Continuous deformation versus faulting through the continental lithosphere of new zealand
Seismic anisotropy and P-wave delays in New Zealand imply widespread deformation in the underlying mantle, not slip on a narrow fault zone, which is characteristic of plate boundaries in oceanic regions. Large magnitudes of shear-wave splitting and orientations of fast polarization parallel to the Alpine fault show that pervasive simple shear of the mantle lithosphere has accommodated the cumulative strike-slip plate motion. Variations in P-wave residuals across the Southern Alps rule out underthrusting of one slab of mantle lithosphere beneath another but permit continuous deformation of lithosphere shortened by about 100 kilometers since 6 to 7 million years ago.
Molnar
P
Quaternary Research Center and Geophysics Program, University of Washington, Seattle, WA, 98195-1360, USA, and Department of Earth Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, US.
Anderson
HJ
Audoine
E
Eberhart-Phillips
D
Gledhill
KR
Klosko
ER
McEvilly
TV
Okaya
D
Savage
MK
Stern
T
Wu
FT