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.
Original language | English |
---|---|
Number of pages | 4 |
Journal | Geology |
Volume | 46 |
Issue number | 4 |
Early online date | 6 Apr 2018 |
DOIs | |
Publication status | E-pub ahead of print - 6 Apr 2018 |
Fingerprint Dive into the research topics of 'Tectonic and glacial contributions to focused exhumation in the Olympic Mountains, Washington, USA'. Together they form a unique fingerprint.
Profiles
-
Dr Byron A Adams
- Cabot Institute for the Environment
- Marine and Terrestrial Environments
- School of Earth Sciences - Royal Society Dorothy Hodgkin Fellow
Person: Academic , Member