Adriana Ocampo has led six research expeditions to study what geological formation that is more than 180 km in diameter and 20 km in depth
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Adriana Ocampo Adriana Ocampo is a Colombian planetary geologist and the Science Program Manager at NASA Headquarters. Her research contributed to the understanding of the Chicxulub impact crater. She has led six research expeditions to the Chicxulub impact site. Ocampo and her colleagues also discovered the Aorounga Crater Chain in Chad in 1996.
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Chicxulub crater The Chicxulub crater ( ; ] ) is an impact crater buried underneath the Yucatán Peninsula in Mexico. Its center is located near the town of Chicxulub, after which the crater is named. It was formed by a large asteroid or comet about 10 to 15 kilometres (6 to 9 miles) in diameter, the Chicxulub impactor, striking the Earth. The date of the impact coincides precisely with the Cretaceous–Paleogene boundary (K–Pg boundary), slightly less than 66 million years ago, and a widely accepted theory is that worldwide climate disruption from the event was the cause of the Cretaceous–Paleogene extinction event, a mass extinction in which 75% of plant and animal species on Earth suddenly became extinct, including all non-avian dinosaurs. The crater is more than 180 km in diameter and 20 km in depth, well into the continental crust of the region of about 10–30 km depth. It makes the feature the third of the largest confirmed impact structures on Earth.
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Surface features of Venus The surface of Venus is dominated by geologic features that include volcanoes, large impact craters, and aeolian erosion and sedimentation landforms. Venus has a topography reflecting its single, strong crustal plate, with a unimodal elevation distribution (over 90% of the surface lies within an elevation of -1.0 and 2.5 km) that preserves geologic structures for long periods of time. Studies of the Venusian surface are based on imaging, radar, and altimetry data collected from several exploratory space probes, particularly "Magellan", since 1961 (see Venus Exploration). Despite its similarities to Earth in size, mass, density, and possibly composition, Venus has a unique geology that is unlike Earth's. Although much older than Earth's, the surface of Venus is relatively young compared to other terrestrial planets (<500 million years old), possibly due to a global-scale resurfacing event that buried much of the previous rock record. Venus is believed to have approximately the same bulk elemental composition as Earth, due to the physical similarities, but the exact composition is unknown. The surface conditions on Venus are more extreme than on Earth, with temperatures ranging from 453 to 473 °C and pressures of 95 bar. Venus lacks water, which makes crustal rock stronger and helps preserve surface features. The features observed provide evidence for the geological processes at work. Twenty feature types have been categorized thus far. These classes include local features, such as craters, coronae, and undae, as well as regional-scale features, such as planitiae, plana, and tesserae.
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Pasochoa Pasochoa (4,200 metres) is an extinct volcano located in the Guayllabamba river basin in the Ecuadorian Andes. The current mountain form is a collapsed crater with a semicircular shape. This structure emerged approximately 100 thousand years ago due to an eruption which destroyed the crater and occidental slope of the previous volcanic cone.
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Santos Basin The Santos Basin (Portuguese: "Bacia de Santos" ) is an approximately 352000 km2 large mostly offshore sedimentary basin. It is located in the south Atlantic Ocean, some 300 km southeast of Santos, Brazil. The basin is one of the Brazilian basins to have resulted from the break-up of Gondwana since the Early Cretaceous, where a sequence of rift basins formed on both sides of the South Atlantic; the Pelotas, Santos, Campos and Espírito Santo Basins in Brazil, and the Namibia, Kwanza and Congo Basins in southwestern Africa.
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Brasiliano orogeny Brasiliano orogeny or Brasiliano cycle (Portuguese: "Orogênese Brasiliana" and "Ciclo Brasiliano") refers to a series of orogenies of Neoproterozoic age exposed chiefly in Brazil but also in other parts of South America. The Brasiliano orogeny is a regional name for the larger Pan-African/Brasiliano orogeny that extended not only in South America but across most of Gondwana. In a wide sense the Brasiliano orogeny includes also the Pampean orogeny. Almeida "et al". coined the term Brasiliano Orogenic Cycle in 1973. The orogeny led to the closure of several oceans and aulacogens including the Adamastor Ocean, the Goianides Ocean, the Puncoviscana Ocean and the Peri-Franciscano Ocean.
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Eramosa The term was first used for a stratigraphic unit by Williams (1915) who named the Eramosa Member (of the Lockport Formation) for the bituminous dolomites exposed below the Guelph Formation along the Eramosa River, northeast of Guelph, Ontario. No detailed description of the type section has ever been published, and the status of the unit has been subject to many different interpretations. Until recently, the Eramosa in Ontario was regarded as the highest Member of the Lockport Formation, with gradational contacts with the Goat Island Member (below) and the Guelph Formation (above). In 1995, the US Geological Survey proposed a revised stratigraphy based on studies in the Niagara region. It extended the Lockport to Group status and included, from base to top, the Gasport, Goat Island, Eramosa, and Guelph as Formations within the Lockport Group. In a “reference section” in the Niagara River Gorge, the Eramosa was divided into six “units” recognized throughout the Niagara region, but a shaley lower unit previously named for the Hamilton area (the Vinemount Member) was transferred to the Goat Island Formation. Brunton (2009) has proposed a revision for Ontario which restores the Vinemount Member to the Eramosa and recognizes two other members.
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La Negra Formation La Negra Formation (Spanish: "Formación La Negra" ) is a geologic formation of Jurassic age, composed chiefly of volcanic and volcaniclastic rocks, located in the Coast Range of northern Chile. The formation originated in marine and continental (terrestrial) conditions, and bears evidence of submarine volcanism as well as large explosive eruptions. The volcanism of La Negra Formation is thought to have lasted for about five million years.
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Meteora The Meteora ( ; Greek: Μετέωρα , ] ) is a rock formation in central Greece hosting one of the largest and most precipitously built complexes of Eastern Orthodox monasteries, second in importance only to Mount Athos. The six monasteries are built on immense natural pillars and hill-like rounded boulders that dominate the local area. It is located near the town of Kalambaka at the northwestern edge of the Plain of Thessaly near the Pineios river and Pindus Mountains.
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Alcheringa (journal) Alcheringa: An Australasian Journal of Palaeontology is the official journal of the Association of Australasian Palaeontologists. The journal is international in scope and publishes articles on all aspects of palaeontology and its ramifications into the earth and biological sciences, including: taxonomy, biostratigraphy, micropalaeontology, vertebrate palaeontology, palaeobotany, palynology, palaeobiology, palaeoanatomy, palaeoecology, biostratinomy, biogeography, chronobiology, biogeochemistry and palichnology. The journal was established in 1975 and is currently published as four issues per year. Alcheringa is derived from the Arrernte language of the Arrernte aboriginal people of the Alice Springs area of central Australia. Alcheringa (also spelt "altjeringa") is the popularized English version of an Arunta expression that means 'in the beginning' or 'from all eternity'. "Alcheringa" is also the name given to a 2.7-2.8 billion year old stromatolite from the Pilbara region of Western Australia, and symbolizes the antiquity of life and its record in sedimentary rocks. An image of the stromatolite is illustrated on the cover of the journal.
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Wallaby Plateau The Wallaby Plateau, which is also known as the Cuvier Plateau, is a large bathymetric high that is located about 450 km west of Carnarvon, Western Australia. The Wallaby Plateau covers approximately 100,000 km2 and lies in water depths of 2,200 m to greater than 5,000 m . In the west, the Wallaby Plateau is separated from the Zenith Plateau by a 100-150 km wide, north to northeast-trending bathymetric trough. "Wallaby Plateau" is the name used by the Australian geologists and government for this undersea plateau. This name was first used in a "Hartog" AGSO bathymetric map and formally recognized in a peer-reviewed paper by Symonds and Cameron in 1977. In contrast, the internationally recognized name for it is "Cuvier Plateau". "Cuvier" is a historical name that is presumably derived from the adjacent Cape Cuvier. Cape Cuvier was named for Georges Cuvier, zoologist and statesman, by a French expedition led by Baudin in 1800 – 1803. The Wallaby Plateau lies inside the Australian Exclusive Economic Zone.
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Olstad Glacier Olstad Glacier ( ) is a heavily crevassed glacier descending to the west coast of Peter I Island about 2 nautical miles (3.7 km) south of Tofte Glacier. Peter I Island was circumnavigated by the Norwegian whale catcher "Odd I" in January 1927 and was explored from the "Norvegia" in February 1929. The glacier is named for Ola Olstad, Norwegian zoologist who, transported by various whaling ships, conducted research in South Georgia, South Shetland Islands and Palmer Archipelago in 1927-28.
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Veldhoven Formation The Veldhoven Formation (Dutch: "Formatie van Veldhoven" ; abbreviation: VE) is a geologic formation in the subsurface of the Netherlands. The formation consists of an alternation of marine clay and sand from the Oligocene epoch.
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Large low-shear-velocity provinces Large low-shear-velocity provinces, LLSVPs, also called superplumes, are characteristic structures of parts of the lowermost mantle (the region surrounding the outer core) of the Earth. These provinces are characterized by slow shear wave velocities and were discovered by seismic tomography of the deep Earth. There are two main provinces: the African LLSVP and the Pacific LLSVP. Both extend laterally for thousands of kilometers and possibly up to 1000 km vertically from the core-mantle boundary. The Pacific LLSVP has specific dimensions of 3000 km across and 300 m higher than the surrounding ocean-floor, and is situated over four hotspots that suggest multiple mantle plumes underneath. These zones represent around 3% of the volume of the Earth. Other names for LLSVPs include "superwells", "thermo-chemical piles", or "hidden reservoirs". Some of these names, however, are more interpretive of their geodynamical or geochemical effects, while many questions remain about their nature.
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Geodynamics of Venus NASA's Magellan spacecraft mission discovered that Venus has a geologically young surface with a relatively uniform age of 500±200 Ma (million years). The age of Venus was revealed by the observation of over 900 impact craters on the surface of the planet. These impact craters are nearly uniformly distributed over the surface of Venus and less than 10% have been modified by plains of volcanism or deformation. These observations indicate that a catastrophic resurfacing event took place on Venus around 500 Ma, and was followed by a dramatic decline in resurfacing rate. The radar images from the Magellan missions revealed that the terrestrial style of plate tectonics is not active on Venus and the surface appears to be immobile at the present time. Despite these surface observations, there are numerous surface features that indicate an actively convecting interior. The Soviet Venera landings revealed that the surface of Venus is essentially basaltic in composition based on geochemical measurements and morphology of volcanic flows. The surface of Venus is dominated by patterns of basaltic volcanism, and by compressional and extensional tectonic deformation, such as the highly deformed tesserae terrain and the pancake like volcano-tectonic features known as coronae. The planet's surface can be broadly characterized by its low lying plains, which cover about 80% of the surface, 'continental' plateaus and volcanic swells. There is also an abundance of small and large shield volcanoes distributed over the planet's surface. Based on its surface features, it appears that Venus is tectonically and convectively alive but has a lithosphere that is static.
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Miño Volcano Miño Volcano is a symmetrical cone-shaped stratovolcano located in El Loa Province, Antofagasta Region, Chile. It lies a few kilometres northwest of Aucanquilcha volcano and at its foot originates Loa River. The major settlement in its vicinity is Ollagüe. The volcano has erupted mafic andesite. Potassium-argon dating has yielded ages of 3.59±0.11 and 3.27±0.40 million years ago for Miño. This volcano is usually considered part of Aucanquilcha, and lava flows appear to originate from the summit.
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Guadalupe Group The Guadalupe Group (Spanish: "Grupo Guadalupe" , KG, Ksg) is a geological group of the Altiplano Cundiboyacense, Eastern Ranges of the Colombian Andes. The group, a sequence of shales and sandstones, is subdivided into three formations; Arenisca Dura, Plaeners and Arenisca Labor-Tierna, and dates to the Late Cretaceous period; Campanian-Maastrichtian epochs and at its type section has a thickness of 750 m .
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Gustava Aigner Dr. Gustava Kahler, née Aigner, (29 April 190622 March 1987) was an Austrian geologist and palaeontologist. She was noted in particular for her work with Franz Heritsch and with her husband, Franz Kahler. In recognition of her discovery of graptolites in the northern greywacke zone, her former fellow student, Ida Peltzmann, named two species for her.
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Guaratiba Group The Guaratiba Group (Portuguese: "Grupo Guaratiba" ) is a geological group of the Santos Basin offshore of the Brazilian states of Rio de Janeiro, São Paulo, Paraná and Santa Catarina. The group forms the pre-salt layer in the petroleum-rich basin and hosts the biggest oil fields of Brazil, as Lula, Júpiter and many more. The group contains, depending on the definition, three to four formations and dates to the Early Cretaceous period; Hauterivian to Early Aptian epochs. The total thickness of the group, representing the first phase of sedimentation after the break-up of Gondwana in the Santos Basin, is estimated at 4200 m .
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Large igneous province In geology, a large igneous province (LIP) is an extremely large accumulation of igneous rocks, including plutonic rocks (intrusive) or volcanic rock formations (extrusive), arising when hot magma extrudes from inside the Earth and flows out. The source of many or all LIPs is variously attributed to mantle plumes or to processes associated with plate tectonics. Types of LIPs can include "large volcanic provinces" (LVP), created through flood basalt, and "large plutonic provinces" (LPP). Rampino and Stothers (1988) cite eleven distinct flood-basalt episodes - occurring in the past 250 million years - which created volcanic provinces and plateaus and coincided with mass extinctions. However, more flood basalts have been recognized, such as the large Ontong Java Plateau, and the medium-sized Chilcotin Group, though the latter may be linked to the Columbia River Basalt Group. Formation depends on a range of factors, such as continental configuration, latitude, volume, rate, duration of eruption, style and setting (continental vs. oceanic), the pre-existing climate state, and the biota resilience to change.
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Cheuquemó Formation Cheuquemó Formation (Spanish: "Formación Cheuquemó" ) is a geological formation of sedimentary rock in south-central Chile. The sediments of the formation were deposited during the Late Oligocene and Early Miocene epochs. The formations lower sections are made up of conglomerate, then successions of sandstone, tuff and mudstone rich in organic material follows. The formation indicates that sedimentation occurred in a estuarine (paralic) and other non-marine (continental) environments. It contains fossils of the following genera: "Mytilus", "Cardium" and "Turritella". Stratigraphically it overlies the Bahía Mansa Metamorphic Complex and underlies the Miocene Santo Domingo Formation.
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Coquimbo Formation Coquimbo Formation (Spanish: "Formación Coquimbo" ) is a Miocene and Pliocene sedimentary formation located in Coquimbo Region in Norte Chico, Chile. In the area of Tongoy the Coquimbo Formation was deposited in an ancient bay that was formed in a graben or half-graben, with a normal fault dipping east. Sea level changes during the Holocene have caused erosion to cut several marine terraces into the formation.