Master of Science (MS)
First Committee Member
Rodney V. Metcalf
Second Committee Member
Third Committee Member
Fourth Committee Member
Number of Pages
Zircon separates from migmatite samples from the East Humboldt Range (EHR), northern Nevada were U-Pb dated using secondary ionization mass spectrometry. Cathodoluminescence images of zircons show bright anhedral cores with abundant euhedral overgrowths surrounding them.
The overgrowths give U-Pb dates indicating two periods of zircon growth. Inner rims have a Cretaceous age population at 70.6 ± 2.6 Ma. Outer rims give Eocene ages that either fall in to a single-age population at 45 ± 1.3 Ma or are part of a range from 41-31 Ma. Discordant zircon cores have upper intercepts between 1.8 -1.0 Ga.
Cretaceous and Eocene ages are interpreted as recording protracted growth of anatectic zircon during Mesozoic thrust burial and Cenozoic regional extension. McGrew et al. (2000) reported a U-Pb TIMS age of 84.8 ± 2.8 Ma on zircons from the EHR, while Premo et al. (2008) reported ion probe ages of 90-71 Ma from zircons in the same area.
Cretaceous geologic period; Eocene geologic period; Migmatite; Nevada – East Humboldt Range; Uranium-lead dating; Zircons
Geology | Volcanology
Drew, Jordan, "Cretaceous and Eocene U-Pb Zircon Migmatite Ages from the East Humboldt Range Metamorphic Core Complex, Nevada" (2013). UNLV Theses, Dissertations, Professional Papers, and Capstones. 1820.