La deflexión de Abancay se encuentra al norte del Altiplano peruano (12-13.5°S) y marca la transición entre los Andes estrechos del norte y los Andes anchos del sur. Es una anomalía excepcional de escala litosférica. En esta área peculiar de la Cordillera Oriental, numerosos macizos de rocas intrusivas afloran, conformando un relieve abrupto. Las quebradas muestran zonas de knickpoints ≥1000 m de desnivel, estas zonas en muchos casos coinciden con sistema de fallas regionales. Geológicamente, esta zona de transición arqueada, se extiende sobre ~200 km y presenta fallas regionales E-O, que cruzan el eje principal de elongación de la cadena. Esta área se caracteriza también por tener elevaciones >5500 m, siendo el pico más elevado el nevado del Salcantay (6271 m). A pesar de constituir una zona topográficamente importante en los Andes centrales, no existen suficientes trabaj...

Trabajo presentado en el 8th International Symposium on Andean Geodynamics (ISAG), realizado en Quito-Ecuador, del 24-26 setiembre, 2019. Evento organizado por el Instituto Geofísico, Escuela Politécnica Nacional (IG-EPN) del Ecuador, y el French Institut de Recherche pour le Développement (IRD).

The Abancay Deflection, forming the northern edge of the Altiplano in the Peruvian Andes, is a remarkable geomorphological feature marking the along-strike segmentation of the Andes. Little is known about the timing and spatial distribution of exhumation in this area. To constrain the exhumation history of the Abancay Deflection and its drivers, we present apatite (U–Th)/He and fission-track thermochronology data from samples collected along an elevation transect at Machu Picchu. Geomorphological analysis demonstrates recent and continuing drainage reorganization recorded by the spatial distribution of the normalized steepness index (ksn) and normalized integrated drainage area (χ) parameters. Thermochronologically derived cooling rates are converted into exhumation using regionally constrained geothermal gradients between 16 and 26°C km−1. Time–temperature inversions imply ste...

Thermochronological data are essential to constrain thermal and exhumation histories in active mountain ranges. In the Central Andes, bedrock outcrops are rare, being blanketed by widespread late Palaeogene–Neogene and younger volcanic formations. For this reason, the exhumation history of the Western Cordillera (WC) in the Peruvian Andes has only been investigated locally along the mountain range. Dense thermochronological data are only available in canyons of the Arequipa (16° S) and Cordillera Negra regions (10° S). We present new apatite (U-Th)/He and fission-track data from the 1 km deep Cañete Canyon (13° S), where the Oligo-Miocene deposits are preserved lying conformably on an Eocene palaeo-topographic surface. Thermal modelling of thermochronological data indicate that the 30–20 Ma ignimbrite deposits overlying the bedrock were thick enough to cause burial rehe...