MIT Professor Emeritus Frederick A. Frey, a geochemist whose innovative research unlocked many mysteries of the Earth’s interior, died Sept. 13 in Natick, Massachusetts. He was 83. Frey was a pioneer of trace element geochemistry in the study of Earth’s mantle. He established himself as a leading geochemist early in his career by introducing novel applications of techniques and instrumentation — such as radiochemical neutron activation analysis, integrating it with X-ray fluorescence, isotope dilution, radiogenic isotope ratios and field studies — to study variations in the composition of the Earth’s…
