Browse/search for people

Publication - Dr Byron Adams

    Tectonic and glacial contributions to focused exhumation in the Olympic Mountains, Washington, USA

    Citation

    Michel, L, Ehlers, TA, Glotzbach, C, Adams, B & Stübner, K, 2018, ‘Tectonic and glacial contributions to focused exhumation in the Olympic Mountains, Washington, USA’. Geology, vol 46.

    Abstract

    Tectonics and climate are major contributors to the topographic
    evolution of mountain ranges. Here, we investigate temporal variations
    in exhumation due to the onset of Pleistocene glaciation in the
    Olympic Mountains (Washington State, USA). We present 29 new
    apatite and zircon (U-Th)/He ages (AHe and ZHe), showing a decrease
    in ages toward the interior of the mountain range for both thermochronometric
    systems. Young AHe ages (<2 Ma) can be found on the
    western side and the interior of the mountain range. Thermokinematic
    modeling of sample cooling ages suggests, that ZHe ages can
    be explained by an ellipse-shaped exhumation pattern with lowest/
    highest rates of ~0.25 and 0.9 km/m.y. These rates are interpreted as
    tectonically driven rock uplift, where the pattern of rates is governed
    by the shape of the subducted plate. However, the youngest AHe ages
    require a 50–150% increase in exhumation rates in the past 2–3 m.y.
    This increase in rates is contemporaneous with Pliocene-Pleistocene
    alpine glaciation of the orogen, indicating that tectonic rock uplift is
    perturbed by glacial erosion.

    Full details in the University publications repository