Anomalous upper mantle beneath the Central Andes : isostasy and Andean uplift

Four theoretical models isostatically compensated were prepared and compared between themselves in order to analyze either the isostatic equilibrium or the probable mechanisms for justifying the Central Andean uplift. They are: Model 1, or Airy Model: in this classical model the isostatic compensati...

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Autor principal: Introcaso, Antonio
Formato: article artículo publishedVersion
Lenguaje:Inglés
Publicado: Instituto de Fisiografía y Geología 2008
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Acceso en línea:http://hdl.handle.net/2133/672
http://hdl.handle.net/2133/672
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id I15-R121-2133-672
record_format dspace
institution Universidad Nacional de Rosario
institution_str I-15
repository_str R-121
collection Repositorio Hipermedial de la Universidad Nacional de Rosario (UNR)
language Inglés
orig_language_str_mv eng
topic Central Andean uplift
isostatic equilibrium
gravimetric models
thermal root
crustal root
levantamiento de los Andes Centrales
equilibrio isostático
modelos gravimétricos
raíz térmica
raíz cortical
spellingShingle Central Andean uplift
isostatic equilibrium
gravimetric models
thermal root
crustal root
levantamiento de los Andes Centrales
equilibrio isostático
modelos gravimétricos
raíz térmica
raíz cortical
Introcaso, Antonio
Anomalous upper mantle beneath the Central Andes : isostasy and Andean uplift
topic_facet Central Andean uplift
isostatic equilibrium
gravimetric models
thermal root
crustal root
levantamiento de los Andes Centrales
equilibrio isostático
modelos gravimétricos
raíz térmica
raíz cortical
description Four theoretical models isostatically compensated were prepared and compared between themselves in order to analyze either the isostatic equilibrium or the probable mechanisms for justifying the Central Andean uplift. They are: Model 1, or Airy Model: in this classical model the isostatic compensation would take place at the maximum Moho depth's level: 61.7 km. Model 2: this model justifies the Andean elevation by means of a combination of lithospherical thermal root and crustal root. In this case, the last one is diminished 5.3 km respect to crustal root's thickness of Model 1. Isostatic compensation takes place here at the bottom of thermal lithosphere: 140 km deep. Model 3: this model explains the elevation by means of a combination of the subsidence that the subducted Nazca Plate could produce, and the crustal root effect, that is 6 km thicker than the first model's root. The isostatic compensation could take place at a depth of 300 km. Model 4: this model involves Models 1, 2 and 3 mechanisms; the isostatic compensation takes place at a depth of 300 km. Crustal shortenings S are sensitive to the upper mantle's heterogeneity, varying from 17% to +18%, h as it is shown by the following values: S = 278 km (Model 1), S = 230 km (Model 2), S = 338 km (Model 3) and h h h S = 288 km (Model 4). h We also demonstrate that the model selected for evaluating the Andean isostatic equilibrium in this zone of the anomalous upper mantle is not critical. The analysis of the two EW gravity sections at 22°S and 24.5°S latitudes favors Model 2 as the most likely, since the crustal thickness found from it is clearly consistent with seismic data available at 24.5°S. Nevertheless, we can admit other gravimetric models.
format article
artículo
publishedVersion
author Introcaso, Antonio
author_facet Introcaso, Antonio
author_sort Introcaso, Antonio
title Anomalous upper mantle beneath the Central Andes : isostasy and Andean uplift
title_short Anomalous upper mantle beneath the Central Andes : isostasy and Andean uplift
title_full Anomalous upper mantle beneath the Central Andes : isostasy and Andean uplift
title_fullStr Anomalous upper mantle beneath the Central Andes : isostasy and Andean uplift
title_full_unstemmed Anomalous upper mantle beneath the Central Andes : isostasy and Andean uplift
title_sort anomalous upper mantle beneath the central andes : isostasy and andean uplift
publisher Instituto de Fisiografía y Geología
publishDate 2008
url http://hdl.handle.net/2133/672
http://hdl.handle.net/2133/672
work_keys_str_mv AT introcasoantonio anomalousuppermantlebeneaththecentralandesisostasyandandeanuplift
bdutipo_str Repositorios
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