Rodeo, New Mexico
April 5, 2004
So Bob and I took our time and reveled in viewing and photographing the orange-red mesas, buttes, and spires. We frequently stopped and got out of the car to look more closely and at different angles, and enjoy the peaceful quiet of the valley with the engine turned off. At a few locations, tables were set up where Diné vendors were selling jewelry.
I’ve read that Monument Valley isn’t really a valley but a plateau, and it did appear that way from our vantage points. In fact, this area is part of the Colorado Plateau, and used to form the bottom of a large inland sea millions of years ago. A combination of the forces of water plus pressures from within the earth created the landforms we see here. The reddish hue of many of the rocks comes from iron oxide in a type of sedimentary rock called siltstone, a transitional rock between shale (with finer particles) and sandstone (whose particles are more coarse).
Mesas emerged cut by the erosional forces of water, and/or pushed up by a fault. As erosion continues, the mesa shrinks and eventually becomes a butte (a small mesa). Eventually the butte is worn away into a spire. The mittens are buttes with one side a spire, creating a thumb-like effect. A typical butte is composed of a base of soft shale, a large mid-portion of sandstone, and capped by harder shale topped with siltstone. Vertical lines called "joints" determine how the rock will continue to erode. The floor upon which the rock formations stand is mostly red sand or siltstone.
It was late afternoon when we emerged from the valley, parked the car in our camp space, and settled into our motor home next to it to watch another stunning sunset. Not a bad way to live!
From journal Walking in Beauty -- Monument Valley