The Navajo Section is a physiographic section of the larger Colorado Plateaus Province, which in turn is part of the larger Intermontane Plateaus physiographic Division. [1]
The Navajo Section is located in northeastern Arizona and northwestern New Mexico. It is named for the Navajo Nation, with about half of the area of the section on the Navajo Reservation.
The section is characterized by broad rolling plains on easily eroded and carved rocks, with cuestas (ridges) and tablelands capped by gently dipping resistant sandstone beds. One of the most prominent landform features of the Navajo Section is Shiprock, a 7,177 feet (2,188 m) monadnock formation near the town of Shiprock, New Mexico.
The lowest point in the Navajo Section is about 4,700 feet (1,400 m), near the Four Corners area. The boundary between this section and the Canyon Lands Section is nearby, in the San Juan River basin. The highest point of the Navajo Section is 9,916 feet (3,022 m) at Chromo Mountain on the Continental Divide near Chama, New Mexico. [2]
Adjacent to the Navajo Section are the:
The area is predominantly generally horizontal sandstone beds with some shale sequences of late Cretaceous and early Cenozoic age. A few areas of the section also have abundant volcanic necks and buttes, but due to the arid weather and soft sandstone, many of the rock formations of the area have eroded to form distinctive features of long cuestas, shallow canyons and valleys, narrow fan terraces, undulating plateaus, isolated mesas, steep hills, and some shale badlands. [2]
Near the Four Corners area is a steeply tilted monocline known as The Hogback, which trends southwestward from where the San Juan River enters the area. Here the San Juan River flows into an area known as the San Juan Basin, where the western San Juan Basin is typified by exposures of the Fruitland and Menefee Formations. A stepped sequence of high stream terraces, present above the San Juan River and its tributaries, represents abandoned Pleistocene flood plains. [3]
In the context of physical geography, the Intermontane Plateaus is one of eight physiographic regions of the contiguous United States. The region consists mostly of plateaus and mountain ranges lying between the Rocky Mountains on the east and the Cascade and Sierra Nevada Mountains on the west. It is subdivided into three physiographic provinces: the Columbia Plateau in the north, the Basin and Range Province in the central and southwestern portions, and the Colorado Plateau in the southeast. In turn, each of these provinces are each subdivided into a number of physiographic sections.
The San Juan River is a major tributary of the Colorado River in the Southwestern United States, providing the chief drainage for the Four Corners region of Colorado, New Mexico, Utah, and Arizona. Originating as snowmelt in the San Juan Mountains of Colorado, it flows 383 miles (616 km) through the deserts of northern New Mexico and southeastern Utah to join the Colorado River at Glen Canyon.
The geology of the Zion and Kolob canyons area includes nine known exposed formations, all visible in Zion National Park in the U.S. state of Utah. Together, these formations represent about 150 million years of mostly Mesozoic-aged sedimentation in that part of North America. Part of a super-sequence of rock units called the Grand Staircase, the formations exposed in the Zion and Kolob area were deposited in several different environments that range from the warm shallow seas of the Kaibab and Moenkopi formations, streams and lakes of the Chinle, Moenave, and Kayenta formations to the large deserts of the Navajo and Temple Cap formations and dry near shore environments of the Carmel Formation.
The Colorado Plateau, also known as the Colorado Plateau Province, is a physiographic and desert region of the Intermontane Plateaus, roughly centered on the Four Corners region of the southwestern United States. This province covers an area of 336,700 km2 (130,000 mi2) within western Colorado, northwestern New Mexico, southern and eastern Utah, northern Arizona, and a tiny fraction in the extreme southeast of Nevada. About 90% of the area is drained by the Colorado River and its main tributaries: the Green, San Juan, and Little Colorado. Most of the remainder of the plateau is drained by the Rio Grande and its tributaries.
The Highland Rim is a geographic term for the area in Tennessee, North Alabama, and Kentucky which surrounds the Central Basin. Geologically, the Central Basin is a dome. The Highland Rim is a cuesta surrounding the basin, and the border where the difference in elevation is sharply pronounced is an escarpment.
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 exposed geology of the Capitol Reef area presents a record of mostly Mesozoic-aged sedimentation in an area of North America in and around Capitol Reef National Park, on the Colorado Plateau in southeastern Utah.
The Navajo Sandstone is a geological formation in the Glen Canyon Group that is spread across the U.S. states of southern Nevada, northern Arizona, northwest Colorado, and Utah as part of the Colorado Plateau province of the United States.
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.
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 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 Chuska Mountains are an elongate range on the southwest Colorado Plateau and within the Navajo Nation whose highest elevations approach 10,000 feet. The range is about 80 by 15 km. It trends north-northwest and is crossed by the state line between Arizona and New Mexico. The highlands are a dissected plateau, with an average elevation of about 2,740 m (8,990 ft), and subdued topography. The highest point is Roof Butte at 2,994 m (9,823 ft), near the northern end of the range in Arizona. Other high points include the satellite Beautiful Mountain at 2,861 m (9,386 ft) and Lukachukai Mountains at 2,885 m (9,465 ft), both also near the northern end, and Matthews Peak at 2,911 m (9,551 ft). The San Juan Basin borders the Chuskas on the east, and typical elevations in nearby parts of that basin are near 1,800 m (5,900 ft). The eastern escarpment of the mountains is marked by slumps and landslides that extend out onto the western margin of the San Juan Basin. To the north, the Chuskas are separated from the Carrizo Mountains by Red Rock Valley, which is today commonly referred to as Red Valley.
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 Datil-Mogollon Section is a physiographic section of the larger Colorado Plateau province, which in turn is part of the larger Intermontane Plateaus physiographic division. It is a transitional area between the Basin and Range Province and the Colorado Plateau Province. It is also a newly defined unit that includes the southern part of the area previously designated the Datil Section.
The Canyon Lands Section of the Colorado Plateau is a physiographic section of the larger Colorado Plateaus province, which in turn is part of the larger Intermontane Plateaus physiographic division in the Western United States
The geology of Kansas encompasses the geologic history and the presently exposed rock and soil. Rock that crops out in the US state of 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 Crevasse Canyon Formation is a coal-bearing Cretaceous geologic formation in New Mexico and Arizona.
The Mancos Shale or Mancos Group is a Late Cretaceous geologic formation of the Western United States.
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.