Gondwana, was a supercontinent that existed from the Neoproterozoic until the Jurassic. It was formed by the accretion of several cratons. Gondwana became the largest piece of continental crust of the Paleozoic Era, covering an area of about 100,000,000 km2. During the Carboniferous Period, it merged with Laurussia to form a larger supercontinent called Pangaea. Gondwana broke up during the Mesozoic Era; the remnants of Gondwana make up about two thirds of today's continental area, including South America, Antarctica and the Indian Subcontinent. The formation of Gondwana began c. 800 to 650 Ma with the East African Orogeny, the collision of India and Madagascar with East Africa,and was completed c. 600 to 530 Ma with the overlapping Brasiliano and Kuunga orogenies, the collision of South America with Africa and the addition of Australia and Antarctica, respectively. The continent of Gondwana was named by Austrian scientist Eduard Suess, after the Gondwana region of central India, derived from Sanskrit for "forest of the Gonds".
The name had been used in a geological context, first by H. B. Medlicott in 1872, from which the Gondwana sedimentary sequences are described; the term "Gondwanaland" is preferred by some scientists in order to make a clear distinction between the region and the supercontinent. The assembly of Gondwana was a protracted process during the Neoproterozoic and Paleozoic, which however remains incompletely understood because of the lack of paleo-magnetic data. Several orogenies, collectively known as the Pan-African orogeny, led to the amalgamation of most of the continental fragments of a much older supercontinent, Rodinia. One of those orogenic belts, the Mozambique Belt, formed 800 to 650 Ma and was interpreted as the suture between East and West Gondwana. Three orogenies were recognized during the 1990s: the East African Orogeny and Kuunga orogeny, the collision between East Gondwana and East Africa in two steps, the Brasiliano orogeny, the successive collision between South American and African cratons.
The final stages of Gondwanan assembly overlapped with the opening of the Iapetus Ocean between Laurentia and western Gondwana. During this interval, the Cambrian explosion occurred. Laurentia was docked against the western shores of a united Gondwana for a short period near the Precambrian/Cambrian boundary, forming the short-lived and still disputed supercontinent Pannotia; the Mozambique Ocean separated the Congo–Tanzania–Bangweulu Block of central Africa from Neoproterozoic India. The Azania continent was an island in the Mozambique Ocean; the Australia/Mawson continent was still separated from India, eastern Africa, Kalahari by c. 600 Ma, when most of western Gondwana had been amalgamated. By c. 550 Ma, India had reached its Gondwanan position. Meanwhile, on the other side of the newly-forming Africa, Kalahari collided with Congo and Rio de la Plata which closed the Adamastor Ocean. C. 540–530 Ma, the closure of the Mozambique Ocean brought India next to Australia–East Antarctica, both North and South China were located in proximity to Australia.
As the rest of Gondwana formed, a complex series of orogenic events assembled the eastern parts of Gondwana c. 750 to 530 Ma. First the Arabian-Nubian Shield collided with eastern Africa in the East African Orogeny c.750 to 620 Ma. Australia and East Antarctica were merged with the remaining Gondwana c. 570 to 530 Ma in the Kuunga Orogeny. The Malagasy orogeny at about 550–515 Mya affected Madagascar, eastern East Africa and southern India. In it, Neoproterozoic India collided with the combined Azania and Congo–Tanzania–Bangweulu Block, suturing along the Mozambique Belt; the 18,000 km -long Terra Australis Orogen developed along Gondwana's western and eastern margins. Proto-Gondwanan Cambrian arc belts from this margin have been found in eastern Australia, New Zealand, Antarctica. Though these belts formed a continuous arc chain, the direction of subduction was different between the Australian-Tasmanian and New Zealand-Antarctica arc segments. A large number of terranes were accreted to Eurasia during Gondwana's existence but the Cambrian or Precambrian origin of many of these terranes remains uncertain.
For example, some Palaeozoic terranes and microcontinents that now make up Central Asia called the "Kazakh" and "Mongolian terranes", were progressively amalgamated into the continent Kazakhstania in the Late Silurian. Whether these blocks originated on the shores of Gondwana is not known. In the Early Palaeozoic the Armorican terrane, which today form large parts of France, was part of either Peri-Gondwana or core Gondwana. Precambrian rocks from the Iberian Peninsula suggest it too formed part of core Gondwana before its detachment as an orocline in the Variscan orogeny close to the Carboniferous–Permian boundary. South-east Asia is made of Gondwanan and Cathaysian continental fragments that were assembled during the Mid-Palaeozoic and Cenozoic; this p
The Permian is a geologic period and system which spans 47 million years from the end of the Carboniferous Period 298.9 million years ago, to the beginning of the Triassic period 251.902 Mya. It is the last period of the Paleozoic era; the concept of the Permian was introduced in 1841 by geologist Sir Roderick Murchison, who named it after the city of Perm. The Permian witnessed the diversification of the early amniotes into the ancestral groups of the mammals, turtles and archosaurs; the world at the time was dominated by two continents known as Pangaea and Siberia, surrounded by a global ocean called Panthalassa. The Carboniferous rainforest collapse left behind vast regions of desert within the continental interior. Amniotes, who could better cope with these drier conditions, rose to dominance in place of their amphibian ancestors; the Permian ended with the Permian–Triassic extinction event, the largest mass extinction in Earth's history, in which nearly 96% of marine species and 70% of terrestrial species died out.
It would take well into the Triassic for life to recover from this catastrophe. Recovery from the Permian–Triassic extinction event was protracted; the term "Permian" was introduced into geology in 1841 by Sir R. I. Murchison, president of the Geological Society of London, who identified typical strata in extensive Russian explorations undertaken with Édouard de Verneuil; the region now lies in the Perm Krai of Russia. Official ICS 2017 subdivisions of the Permian System from most recent to most ancient rock layers are: Lopingian epoch Changhsingian Wuchiapingian Others: Waiitian Makabewan Ochoan Guadalupian epoch Capitanian stage Wordian stage Roadian stage Others: Kazanian or Maokovian Braxtonian stage Cisuralian epoch Kungurian stage Artinskian stage Sakmarian stage Asselian stage Others: Telfordian Mangapirian Sea levels in the Permian remained low, near-shore environments were reduced as all major landmasses collected into a single continent—Pangaea; this could have in part caused the widespread extinctions of marine species at the end of the period by reducing shallow coastal areas preferred by many marine organisms.
During the Permian, all the Earth's major landmasses were collected into a single supercontinent known as Pangaea. Pangaea straddled the equator and extended toward the poles, with a corresponding effect on ocean currents in the single great ocean, the Paleo-Tethys Ocean, a large ocean that existed between Asia and Gondwana; the Cimmeria continent rifted away from Gondwana and drifted north to Laurasia, causing the Paleo-Tethys Ocean to shrink. A new ocean was growing on its southern end, the Tethys Ocean, an ocean that would dominate much of the Mesozoic era. Large continental landmass interiors experience climates with extreme variations of heat and cold and monsoon conditions with seasonal rainfall patterns. Deserts seem to have been widespread on Pangaea; such dry conditions favored gymnosperms, plants with seeds enclosed in a protective cover, over plants such as ferns that disperse spores in a wetter environment. The first modern trees appeared in the Permian. Three general areas are noted for their extensive Permian deposits—the Ural Mountains and the southwest of North America, including the Texas red beds.
The Permian Basin in the U. S. states of Texas and New Mexico is so named because it has one of the thickest deposits of Permian rocks in the world. The climate in the Permian was quite varied. At the start of the Permian, the Earth was still in an ice age. Glaciers receded around the mid-Permian period as the climate warmed, drying the continent's interiors. In the late Permian period, the drying continued although the temperature cycled between warm and cool cycles. Permian marine deposits are rich in fossil mollusks and brachiopods. Fossilized shells of two kinds of invertebrates are used to identify Permian strata and correlate them between sites: fusulinids, a kind of shelled amoeba-like protist, one of the foraminiferans, ammonoids, shelled cephalopods that are distant relatives of the modern nautilus. By the close of the Permian, trilobites and a host of other marine groups became extinct. Terrestrial life in the Permian included diverse plants, fungi and various types of tetrapods; the period saw a massive desert covering the interior of Pangaea.
The warm zone spread in the northern hemisphere. The rocks formed at that time were stained red by iron oxides, the result of intense heating by the sun of a surface devoid of vegetation cover. A number of older types of plants and animals became marginal elements; the Permian began with the Carboniferous flora still flourishing. About the middle of the Permian a major transition in vegetation began; the swamp-loving
Patagonia is a sparsely populated region at the southern end of South America, shared by Chile and Argentina. The region comprises the southern section of the Andes mountains and the deserts and grasslands to the east. Patagonia is one of the few regions with coasts on three oceans, with the Pacific Ocean to the west, the Atlantic Ocean to the east, the Southern Ocean to the south; the Colorado and Barrancas rivers, which run from the Andes to the Atlantic, are considered the northern limit of Argentine Patagonia. The archipelago of Tierra del Fuego is sometimes included as part of Patagonia. Most geographers and historians locate the northern limit of Chilean Patagonia at Huincul Fault, in Araucanía Region; the name Patagonia comes from the word patagón, used by Magellan in 1520 to describe the native tribes of the region, whom his expedition thought to be giants. It is now believed that the people he called the Patagons were Tehuelches, who tended to be taller than Europeans of the time; the Argentine researcher Miguel Doura observed that the name Patagonia derives from the ancient Greek region of modern Turkey called Paphlagonia, possible home of the patagon personage in the chivalric romances Primaleon printed in 1512, ten years before Magellan arrived in these southern lands.
The hypothesis was published in a 2011 New Review of Spanish Philology report. Argentine Patagonia is for the most part a region of steppelike plains, rising in a succession of 13 abrupt terraces about 100 metres at a time, covered with an enormous bed of shingle bare of vegetation. In the hollows of the plains are ponds or lakes of fresh and brackish water. Towards Chilean territory the shingle gives place to porphyry and basalt lavas, animal life becomes more abundant and vegetation more luxuriant, consisting principally of southern beech and conifers; the high rainfall against the western Andes and the low sea surface temperatures offshore give rise to cold and humid air masses, contributing to the ice-fields and glaciers, the largest ice-fields in the Southern hemisphere outside of Antarctica. Among the depressions by which the plateau is intersected transversely, the principal ones are the Gualichu, south of the Río Negro, the Maquinchao and Valcheta, the Senguerr, the Deseado River. Besides these transverse depressions, there are others which were occupied by more or less extensive lakes, such as the Yagagtoo and Colhue Huapi, others situated to the south of Puerto Deseado, in the centre of the country.
In the central region volcanic eruptions, which have taken part in the formation of the plateau during the Cenozoic, cover a large part of the land with basaltic lava-caps. There, caused principally by the sudden melting and retreat of ice aided by tectonic changes, has scooped out a deep longitudinal depression, best in evidence where in contact with folded Cretaceous rocks which are uplifted by the Cenozoic granite, it separates the plateau from the first lofty hills, whose ridges are called the pre-Cordillera. To the west of these, a similar longitudinal depression extends all along the foot of the snowy Andean Cordillera; this latter depression contains the richest and most fertile land of Patagonia. Lake basins along the Cordillera were excavated by ice-streams, including Lake Argentino and Lake Fagnano, as well as coastal bays such as Bahía Inútil; the geological limit of Patagonia has been proposed to be Huincul Fault which forms a major discontinuity. The fault truncates various structures including the Pampean orogen found further north.
The ages of base arocks change abruptly across the fault. There have been discrepancies among geologists on the origin of the Patagonian landmass. Víctor Ramos has proposed that the Patagonian landmass originated as an allochthonous terrane that separated from Antarctica and docked in South America 250 to 270 Ma in the Permian era. A 2014 study by R. J. Pankhurst and coworkers rejects any idea of a far-travelled Patagonia claiming it is of parautochtonous origin; the Mesozoic and Cenozoic deposits have revealed a most interesting vertebrate fauna. This, together with the discovery of the perfect cranium of a chelonian of the genus Niolamia, identical with Ninjemys oweni of the Pleistocene age in Queensland, forms an evident proof of the connection between the Australian and South American continents; the Patagonian Niolamia belongs to the Sarmienti Formation. Fossils of the mid-Cretaceous Argentinosaurus, which may be the largest of all dinosaurs, have been found in Patagonia, a model of the mid-Jurassic Piatnitzkysaurus graces the concourse of the Trelew airport.
Of more than paleontological interest, the middle Jurassic Los Molles Formation and the still richer late Jurassic and early Cretaceous Vaca Muerta formation above it in the Neuquén basin are reported to contain huge hydrocarbon reserves accessible through hydraulic fracturing. Other specimens of the interesting fauna of Patagonia, belonging to the Middle Cenozoic, are the gigantic wingless birds, exceeding in size any hitherto known, the singular mammal Pyrotherium of large dimensions. In
University of Chile
The University of Chile is a public university in Santiago, Chile. It was founded on November 19, 1842 and inaugurated on September 17, 1843, it is the most prestigious in the country. It was established as the continuation of the former colonial Royal University of San Felipe, has a rich history in academic and social outreach; the university seeks to solve national and regional issues and to contribute to the development of Chile. It is recognized as one of the best universities Latin America for its leadership and innovation in science, social sciences, arts through the functions of creation, extension and research, its five campuses comprise more than 3.1 square kilometres of research buildings, health care centers, theaters and sports infrastructure. The institution has more than 40,000 undergraduate and graduate students, offering more than 60 different bachelor and professional degrees, 38 doctoral programs and 116 master programs. Notable alumni include Nobel laureates Pablo Neruda and Gabriela Mistral, twenty Chilean presidents.
The QS University Ranking ranks the University of Chile as the sixth in Latin America and 208 in the world. The school boasts an outstanding 100 points in both Employer Reputation categories; the world ranking of universities, elaborated by Shanghai JiaoTong University and the European Union based on research sciences indicators, places it among the 400 best universities in the world. SCImago Institutions Rankings makes a characterization of institutions based on research and visibility on the web, in 2017 report on investigation, which included more than 4,500 institutions of higher education and other centers in the world, the University of Chile ranked first in Chile, 10 in Latin America and 424 in the world. Another study which highlights the performance of this institution is the Ranking Web of Universities, which measures the presence and impact on the web of over 11,000 universities and qualifies this college as leader of the country, six in Latin America and 371 worldwide. In the 2016 version of the ranking made by AméricaEconomía, University of Chile was ranked first in Chile with the top rating in quality indicators of research, accreditation and inclusion.
In December 21, 2011 the University of Chile was notified by the National Accreditation Commission of the positive evaluation in all obligatory areas and electives. Thus the University is accredited by seven years, the maximum awarded by the agency, for the period between 2011 and 2018; the University of Chile, the Catholic University and the University of Concepción are the only institutions in this country that have the highest accreditation. In 1841 the minister of public education, Manuel Montt, conceived the idea of funding a corporation for the "advancement and development of sciences and humanities". Andrés Bello a Venezuelan poet and humanist, formulated the project which with small modifications became a law on November 19, 1842, creating the Universidad de Chile; the foundation answered the need to modernize the country which a little more than two decades before had become independent from Spain. It replaced the Real Universidad de San Felipe, established in 1738; the University was formally opened on September 17, 1843.
During this period, the university consisted of five faculties: Humanities & Philosophy, Physical & Mathematical Sciences, Law & Political Sciences and Theology. During its first years the University gave considerable support to education, institutional organization, the building of the road network to join together the territory, the energy and production infrastructure. By 1931, the number of colleges had increased to six: Philosophy & Education Sciences, Legal & Social Sciences, Biology & Medical Sciences, Physical & Mathematical Sciences, Agronomy & Veterinary, Fine Arts; the institution has contributed to the formation of the intellectual elites and leaders of the country. Most of the Chilean presidents have studied in its lecture halls, as well as people with prominent roles in politics and culture. During Augusto Pinochet's military regime from 1973 to 1989, the University experienced many profound changes. On October 2, 1973, Decree number 50 of 1973 stated that the University's presidents would be designated by the military regime.
The second major change came on January 3, 1981, when another decree restructured the University. All of its provincial campuses were separated, cojoined with provincial campuses of the Universidad Técnica del Estado and designated as separate universities, such as the Universidad de Talca, Universidad de Valparaiso, the Instituto Pedagógico, the Universidad de Antofagasta, the Universidad de Tarapacá, Instituto Professional de Osorno, Instituto Professional de Chillán, Universidad de la Frontera, Universidad de la Serena; some faculties, such as the one located in avenida Portugal and which now belongs to the Universidad Mayor, were privatized and sold at bargain prices to Pinochet cronies. These changes were orchestrated by influential advisors to the dictatorship as a way to moderate the University's influence on the nation's politics, public policies and intellectual movements, considered leftist by Augusto Pinochet and other righ
Biostratigraphy is the branch of stratigraphy which focuses on correlating and assigning relative ages of rock strata by using the fossil assemblages contained within them. The aim is correlation, demonstrating that a particular horizon in one geological section represents the same period of time as another horizon at some other section; the fossils are useful because sediments of the same age can look different because of local variations in the sedimentary environment. For example, one section might have been made up of clays and marls while another has more chalky limestones, but if the fossil species recorded are similar, the two sediments are to have been laid down at the same time. Biostratigraphy originated in the early 19th century, where geologists recognised that the correlation of fossil assemblages between rocks of similar type but different age decreased as the difference in age increased; the method was well-established. Ammonites, graptolites and trilobites are index fossils that are used in biostratigraphy.
Microfossils such as acritarchs, conodonts, dinoflagellate cysts, pollen and foraminiferans are frequently used. Different fossils work well for sediments of different ages. To work well, the fossils used must be widespread geographically, so that they can occur in many different places, they must be short lived as a species, so that the period of time during which they could be incorporated in the sediment is narrow. The longer lived the species, the poorer the stratigraphic precision, so fossils that evolve such as ammonites, are favoured over forms that evolve much more like nautiloids. Biostratigraphic correlations are based on a fauna, not an individual species, as this allows greater precision. Further, if only one species is present in a sample, it can mean that the strata were formed in the known fossil range of that organism. For instance, the presence of the trace fossil Treptichnus pedum was used to define the base of the Cambrian period, but it has since been found in older strata.
Fossil assemblages were traditionally used to designate the duration of periods. Since a large change in fauna was required to make early stratigraphers create a new period, most of the periods we recognise today are terminated by a major extinction event or faunal turnover. A stage is a major subdivision of strata, each systematically following the other each bearing a unique assemblage of fossils. Therefore, stages can be defined as a group of strata containing the same major fossil assemblages. French palaeontologist Alcide d'Orbigny is credited for the invention of this concept, he named stages after geographic localities with good sections of rock strata that bear the characteristic fossils on which the stages are based. In 1856 German palaeontologist Albert Oppel introduced the concept of zone. A zone includes strata characterised by the overlapping range of fossils, they represent the time between the appearance of species chosen at the base of the zone and the appearance of other species chosen at the base of the next succeeding zone.
Oppel's zones are named after a particular distinctive fossil species, called an index fossil. Index fossils are one of the species from the assemblage of species; the zone is the fundamental biostratigraphic unit. Its thickness range from a few to hundreds of metres, its extant range from local to worldwide. Biostratigraphic units are divided into six principal kinds of biozones: Taxon range biozones represent the known stratigraphic and geographic range of occurrence of a single taxon. Concurrent range biozone include the concurrent, coincident, or overlapping part of the range of two specified taxa. Interval biozone include the strata between two specific biostratigraphic surfaces, it can be based on highest occurrences. Lineage biozone are strata containing species representing a specific segment of an evolutionary lineage. Assemblage biozones are strata. Abundance biozones are strata in which the abundance of a particular taxon or group of taxa is greater than in the adjacent part of the section.
To be useful in stratigraphic correlation index fossils should be: Independent of their environment Geographically widespread Rapidly evolvingEasy to preserve Easy to identify Fossil organisms succeed one another in a definite and determinable order and therefore any time period can be recognized by its fossil content. Biostratigraphic Lithostratigraphic Column Generator
The Jurassic period was a geologic period and system that spanned 56 million years from the end of the Triassic Period 201.3 million years ago to the beginning of the Cretaceous Period 145 Mya. The Jurassic constitutes the middle period of the Mesozoic Era known as the Age of Reptiles; the start of the period was marked by the major Triassic–Jurassic extinction event. Two other extinction events occurred during the period: the Pliensbachian-Toarcian extinction in the Early Jurassic, the Tithonian event at the end; the Jurassic period is divided into three epochs: Early and Late. In stratigraphy, the Jurassic is divided into the Lower Jurassic, Middle Jurassic, Upper Jurassic series of rock formations; the Jurassic is named after the Jura Mountains within the European Alps, where limestone strata from the period were first identified. By the beginning of the Jurassic, the supercontinent Pangaea had begun rifting into two landmasses: Laurasia to the north, Gondwana to the south; this created more coastlines and shifted the continental climate from dry to humid, many of the arid deserts of the Triassic were replaced by lush rainforests.
On land, the fauna transitioned from the Triassic fauna, dominated by both dinosauromorph and crocodylomorph archosaurs, to one dominated by dinosaurs alone. The first birds appeared during the Jurassic, having evolved from a branch of theropod dinosaurs. Other major events include the appearance of the earliest lizards, the evolution of therian mammals, including primitive placentals. Crocodilians made the transition from a terrestrial to an aquatic mode of life; the oceans were inhabited by marine reptiles such as ichthyosaurs and plesiosaurs, while pterosaurs were the dominant flying vertebrates. The chronostratigraphic term "Jurassic" is directly linked to the Jura Mountains, a mountain range following the course of the France–Switzerland border. During a tour of the region in 1795, Alexander von Humboldt recognized the limestone dominated mountain range of the Jura Mountains as a separate formation that had not been included in the established stratigraphic system defined by Abraham Gottlob Werner, he named it "Jura-Kalkstein" in 1799.
The name "Jura" is derived from the Celtic root *jor via Gaulish *iuris "wooded mountain", borrowed into Latin as a place name, evolved into Juria and Jura. The Jurassic period is divided into three epochs: Early and Late. In stratigraphy, the Jurassic is divided into the Lower Jurassic, Middle Jurassic, Upper Jurassic series of rock formations known as Lias and Malm in Europe; the separation of the term Jurassic into three sections originated with Leopold von Buch. The faunal stages from youngest to oldest are: During the early Jurassic period, the supercontinent Pangaea broke up into the northern supercontinent Laurasia and the southern supercontinent Gondwana; the Jurassic North Atlantic Ocean was narrow, while the South Atlantic did not open until the following Cretaceous period, when Gondwana itself rifted apart. The Tethys Sea closed, the Neotethys basin appeared. Climates were warm, with no evidence of a glacier having appeared; as in the Triassic, there was no land over either pole, no extensive ice caps existed.
The Jurassic geological record is good in western Europe, where extensive marine sequences indicate a time when much of that future landmass was submerged under shallow tropical seas. In contrast, the North American Jurassic record is the poorest of the Mesozoic, with few outcrops at the surface. Though the epicontinental Sundance Sea left marine deposits in parts of the northern plains of the United States and Canada during the late Jurassic, most exposed sediments from this period are continental, such as the alluvial deposits of the Morrison Formation; the Jurassic was a time of calcite sea geochemistry in which low-magnesium calcite was the primary inorganic marine precipitate of calcium carbonate. Carbonate hardgrounds were thus common, along with calcitic ooids, calcitic cements, invertebrate faunas with dominantly calcitic skeletons; the first of several massive batholiths were emplaced in the northern American cordillera beginning in the mid-Jurassic, marking the Nevadan orogeny. Important Jurassic exposures are found in Russia, South America, Japan and the United Kingdom.
In Africa, Early Jurassic strata are distributed in a similar fashion to Late Triassic beds, with more common outcrops in the south and less common fossil beds which are predominated by tracks to the north. As the Jurassic proceeded and more iconic groups of dinosaurs like sauropods and ornithopods proliferated in Africa. Middle Jurassic strata are neither well studied in Africa. Late Jurassic strata are poorly represented apart from the spectacular Tendaguru fauna in Tanzania; the Late Jurassic life of Tendaguru is similar to that found in western North America's Morrison Formation. During the Jurassic period, the primary vertebrates living in the sea were marine reptiles; the latter include ichthyosaurs, which were at the peak of their diversity, plesiosaurs and marine crocodiles of the families Teleosauridae and Metriorhynchidae. Numerous turtles could be found in rivers. In the invertebrate world, several new groups appeared, including rudists (a reef-formi
University of Buenos Aires
The University of Buenos Aires is the largest university in Argentina and the largest university by enrollment in Latin America. Founded on August 12, 1821 in the city of Buenos Aires, it consists of 13 departments, 6 hospitals, 10 museums and is linked to 4 high schools: Colegio Nacional de Buenos Aires, Escuela Superior de Comercio Carlos Pellegrini, Instituto Libre de Segunda Enseñanza and Escuela de Educación Técnica Profesional en Producción Agropecuaria y Agroalimentaria. Entry to any of the available programmes of study in the university is open to anyone with a secondary school degree. Only upon completion of this first year may the student enter the chosen school; each subject is of one semester duration. If someone passes all 6 subjects in their respective semester, the CBC will take only one year. Potential students of economics, take a 2-year common cycle, the "CBG", comprising 12 subjects; the UBA has no central campus. A centralized Ciudad Universitaria was started in the 1960s, but contains only two schools, with the others at different locations in Buenos Aires.
Access to the university is free of charge including foreigners. However, the postgraduate programs charge tuition fees that can be covered with research scholarships for those students with outstanding academic performance; the university has produced four Nobel Prize laureates, one of the most prolific institutions in the Spanish-speaking world. According to the QS World University Rankings the University of Buenos Aires ranked number 75 in the world, making it the highest ranked university in Ibero-America; the schools that comprise the university are: Ciclo Básico Común Facultad de Psicología Facultad de Ingeniería Facultad de Odontología Facultad de Farmacia y Bioquímica Facultad de Filosofía y Letras Facultad de Derecho Facultad de Medicina Facultad de Ciencias Sociales Facultad de Veterinaria Facultad de Agronomía Facultad de Ciencias Económicas Facultad de Ciencias Exactas y Naturales Facultad de Arquitectura, Diseño y Urbanismo Of these, only the last two have their buildings located in Ciudad Universitaria, a campus-like location in Núñez, in northern Buenos Aires along the banks of the Río de la Plata.
The others are scattered around the city in buildings of various sizes, with some having more than one building. There are projects to move more schools to Ciudad Universitaria, the first one in order of importance is the School of Psychology, whose building is designed to be placed on this Campus. There are no existing Argentinian or Latin-American university ranking systems, but several international rankings have ranked the University of Buenos Aires; the reputed Academic Ranking of World Universities known as the Shanghai Ranking ranked UBA not only above all other Argentinian universities but all other Latin-American ones. The QS World University Rankings ranks UBA in the 75th place, above all other Spanish or Portuguese speaking universities in its worldwide ranking but relegates it to the 11th place in its Latin-American ranking. Luis Agote, physician Diana Agrest, Argentine born American architect and theorist Viviana Alder, marine microbiologist, Argentine Antarctic researcher Teodosio Cesar Brea and founder of Allende & Brea Alejandro Bulgheroni, oil billionaire Juan Cabral, film director Luis Caffarelli, mathematician Alberto Calderón, mathematician Primarosa Chieri, geneticist Julio Cortázar, writer Augusto Claudio Cuello and Charles E. Frosst/Merck Chair in Pharmacology and Therapeutics at McGill University Che Guevara, revolutionary leader and physician Esther Hermitte, anthropologist Salvador Maciá, physician and politician Jose Pedro Montero De Candia, 27th President of Paraguay Luis Moreno-Ocampo, lawyer and Chief Prosecutor of the International Criminal Court Patricio Pouchulu and educator Alberto Prebisch, architect Raul Prebisch, economist Teresa Ratto, physician Juan Rosai, Italian-born American surgical pathologist José Luis Murature, foreign minister of Argentina Irene Schloss, plankton biologist, Argentine Antarctic researcher Clorindo Testa and painter Richard Tomlinson, former British spy Claudio Vekstein, architect specialized in public architecture Rafael Viñoly, Uruguayan architect Inés Mónica Weinberg de Roca, former Judge at the International Criminal Tribunal for RwandaThe following former students and professors of the university have received the Nobel Prize: Carlos Saavedra Lamas, Peace, 1936.
Adolfo Pérez Esquivel, Peace, 1980. Bernardo Houssay, Physiology, 1947. Luis Federico Leloir, Chemistry, 1970. César Milstein, Medicine, 1984; the following Presidents of Argentina have earned their degrees at the university: Carlos Pellegrini, lawyer. Luis Sáenz Peña, lawyer. Manuel Quintana, lawyer. Roque Sáenz Peña, lawyer. Victorino de la Plaza, lawyer. Hipólito Yrigoyen (1916–1922 and 1928–1930, Radical Civic U