Uplift of the western margin of the Andean plateau revealed from canyon incision history, southern Peru

Taylor F. Schildgen, Kip V. Hodges, Peter W. Whipple, Peter W. Reiners, Malcolm S. Pringle

Research output: Contribution to journalArticle

124 Scopus citations

Abstract

We explore canyon incision history of the western margin of the Andean (Altiplano-Puna) plateau in the central Andes as a proxy for surface uplift. (U-Th)/He apatite data show rapid cooling beginning at ca. 9 Ma and continuing to ca. 5.1 Ma in response to incision. A minimum of 1.0 km of incision took place during that interval. The youngest apatite date and a volcanic flow perched 125 m above the present valley floor dated at 2.261 ± 0.046 Ma (40Ar/39Ar) show that an additional ∼1.4 km of incision occurred between ca. 5.1 and 2.3 Ma. Thus, we infer that a total of at least 2.4 km, or 75% of the present canyon depth was incised after ca. 9 Ma. (U-Th)/He zircon data collected along the same transect imply that the western margin of the plateau was warped upward into its present monoclinal form, rather than uplift being accommodated on major surface-breaking faults.

Original languageEnglish (US)
Pages (from-to)523-526
Number of pages4
JournalGeology
Volume35
Issue number6
DOIs
StatePublished - Jun 1 2007

Keywords

  • Altiplano
  • Geochronology
  • Geomorphology
  • Helium
  • Peru
  • Tectonics

ASJC Scopus subject areas

  • Geology

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