Soft rocks that would normally form slopes can also become spires if they have a layer of erosion resistant caprock on top. A good place to see caprock spires is Monument Basin, visible from Grandview Point in Island in the Sky. Profile of a Cliff Face Most cliffs of Canyonlands show classic profiles which can be seen throughout the southwest. Some of Canyonlands' rocks are massive layers of uniform sand which have become cemented. They are the cliff formers such as the Wingate and Cedar Mesa Sandstones.
Gravity is an important partner, contributing to erosion as much as the infrequent rains.
The softer, underlying rock layers erode more quickly. This undercuts the harder, upper layers and they break off in huge slabs. Sometimes they form beautiful arched alcoves and, more frequently, the falling rock leaves vertical cliffs. Poorly cemented and softer layers of sand and shale tend to be slope formers such as the Organ Rock Shale and the Chinle Formation. Their surfaces are usually covered with loose sediment and are often littered with fallen rock slabs from overlying cliffs.