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Single-crystal U-Pb zircon age determination of the Red Mountain pluton, Laramie Anorthosite Complex, Wyoming

Journal Article · · American Mineralogist; (USA)
OSTI ID:6033912
 [1]; ;  [2]
  1. Univ. of Wyoming, Laramie (USA)
  2. Swiss Federal Institute of Technology, Zurich (Switzerland)
In order to provide a precise age for the Red Mountain pluton, the youngest of the syenitic bodies of the Laramie Anorthosite Complex, Wyoming, zircons were extracted and analyzed for U-Pb isotopes. Zircon grains were selected and individually analyzed in order to minimize potential complications of inherited components. No grains with inherited cores were identified, either by microscopic examination or from the isotopic data. On a concordia diagram, the U-Pb data form a slightly discordant array. A best-fit line intersects concordia at 1,439{sup +7}{sub {minus}6} Ma and 102 {plus minus} 64 Ma (95% confidence level). The upper intercept is interpreted as the crystallization age of the Red Mountain pluton and provides a younger age limit for the rest of the Laramie Anorthosite Complex.
OSTI ID:
6033912
Journal Information:
American Mineralogist; (USA), Journal Name: American Mineralogist; (USA) Vol. 75:1-2; ISSN AMMIA; ISSN 0003-004X
Country of Publication:
United States
Language:
English