Day 2, Stop 3
38o 17.296' N
111o 09.774' W
Early - Middle Jurassic
The waterfall overlook is a good place to view the contact between the Navajo Sandstone and the overlying Page Sandstone. Because they are of very similar lithology, the Page Sandstone and Navajo Sandstone were not originally differentiated as separate formations. It was not until the recognition that the J-2 unconformity, subtly indicated by a lag deposit, was a disconformable surface separating the two formations that stratigraphers identified them as two separate formations. The Page Sandstone is separated into three members, which are identified below (Mathis 2000).
Across Hwy 24 from the waterfall overlook is the abandoned former channel of the Fremont River. In 1962 the Fremont River was rerouted as part of construction of Hwy 24. Exposed in the east wall of this former channel are soft sediment deformation structures in the uppermost Navajo Sandstone. In general, the upper third of the Navajo Sandstone formation contains more soft sediment deformation than lower portions. This may indicate that it was deposited in a wetter environment, or perhaps that watertable flucuations were an important factor in soft sediment deformation.