Rapid Uplift of the Altiplano Revealed Through 13 C- 18 O Bonds in Paleosol Carbonates

Abstract

The elevation of Earth's surface is among the most difficult environmental variables to reconstruct from the geological record. Here we describe an approach to paleoaltimetry based on independent and simultaneous determinations of soil temperatures and the oxygen isotope compositions of soil waters, constrained by measurements of abundances of ¹³ C- ¹⁸ O bonds in soil carbonates. We use this approach to show that the Altiplano plateau in the Bolivian Andes rose at an average rate of 1.03 ± 0.12 millimeters per year between ∼10.3 and ∼6.7 million years ago. This rate is consistent with the removal of dense lower crust and/or lithospheric mantle as the cause of elevation gain.