Andean surface uplift constrained by radiogenic isotopes of arc lavas
Authors
Climate and tectonics have complex feedback systems which are difficult to resolve and remain controversial. Here we propose a new climate-independent approach to constrain regional Andean surface uplift. 87Sr/86Sr and 143Nd/144Nd ratios of Quaternary frontal-arc lavas from the Andean Plateau are distinctly crustal (>0.705 and
Fig. 2 Andean lavas are produced by mixing of depleted mantle melts with radiogenic crust. Sr-Nd radiogenic isotope plot of Quaternary lavas from the NVZ, CVZ and SVZ (compilation from this study, Methods and Supplementary Data 1) and CVZ ignimbrites73 in comparison to Palaeozoic continental crust and mantle end members, including Depleted Mantle (Pacific MORB), enriched sub-continental lithospheric mantle (SCLM) and Enriched Mantle I (EMI); from ref. 56 and references therein. Andean frontal-arc lavas follow a trend from a depleted mantle source to Palaeozoic crust and are not thought to be influenced by enriched mantle sources.
