Pliocene exhumation and landscape evolution of central North Island, New Zealand: The role of the upper mantle

摘要: [1] Mudstone porosity analyses show that over 2 km of exhumation has occurred in central North Island, New Zealand, since 5 Ma. This, combined with a coeval surface uplift ∼500 m, indicates maximum 2.5 rock Island. The magnitude and wavelength (∼400 km) the is similar to some topographic doming observed continental areas associated mantle upwelling, yet Island recognized as region back arc extension. Marine terraces 100–150 from center rates ∼0.2–0.3 mm yr−1, consistent about 1 if averaged 4–5 Myr, which compares well mudstone analyses. Seismic attenuation slow Pn velocities indicate thermal anomaly upper source this uplift. may be explained by replacement 100-km-thick lid asthenosphere density ∼66 kg m−3 less than lid. About half contrast can expansion, rest ascribed partial melts mantle. Southward migration for locus zone incision erosion, being 50 south southernmost volcano. Such keeping other geological markers volcanic phenomena further strengthens link landscape evolution at active margins processes