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40Ar/39Ar Ages, Compositions, And Likely Source Of The Eocene Fallout Tuffs In The Duchesne River Formation, Northeastern Utah, Michael Seth Jensen
40Ar/39Ar Ages, Compositions, And Likely Source Of The Eocene Fallout Tuffs In The Duchesne River Formation, Northeastern Utah, Michael Seth Jensen
Theses and Dissertations
Thin fallout tuffs in the Duchesne River Formation in the Uinta Basin, Utah are evidence that volcanism was active in northern Nevada and Utah in the late Eocene. The Uinta Basin is a sedimentary basin that formed during the Laramide orogeny. Ponded lakes of various salinity filled and emptied and during the late Eocene the northern rim was dominated by a wetland/floodplain depositional setting. Most of the tuffs have rhyolitic mineral assemblages including quartz, biotite, sanidine, and allanite. Rhyolitic glass shards were also found in one of the ash beds. Biotite compositions have Fe/(Fe+Mg) ratios typical of calc-alkaline igneous rocks …
40ar/39ar Ages, Compositions, And Likely Source Of The Eocene Fallout Tuffs In The Duchesne River Formation, Northeastern Utah, Michael Seth Jensen
40ar/39ar Ages, Compositions, And Likely Source Of The Eocene Fallout Tuffs In The Duchesne River Formation, Northeastern Utah, Michael Seth Jensen
Theses and Dissertations
Thin fallout tuffs in the Duchesne River Formation in the Uinta Basin, Utah are evidence that volcanism was active in northern Nevada and Utah in the late Eocene. The Uinta Basin is a sedimentary basin that formed during the Laramide orogeny. Ponded lakes of various salinity filled and emptied and during the late Eocene the northern rim was dominated by a wetland/floodplain depositional setting. Most of the tuffs have rhyolitic mineral assemblages including quartz, biotite, sanidine, and allanite. Rhyolitic glass shards were also found in one of the ash beds. Biotite compositions have Fe/(Fe+Mg) ratios typical of calc-alkaline igneous rocks …