Figure 217 (left). Stream erosion on inclined strata-Colorado Plateau, central Utah.

A sequence of tilted sedimentary rocks commonly exposes formations which become eroded in a variety of ways. In arid regions sandstone and limestone are usually hard and resistant, whereas shale is weak and easily eroded.

Figure 217 (right). o .5 mile Problems - 1. What type of rock would tend to develop the most intricate system of tributaries? 2. Make a sketch map showing how the plateau will appear in the future. 3. Make a geologic map of the area. Show dip and strike symbols for the major formations and

for the major joint systems.