Opportunities and Challenges for Paleoaltimetry in Small Orogens: Insights From the European Alps

Many stable isotope paleoaltimetry studies have focused on paleoelevation reconstructions of orogenic plateaus such as the Tibetan or Andean Plateaus. We address the opportunities and challenges of applying stable isotope paleoaltimetry to smaller orogens. We do this using a high-resolution isotope tracking general circulation model (ECHAM5-wiso) and explore the precipitation delta O-18 (delta O-18(p)) signal of Cenozoic paleoclimate and topographic change in the European Alps. Results predict a maximum delta O-18(p) change of 4-5% (relative to present day) during topographic development of the Alps. This signal of topographic change has the same magnitude as changes in delta O-18(p) values resulting from Pliocene and Last Glacial Maximum global climatic change. Despite the similar magnitude of the isotopic signals resulting from topographic and paleoclimate changes, their spatial patterns across central Europe differ. Our results suggest that an integration of paleoclimate modeling, multiproxy approaches, and low-elevation reference proxy records distal from an orogen improve topographic reconstructions. Plain Language Summary Here we use a climate model with water isotopes implemented to explore the maximum precipitation isotopic signal of Cenozoic topographic and paleoclimate change in the European Alps. Our results show that the impact of topography change has the same magnitude as changes in the isotopic composition of local precipitation resulting from Pliocene and Last Glacial Maximum global climatic change.