Serpentinites: Geologic Origin & Unique Associated Minerals - C. Leigh Broadhurst, Ph.D.

Serpentinites are full of stories. They are metamorphic rocks that originate from the Earth’s mantle. Older serpentinites – “alpine ultramafics” – have distinctive mineralogy that helps geologists reconstruct past plate margins and how plate tectonics worked when the Earth was much younger. These older serpentinites are found within ancient regionally metamorphosed piedmont or shield locales. Serpentinites of more recent origin are found in active or recently active subductive plate margins. Distinctive soils have developed from serpentine rocks, like the immensely fertile Central Valley of California. Dr. C. Leigh Broadhurst guides us through serptentinite’s origins, mineralogical significance, and commercial value. She holds a Ph.D. Planetary Geochemistry and Physical Chemistry from the University of Arizona, and a B.S in Geology from the University of Maryland. Her geological research has been focused on rocks of mantle origin — including serpentinites — that help to categorize the origin of the Earth and its plate tectonic system. Dr. Broadhurst recently retired from the Dr. Rufus Chaney research group at the U.S. Department of Agriculture Agricultural Research Service.