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Geological Formation

Bright Angel Shale

Named Rock Formations and Groups

The Bright Angel Shale is one of five formations making up the Cambrian Tonto Group, exposed in the Grand Canyon of northern Arizona as well as southeast California, southern Nevada and southcentral Utah, dating to the Middle Cambrian, roughly 507 to 502 million years ago. It consists mainly of greenish, micaceous, fissile shale and siltstone bearing illite, chlorite and kaolinite, with red-brown, hematite-bearing sandstone and siltstone, isolated limestone beds and glauconite-rich layers, ranging from 57 to 450 feet thick and thickest in the western Grand Canyon; its cross-stratification, laminations and wavy bedding record tidal and shallow marine environments. It is the most fossiliferous of the five Tonto Group formations, yielding at least 15 trilobite species along with brachiopods, hyoliths and trace fossils including arthropod tracks and worm burrows.

Connections

Associated With

Cambrian, Eras
Source Bright Angel Shale (Wikipedia)
Limestone, Materials
Source Bright Angel Shale (Wikipedia)
Mudstone, Materials
Source Bright Angel Shale (Wikipedia)
Sandstone, Materials
Source Bright Angel Shale (Wikipedia)
Shale, Materials
Source Bright Angel Shale (Wikipedia)
Siltstone, Materials
Source Bright Angel Shale (Wikipedia)

In Discipline

Stratigraphy, Disciplines
Source Bright Angel Shale (Wikipedia)
In the Other Atlases

Found In

United States

Also in Geography Atlas: where this subject is found.

Sources
Bright Angel Shale (Wikipedia)
  • Associated With: Siltstone, Lead paragraph
    The Bright Angel Shale consists of locally fossiliferous, green and red-brown, micaceous, fissile shale (mudstone) and siltstone with local, thicker beds of brown to tan sandstone and limestone.
  • Associated With: Sandstone, Lead paragraph
    The Bright Angel Shale consists of locally fossiliferous, green and red-brown, micaceous, fissile shale (mudstone) and siltstone with local, thicker beds of brown to tan sandstone and limestone.
  • Associated With: Cambrian, Lead, age Cambrian
    The Bright Angel Shale is one of five geological formations that comprise the Cambrian Tonto Group.
  • Associated With: Shale, Lead, rock Shale
    The Bright Angel Shale consists of locally fossiliferous, green and red-brown, micaceous, fissile shale (mudstone) and siltstone with local, thicker beds of brown to tan sandstone and limestone.
  • Associated With: Mudstone, Lead, rock Mudstone
    The Bright Angel Shale consists of locally fossiliferous, green and red-brown, micaceous, fissile shale (mudstone) and siltstone with local, thicker beds of brown to tan sandstone and limestone.
  • Associated With: Siltstone, Lead, rock Siltstone
    The Bright Angel Shale consists of locally fossiliferous, green and red-brown, micaceous, fissile shale (mudstone) and siltstone with local, thicker beds of brown to tan sandstone and limestone.
  • Associated With: Sandstone, Lead, rock Sandstone
    The Bright Angel Shale consists of locally fossiliferous, green and red-brown, micaceous, fissile shale (mudstone) and siltstone with local, thicker beds of brown to tan sandstone and limestone.
  • Associated With: Limestone, Lead, rock Limestone
    The Bright Angel Shale consists of locally fossiliferous, green and red-brown, micaceous, fissile shale (mudstone) and siltstone with local, thicker beds of brown to tan sandstone and limestone.
  • In Discipline: Stratigraphy, Lead paragraph
    The Bright Angel Shale is one of five geological formations that comprise the Cambrian Tonto Group
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