John W. Valley is the Charles R. Van Hise Distinguished Professor of Geology at the University of Wisconsin–Madison. He received his AB from Dartmouth College and PhD from the University of Michigan (1980). He was Chair of the Department of Geoscience at UW–Madison from 1996 to 1999, and has taught a range of graduate and undergraduate courses including Introductory Geology (33 times), Mineralogy and Petrology. He has advised 34 MS and 17 PhD students, and 25 post-doctoral scholars.
Valley’s earliest research concerned high-grade metamorphism and Precambrian geology with fieldwork in many areas of Asia, Australia, Europe, and North America. More recently, he has investigated isotope geochemistry of magmas of known age from 4.4 billion years to recent. His studies of zircons from the Earth’s earliest crust have shown that the planet’s surface cooled more quickly than previously thought, that hot “Hadean” conditions lasted less than 100 million years after the formation of the Earth and Moon and that habitable conditions and oceans existed on Earth over 800 million years before the earliest known microfossils. He has also shown that these ancient fossils lived in a complex community of microbial life 3,465 million years ago, indicating that the first life came earlier.
Valley’s other interests include mineralogy, paleoclimatology, and astrobiology. In 2005, he established the WiscSIMS Lab at UW–Madison, which is dedicated to developing procedures for microanalysis and novel applications of stable isotope geochemistry. Valley has published over 380 professional papers; is a Fellow of six professional societies; received the N.L. Bowen Award from the American Geophysical Union and Hilldale Award from UW-Madison; and is past-President of the Mineralogical Society of America. He presently serves on the Board of Governors for the Gemological Institute of America. The mineral valleyite (Ca4Fe6O13) is named in his honor.
