Posted by:
Amyjo
(
)
Date: December 07, 2017 05:29PM
The entire rock formations of southern Utah (northern tip of the Mojave Desert,) are filled with oxidized iron and trace minerals - that's what gives them the splendid hues they're famous for. I'm sure if some enterprising businessmen wanted to "harvest" that potential 'gold mine' they'd be doing it given the opportunity.
"So what’s behind the spectacular hues for which Utah is so famous? The color of rock is primarily influenced by trace minerals. The red, brown, and yellow colors so prevalent in southern UT result from the presence of oxidized iron–that is iron that has undergone a chemical reaction upon exposure to air or oxygenated water. The iron oxides released from this process form a coating on the surface of the rock or rock grains containing the iron.
Just think of what happens to a nail when you leave it outside. Upon prolonged exposure, the iron in the nail oxidizes and rust is formed as a coating on the surface of the nail. So basically what we have in red rock country is a lot of rusting sandstones and shales. Hematite is an especially common mineral form of iron oxide in Utah, the name coming from the Greek word “heama” or red blood. It only takes a tiny bit of hematite make a lot of red rock.
Geologists refer to rock layers of similar composition and origin within a given geographic area as “formations.” Certain formations in Utah are especially known for their beautiful reds or pinks. The Permian Period gave us Organ Rock shale which caps the buttes and pinnacles of Monument Valley. The deep ruddy browns of the Moenkopi formation were formed in the Triassic. In the early Jurassic, eastern Utah was a vast sea of sand with wind-blown dunes. These dunes became the red bed deposits of the Wingate Formation which today forms massive vertical cliffs. Entrada sandstone, from the late Jurassic, forms the spectacular red, slickrock around Moab."
http://wildaboututah.org/red-rock-country/Here's what makes those beautiful red rocks:
"In many of Southern Utah’s rock formations, the sand or mud is cemented together with hematite – a rusty red iron oxide mineral – and limonite – a yellow iron oxide mineral.
Take, for instance, the Navajo sandstone that makes up the sheer cliffs ofZionNational Park. During the Jurassic Period – about 180 million years ago – this area was covered by a vast desert. Some of the sand may have been red at the time from the iron mineral (geologists can’t be sure, there are no photos from that time) but it is more likely the sand was your typical tan color. Those sand grains haven’t changed color. If you look at a piece of Navajo sandstone under a microscope, the grains themselves are still white, gray or tan, but the grains are completely coated with the hematite cement, giving the appearance that the rock is totally red."
https://southernutahwriter.wordpress.com/2011/08/28/science-matters-what-makes-the-rocks-red/