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.