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Ryan E Frazer, Ph.D.


I am an isotope geochemist interested in applying high-precision measurements of radiogenic isotopes such as Sr, Nd, and Pb to a variety of problems in igneous petrology, tectonics, and the stratigraphic record.

I joined the USGS as a Mendenhall Postdoctoral Fellow to examine the ages and sources of igneous rocks in the central Colorado Mineral Belt. I will do this using whole rock radiogenic isotope geochemistry and high-precision U-Pb zircon geochronology acquired by chemical abrasion-isotope dilution-thermal ionization mass spectrometry (CA-ID-TIMS) in the Denver Radiogenic Isotope Lab.

Prior to joining the USGS, I spent three years working in the Bowring Isotope Laboratory at MIT. There, I primarily performed U-Pb zircon CA-ID-TIMS analyses to 1) understand chronostratigraphy of the Permian-Triassic Karoo Basin of South Africa; 2) determine the timing of magmatism and deformation in the Scottish Caledonides, and 3) unravel the magmatic history of the early Paleozoic Rye Complex of New Hampshire and Maine. Prior to that, I completed my M.S. and Ph.D. at UNC–Chapel Hill, studying the rates and sources of magmatism in the central Sierra Nevada, CA and the Grizzly Peak magmatic system, CO, particularly with respect to the links between plutonic and volcanic rocks, supervolcano eruptions, and the tectonic history of magmatic arcs. I first became interested in the geology and geochemistry of the Sierra Nevada through undergraduate research at Pomona College.