American geochemists

Clair Cameron Patterson (June 2, 1922 – December 5, 1995) was an American geochemist. Born in Mitchellville, Iowa, Patterson graduated from Grinnell College. He later received his Ph.D. from the University of Chicago and spent his entire professional career at the California Institute of Technology (Caltech).
In collaboration with George Tilton, Patterson developed the uranium–lead dating method into lead–lead dating. By using lead isotopic data from the Canyon Diablo meteorite, he calculated an age for the Earth of 4.55 billion years, which was a figure far more accurate than those that existed at the time, and one that has remained largely unchallenged since 1956.
Patterson first encountered lead contamination in the late 1940s as a graduate student at the University of Chicago. His work on this subject led to a total re-evaluation of the growth in industrial lead concentrations in the atmosphere and the human body, and his subsequent activism was seminal in the banning of tetraethyllead in gasoline and lead solder in food cans.

Charles Carter Schnetzler (June 3, 1930 – December 15, 2009) was a planetary scientist at NASA's Goddard Space Flight Center. Schnetzler is best known for analyzing Moon rocks brought back by the Apollo program and for studying the Earth's environment using the Landsat and the Earth Observing System. Schnetzler was born in Whiting, Indiana and grew up in Neodesha, Kansas. On November 4, 2009, Schnetzler was seriously injured after being hit by a motorist while walking near his home on Little Patuxent Parkway in Columbia, Maryland. He later died in his home on December 15, 2009.

Robert Minard Garrels (August 24, 1916 – March 8, 1988) 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 University 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.

Gerald J. Wasserburg (March 25, 1927 – June 13, 2016) was an American geologist. At the time of his death, he was the John D. MacArthur Professor of Geology and Geophysics, emeritus, at the California Institute of Technology. He was known for his work in the fields of isotope geochemistry, cosmochemistry, meteoritics, and astrophysics.