Search results for " America."
showing 10 items of 686 documents
Subduction of the Nazca Ridge and the Inca Plateau: Insights into the formation of ore deposits in Peru
2005
A large number of ore deposits that formed in the Peruvian Andes during the Miocene (15-5 Ma) are related to the subduction of the Nazea plate beneath the South American plate. Here we show that the spatial and temporal distribution of these deposits correspond with the arrival of relatively buoyant topographic anomalies, namely the Nazca Ridge in central Peru and the now-consumed Inca Plateau in northern Peru, at the subduction zone. Plate reconstruction shows a rapid metallogenic response to the arrival of the topographic anomalies at the subduction trench. This is indicated by clusters of ore deposits situated within the proximity of the laterally migrating zones of ridge subduction. It …
Speculations on the impact of catastrophic subduction initiation on the Earth System
2016
Abstract The physics of subduction initiation can be studied with numerical models of lithosphere dynamics, to the extent where we can now test the potential consequences of a catastrophic subduction initiation event on the Earth System. The South American Atlantic passive margin is here used to show that, once subduction has catastrophically initiated there, a major geodynamic reconfiguration of the South American plate (SAm) is likely to take place: (1) compression in the east will be inverted to extension, because ridge push will be replaced by subduction rollback and trench retreat; (2) compression in the west will be inverted to extension due to absolute rollback; and (3) without buttr…
Tectonic evolution of the Sierra Maestra Mountains, SE Cuba, during Tertiary times: From arc-continent collision to transform motion
2008
Abstract A structural study was carried out along the southern Sierra Maestra mountain range, SE Cuba. This was aimed to monitor the effects of Paleogene island arc formation and collision due to convergence of the Caribbean and North American plates and subsequent Neogene disruption of the arc by initiation of the North Caribbean Transform Fault. In the Sierra Maestra two different and unrelated volcanic arcs are exposed, one of Cretaceous age (pre-Maastrichtian) and the other of Paleogene age, the latter forming the main expression of the mountain range. The volcanic arcs are overlain by Middle–Upper Eocene siliciclastic, carbonate and terrigenous rocks. Six distinct phases of deformation…
Cambio académico. Los grados universitarios. De la escolástica a los primeros ensayos decimonónicos
2013
ResumenEn este trabajo analizamos las transformaciones experimentadas en el contenido académico de los grados universitarios a lo largo de la historia. Partimos del modelo medieval europeo para conocer el sentido original de los grados. Utilizamos, luego, el caso mexicano para seguir los cambios. Veremos cómo el significado docente y corporativo de los grados académicos se fue perdiendo y, en su lugar, ganó importancia la adquisición de conocimientos para el ejercicio profesional. El trabajo termina en 1854-1855, con el Plan de estudios que concibe, por primera vez y de manera estructurada, un sistema educativo, en el que todos los grados están escolarizados, requieren para su obtención apr…
The Habitual ‘Saber + Infinitive’ in South American Spanish
2022
The present paper aims to describe both synchronic and diachronic distributions of the habitual aspectual periphrasis ‘saber + infinitive’ in the varieties of Spanish spoken in the South American continent. The data used for the present analysis come from the Corpus de Referencia del Español Actual and the Corpus del Español del Siglo XXI.
Le récit d’esclave africain-américain : réflexions sur une appellation générique
2015
What do we talk about when we talk about 'slave narratives?' African American slave narratives have been a staple of American literary studies over the past decades. The narratives of Frederick Douglass, Harriet Jacobs and other ex-slaves have been recovered, anthologized and discussed by eminent critics such as Marion Wilson Starling, Henry Louis Gates Jr., Frances Smith Foster and William L. Andrews. For all its ubiquity, however, the generic label 'slave narrative' has been used in many different ways by specialists of African American literature. In this essay I argue that the systematic and sometimes uncritical use of the label has led to generalizations that limit our understanding of…
A casual alien plant new to Mediterranean Europe: Ceiba speciosa (Malvaceae) in the suburban area of Palermo (NW Sicily, Italy)
2014
The abiotic and biotic characteristics of the first sites where floss silk tree behaves as a casual alien plant in the Mediterranean Europe are described. The species was probably first planted in botanical gardens of southern France few decades before mid XIX century. It was introduced in Palermo in 1896, a city which appears to match very well its climatic requirements. According to the available information on its biology and ecology in both its original and secondary range, the floss silk tree should not become an invasive alien plant in the Mediterranean. Nevertheless, several gaps need to be filled in order to increase our understanding of future trends of Ceiba speciosa in southern E…
Pēckara amerikāņu vēstures interpretācija Čanga Reja Lī romānā Nodotie
2019
Bakalaura darba mērķis ir izanalizēt ASV vēstures reprezentāciju Čanga-reja Lī vēsturiskajā romānā Nodotie no transnacionālā viedokļa. Pētījuma mērķa sasniegšanai, tiek izmantotas tādas metodes kā žanra un teksta analīze, akcentējot uzmanību uz romāna tēmām un varoņiem, kā arī izmantojot transnacionālo pieeju konteksta interpretācijai. Empīriskajā daļā tiek apspriests kāpēc Nodotie pieder pie vēsturiskā romāna žanra. Turklāt, galveno varoņu traumatisko pieredžu un likteņu krustošanās nozīme romānā. Analizējot tiek noskaidrota romāna pozīcija Āzijas amerikāņu literatūrā, kā arī kādā veidā tā veicina ASV vēstures pārskatīšanu.