La Cordillera Bética, un orógeno desmembrado extensionalmente y sin raíz orogénica en sus zonas internas¿Qué empuja a Sierra Nevada a mantenerse por encima de los 3000 m de altitud?
- J.M. Azañón 1
- G. Booth-Rea 1
- J.V. Pérez- Peña 1
- J. Morales 2
- D. Stich 2
- F.L. Mancilla 2
- J.P. Galve 1
- F.J. Roldán 3
- J. Rodríguez-Fernández 4
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1
Universidad de Granada
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- 2 Instituto Andaluz de Geofísica y Prevención de Desastres Sísmicos, Universidad de Granada
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3
Instituto Geológico y Minero de España
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- 4 Instituto Andaluz de Ciencias de la Tierra, CSIC-UGR
ISSN: 1576-5172
Year of publication: 2016
Issue Title: IX CONGRESO GEOLÓGICO DE ESPAÑA
Issue: 16
Pages: 543-546
Type: Article
More publications in: Geotemas (Madrid)
Abstract
Sierra Nevada reaches the highest heights in Iberia and in it crop out the deepest domains of the Internal Betics. This mountain range has uplifted during the last 8 My at average rates of 400m/My. Morphometric data show that it continues uplifting, especially in its westernmost region. However, new geophysical data that show the lithospheric structure of this region reveal that Sierra Nevada does not have a crustal root as would be expected in the internal zone of an active orogen. This lack of a crustal root represents a paradox, as uplift has continued through the Plio -Quaternary. Here we put together geophysical and relief data to calculate the residual topography of the Betics. We show for the first time the existence of dynamic topography induced by the effects of the sinking Iberian lithosphere and the associated mantle flow. Furthermore, we show the geometry of these anomalies that are strongly influenced by NNW -SSE crustal necks, perpendicular to the active extension in the Betics. This extension thinned the crustal domains of both the external Betics and the southIberian margin units involved in the collision.