The Nittany Arch or Nittany anticline is an anticline geologic formation in the western part of the Ridge-and-Valley physiographic province of the Appalachian Mountains of Central Pennsylvania, United States. The Nitany Arch is more than 100 miles (160 kilometers) long, stretching from Muncy to Hollidaysburg, with a maximum width of approximately 9 miles (15 kilometers). [1]
During the Appalachian orogeny, the sedimentary rock layers in this area folded up, forming the Nittany Arch. The arch was an ancient Himalayan scale mountain that towered above what is now Nittany Valley. It has since eroded leaving its many rock layers exposed with the youngest rock layers at the foot of the Allegheny Front. The more durable rock layers have left the surrounding sandstone ridges above the limestone valleys.
The Appalachian Mountains, often called the Appalachians, are a system of mountains in eastern North America. The Appalachians first formed roughly 480 million years ago during the Ordovician Period. They once reached elevations similar to those of the Alps and the Rocky Mountains before experiencing natural erosion. The Appalachian chain is a barrier to east–west travel, as it forms a series of alternating ridgelines and valleys oriented in opposition to most highways and railroads running east–west.
The geology of the Appalachians dates back to more than 480 million years ago. A look at rocks exposed in today's Appalachian Mountains reveals elongate belts of folded and thrust faulted marine sedimentary rocks, volcanic rocks and slivers of ancient ocean floor – strong evidence that these rocks were deformed during plate collision. The birth of the Appalachian ranges marks the first of several mountain building plate collisions that culminated in the construction of the supercontinent Pangaea with the Appalachians and neighboring Little Atlas near the center. These mountain ranges likely once reached elevations similar to those of the Alps and the Rocky Mountains before they were eroded.
The Cumberland Mountains are a mountain range in the southeastern section of the Appalachian Mountains. They are located in western Virginia, southwestern West Virginia, eastern edges of Kentucky, and eastern middle Tennessee, including the Crab Orchard Mountains. Their highest peak, with an elevation of 4,223 feet (1,287 m) above mean sea level, is High Knob, which is located near Norton, Virginia.
In structural geology, a syncline is a fold with younger layers closer to the center of the structure, whereas an anticline is the inverse of a syncline. A synclinorium is a large syncline with superimposed smaller folds. Synclines are typically a downward fold (synform), termed a synformal syncline, but synclines that point upwards can be found when strata have been overturned and folded.
In structural geology, an anticline is a type of fold that is an arch-like shape and has its oldest beds at its core, whereas a syncline is the inverse of a anticline. A typical anticline is convex up in which the hinge or crest is the location where the curvature is greatest, and the limbs are the sides of the fold that dip away from the hinge. Anticlines can be recognized and differentiated from antiforms by a sequence of rock layers that become progressively older toward the center of the fold. Therefore, if age relationships between various rock strata are unknown, the term antiform should be used.
Mount Nittany is the common name for Nittany Mountain, a prominent geographic feature in Centre County, Pennsylvania, USA. The mountain is part of a ridge that separates Nittany Valley from Penns Valley, with the enclosed Sugar Valley between them. On USGS topographic maps, Nittany Mountain is generally shown as the lower ridge line that runs below Big Mountain on the west and Big Kettle Mountain on the east side, coming together to form a single ridge line at the southern terminus. This nomenclature is not always consistently applied to the same geologic formation, and there is a shorter Nittany Mountain ridge shown above the Sugar Valley as well.
The Bald Eagle Valley of central Pennsylvania, United States is the low-lying area draining into the Bald Eagle Creek between the Allegheny Front and the Bald Eagle Mountain ridge, south of the West Branch Susquehanna River, in the Ridge-and-valley Appalachians. It is southwest of the West Branch Susquehanna Valley that includes Williamsport and Northwest of the Nittany Valley that includes State College.
Bald Eagle Mountain – once known locally as Muncy Mountain – is a stratigraphic ridge in the Ridge-and-Valley Appalachians of central Pennsylvania, USA, running east of the Allegheny Front and northwest of Mount Nittany. It lies along the southeast side of Bald Eagle Creek, and south of the West Branch Susquehanna River, and is the westernmost ridge in its section of the Ridge-and-valley Appalachians. The ridge line separates the West Branch Susquehanna Valley from the Nippenose and White Deer Hole Valleys, and Bald Eagle Valley from Nittany Valley.
The Nittany Valley is an eroded anticlinal valley in the central portion of Centre County, Pennsylvania in the United States. It is separated from the Bald Eagle Valley by Bald Eagle Mountain and from Penns Valley by Mount Nittany. The valley is closed to the north by a high plateau that joins these two mountain ridges, but is open to the south at the southern terminus of Mount Nittany. The valley drains to the Bald Eagle Creek through water gaps in Bald Eagle Mountain formed by Spring Creek, and Fishing Creek, along with smaller streams running through Curtain Gap and Howard Gap. The Northwest side of the valley between the Bald Eagle Mountain ridge and the lower Sand Ridge is also known as the "Little Nittany Valley".
Penns Valley is an eroded anticlinal valley of the Pennsylvania ridge and valley geologic region of the Appalachian Mountain range. The valley is located in southern Centre County, Pennsylvania. Along with the Nittany Valley to the north and east, it is part of the larger Nittany Anticlinorium. It is bordered by Nittany Mountain to the north, the Seven Mountains range to the south, and connects to the larger Nittany Valley to the west. There are two smaller subordinate valleys typically associated with the greater valley: Georges Valley in the south, separated by Egg Hill, and Brush Valley in the north, separated by Brush Mountain.
Brush Mountain is a stratigraphic ridge in the Appalachian Mountains of central Pennsylvania, USA, running east of the Allegheny Front and west of Tussey Mountain. It lies along the southeast side of Little Juniata River and both sides of the Sinking Run, and is the westernmost ridge in its section of the Ridge-and-valley Appalachians. The western ridge line separates the Logan Valley from the Sinking Valley.
Wills Mountain is a quartzite-capped ridge in the Ridge and Valley physiographic province of the Appalachian Mountains in Pennsylvania and Maryland, United States, extending from near Bedford, Pennsylvania, to near Cumberland, Maryland. It is the northernmost of several mountain ridges included within the Wills Mountain Anticline.
Tussey Mountain is a stratigraphic ridge in central Pennsylvania, United States, trending east of the Bald Eagle, Brush, Dunning and Evitts Mountain ridges. Its southern foot just crosses the Mason–Dixon line near Flintstone, Maryland, running north 130 km (80 mi) to the Seven Mountains of central Pennsylvania, near Tusseyville, making it one of the longest named ridges in this section of the Ridge-and-valley Appalachians. The ridge line separates Morrison Cove from the Woodcock Valley and Friends Cove from the Black Valley. Tussey Mountain lies in, and the ridge line forms parts of the borders of, Centre, Blair, Bedford and Huntingdon counties.
The Geology of Pennsylvania consists of six distinct physiographic provinces, three of which are subdivided into different sections. Each province has its own economic advantages and geologic hazards and plays an important role in shaping everyday life in the state. They are: the Atlantic Coastal Plain Province, the Piedmont Province, the New England Province, the Ridge and Valley Province, the Appalachian Plateau Province, and the Central Lowlands Province.
The Silurian Tuscarora Formation — also known as Tuscarora Sandstone or Tuscarora Quartzite — is a mapped bedrock unit in Pennsylvania, Maryland, West Virginia, and Virginia, USA.
For other "River Knobs", see River Knobs (disambiguation).
The Metacomet Ridge, Metacomet Ridge Mountains, or Metacomet Range of southern New England is a narrow and steep fault-block mountain ridge known for its extensive cliff faces, scenic vistas, microclimate ecosystems, and rare or endangered plants. The ridge is an important recreation resource located within 10 miles (16 km) of more than 1.5 million people, offering four long-distance hiking trails and over a dozen parks and recreation areas, including several historic sites. It has been the focus of ongoing conservation efforts because of its natural, historic, and recreational value, involving municipal, state, and national agencies and nearly two dozen non-profit organizations.
Jacks Mountain is a stratigraphic ridge in central Pennsylvania, United States, trending southeast of the Stone Mountain ridge and Jacks Mountain Anticline. The ridge line separates Kishacoquillas Valley from the Ferguson and Dry Valleys. Jacks Mountain lies in Mifflin, Huntingdon, Snyder, and Union Counties, and the ridge line forms part of the border between Huntingdon and Mifflin Counties.
The Ordovician Reedsville Formation is a mapped surficial bedrock unit in Pennsylvania, Maryland, Virginia, West Virginia, and Tennessee, that extends into the subsurface of Ohio. This rock is a slope-former adjacent to the prominent ridge-forming Bald Eagle sandstone unit in the Appalachian Mountains. It is often abbreviated Or on geologic maps.
Stone Mountain is a stratigraphic ridge in central Pennsylvania, United States, trending northwest of the Jacks Mountain ridge and Jacks Mountain Anticline. The ridge line separates Kishacoquillas Valley from the Seven Mountains area. Stone Mountain lies in, and the ridge line forms part of the border between, Mifflin and Huntingdon counties.
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