What is Coconino Sandstone made of?
The Coconino Sandstone is typically buff to white in color. It consists primarily of fine well-sorted quartz grains, with minor amounts of potassium feldspar grains deposited by eolian processes (wind-deposited) approximately 275 million years ago.
What kind of landscape formed the Coconino Sandstone?
The Coconino Sandstone was a Sahara-like sand sea, called an erg. It was a wind-blown dune desert that stretched from present-day Arizona all the way to Canada.
How thick is the Coconino Sandstone?
Coconino Sandstone. Chiefly a cliff-forming, white, fine- to medium-grained, cross-bedded sandstone. Thickness 51.6 feet (15.7 m).
How old is the Coconino Sandstone layer?
about 260 million years old
Coconino Sandstone – This layer averages about 260 million years old and is composed of pure quartz sand, which are basically petrified sand dunes. Wedge-shaped cross bedding can be seen where traverse-type dunes have been petrified. The color of this layer ranges from white to cream colored.
What fossils are found in Coconino Sandstone?
The only fossils preserved within the Permian-age Coconino Sandstone are trace fossils. Footprints, tracks, and burrows created by prehistoric vertebrate and invertebrate animals indicate life in a vast, sandy desert. This is a photo of reptile tracks, which are common in the Coconino Sandstone.
Where it is exposed in Grand Canyon the Coconino Sandstone takes the form of?
Dating to approximately 260 million years ago, the Coconino is composed of nearly pure quartz sand. The cross-bedded features indicate that the Coconino Sandstone is basically petrified sand dunes.
How was the Hermit shale formed?
The mudstones and siltstones of the Hermit Shale and Supai Group were laid down by a meandering system of rivers and streams in a semi-arid climate about 280 million years ago. The sand grains of the Coconino Sandstone were deposited by wind across large coastal sand dunes about 275 million years ago.
How is Coconino Sandstone formed?
The Coconino Sandstone formed as the area dried out and sand dunes made of pure quartz sand invaded a growing desert some 260 million years ago (see 6b in figure 1). Today, it is a 375 to 650 ft (115 to 200 m) thick golden white to cream-colored cliff-former near the canyon’s rim.
What fossils are in Coconino Sandstone?
How did Coconino Sandstone form?
What is the composition of the Zoroaster granite?
Vishnu Schist and Zoroaster Granite – This layer averages about 1,700 to 2,000 million years old and consists of mica schist. These were originally sediments of sandstone, limestone and shale that were metamorphosed and combined with metamorphosed lava flows to form the schist.
What is the composition of the Grand Canyon?
Grand Canyon’s Rock Layers Sedimentary rocks form the middle and top layers of Grand Canyon. Layers of sediment hardened into sedimentary rocks over time. Most of the canyon’s igneous and metamorphic rocks make up the bottom layers of Grand Canyon, near the Colorado River. Igneous rocks formed when liquid magma cooled.