PT  - JOURNAL ARTICLE
AU  - Willett, C. D.
AU  - Ma, K. F.
AU  - Brandon, M. T.
AU  - Hourigan, J. K.
AU  - Christeleit, E. C.
AU  - Shuster, D. L.
TI  - Transient glacial incision in the Patagonian Andes from ~6 Ma to present
AID  - 10.1126/sciadv.aay1641
DP  - 2020 Feb 01
TA  - Science Advances
PG  - eaay1641
VI  - 6
IP  - 7
4099  - http://advances.sciencemag.org/content/6/7/eaay1641.short
4100  - http://advances.sciencemag.org/content/6/7/eaay1641.full
SO  - Sci Adv2020 Feb 01; 6
AB  - We report a mountain-scale record of erosion rates in the central Patagonian Andes from >10 million years (Ma) ago to present, which covers the transition from a fluvial to alpine glaciated landscape. Apatite (U-Th)/He ages of 72 granitic cobbles from alpine glacial deposits show slow erosion before ~6 Ma ago, followed by a two- to threefold increase in the spatially averaged erosion rate of the source region after the onset of alpine glaciations and a 15-fold increase in the top 25% of the distribution. This transition is followed by a pronounced decrease in erosion rates over the past ~3 Ma. We ascribe the pulse of fast erosion to local deepening and widening of valleys, which are characteristic features of alpine glaciated landscapes. The subsequent decline in local erosion rates may represent a return toward a balance between rock uplift and erosion.