Andean surface uplift constrained by radiogenic isotopes of arc lavas

Scott, E.M.; Allen, M.B.; Macpherson, C.G.; McCaffrey, K.J.W.; Davidson, J.P.; Saville, C.; Ducea, M.N.

Abstract

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 <0.5125, respectively) compared to non-plateau arc lavas, which we identify as a plateau discriminant. Strong linear correlations exist between smoothed elevation and 87Sr/86Sr (R2 = 0.858, n = 17) and 143Nd/144Nd (R2 = 0.919, n = 16) ratios of non-plateau arc lavas. These relationships are used to constrain 200 Myr of surface uplift history for the Western Cordillera (present elevation 4200 ± 516 m). Between 16 and 26°S, Miocene to recent arc lavas have comparable isotopic signatures, which we infer indicates that current elevations were attained in the Western Cordillera from 23 Ma. From 23–10 Ma, surface uplift gradually propagated southwards by ~400 km.

Citation

Scott, E., Allen, M., Macpherson, C., McCaffrey, K., Davidson, J., Saville, C., & Ducea, M. (2018). Andean surface uplift constrained by radiogenic isotopes of arc lavas. Nature Communications, 9, Article 969. https://doi.org/10.1038/s41467-018-03173-4

• Journal Article Type: Article
• Acceptance Date: Jan 24, 2018
• Online Publication Date: Mar 6, 2018
• Publication Date: Mar 6, 2018
• Deposit Date: Jul 21, 2017
• Publicly Available Date: Jan 11, 2018
• Journal: Nature Communications
• Electronic ISSN: 2041-1723
• Publisher: Nature Research
• Peer Reviewed: Peer Reviewed
• Volume: 9
• Article Number: 969
• DOI: https://doi.org/10.1038/s41467-018-03173-4
• Public URL: https://durham-repository.worktribe.com/output/1354274