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When was the Toroweap Formation formed?
Cliffs of the Toroweap Formation can be found in Walnut Canyon National Monument, about 70 mi southeast of the Grand Canyon, and east of Flagstaff, Arizona….Toroweap Formation.
| Toroweap Formation Stratigraphic range: Early Permian, 272–270 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓ | |
|---|---|
| Overlies | Coconino Sandstone |
How was Toroweap Formation formed?
The Toroweap formation is made up of darker gypsum, shale, and limestone. There are erosion-resistant areas made of sandstone that can cause different shapes to form in the canyon. It was formed from being deposited in a sea, as its shoreline invaded and retreated over the land.
How old is the Supai Group?
315-285 million years
View of the Supai Group from along the Bright Angel Trail on the Grand Canyon’s South Rim. Age of 315-285 million years.
When was Coconino Sandstone formed?
approximately 275 million years ago
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.
How did Kaibab Limestone form?
The Kaibab Formation consists of marine limestone and siltstone that was deposited in a shallow tropical sea and coastal flats on the west coast of the supercontinent Pangaea.
Why is the Supai Group Red?
The Supai Group represents a wide variety of environments, but recent study shows the most prevalent is coastal desert eolian (wind-blown) sands. Each formation was covered by the sea at least once, but most of the formation represents dry land. As in the Hermit, the red color is from iron oxide.
How old is the Vishnu Schist?
About 1.75 billion years old
Vishnu Schist—Quartz-mica schist, pelitic schist, and meta-arenites of metamorphosed, arc-basin, submarine sedimentary rocks. About 1.75 billion years old.
How deep in the earth was the Vishnu Schist?
In the case of the unconformity between the Vishnu Basement Rocks and the Unkar Group, studies of the underlying Vishnu Basement Rocks indicate they were uplifted from a depth of about 25 kilometres (16 mi) to a depth of about 10 kilometres (6.2 mi), between 1.75 and 1.66 billion years ago, and from a depth of about 10 …
Is the Kaibab Formation similar to the Toroweap Formation?
The Toroweap environment may have been analogous to this scene from the Gulf of California. North and west of the Canyon, the Toroweap contains gypsum and salt deposits attesting to evaporation in a shallow sea. The Toroweap is not as fossil-rich as the Kaibab Formation.
What was the environment like for the Toroweap?
The Toroweap was deposited near the shore of a shallow sea whose incursion was interrupted by several temporary retreats. The retreats left the sediments exposed to air in salty tidal mudflats. The Toroweap environment may have been analogous to this scene from the Gulf of California.
What kind of rock is in the Toroweap Canyon?
Hikers first notice the formation when they descend to the first pinkish mudstone layer. From the rim, look for these pink beds just below the Kaibab cliff. The Toroweap has one of the most diverse rock varieties in the Canyon: sandstone, mudstone redbeds, gypsum, limestone and dolomite.
Is the Toroweap part of the Brady Canyon?
North and west of the Canyon, the Toroweap contains gypsum and salt deposits attesting to evaporation in a shallow sea. The Toroweap is not as fossil-rich as the Kaibab Formation. The limestone cliff part way down, called the Brady Canyon Member, represents the deepest water and contains various shellfish.