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Continental-scale geographic change across Zealandia during Paleogene subduction initiation

Sutherland, R.; Dickens, G. R.; Blum, P.; Agnini, C.; Alegret, L.; Asatryan, G.; Bhattacharya, J.; Bordenave, A.; Chang, L.; Collot, J.; Cramwinckel, M. J.; Dallanave, E.; Drake, M. K.; Etienne, S. J. G.; Giorgioni, M.; Gurnis, M.; Harper, D. T.; Huang, H-

GEOLOGY
2020
VL / 48 - BP / 419 - EP / 424
abstract
Data from International Ocean Discovery Program (IODP) Expedition 371 reveal vertical movements of 1-3 km in northern Zealandia during early Cenozoic subduction initiation in the western Pacific Ocean. Lord Howe Rise rose from deep (similar to 1 km) water to sea level and subsided back, with peak uplift at 50 Ma in the north and between 41 and 32 Ma in the south. The New Caledonia Trough subsided 2-3 km between 55 and 45 Ma. We suggest these elevation changes resulted from crust delamination and mantle flow that led to slab formation. We propose a "subduction resurrection" model in which (1) a subduction rupture event activated lithospheric-scale faults across a broad region during less than similar to 5 m.y., and (2) tectonic forces evolved over a further 4-8 m.y. as subducted slabs grew in size and drove plate-motion change. Such a subduction rupture event may have involved nucleation and lateral propagation of slip-weakening rupture along an interconnected set of preexisting weaknesses adjacent to density anomalies.

AccesS level

Green accepted, Green published

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