yale where he held an adjunct professorship, the Université Louis Pasteur, Strasbourg, and the Université Libre, Brussels. During this time he published "The Carbonate-Silicate Geochemical Cycle and Its Effect on Atmospheric Carbon Dioxide over the Past 100 Million Years" in 1983. This concerned the BLAG model, named for the collaborators including Tony Lasaga and Robert Berner. He continued to be active while fighting cancer, publishing "Modeling Atmospheric 02 in the Global Sedimentary Redox Cycle" and "A Model for the Deposition of the Microbanded Precambrian Iron Formations."
