What happens in between? How do we transition between 100 million years of geologic history? As we drove beyond Kanab and Fredonia onto the sage-covered plains, we could look north and see the Grand Staircase. It is a series of cliffs that contain all of the sediments that once covered the Grand Canyon region, but which have been eroded away in a northward direction. Clarence Dutton coined the term in the 1870s and identified each cliff by color: Chocolate, Vermilion, White, Gray and Pink.
|Source: National Park Service|
The Grand Staircase is preserved today as the western part of Grand Staircase-Escalante National Monument. It is a larger park than Grand Canyon, and contains a diverse landscape of deep slot canyons, high plateaus, faults and monoclines. The origin of the park was clouded by controversy (President Clinton established the park over the objections of local politicians), but new national monuments often are controversial.
It is odd that literally no streams or rivers cross the surface of the plateau. It turns out that the Kaibab Plateau is covered by the Permian-aged Kaibab Formation, a layer composed mostly of limestone. Limestone is soluble in slightly acidic water and joints and fissures will grow into caverns. The ceilings of some caverns will collapse, forming sinkholes. Any surface water tends to disappear into the subsurface quickly. Such surfaces are said to exhibit karst topography.
Some of the sinkholes will fill with clay or mud, forming an impermeable layer. It is these sinkholes that will develop into the lakes and ponds occasionally found on the North Rim. They are pretty much the only source of open water and thus are important to the animals that live here.
It was exciting to see these creatures, a feeling reminiscent of being in Yellowstone National Park, but it was disturbing as well. The animals trample springs and meadows, and may be upsetting the checks and balances of the local ecosystem. The park service is quite unsure about what to do.
|Definitely a bunch of bull!|