Contrasting exhumation histories from vertical profiles in the Calchaquies and Aconquija ranges, northwest Argentina

• Autores: E.R. Sobel, Manfred R. Strecker
• Localización: Geotemas (Madrid), ISSN 1576-5172, Nº. 4, 2002 (Ejemplar dedicado a: INTERNATIONAL WORKSHOP ON FISSION TRACK ANALISIS: THEORY AND APPLICATIONS), págs. 139-142
• Idioma: inglés
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• Resumen

  • The Argentine Andean foreland between 26 and 33°S are tectonically active reverse-fault bounded crystalline basement blocks which partly preserve a polygenetic basement peneplain at elevations in excess of 5000 m.

    Uplift of these ranges is thought to have started in the Pliocene. In order to constrain the timing of this uplift as well as the development of this peneplain, the Aconquija and Calchaquies ranges were studied by apatite fission-track thermochronology. Samples were collected from vertical transects extending from the basal contact with basin sediments to the range crest at both localities. The Cumbres Calchaquies range experienced significant Cretaceous cooling, interpreted to be linked to a rift shoulder uplift, but only minimal Cenozoic cooling. In contrast, Sierra Aconquija cooled rapidly between 5.5 and 4.5 My