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Isotopic studies of the late Archean plutonic rocks of the Wind River Range, Wyoming.

January 1, 1985

Two late Archaean intrusive events were documented in the Wind River Range by isotopic studies of the Rb-Sr and U-Th-Pb systems in whole-rock samples and the U-Pb systematics for zircon. An age of approx 2630(20) m.y. for the Louis Lake batholith and apparent ages of 2504(40) to 2575(50) m.y. for the Bear Ears pluton were obtained. Post-magmatic hydrothermal events approximately Tertiary in age, lowered delta 18O values and disturbed parent-daughter relationships in most of the isotopic systems investigated. The two intrusive units apparently were derived from different protoliths. Initial isotopic ratios and petrochemistry for the Louis Lake batholith are consistent with an early Archaean trondhjemitic to tonalitic source. The protolith for the Bear Ears pluton must have been subjected to high-grade metamorphism that caused loss of Rb and U prior to magma generation. -L.C.H.

Publication Year 1985
Title Isotopic studies of the late Archean plutonic rocks of the Wind River Range, Wyoming.
Authors J. S. Stuckless, C. E. Hedge, R. G. Worl, K. R. Simmons, Ignatius T. Nkomo, D. B. Wenner
Publication Type Article
Publication Subtype Journal Article
Series Title Geological Society of America Bulletin
Index ID 70013022
Record Source USGS Publications Warehouse