Laserfiche WebLink
8 <br />a mile at the entrance to the canyon (mile 45), but it dominates the canyon <br />walls below mile 21 (Fig. 1). Through this reach, the canyon is characterized <br />by a high sinuosity and low average river gradient. The high sheer cliffs often <br />terminate with sandstone talus slopes, but sometimes extend directly into the <br />river. Overhangs are formed occasionally in the canyon wall along the outer <br />curves of meanders. In places, such as Harding Ho 1e, the sandstone on the <br />inside of the meanders is eroded to slopes and terraces. Quaternary river <br />terraces at the base of the Weber sandstone also occur at Castle Park, <br />Laddie Park, Outlaw Park, and Echo Park. <br />2. ~Jpper Morgan Formation (Middle Pennsylvanian) <br />The upper part of the Morgan Formation is a resistant stratum composed <br />of sandstone interbedded with limestone (Fig. 2). It contacts the river <br />for approximately one mile .near the entrance to the canyon, and extensively <br />between Big Joe Rapids and the conf luence with the Green. The reddish <br />colored, ledgy cliffs of this unit are particularly prevalent between miles <br />8.2 and 3.0 where it forms the base of the Weber Sandstone cliffs. <br />3. Lower Morgan Formation (Middle Pennsylvanian) <br />In the lower part of the Morgan Formation, shale and siltstone interbed <br />with the limestone to form a relatively weak structural unit. Exposures of <br />this unit at river level occur principally between miles 44 and 30, but it <br />is also seen at Big Joe Rapids (mile 23.5) and Warm Springs Rapids (mile 4). <br />Due to its high erodability, contact with the river or large side drainages <br />often results in the undermining and consequent structural failure and <br />landsliding of the more resistant strata above. Such landslide deposits can <br />be seen on the right bank of the river at Anderson Ho 1e, Tepee Draw, Browns <br />