Traprock mountains
Encyclopedia
Traprock mountains, ridges, (or just traps) are elevated landscape features made of the rock known as basalt
and its close relatives. Basalt, an iron-rich rock otherwise known as traprock, is a characteristically dark-colored rock that weathers to shades of red and purplish-red when exposed to the air. Basalt is the substance of many elevated topographic features worldwide (hills, mountains, ridges, rock formations, etc.). Landscape features composed of basalt may include:
Because basalt has a tendency to fracture at abrupt angles, topographic features made of basalt often have a "postpile" appearance (Devil's Tower
of Wyoming
is a good example). Basalt ridges make up hundreds of square miles of topographic features in the northwestern United States, from Wyoming to Oregon
.
Basalt
Basalt is a common extrusive volcanic rock. It is usually grey to black and fine-grained due to rapid cooling of lava at the surface of a planet. It may be porphyritic containing larger crystals in a fine matrix, or vesicular, or frothy scoria. Unweathered basalt is black or grey...
and its close relatives. Basalt, an iron-rich rock otherwise known as traprock, is a characteristically dark-colored rock that weathers to shades of red and purplish-red when exposed to the air. Basalt is the substance of many elevated topographic features worldwide (hills, mountains, ridges, rock formations, etc.). Landscape features composed of basalt may include:
- Elevated sections of prehistoric ocean floor that have been raised above sea level via plate tectonicsPlate tectonicsPlate tectonics is a scientific theory that describes the large scale motions of Earth's lithosphere...
- Prehistoric terrestrial lava floods that have become upended and/or exposed via faulting and erosionErosionErosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...
- Various surface volcanic landforms both recent and ancient.
Because basalt has a tendency to fracture at abrupt angles, topographic features made of basalt often have a "postpile" appearance (Devil's Tower
Devils Tower National Monument
Devils Tower is an igneous intrusion or laccolith located in the Black Hills near Hulett and Sundance in Crook County, northeastern Wyoming, above the Belle Fourche River...
of Wyoming
Wyoming
Wyoming is a state in the mountain region of the Western United States. The western two thirds of the state is covered mostly with the mountain ranges and rangelands in the foothills of the Eastern Rocky Mountains, while the eastern third of the state is high elevation prairie known as the High...
is a good example). Basalt ridges make up hundreds of square miles of topographic features in the northwestern United States, from Wyoming to Oregon
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
.
Notable landforms
Prominent basalt ridges, mountains, buttes, canyons, and other landscape features include:In the United States
- Devil's TowerDevils Tower National MonumentDevils Tower is an igneous intrusion or laccolith located in the Black Hills near Hulett and Sundance in Crook County, northeastern Wyoming, above the Belle Fourche River...
in WyomingWyomingWyoming is a state in the mountain region of the Western United States. The western two thirds of the state is covered mostly with the mountain ranges and rangelands in the foothills of the Eastern Rocky Mountains, while the eastern third of the state is high elevation prairie known as the High... - The ridges and cliffs of the Columbia River GorgeColumbia River GorgeThe Columbia River Gorge is a canyon of the Columbia River in the Pacific Northwest of the United States. Up to deep, the canyon stretches for over as the river winds westward through the Cascade Range forming the boundary between the State of Washington to the north and Oregon to the south...
in Oregon and Washington (state) - Basalt Mountain in ColoradoColoradoColorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...
, for which the town of Basalt, ColoradoBasalt, ColoradoBasalt is a Statutory Town in Eagle and Pitkin counties in the U.S. state of Colorado. The population was 2,681 at the 2000 census.-Geography:...
is named. - The Metacomet RidgeMetacomet RidgeThe Metacomet Ridge, Metacomet Ridge Mountains, or Metacomet Range of southern New England, United States, is a narrow and steep fault-block mountain ridge known for its extensive cliff faces, scenic vistas, microclimate ecosystems, and communities of plants considered rare or endangered...
of ConnecticutConnecticutConnecticut is a state in the New England region of the northeastern United States. It is bordered by Rhode Island to the east, Massachusetts to the north, and the state of New York to the west and the south .Connecticut is named for the Connecticut River, the major U.S. river that approximately...
and MassachusettsMassachusettsThe Commonwealth of Massachusetts is a state in the New England region of the northeastern United States of America. It is bordered by Rhode Island and Connecticut to the south, New York to the west, and Vermont and New Hampshire to the north; at its east lies the Atlantic Ocean. As of the 2010...
. - The New Jersey PalisadesNew Jersey PalisadesThe Palisades, also called the New Jersey Palisades or the Hudson Palisades are a line of steep cliffs along the west side of the lower Hudson River in northeastern New Jersey and southern New York in the United States. The cliffs stretch north from Jersey City approximately 20 mi to near...
and Watchung MountainsWatchung MountainsThe Watchung Mountains are a group of three long low ridges of volcanic origin, between 400 ft. and 500 ft. high, lying parallel to each other in northern New Jersey in the United States... - Parts of CaliforniaCaliforniaCalifornia is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
's inner coastal range. - Most of the Hawaiian IslandsHawaiian IslandsThe Hawaiian Islands are an archipelago of eight major islands, several atolls, numerous smaller islets, and undersea seamounts in the North Pacific Ocean, extending some 1,500 miles from the island of Hawaii in the south to northernmost Kure Atoll...
and their mountains are composed of basalt or similar volcanic rock.
Other parts of the world
- The Paraná Traps of BrazilBrazilBrazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
- The Deccan TrapsDeccan TrapsThe Deccan Traps are a large igneous province located on the Deccan Plateau of west-central India and one of the largest volcanic features on Earth. They consist of multiple layers of solidified flood basalt that together are more than thick and cover an area of and a volume of...
of IndiaIndiaIndia , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world... - The Siberian TrapsSiberian TrapsThe Siberian Traps form a large region of volcanic rock, known as a large igneous province, in the Russian region of Siberia. The massive eruptive event which formed the traps, one of the largest known volcanic events of the last 500 million years of Earth's geological history, continued for...
of RussiaRussiaRussia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects... - The Green Gardens region of Gros Morne National ParkGros Morne National ParkGros Morne National Park is a world heritage site located on the west coast of Newfoundland. At , it is the second largest national park in Atlantic Canada ....
in NewfoundlandNewfoundland and LabradorNewfoundland and Labrador is the easternmost province of Canada. Situated in the country's Atlantic region, it incorporates the island of Newfoundland and mainland Labrador with a combined area of . As of April 2011, the province's estimated population is 508,400... - The island of SurtseySurtseySurtsey is a volcanic island off the southern coast of Iceland. At it is also the southernmost point of Iceland. It was formed in a volcanic eruption which began 130 metres below sea level, and reached the surface on 15 November 1963. The eruption lasted until 5 June 1967, when the island...
in IcelandIcelandIceland , described as the Republic of Iceland, is a Nordic and European island country in the North Atlantic Ocean, on the Mid-Atlantic Ridge. Iceland also refers to the main island of the country, which contains almost all the population and almost all the land area. The country has a population...
, a new (1963) volcanic island.