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Intense localized rock uplift and erosion in the St Elias orogen of Alaska

Nature Geoscience volume 2, pages 360363 (2009) | Download Citation

  • An Erratum to this article was published on 21 May 2009


The timing and role of exhumation in the St Elias orogen, the world’s highest coastal mountain range, has been unclear. Sampling is limited to high mountain ridges that tower over widespread ice fields that sit in deeply eroded parts of the orogen. Existing bedrock studies1,2,3 in the region are therefore prone to bias. Here we analyse detrital material of active sediment systems in the St Elias orogen to obtain age information from the inaccessible ice-covered valley bottoms. We present 1,674 detrital zircon fission-track ages from modern rivers that drain the glaciers. We find a population of very young ages of less than 3 Myr from the Seward–Malaspina glacier systems that is sharply localized in the area of the orogen’s highest relief, highest seismicity and at the transition from transform to subduction tectonics. Our data provide evidence for intense localized exhumation that is driven by coupling between erosion and active tectonic rock uplift.

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We thank collaborators of the STEEP project for their help during field work and fruitful discussions. We also thank G. Gehrels and V. Valencia for their guidance on U/Pb dating. Sample irradiation was facilitated by the Reactor Use Sharing Program (US DOE) to the Oregon State Nuclear Reactor. A review by P. Reiners improved the manuscript significantly. This study was supported by the NSF grants, EAR-0409132 and 0735402.

Author information


  1. Earth and Environmental Science, Lehigh University, 31 Williams Dr., Bethlehem, Pennsylvania 18015, USA

    • E. Enkelmann
    •  & P. K. Zeitler
  2. Department of Geological Sciences, University of Texas at El Paso, 500 West University Ave., El Paso, Texas 79968, USA

    • T. L. Pavlis
  3. Department of Geology, Union College, 807 Union St., Schenectady, New York 12308-2311, USA

    • J. I. Garver
  4. Department of Earth and Atmospheric Sciences, Purdue University, 550 Stadium Mall Dr., West Lafayette, Indiana 47907, USA

    • K. D. Ridgway


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All authors contributed to the writing and interpretation. Data analysis was carried out by E.E., P.K.Z., J.I.G. and K.D.R., field work by E.E., T.L.P. and K.D.R. and project planning was done by T.L.P., P.K.Z. and K.D.R.

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Correspondence to E. Enkelmann.

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