Slow Cenozoic uplift of the western Andean Cordillera indicated by cosmogenic 3He in alluvial boulders from the Pacific Planation Surface

Laura A. Evenstar*, Finlay M. Stuart, Adrian J. Hartley, Brain Tattitch

*Corresponding author for this work

Research output: Contribution to journalArticle

24 Citations (Scopus)
7 Downloads (Pure)

Abstract

To determine the mechanisms responsible for mountain belt growth, it is important to accurately establish the timing of surface uplift. Here we exploit the altitude control on the production rate of in situ cosmogenic nuclides to test the hypothesis that the Andes was uplifted in the late Miocene. High concentrations of in situ cosmogenic 3He (3Hecos) have previously been measured in alluvial boulders on the western flank of the Central Andes, northern Chile (Evenstar et al. 2009). These are consistent with deposition soon after formation of the surface (13–14 Ma). We have modeled the accumulation of cosmogenic 3He in several different surface uplift scenarios and compared them to the measured concentrations. The measured 3Hecos concentrations are too high to be produced by late Miocene uplift and imply that the western flank of the Andean Cordillera attained a substantial part of its current elevation prior to 14 Myr ago.

Original languageEnglish
Pages (from-to)8448-8455
Number of pages8
JournalGeophysical Research Letters
Volume42
Issue number20
Early online date12 Oct 2015
DOIs
Publication statusPublished - 28 Oct 2015

Keywords

  • Andean uplift
  • Chile
  • cosmogenic Isotopes
  • Longitudinal Valley
  • paleoelevation

Fingerprint Dive into the research topics of 'Slow Cenozoic uplift of the western Andean Cordillera indicated by cosmogenic <sup>3</sup>He in alluvial boulders from the Pacific Planation Surface'. Together they form a unique fingerprint.

  • Cite this