Curtis Formation

Last updated
Curtis Formation
Stratigraphic range: Callovian
O
S
D
C
P
T
J
K
Pg
N
Curtis Formation type.jpg
Curtis Formation type
Type Formation
Unit of San Rafael Group
Underlies Summerville Formation
Overlies Entrada Sandstone
Lithology
Primary Sandstone
Other Mudstone, limestone
Location
Coordinates 39°07′36″N110°26′51″W / 39.126665°N 110.447615°W / 39.126665; -110.447615
Region Utah
Country United States
Type section
Named forCurtis Point, Emery County, Utah
Named byGilluly and Reeside
Year defined1928
Light-colored beds of the Curtis Formation in abrupt contact with the underlying Entrada Formation. This contact marks the J3 unconformity, Curtis over Slickrock.jpg
Light-colored beds of the Curtis Formation in abrupt contact with the underlying Entrada Formation. This contact marks the J3 unconformity,

The Curtis Formation is a geologic formation in Utah. It preserves fossils dating back to the Callovian age of the Jurassic period.

Contents

Curtis Point, namesake for the Curtis Formation visible as the light gray strata. Curtis Point type locality of the Curtis Formation.jpg
Curtis Point, namesake for the Curtis Formation visible as the light gray strata.

Description

Lightly-colored Curtis Formation at Wild Horse Butte Wild Horse Butte detail.jpg
Lightly-colored Curtis Formation at Wild Horse Butte

The Curtis Formation is composed of shallow marine sandstone, with thin beds of mudstone and minor limestone and gypsum. The sandstone is grayish-green in color and flat bedded or cross bedded. The presence of glauconite and marine invertebrate fossils indicates it was laid down in a shallow marine environment that became hypersaline towards the end of deposition. It represents a high stand of the Sundance Sea in the Callovian. [1]

History of investigation

The formation was first described by Gilluly and Reeside in 1928 and named for exposures in the northeast San Rafael Reef at Curtis Point ( 39°07′36″N110°26′51″W / 39.126665°N 110.447615°W / 39.126665; -110.447615 ). Pipiringos and Imlay reassigned the Curtis as a member of the Stump Formation in 1979, [2] but this was rejected by Peterson in 1988. [3]

Footnotes

  1. Lucas and Anderson 1992
  2. Pipiringos and Imlay 1979
  3. Peterson 1988

See also

Related Research Articles

<span class="mw-page-title-main">Entrada Sandstone</span> Geological formation in Utah, USA

The Entrada Sandstone is a formation in the San Rafael Group found in the U.S. states of Wyoming, Colorado, northwest New Mexico, northeast Arizona, and southeast Utah. Part of the Colorado Plateau, this formation was deposited during the Jurassic Period sometime between 180 and 140 million years ago in various environments, including tidal mudflats, beaches, and sand dunes. The Middle Jurassic San Rafael Group was dominantly deposited as ergs in a desert environment around the shallow Sundance Sea.

<span class="mw-page-title-main">Morrison Formation</span> Rock formation in the western United States

The Morrison Formation is a distinctive sequence of Upper Jurassic sedimentary rock found in the western United States which has been the most fertile source of dinosaur fossils in North America. It is composed of mudstone, sandstone, siltstone, and limestone and is light gray, greenish gray, or red. Most of the fossils occur in the green siltstone beds and lower sandstones, relics of the rivers and floodplains of the Jurassic period.

<span class="mw-page-title-main">Cutler Formation</span> Geologic formation in the Four Corners, US

The Cutler Formation or Cutler Group is a rock unit that is exposed across the U.S. states of Arizona, northwest New Mexico, southeast Utah and southwest Colorado. It was laid down in the Early Permian during the Wolfcampian epoch.

<span class="mw-page-title-main">Moenkopi Formation</span> Geologic formation in the southwestern United States

The Moenkopi Formation is a geological formation that is spread across the U.S. states of New Mexico, northern Arizona, Nevada, southeastern California, eastern Utah and western Colorado. This unit is considered to be a group in Arizona. Part of the Colorado Plateau and Basin and Range, this red sandstone was laid down in the Lower Triassic and possibly part of the Middle Triassic, around 240 million years ago.

<span class="mw-page-title-main">Kaibab Limestone</span> Geologic formation in the southwestern United States

The Kaibab Limestone is a resistant cliff-forming, Permian geologic formation that crops out across the U.S. states of northern Arizona, southern Utah, east central Nevada and southeast California. It is also known as the Kaibab Formation in Arizona, Nevada, and Utah. The Kaibab Limestone forms the rim of the Grand Canyon. In the Big Maria Mountains, California, the Kaibab Limestone is highly metamorphosed and known as the Kaibab Marble.

<span class="mw-page-title-main">Glen Canyon Group</span> Group of geologic formations in the Colorado Plateau, USA

The Glen Canyon Group is a geologic group of formations that is spread across the U.S. states of Nevada, Utah, northern Arizona, north west New Mexico and western Colorado. It is called the Glen Canyon Sandstone in the Green River Basin of Colorado and Utah.

The San Rafael Group is a geologic group or collection of related rock formations that is spread across the U.S. states of New Mexico, Arizona, Utah and Colorado. As part of the Colorado Plateau, this group of formations was laid down in the Middle Jurassic during the Bajocian, Bathonian and Callovian Stages.

<span class="mw-page-title-main">Carmel Formation</span> Geological formation in Utah, USA

The Carmel Formation is a geologic formation in the San Rafael Group that is spread across the U.S. states of Wyoming, Utah, Colorado, north east Arizona and New Mexico. Part of the Colorado Plateau, this formation was laid down in the Middle Jurassic during the late Bajocian, through the Bathonian and into the early Callovian stages.

<span class="mw-page-title-main">Geology of Bangladesh</span>

The Geology of Bangladesh is affected by the country's location, as Bangladesh is mainly a riverine country. It is the eastern two-thirds of the Ganges and Brahmaputra river delta plain stretching to the north from the Bay of Bengal. There are two small areas of slightly higher land in the north-centre and north-west composed of old alluvium called the Madhupur Tract and the Barind Tract, and steep, folded, hill ranges of older (Tertiary) rocks along the eastern border.

<span class="mw-page-title-main">Group (stratigraphy)</span> A group of geologic formations

In geology, a group is a lithostratigraphic unit consisting of a series of related formations that have been classified together to form a group. Formations are the fundamental unit of stratigraphy. Groups may sometimes be combined into supergroups.

<span class="mw-page-title-main">Summerville Formation</span> Geologic formation in Four Corners region, US

The Summerville Formation is a geological formation in New Mexico, Colorado, and Utah of the Southwestern United States. It dates back to the Oxfordian stage of the Late Jurassic.

<span class="mw-page-title-main">Moenave Formation</span> Geologic formation in Utah and Arizona

The Moenave Formation is a Mesozoic geologic formation, in the Glen Canyon Group. It is found in Utah and Arizona.

<span class="mw-page-title-main">Mancos Shale</span> Late Cretaceous geologic formation of the Western United States

The Mancos Shale or Mancos Group is a Late Cretaceous geologic formation of the Western United States.

<span class="mw-page-title-main">Tapeats Sandstone</span> Cambrian geologic formation found in the Southwestern United States

Except where underlain by the Sixtymile Formation, the Tapeats Sandstone is the Cambrian geologic formation that is the basal geologic unit of the Tonto Group. Typically, it is also the basal geologic formation of the Phanerozoic strata exposed in the Grand Canyon, Arizona, and parts of northern Arizona, central Arizona, southeast California, southern Nevada, and southeast Utah. The Tapeats Sandstone is about 230 feet (70 m) thick, at its maximum. The lower and middle sandstone beds of the Tapeats Sandstone are well-cemented, resistant to erosion, and form brownish, vertical cliffs that rise above the underlying Precambrian strata outcropping within Granite Gorge. They form the edge of the Tonto Platform. The upper beds of the Tapeats Sandstone form the surface of the Tonto Platform. The overlying soft shales and siltstones of the Bright Angel Shale underlie drab-greenish slopes that rise from the Tonto Platform to cliffs formed by limestones of the Muav Limestone and dolomites of the Frenchman Mountain Dolostone.

<span class="mw-page-title-main">Bright Angel Shale</span> Cambrian geologic formation found in the Southwestern United States

The Bright Angel Shale is one of five geological formations that comprise the Cambrian Tonto Group. It and the other formations of the Tonto Group outcrop in the Grand Canyon, Arizona, and parts of northern Arizona, central Arizona, southeast California, southern Nevada, and southeast Utah. 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. It ranges in thickness from 57 to 450 feet. Typically, its thin-bedded shales and sandstones are interbedded in cm-scale cycles. They also exhibit abundant sedimentary structures that include current, oscillation, and interference ripples. The Bright Angel Shale also gradually grades downward into the underlying Tapeats Sandstone. It also complexly interfingers with the overlying Muav Limestone. These characters make the upper and lower contacts of the Bright Angel Shale often difficult to define. Typically, its thin-bedded shales and sandstones erode into green and red-brown slopes that rise from the Tonto Platform up to cliffs formed by limestones of the overlying Muav Limestone and dolomites of the Frenchman Mountain Dolostone.

<span class="mw-page-title-main">Sandia Formation</span> Geologic formation in New Mexico, United States

The Sandia Formation is a geologic formation in New Mexico, United States. Its fossil assemblage is characteristic of the early Pennsylvanian.

<span class="mw-page-title-main">Burro Canyon Formation</span> Geologic formation in the southwestern US

The Burro Canyon Formation is an Early Cretaceous Period sedimentary geologic formation, found in western Colorado, the Chama Basin and eastern San Juan Basin of northern New Mexico, and in eastern Utah, US.

<span class="mw-page-title-main">Sinbad Formation</span>

The Sinbad Formation is a geologic formation in Utah initially named and described by James Gilluly and J. B. Reeside Junior in the 1920s. It is known for preserving fossils dating back to the Early Triassic epoch.

<span class="mw-page-title-main">Bluff Formation</span> Geologic formation in the western United States

The Bluff Formation is a geological formation found in the Four Corners area. It was deposited in the late Jurassic Period.

The Beclabito Formation is a late Jurassic sedimentary geologic formation, found in northwestern New Mexico and northeastern Arizona.

References