This detailed astronaut photograph shows part of Big Thomson Mesa, near the southern end of Capitol Reef National Park.
Capitol Reef National Park is located on the Colorado Plateau, which
occupies the adjacent quarters of Arizona, Colorado, New Mexico, and
Utah. Big Thomson Mesa (image left) is part of a large feature known as
the Waterpocket Fold.
The Fold is a geologic structure called a monocline—layers of
generally flat-lying sedimentary rock with a steep, one-sided bend,
like a carpet runner draped over a stair step. Geologists think that
monoclines on the Colorado Plateau result from faulting (cracking) of
deeper and more brittle crystalline rocks under tectonic pressure;
while the crystalline rocks were broken into raised or lowered blocks,
the overlaying, less brittle sedimentary rocks were flexed without
The portion of the Waterpocket Fold illustrated in this image
includes layered rocks formed during the Mesozoic Era (about 250 – 65
million years ago). The oldest layers are at the bottom of the
sequence, with each successive layer younger than the preceding one
going upwards in the sequence. Not all of the Fold's rock layers [diagram of strata (pdf)] are clearly visible, but some of the major layers (units to geologists) can be easily distinguished.
The top half of the image includes the oldest rocks in the view:
dark brown and dark green Moenkopi and Chinle Formations. Moving toward
the foot of the mesa, two strikingly colored units are visible near
image center: light red to orange Wingate Sandstone and white Navajo
Sandstone. Beyond those units, reddish brown to brown Carmel Formation
and Entrada Sandstone occupy a topographic bench at the foot of a
cliff. The top of the cliff face above this bench—Big Thomson Mesa—is
comprised of brown Dakota Sandstone. This sequence represents more than
100 million years of sediments being deposited and turned into rock.
Much younger Quaternary (2-million- to approximately 10,000-year-old)
deposits are also present in the view.
Astronaut photograph ISS020-E-9861
was acquired on June 14, 2009, with a Nikon D3 digital camera fitted
with an 800 mm lens, and is provided by the ISS Crew Earth Observations
experiment and Image Science & Analysis Laboratory, Johnson Space
Center. The image was taken by the Expedition 20 crew . The image in this article has been cropped and enhanced to improve contrast. Lens artifacts have been removed. The International Space Station Program
supports the laboratory to help astronauts take pictures of Earth that
will be of the greatest value to scientists and the public, and to make
those images freely available on the Internet. Additional images taken
by astronauts and cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth. Caption by William L. Stefanov, NASA-JSC.