Cordillera Blanca, Peru 2024

In June 2024 Peter van der Beek and Isabel Wapenhans flew from Berlin to Lima, Perú, to meet with Víctor Hugo García at the Pontificia Universidad Católica del Perú (PUCP), where they gave a seminar on ongoing work in the COOLER Group. That night, the three travelled by bus for eleven hours, together with Rodrigo Quiroga (from Universidad Mayor, Chile), and PUCP Masters student Marisol Medina and Bachelors students Arhel and Christian, to reach the impressive Cordillera Blanca in the Central Andes.

The Cordillera Blanca in the Peruvian Andes is the world’s highest tropical mountain range, and with dozens of glaciated peaks over 6000m tall standing at the foot of the large Santa Valley which is only around ~2000m elevation above sea level, this mountain range has some of the world’s most impressive relief. To the west, the older Cordillera Negra peaks reach more modest elevations of ~4000m, and to the east, behind the Pacific-Atlantic drainage divide which cuts through the Cordillera Blanca, the Marañón River flows through drier and shallower topography.

So, why is this mountain range so tall? The high topography of the Cordillera Blanca was, to first order, formed by a 28km by 180km batholith which exhumed between 12-5 million years ago along a large NNW striking normal fault running parallel to the Santa Valley. To second order, there still many questions about which process(es) could grow such high peaks compared to the surround elevations, and further, how such large relief gradients could be created.  

It is evident that glacial carving has reshaped topography substantially; impressive, actively deforming glaciers are visible near the peaks today, and U-shaped valleys flanked by large successions of past moraines hint at more extensive glaciation in the past.

We collected several bedrock samples from the area with our PUCP collaborators and the permission of SERNANP (Peruvian national parks administration), in order to analyse these for a suite of low-temperature thermochronology systems. We hope to further investigate the relative importance of glacial erosion of the region on the young creation of high topography and relief, by also improving the spatial data coverage, and subsequently, our understanding of the tectonic exhumation history of the batholith before and during glaciation. This work encompasses several studies as part of our collaboration with PUCP, including a PhD thesis chapter for Isabel and the Masters thesis for Marisol.