Sometimes the Navajo Sandstone is weathered in amazing formations. When nature’s forces of wind, rain, freeze and thaw have so many millions of years to effect these surfaces even the smallest scale action is amplified.
Here pockets have opened in the sandstone along the shores of Lake Powell. Softer materials have been washed or blown away in favor of the harder minerals. The oranges, pinks, reds and purples of the sandstone are caused by a mix of hematite, goethite, and limonite which has seeped within the quartz sand. The whiter material, often found at the tops of the formations, have had most of these iron oxides leach into the deeper layers, revealing mostly silica.
One of the most magnificent sights of Lake Powell and the Glen Canyon National Recreation Area is the juxtaposition of the waves of Colorado River water and the frozen waves of Navajo Sandstone. Both exhibiting relaxing, fluid motion, but the sandstone echoing waves of sandy beaches and earthen deposits of about 200 million years ago, now frozen in time.
The soft sandstone undulations around the Glen Canyon, Lake Powell and Grand Staircase have a mesmerizing quality to them. They are so unlike the rock that you may see elsewhere in the world, in fact, the slickrock is really not rock at all. It’s a sandstone. To be specific, it is layers of stratified, petrified ocean bottom! It’s ancient beach. The stripes and patterns reflect the flow and direction of different types of sediment and sand, dunes and mudflows. Some of the most famous and recognizable of these formations is in Coyote Butte in Southern Utah towards Kanab.
As a stark contrast to these soft forms is the appearance of the “tub ring”, a salty, alkaline mineral deposit left behind from Lake Powell as its Colorado river water leaches these minerals out of the surrounding land on its way to the reservoir. When the lake level was rising from the day the Glen Canyon dam was completed this ring was not an issue.
Once Lake Powell filled Glen Canyon the fluctuations of water level (drought, flood, water release from the dam) started to reveal this white deposit on the porous shore surfaces.