Premo et al. (2008) present new SHRIMP-RG U-Pb zircon data from the orthogneiss of Angel Lake in the East Humboldt Range, Nevada, reinterpreting the age and origin of a rock body that previously had been interpreted as delimiting the southwestern extent of the Archean Wyoming province based on integrated field study and U-Pb ID-TIMS zircon analysis (Lush et al., 1988). Using zircons from the same sample originally collected by A.W. Snoke and J.E. Wright (RM-9), Premo et al. (2008) document Late Cretaceous ages of 91–72 Ma for the clear, oscillatory-zoned rims of many zircons from this sample, conclusively demonstrating the presence of Late Cretaceous melt in this migmatitic gneiss. Furthermore, they reinterpret the core grains as detrital zircons inherited from Meso- to Neoproterozoic metasedimentary source rocks. The potential detrital grains chiefly yield Late Archean apparent ages but also include a variety of Proterozoic apparent ages.
- Received 1 June 2009.
- Accepted 17 March 2010.
- © Geological Society of America