Pinkerton Trail Formation Stratigraphic range: | |
---|---|
Type | Formation |
Unit of | Hermosa Group |
Underlies | Paradox Formation |
Overlies | Molas Formation |
Thickness | 180 m (600 ft) |
Lithology | |
Primary | Limestone |
Other | Shale |
Location | |
Coordinates | 37°27′22″N107°48′14″W / 37.456°N 107.804°W |
Region | Four Corners |
Country | United States |
Type section | |
Named for | Pinkerton Trail |
Named by | Wengerd and Strickland |
Year defined | 1954 |
The Pinkerton Trail Formation is a geologic formation that is found in the Four Corners region of the United States. It contains fossils characteristic of the Atokan and Desmoinesian Ages of the Pennsylvanian.
The Pinkerton Trail Formation is the lowest member of the Hermosa Group, a group of geological formations deposited in the interior and margins of the Paradox basin during the Pennsylvanian. The Pinkerton Trail Formation consists of gray limestone with occasional beds of black shale. North of Durango, it contains significant clastic sediments. It rests on the Molas Formation and is overlain by the Paradox Formation. [1] Its thickness is up to 600 feet (180 m) in the subsurface. [2]
The formation is exposed in the Durango, Colorado area and is present in the subsurface in the San Juan basin [1] and the Paradox basin. [3] It was deposited by the advance of the sea (a transgression ) over the region, which deposited limestone atop the continental sediments of the Molas Formation. [1]
The formation is fossiliferous, containing crinoids and fusulinids that place its age in the Atokan to Desmoinesian Ages of the Pennsylvanian. [1]
The formation was first designated by Sherman Wengerd and John Strickland in 1954 as part of their work raising the Hermosa Formation to group stratigraphic rank. It was named for exposures at the Pinkerton Trail, about 12 miles (19 km) north of Durango, Colorado. [4] Baars, Parker, and Chronic proposed a subsurface reference section in 1967 in the Paradox basin. [2]
The exposed geology of the Canyonlands area is complex and diverse; 12 formations are exposed in Canyonlands National Park that range in age from Pennsylvanian to Cretaceous. The oldest and perhaps most interesting was created from evaporites deposited from evaporating seawater. Various fossil-rich limestones, sandstones, and shales were deposited by advancing and retreating warm shallow seas through much of the remaining Paleozoic.
The Cutler Formation or Cutler Group is a rock unit that is spread 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 stage. Its subunits, therefore, are variously called formations or members depending on the publication. Members :
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.
The San Juan Basin is a geologic structural basin located near the Four Corners region of the Southwestern United States. The basin covers 7,500 square miles and resides in northwestern New Mexico, southwestern Colorado, and parts of Utah and Arizona. Specifically, the basin occupies space in the San Juan, Rio Arriba, Sandoval, and McKinley counties in New Mexico, and La Plata and Archuleta counties in Colorado. The basin extends roughly 100 miles (160 km) N-S and 90 miles (140 km) E-W.
The Geology of Kansas encompasses the geologic history of the US state of Kansas and the present-day rock and soil that is exposed there. Rock that crops out in Kansas was formed during the Phanerozoic eon, which consists of three geologic eras: the Paleozoic, Mesozoic and Cenozoic. Paleozoic rocks at the surface in Kansas are primarily from the Mississippian, Pennsylvanian and Permian periods.
The Paradox Basin is an asymmetric foreland basin located mostly in southeast Utah and southwest Colorado, but extending into northeast Arizona and northwest New Mexico. The basin is a large elongate northwest to southeast oriented depression formed during the late Paleozoic Era. The basin is bordered on the east by the tectonically uplifted Uncompahgre Plateau, on the northwest by the San Rafael Swell and on the west by the Circle Cliffs Uplift.
In geology, the Paradox Formation Is a Pennsylvanian age formation which consists of abundant evaporites with lesser interbedded shale, sandstone, and limestone. The evaporites are largely composed of gypsum, anhydrite, and halite. The formation is found mostly in the subsurface, but there are scattered exposures in anticlines in eastern Utah and western Colorado. These surface exposures occur in the Black Mesa, San Juan and Paradox Basins and the formation is found in the subsurface in southwestern Colorado, southeastern Utah, northeastern Arizona and northeastern New Mexico.
The Mancos Shale or Mancos Group is a Late Cretaceous geologic formation of the Western United States.
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The Lower Permian Esplanade Sandstone is a cliff-forming, resistant sandstone, dark red, geologic unit found in the Grand Canyon. The rock unit forms a resistant shelf in the west Grand Canyon, south side of the Colorado River, at the east of the Toroweap Fault, down-dropped to west, southeast of Toroweap Overlook, and west of Havasupai. The red, sandstone shelf, The Esplanade is about 20-mi long. At Toroweap Overlook region, Toroweap Valley with Vulcan's Throne, Uinkaret volcanic field, the resistant Esplanade Sandstone is described in access routes exploring the Toroweap Lake area.
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The Lewis Shale is a geologic formation in the Western United States. It preserves fossils dating back to the Campanian to Maastrichtian stages of the late Cretaceous period.
The Sandia Formation is a geologic formation in New Mexico, United States. Its fossil assemblage is characteristic of the early Pennsylvanian.
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.
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The Hermosa Creek Wilderness is a 37,236-acre (15,069 ha) U.S. Wilderness Area in La Plata County, Colorado. It s located in the San Juan National Forest 12 miles (19 km) north of Durango. It was established by the Hermosa Creek Protection Act of 2014, which also created the adjacent Hermosa Creek Special Management Area, which shares its eastern border, Hermosa Creek. Elevation in the wilderness ranges from 7,500 feet (2,300 m) along Hermosa Creek to 12,338 feet (3,761 m) at the high point of Indian Trail Ridge.
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The Elbert Formation is a geologic formation that crops out in the San Juan Mountains of southwestern Colorado. The formation contains fossils indicating it is upper Devonian in age.
The Molas Formation is a geologic formation that is found in the Four Corners region of the United States. Its age is poorly constrained but is thought to be Namurian.