Stable isotope paleoaltimetry and the evolution of landscapes and life

Reconstructing topography of our planet not only advances our knowledge of the geodynamic processes that shape the Earth's surface; equally important it adds a key element towards understanding long-term continental moisture transport, atmospheric circulation and the distribution of biomes and biodiversity. Stable isotope paleoaltimetry exploits systematic decreases in the oxygen (delta O-18) or hydrogen (delta D) isotopic composition of precipitation along a mountain front when the interaction of topography and advected moist air masses induces orographic precipitation. These changes in delta O-18 or delta D can be recovered from the geologic record and recent geochemical and modeling advances allow a broad range of proxy materials to be evaluated. Over the last 10 yr stable isotope paleoaltimetry has witnessed rapidly expanding research activities and has produced a broad array of fascinating tectonic and geomorphologic studies many of which have concentrated on determining the elevation history of continental plateau regions. These single-site studies have greatly expanded what used to be very sparse global paleoaltimetric data. The challenge now lies in disentangling the surface uplift component from the impact of climate change on delta O-18 and delta D in precipitation. The robustness of stable isotope paleoaltimetry can be enhanced when high-elevation delta O-18 or delta D data are referenced against low-elevation sites that track climate-modulated sea level delta O-18 or delta D of precipitation through time ('delta-delta approach'). Analysis of central Andean paleosols documents that differences in delta O-18 of soil carbonate between the Subandean foreland and the Bolivian Altiplano are small between 11 and 7 Ma but rise rapidly to ca. 2.9 parts per thousand after 7 Ma, corroborating the magnitude of late Miocene change in delta O-18 on the Altiplano. Future advances in stable isotope paleoaltimetry will greatly benefit from addressing four key challenges: (1) Identifying topographically-induced changes in atmospheric circulation and associated teleconnections in the global climate system that affect delta O-18 or delta D of precipitation; (2) Evaluating on a case-by-case basis if temporal and spatial changes in isotope lapse rates influence interpretations of paleoelevation; (3) Interfacing with phylogenetic techniques to evaluate competing hypotheses with respect to the timing of surface uplift and the diversification of lineages; (4) Characterizing feedbacks between changes in surface elevation and atmospheric circulation as these are likely to be equally important to the diversification of lineages than changes in surface elevation alone. Tackling these challenges will benefit from the accelerating pace of improved data-model comparisons and rapidly evolving geochemical techniques for reconstructing precipitation patterns. Most importantly, stable isotope paleoaltimetry has the potential to develop into a truly interdisciplinary field if innovative tectonic/paleoclimatic and evolutionary biology/phylogenetic approaches are integrated into a common research framework. It therefore, opens new avenues to study the long-term evolution of landscapes and life. (C) 201 5 Elsevier B.V. All rights reserved.