Uplift in the Fiordland Region, New Zealand: Implications for Incipient Subduction
M. A. House,1*
M. Gurnis,1
P. J. J. Kamp,2
R. Sutherland3
Low-temperature thermochronometry reveals regional Late
Cenozoic denudation in Fiordland, New Zealand, consistent with
geodynamic models showing uplift of the overriding plate during
incipient subduction. The data show a northward progression of
exhumation in response to northward migration of the initiation of
subduction. The locus of most recent uplift coincides with a large
positive Bouguer gravity anomaly within Fiordland.
Thermochronometrically deduced crustal thinning, anomalous gravity, and
estimates of surface uplift are all consistent with ~2 kilometers of
dynamic support. This amount of dynamic support is in accord with
geodynamic predictions, suggesting that we have dated the initiation of
subduction adjacent to Fiordland.
1 Division of Geological and Planetary
Sciences, Caltech, Pasadena, CA 91125, USA.
2 Department of Earth Sciences, University of
Waikato, Hamilton 2001, New Zealand.
3 IGNS Ltd.,
Lower Hutt, Private Bag 30368, New Zealand
*
To whom correspondence should be addressed. E-mail:
mhouse{at}gps.caltech.edu
