Comparison of Unconsolidated Deposits on Areas of Anomalous Altitude and Flatness in and around the Southern Wind River Basin, Fremont Co, WY

Table Mountain is a prominent landform flanking the eastern Wind River Mountains. Despite its close proximity to some of the most studied geology in Wyoming, the time of deposition of the surface remains a mystery. Several sources give three different ages, ranging from Eocene to Pleistocene, and Be 10 ages from surface boulders range from 783 to 135 ka. As implied by its name, Table Mountain, elevation 71 00 ft, is quite flat. The surface exists primarily as loose gravel embedded with large boulders, the majority of which are granitic, all superimposed upon uplifted, tilted Paleozoic and Mesozoic layers. The boulders are up to 3 m 3 in size and most are faceted, suggesting glacial depositional origin. Other sites, along the northern front of the Wind River Mountains, at approx. 7100 ft exhibit similar surface deposits, although only the closest surface has extremely large boulders similar to Table Mountain. The implication of this boulder distribution is that early Pleistocene glaciation events in the area extended from the mountains into the basin, prior to canyon formation. By evaluating landforms of similar altitude and topography around the basin, we will gain a deeper understanding of the early Pleistocene glacial history of the Wind River Mountains.