Trough (geology)

Last updated
Satellite image of the Cayman Trough Cayman Trough.jpg
Satellite image of the Cayman Trough
Bathymetric features of the Rockall Trough northwest of Scotland and Ireland Rockall Trough.jpg
Bathymetric features of the Rockall Trough northwest of Scotland and Ireland
Topographic map of Zealandia with New Caledonia Trough Zealandia, topographic map.jpg
Topographic map of Zealandia with New Caledonia Trough

In geology, a trough is a linear structural depression that extends laterally over a distance. Although it is less steep than a trench, a trough can be a narrow basin or a geologic rift. These features often form at the rim of tectonic plates. There are various oceanic troughs, troughs found under oceans.

Contents

Examples

See also

Related Research Articles

Evaporite A water-soluble mineral sediment formed by evaporation from an aqueous solution

Evaporite is the term for a water-soluble mineral sediment that results from concentration and crystallization by evaporation from an aqueous solution. There are two types of evaporite deposits: marine, which can also be described as ocean deposits, and non-marine, which are found in standing bodies of water such as lakes. Evaporites are considered sedimentary rocks and are formed by chemical sediments.

Rift A linear zone where the Earths crust is being pulled apart, and is an example of extensional tectonics

In geology, a rift is a linear zone where the lithosphere is being pulled apart and is an example of extensional tectonics.

Banda Sea A sea between Sulawesi and Maluku

The Banda Sea is a sea in the Maluku Islands of Indonesia, connected to the Pacific Ocean but surrounded by hundreds of islands, as well as the Halmahera and Ceram Seas. It is about 1000 km (600 mi) east to west, and about 500 km (300 mi) north to south.

Depression (geology) Landform sunken or depressed below the surrounding area

In geology, a depression is a landform sunken or depressed below the surrounding area. Depressions form by various mechanisms.

Back-arc basin Submarine features associated with island arcs and subduction zones

Back-arc basins are geologic basins, submarine features associated with island arcs and subduction zones. They are found at some convergent plate boundaries, presently concentrated in the western Pacific Ocean. Most of them result from tensional forces caused by oceanic trench rollback and the collapse of the edge of the continent. The arc crust is under extension or rifting as a result of the sinking of the subducting slab. Back-arc basins were initially a surprising result for plate tectonics theorists, who expected convergent boundaries to be zones of compression, rather than major extension. However, they are now recognized as consistent with this model in explaining how the interior of Earth loses heat.

Rockall Basin bathymetric feature northwest of Scotland and Ireland

The Rockall Trough is a deep-water bathymetric feature to the northwest of Scotland and Ireland, running roughly from southwest to northeast, flanked on the north by the Rockall Plateau and to the south by the Porcupine Seabight. At the northern end, the channel is bounded by the Wyville-Thomson Ridge, named after Charles Wyville Thomson, professor of zoology at the University of Edinburgh and driving force behind the Challenger Expedition. At the southern end, the trough opens into the Porcupine abyssal plain. The Rockall Basin is a large sedimentary basin that lies beneath the trough. Both are named after Rockall, a rocky islet lying 301.4 km west of St Kilda.

Midcontinent Rift System Geological rift in the center of the North American continent

The Midcontinent Rift System (MRS) or Keweenawan Rift is a 2,000 km (1,200 mi) long geological rift in the center of the North American continent and south-central part of the North American plate. It formed when the continent's core, the North American craton, began to split apart during the Mesoproterozoic era of the Precambrian, about 1.1 billion years ago. The rift failed, leaving behind thick layers of igneous rock that are exposed in its northern reaches, but buried beneath later sedimentary formations along most of its western and eastern arms. Those arms meet at Lake Superior, which is contained within the rift valley. The lake's north shore in Ontario and Minnesota defines the northern arc of the rift. From the lake, the rift's eastern arm trends south to central lower Michigan, and possibly into Indiana, Ohio, Kentucky, Tennessee, and Alabama. The western arm runs from Lake Superior southwest through portions of Wisconsin, Minnesota, Iowa, and Nebraska to northeastern Kansas, and possibly into Oklahoma.

Geology of the Iberian Peninsula The origins, structure use and study of the rock formations of Spain, Portugal, Andorra and Gibraltar

The geology of the Iberian Peninsula consists of the study of the rock formations on the Iberian Peninsula, which includes Spain, Portugal, Andorra, and Gibraltar. The peninsula contains rocks from every geological period from the Ediacaran to the Quaternary, and many types of rock are represented. World-class mineral deposits are also found there.

Molloy Deep

The Molloy Deep is a bathymetric feature in the Fram Strait, within the Greenland Sea east of Greenland and about 160 km west of Svalbard. It is the location of the deepest point in the Arctic Ocean.

Red Sea Rift

The Red Sea Rift is a spreading center between two tectonic plates, the African Plate and the Arabian Plate. It extends from the Dead Sea Transform fault system, and ends at an intersection with the Aden Ridge and the East African Rift, forming the Afar Triple Junction in the Afar Depression of the Horn of Africa.

Zealandia Mostly submerged mass of continental crust containing New Zealand and New Caledonia

Zealandia, also known as the New Zealand continent, Te Riu-a-Māui or Tasmantis, is an almost entirely submerged mass of continental crust that subsided after breaking away from Gondwanaland 83–79 million years ago. It has variously been described as a continental fragment, a microcontinent, a submerged continent, and a continent. The name and concept for Zealandia was proposed by Bruce Luyendyk in 1995.

Masaaki Kimura is a Professor Emeritus from the Faculty of Science of the University of the Ryukyus, Okinawa, Japan.

The Timor Trough is an oceanic trough that is a continuation of the Sunda Trench that marks the boundary between Indo-Australian Plate's continental shelf and the Timor Plate to the north. It is separated from the Java Trench by a sag near Sumba Island at the Scott Plateau and North Australian Basin, and on the other end becomes Tanimbar trough southeast of the Tanimbar Islands continuing on to the Aru trough east of the Kai Islands near Bird's Head Peninsula on New Guinea. Lining the north of the trough are numerous islands, of which Timor is the largest. Further west are the Weber Basin and Banda Trench. Oil and natural gas have been found in the Bonaparte Basin south of the trough and the region is geologically active with numerous earthquakes.

Geologically the Australian state of New South Wales consists of seven main regions: Lachlan Fold Belt, the Hunter-Bowen Orogeny or New England Orogen (NEO), the Delamerian Orogeny, the Clarence Moreton Basin, the Great Artesian Basin, the Sydney Basin, and the Murray Basin.

Benue Trough A major geological structure underlying a large part of Nigeria and extending from the Bight of Benin to Lake Chad

The Benue Trough is a major geological structure underlying a large part of Nigeria and extending about 1,000 km northeast from the Bight of Benin to Lake Chad. It is part of the broader West and Central African Rift System.

Persian Gulf Basin

The Persian Gulf Basin, is found between the Eurasian and the Arabian Plate. The Persian Gulf is described as a shallow marginal sea of the Indian Ocean that is located between the south western side of Iran and the Arabian Peninsula and south and southeastern side of Oman and the United Arab Emirates. Other countries that border the Persian Gulf basin include; Saudi Arabia, Qatar, Kuwait, Bahrain and Iraq. The Gulf extends a distance of 1000 km with an area of 240,000 square km. The Persian Gulf basin is a wedge-shaped foreland basin which lies beneath the western Zagros thrust and was created as a result of the collision between the Arabian and Eurasian plates.

Adare Basin

The Adare Basin is a geologic structural basin located north-east of Cape Adare of Antarctica, for which its named, and north of the western Ross Sea. The Adare Basin is an extensional rift basin located along a seafloor spreading center that forms the failed arm of the Tertiary spreading ridge separating East and West Antarctica, known as the West Antarctic Rift System and similar in structure to the East Africa Rift System. Centrally located in the Adare Basin is the Adare Trough. The extension of this rift system is recorded in a series of magnetic anomalies which run along the seafloor at the extinct, north-south trending, Adare spreading axis. The Adare spreading system continues unbroken into the Northern Basin underlying the adjacent Ross Sea continental shelf.

Angola Basin

The Angola Basin is located along the West African South Atlantic Margin which extends from Cameroon to Angola. It is characterized as a passive margin that began spreading in the south and then continued upwards throughout the basin. This basin formed during the initial breakup of the supercontinent Pangaea during the early Cretaceous, creating the Atlantic Ocean and causing the formation of the Angola, Cape, and Argentine basins. It is often separated into two units: the Lower Congo Basin, which lies in the northern region and the Kwanza Basin which is in the southern part of the Angola margin. The Angola Basin is famous for its "Aptian Salt Basins," a thick layer of evaporites that has influenced topography of the basin since its deposition and acts as an important petroleum reservoir.

Geology of Sudan

The geology of Sudan formed primarily in the Precambrian, as igneous and metamorphic crystalline basement rock. Ancient terranes and inliers were intruded with granites, granitoids as well as volcanic rocks. Units of all types were deformed, reactivated, intruded and metamorphosed during the Proterozoic Pan-African orogeny. Dramatic sheet flow erosion prevented almost any sedimentary rocks from forming during the Paleozoic and Mesozoic. From the Mesozoic into the Cenozoic the formation of the Red Sea depression and complex faulting led to massive sediment deposition in some locations and regional volcanism. Sudan has petroleum, chromite, salt, gold, limestone and other natural resources.

The geology of Ukraine is the regional study of rocks, minerals, tectonics, natural resources and groundwater in the country. The oldest rocks in the region are part of the Ukrainian Shield and formed more than 2.5 billion years ago in the Archean eon of the Precambrian. Extensive tectonic evolution and numerous orogeny mountain building events fractured the crust into numerous block, horsts, grabens and depressions and Ukraine was intermittently flooded as the crust downwarped during much of the Paleozoic, Mesozoic and early Cenozoic, before the formation of the Alps and Carpathians defined much of its current topography and tectonics. Ukraine was impacted by the Pleistocene glaciations within the last several hundred thousand years. The country has numerous metal deposits as well as minerals, building stone and high-quality industrial sands.

References

  1. Einsele, Gerhard (2000). Sedimentary Basins: Evolution, Facies, and Sediment Budget (2nd ed.). Springer. p. 630. ISBN   978-3-540-66193-1.
  2. Robert Dinwiddie: Ocean_ The World's Last Wilderness Revealed. Dorling Kindersley, London 2008, S. 452
  3. "Chapter II (Geology of Timor-Leste)". Atlas of mineral resources of the ESCAP region Volume 17 Geology and Mineral Resources of Timor-Leste (PDF). United Nations Economic and Social Commission for Asia and the Pacific. 24 December 2003. Archived from the original (PDF) on 20 May 2005.