Exhumation history of the Central Andean fold-thrust belt (S-Bolivia) by apatite fission track dating
- Autores: H. Ege, E. Sobel, E. Scheuber, P. Silva, V. Jacobshagen
- Localización: Geotemas (Madrid), ISSN 1576-5172, Nº. 4, 2002 (Ejemplar dedicado a: INTERNATIONAL WORKSHOP ON FISSION TRACK ANALISIS: THEORY AND APPLICATIONS), págs. 65-68
- Idioma: inglés
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Resumen
Numerous workers have investigated the structural evolution o f the Central Andean plateau; however, the chronological details o f this evolution are poorly constrained due to poor biostratigraphic resolution o f the nonmarine strata and sparse geochronologic data. This study provides the first extensive apatite fission track study in Bolivia, crossing the highAltiplano plateau and the adjacent Eastern Cordillera and extending into the Subandean zone. Preliminary results show that most AFT cooling ages ofthe Altiplano and Eastern Cordillera are within ca. 30-20 Ma, while track length corrections suggests that these samples all cooled during the Oligocene. The uniformity o f age-pattern apparently correspond to the first stage ofplateau formation: the thermally weakened crust o f the future plateau area underwent distributed deformation in a thick-skinned mode. In the second stage, deformation concentrated at the eastern edge o f the orogen, where the upper crust was thrust over the foreland and the Subandean fold-thrust belt formed in a thin-skinned mode.
