Artículo
Local high relief at the southern margin of the Andean plateau by 9 Ma: evidence from ignimbritic valley fills and river incision
Montero Lopez, Maria Carolina
; Strecker, Manfred R.; Schildgen, Taylor F.; Hongn, Fernando Daniel
; Guzman, Silvina Raquel
; Bookhagen, Bodo; Sudo, Masafumi
Fecha de publicación:
08/2014
Editorial:
Wiley
Revista:
Terra Nova (print)
ISSN:
0954-4879
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
A valley-filling ignimbrite re-exposed through subsequent river incision at the southern margin of the Andean (Puna) plateau preserves pristine geological evidence of pre-late Miocene paleotopography in the northwestern Argentine Andes. Our new 40Ar/39Ar dating of the Las Papas ignimbrites yields a plateau age of 9.24 ± 0.03 Ma, indicating valley relief and orographic-barrier conditions comparable to the present-day. A later infill of Plio- Pleistocene coarse conglomerates has been linked to wetter conditions, but resulted in no additional net incision of the Las Papas valley, considering that the base of the ignimbrite remains unexposed in the valley bottom. Our observations indicate that at least 550 m of local plateau margin relief (and likely >2 km) existed by 9 Ma at the southern Puna margin, which likely increased the efficiency of the orographic barrier to rainfall along the eastern and southeastern flanks of the Puna and caused aridity in the plateau interior.
Palabras clave:
Puna
,
Paleotopography
,
Late-Miocene
,
Orogenic Plateau
Archivos asociados
Licencia
Identificadores
Colecciones
Articulos(IBIGEO)
Articulos de INST.DE BIO Y GEOCIENCIAS DEL NOA
Articulos de INST.DE BIO Y GEOCIENCIAS DEL NOA
Citación
Montero Lopez, Maria Carolina; Strecker, Manfred R.; Schildgen, Taylor F.; Hongn, Fernando Daniel; Guzman, Silvina Raquel; et al.; Local high relief at the southern margin of the Andean plateau by 9 Ma: evidence from ignimbritic valley fills and river incision; Wiley; Terra Nova (print); 26; 6; 8-2014; 454-460
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