Monday, April 26, 2010

The beautiful Red Rocks of Sedona...a part of the Great Basin Desert!

Millions of years, sometimes hundreds of millions of years, went into the creation of what we now know as Sedona. A lot can happen in millions or hundreds of millions of years! Furthermore, the climate of Sedona changed over time - it has been under water, it has been a seacoast, and it has been a desert. Each type made its contribution to what is now Sedona.

The uplift of the Colorado Plateau several million years ago that created the Grand Canyon, also caused a cracking of the earth in the Sedona area. Earlier pressures caused by the movement of huge blocks of the earth’s crust also created cracks. Water followed the cracks and wore away the surrounding rock, resulting in creeks and streams. Because of this wearing away of rock during the last few million years in the Sedona area, we now have Bell Rock, Courthouse Rock, Cathedral Rock, and Coffee Pot Rock, as well as other cliff faces in the Sedona area. In general, they are capped by an erosion-resistant limestone that now protects the underlying softer layers from erosion. (see picture)

The red rocks of Sedona, then, originated, some of them, from sediment in a sea or floodplain, while others originated from blown sand on dry land or in coastal areas. They can be distinguished by their colors, some more bright orange than others, some red, some tan. The bright orange rocks are more than 250 million years old. The white or grey rocks are either limestone that formed at the bottom of a sea, or else they are sandstone that has lost its red color because the color has been flushed out by water. The red one sees is actually dissolved iron as it has drained through the sandstone.

Another interesting tidbit that I learned is that name Arizona was derived from the term "arid" "zone", thus making the name Arizona. Also, Arizona is the only state that has all four deserts in North America. These deserts are the Mojabe,which is shared with California, the Sonoran and Chihuahuan deserts that are shared with Mexico and the Great Basin Desert, which is shared with New Mexico.

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