How would you characterize the Navajo Sandstone?
Navajo Sandstone consists of well-sorted, rounded grains of translucent quartz, many of which are etched and frosted. This, together with the large-scale cross-bedding, indicates that the Navajo sediments accumulated in a vast desert which covered much of Utah, Arizona, and New Mexico during early Jurassic time.
What was the depositional environment for the Navajo Sandstone?
Depositional environment The sandstone was deposited in an arid erg on the Western portion of the Supercontinent Pangaea. This region was affected by annual monsoons that came about each winter when cooler winds and wind reversal occurred.
How was Navajo Sandstone formed?
The Navajo Sandstone consists of thick layers of cross-bedded sandstone formed by windblown sand dunes in a vast ancient desert. In the early Jurassic, the climate of the Colorado Plateau dried significantly, creating desert conditions over a broad region.
What type of sedimentary rock is Navajo Sandstone?
The rocks are predominantly composed of rounded quartz grains and were formed in a vast ancient desert of sand dunes, or erg, similar to the modern Sahara Desert. The Navajo Sandstone is one of the most extensive and most exposed aeolian (wind-blown) systems known in the geologic record.
What is Navajo Sandstone famous for?
The Navajo Sandstone is known for its beautiful red and tan crossbedded sandstones that grace many of the national parks and monuments in the southwest USA. The sands were deposited in dunes within the largest known sand sea (erg) in Earth’s history during the Early Jurassic.
Why is the Navajo Sandstone red?
To start, the Navajo is made of grains of light-colored quartz sand, similar to those found in many modern dune or beach environments. This was due to the chemical breakdown (oxidation) of very small amounts of iron-containing minerals within the sand, and made the earlier Navajo Sandstone a pinkish-red color overall.
Why is there so much sandstone in Utah?
However, in Utah, sandstone is the most common geological substrate for their formation. Several of Utah’s sandstone bedrock units meet the favorable conditions of being strong enough to support the weight of large natural arches, yet soft enough to be easily eroded by the natural processes of wind, water, and gravity.
What color is Navajo sandstone?
red
The range of colors of the Navajo Sandstone –red, brown, pink, salmon, gold, and even white—results from varying amounts and forms of iron oxide within the rock, and in the case of the white upper portion of the Navajo, the overall lack of iron.
What modern day location on Earth will eventually form a rock formation like the Navajo sandstone?
All about Sandstone. The Navajo’s tendency to form huge cliffs is largely responsible for Zion’s stunning, high-wall scenery. Zion sits on the southern end of the Colorado Plateau, an area stretching from central Utah and western Colorado down to northern New Mexico and Arizona.
Is Navajo sandstone a sedimentary rock?
Identifying the source of sedimentary rocks is important for reconstructing ancient landscapes. The thick Navajo sandstone, pictured here in Zion National Park, is one of the largest wind-deposited formations in the geologic record. Geologists have devised a new way to determine the origin of such sedimentary rocks.
What type of rock is sandstone?
Sandstone is a type of sedimentary rock. It forms when grains of sand are compacted together over very long periods of time. Normally this sand has an abundance of quartz but can also contain other minerals and materials. Sandstone comes in a variety of colors including red, yellow, gray, and brown.
What type of rock is Angels Landing?
Navajo Sandstone
| Angels Landing | |
|---|---|
| Geology | |
| Age of rock | Jurassic |
| Mountain type | Monolith |
| Type of rock | Navajo Sandstone |
Where are the Navajo Sandstone formations in Utah?
A prominent cuesta of Navajo Sandstone rims the edge of the San Rafael Swell in eastern Utah. Navajo Sandstone is a geological formation in the Glen Canyon Group that is spread across the U.S. states of southern Nevada, northern Arizona, northwest Colorado, and Utah as part of the Colorado Plateau province of the United States.
What kind of minerals are found in Navajo Sandstone?
Where the oxidizing and reducing fluids mixed, the iron precipitated within the Navajo Sandstone. Depending on local variations within the permeability, porosity, fracturing, and other inherent rock properties of the sandstone, varying mixtures of hematite, goethite, and limonite precipitated within spaces between quartz grains.
What was the process of diagenesis of Navajo Sandstone?
During later diagenesis of the Navajo Sandstone while deeply buried, reducing fluids, likely hydrocarbons, dissolved these coatings. When the reducing fluids containing dissolved iron mixed with oxidizing groundwater, they and the dissolved iron were oxidized.
Why are the Navajo sandstones called Moqui marbles?
The Navajo Sandstone is also well known among rockhounds for its hundreds of thousands of iron oxide concretions. Informally, they are called “Moqui marbles” and are believed to represent an extension of Hopi Native American traditions regarding ancestor worship (“moqui” translates to “the dead” in the Hopi language).