PAINTED  DESERT

 

Eastern Arizona's Painted Desert consists of stunningly beautiful badlands with multicolored, fine-grained siliciclastic sedimentary rocks.  The principal stratigraphic unit is the nonmarine Chinle Formation (Carnian to Norian Stages, Upper Triassic).  In the Painted Desert area, the Chinle is a mudshale-dominated unit.  Many of the shales have variably developed paleosol features.  Some sandstones, minor conglomerates, volcanic ash beds, and terrestrial gypsiferous evaporites also occur.

 

Painted Desert - maroon to red to pink to light gray to white rocks (mostly shales) of the Chinle Formation's Petrified Forest Member (lower Norian Stage, middle Upper Triassic).  View from northern part of Petrified Forest National Park, Arizona, USA.

 

Painted Desert - the Petrified Forest Member of the Chinle Formation (lower Norian Stage, middle Upper Triassic).  View from northern part of Petrified Forest National Park, Arizona, USA.

 

Painted Desert - the Petrified Forest Member of the Chinle Formation (lower Norian Stage, middle Upper Triassic).  View from northern part of Petrified Forest National Park, Arizona, USA.

 

Painted Desert - the Petrified Forest Member of the Chinle Formation (lower Norian Stage, middle Upper Triassic).  View from northern part of Petrified Forest National Park, Arizona, USA.

 

Painted Desert - the Petrified Forest Member of the Chinle Formation (lower Norian Stage, middle Upper Triassic).  View from northern part of Petrified Forest National Park, Arizona, USA.

 

Painted Desert and Pilot Rock - the dark gray to black rocks capping Pilot Rock in the distance are basalts of the Bidahochi Formation (Upper Miocene to Lower Pliocene, 5-8 m.y.).  The reddish to pinkish to whitish rocks in the foreground are part of the Petrified Forest Member of the Chinle Formation (lower Norian Stage, middle Upper Triassic).  View from northern part of Petrified Forest National Park, Arizona, USA.

 

Painted Desert - abundant gypsum (shiny plates) covering slopes of weathered Petrified Forest Member shales.  The gypsum is derived from terrestrial evaporite interbeds.  View from northern part of Petrified Forest National Park, Arizona, USA.

 


 

In contrast with the Petrified Forest Member, the Blue Mesa Member of the lower Chinle Formation consists principally of gray to bluish-gray to purplish-gray mudshales.  These rocks are most readily observed in the Blue Mesa area and "The Teepees" area of Petrified Forest National Park.

 

Painted Desert - light- to medium-gray, bluish-gray, and purplish-gray shales of the Chinle Formation's Blue Mesa Member (upper Carnian Stage, lower Upper Triassic).  View from “The Teepees” in Petrified Forest National Park, Arizona, USA.

 

Painted Desert - light- to medium-gray, bluish-gray, and purplish gray shales of the Chinle Formation's Blue Mesa Member (upper Carnian Stage, lower Upper Triassic).  View from "The Teepees" in Petrified Forest National Park, Arizona, USA.

 

Painted Desert - light- to medium-gray, bluish-gray, and purplish gray shales of the Chinle Formation's Blue Mesa Member (upper Carnian Stage, lower Upper Triassic).  View from “The Teepees” in Petrified Forest National Park, Arizona, USA.

 


 

Painted Desert - the dark colored rocks capping the mesa in the left foreground are basalts of the Bidahochi Formation (Upper Miocene to Lower Pliocene, 5-8 m.y.).  View from the northern part of Petrified Forest National Park, Arizona, USA.

 

Painted Desert - in the right foreground are black basalt caprocks of the Bidahochi Formation (Upper Miocene to Lower Pliocene, 5-8 m.y.).  Reddish to pinkish shales of the Chinle Formation's Petrified Forest Member (lower Norian Stage, middle Upper Triassic) are in the background.  View from the northern part of Petrified Forest National Park, Arizona, USA.

 

Bidahochi Formation - the caprocks of some the mesas in the northern part of Petrified Forest National Park consist of late Cenozoic basalt lava flows.  The rocks are somewhat vesicular.  Vesicles vary from being empty (vesicular basalt) to some or all being secondarily filled with minerals (amygdaloidal basalt).  Lenscap is 7.5 cm in diameter.

 


 

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